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  • 301.
    Brun, Anders
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Westin, Carl-Fredrik
    Laboratory of Mathematics in Imaging Harvard Medical School, Boston, USA.
    Herberthson, Magnus
    Linköpings universitet, Matematiska institutionen, Tillämpad matematik. Linköpings universitet, Tekniska högskolan.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Fast manifold learning based on Riemannian normal coordinates2005Inngår i: Image Analysis: 14th Scandinavian Conference, SCIA 2005, Joensuu, Finland, June 19-22, 2005. Proceedings / [ed] Heikki Kalviainen, Jussi Parkkinen, Arto Kaarna., Springer Berlin/Heidelberg, 2005, s. 920-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present a novel method for manifold learning, i.e. identification of the low-dimensional manifold-like structure present in a set of data points in a possibly high-dimensional space. The main idea is derived from the concept of Riemannian normal coordinates. This coordinate system is in a way a generalization of Cartesian coordinates in Euclidean space. We translate this idea to a cloud of data points in order to perform dimension reduction. Our implementation currently uses Dijkstra’s algorithm for shortest paths in graphs and some basic concepts from differential geometry. We expect this approach to open up new possibilities for analysis of e.g. shape in medical imaging and signal processing of manifold-valued signals, where the coordinate system is “learned” from experimental high-dimensional data rather than defined analytically using e.g. models based on Lie-groups.

  • 302.
    Brun, Anders
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Tekniska högskolan.
    Westin, Carl-Fredrik
    Laboratory of Mathematics in Imaging, Harvard Medical School, Boston, MA, USA.
    Herberthson, Magnus
    Linköpings universitet, Matematiska institutionen, Tillämpad matematik. Linköpings universitet, Tekniska högskolan.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Tekniska högskolan.
    Intrinsic and Extrinsic Means on the Circle -- a Maximum Likelihood Interpretation2007Inngår i: ICASSP 2007. IEEE International Conference on Acoustics, Speech and Signal Processing, 2007, New York, USA: IEEE , 2007, s. III-1053-III-1056Konferansepaper (Fagfellevurdert)
    Abstract [en]

    For data samples in Rn, the mean is a well known estimator. When the data set belongs to an embedded manifold M in Rn, e.g. the unit circle in R2, the definition of a mean can be extended and constrained to M by choosing either the intrinsic Riemannian metric of the manifold or the extrinsic metric of the embedding space. A common view has been that extrinsic means are approximate solutions to the intrinsic mean problem. This paper study both means on the unit circle and reveal how they are related to the ML estimate of independent samples generated from a Brownian distribution. The conclusion is that on the circle, intrinsic and extrinsic means are maximum likelihood estimators in the limits of high SNR and low SNR respectively

  • 303.
    Brun, Anders
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Westin, Carl-Fredrik
    Lab of Mathematics in Imaging Harvard Medical School, Boston, USA.
    Herberthson, Magnus
    Linköpings universitet, Matematiska institutionen, Tillämpad matematik. Linköpings universitet, Tekniska högskolan.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    LOGMAP: Preliminary results using a new method for manifold learning2005Inngår i: Symposium on Image Analysis SSBA,2005, 2005, s. 101-105Konferansepaper (Annet vitenskapelig)
  • 304.
    Brun, Anders
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Westin, Carl-Fredrik
    Harvard Medical School Boston.
    Herberthson, Magnus
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Matematiska institutionen, Tillämpad matematik.
    Knutsson, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Sample Logmaps - Intrinsic processing of empirical manifold data2006Inngår i: SSBA Symposium on Image Analysis,2006, 2006, s. 13-16Konferansepaper (Annet vitenskapelig)
  • 305.
    Brydegaard, Mikkel
    et al.
    Department of Physics, Lund University.
    Haj-Hosseini, Neda
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Andersson-Engels, Stefan
    Department of Physics, Lund University.
    Photobleaching-Insensitive Fluorescence Diagnostics in Skin and Brain Tissue2011Inngår i: IEEE Photonics Journal, ISSN 1943-0655, Vol. 3, nr 3, s. 407-421Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    In this paper, we investigate the possibility of using accurate prediction models for the prediction of protoporphyrin bleaching dynamics to achieve photobleaching-insensitive methods to improve the evaluation of data in an existing clinical fluorescence-guided resection technique. To simulate the scenario, measurements were carried out in vivo on skin of healthy volunteers using a compact fiber-based fluorescence spectroscopy system. We have developed an effective method for the parameterization of sequences of bleaching spectra. We analyze convergence and decay rates with respect to initial conditions and excitation irradiance. We also discuss the consequences and the potential for bleaching-insensitive measurements and their applicability in a few examples from in vivo open brain surgery.

  • 306.
    Burger, Gerard
    et al.
    Symbiant Pathol Expert Centre, Netherlands; University of Amsterdam, Netherlands.
    Abu-Hanna, Ameen
    University of Amsterdam, Netherlands.
    de Keizer, Nicolette
    University of Amsterdam, Netherlands.
    Cornet, Ronald
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska fakulteten. University of Amsterdam, Netherlands.
    Natural language processing in pathology: a scoping review2016Inngår i: Journal of Clinical Pathology, ISSN 0021-9746, E-ISSN 1472-4146, Vol. 69, nr 11, s. 949-955Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Background Encoded pathology data are key for medical registries and analyses, but pathology information is often expressed as free text. Objective We reviewed and assessed the use of NLP (natural language processing) for encoding pathology documents. Materials and methods Papers addressing NLP in pathology were retrieved from PubMed, Association for Computing Machinery (ACM) Digital Library and Association for Computational Linguistics (ACL) Anthology. We reviewed and summarised the study objectives; NLP methods used and their validation; software implementations; the performance on the dataset used and any reported use in practice. Results The main objectives of the 38 included papers were encoding and extraction of clinically relevant information from pathology reports. Common approaches were word/phrase matching, probabilistic machine learning and rule-based systems. Five papers (13%) compared different methods on the same dataset. Four papers did not specify the method(s) used. 18 of the 26 studies that reported F-measure, recall or precision reported values of over 0.9. Proprietary software was the most frequently mentioned category (14 studies); General Architecture for Text Engineering (GATE) was the most applied architecture overall. Practical system use was reported in four papers. Most papers used expert annotation validation. Conclusions Different methods are used in NLP research in pathology, and good performances, that is, high precision and recall, high retrieval/removal rates, are reported for all of these. Lack of validation and of shared datasets precludes performance comparison. More comparative analysis and validation are needed to provide better insight into the performance and merits of these methods.

  • 307.
    Bäck, David
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Neural Network Gaze Tracking using Web Camera2006Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    Gaze tracking means to detect and follow the direction in which a person looks. This can be used in for instance human-computer interaction. Most existing systems illuminate the eye with IR-light, possibly damaging the eye. The motivation of this thesis is to develop a truly non-intrusive gaze tracking system, using only a digital camera, e.g. a web camera.

    The approach is to detect and track different facial features, using varying image analysis techniques. These features will serve as inputs to a neural net, which will be trained with a set of predetermined gaze tracking series. The output is coordinates on the screen.

    The evaluation is done with a measure of accuracy and the result is an average angular deviation of two to four degrees, depending on the quality of the image sequence. To get better and more robust results, a higher image quality from the digital camera is needed.

  • 308.
    Bäckström, Martin
    Linköpings universitet, Institutionen för medicinsk teknik.
    Discrimination between healthy and cancerous lungs with the use of an electronic nose2016Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Lung cancer is one of the most serious and common cancer types of today, with very uncomfortable and potentially cumbersome diagnostic techniques in x-ray, CT, CT-PET scans, bronchoscopies and biopsies. Completing all these steps can also take a long time and be time consuming for hospital staff. So finding a new safer and faster technique to diagnose cancer would be of great benefit.

    The objectives of this pilot study is to create an effective data storage system that can be scaled for larger data sets in a later study. The aim was also to see whether a E-nose can be used to find the differences in smell-prints from a healthy lung and a cancerous lung. As well as seeing if the E-nose can distinguish samples drawn from the lungs from exhaled air samples.

    Samples were taken on patients by the staff at ”Lung kliniken” at Link¨oping University Hospital during a bronchoscopy on patients with one-sided lung cancer. These samples were then analyzed by the E-nose which sensory response is later used to test the classification system that uses a mix of Principal Component Analysis (PCA) and K-Nearest Neighbour (KNN). Using a k = 7, the system was able to correctly classify 60 % of the samples when comparing cancerous and healthy lung samples. Comparing exhaled, healthy and cancerous samples the accuracy was calculated to 55.56 %. Comparing all lung samples against exhaled samples the accuracy was 86.67 %

  • 309.
    Bågenholm, Per
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik.
    Anderskär, Kristina
    IMT .
    Gill, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik.
    Jönsson, K Å
    Dept Medicine University Hospital, Linköping.
    Wigertz, Ove
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik.
    Adding decision support to a clinical information system1994Inngår i: Technology and Health Care, ISSN 0928-7329, Vol. 1, s. 245-251Artikkel i tidsskrift (Fagfellevurdert)
  • 310.
    Bårman, Håkan
    et al.
    n/a.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Granlund, Gösta H.
    Linköpings universitet, Institutionen för systemteknik, Bildbehandling. Linköpings universitet, Tekniska högskolan.
    Using Principal Direction Estimates for Shape and Acceleration Description1991Inngår i: Proceedings of the SSAB Symposium on Image Analysis: Stockholm, 1991Konferansepaper (Fagfellevurdert)
  • 311.
    Caesar, Jenny
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Segmentation of the Brain from MR Images2005Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    KTH, Division of Neuronic Engineering, have a finite element model of the head. However, this model does not contain detailed modeling of the brain. This thesis project consists of finding a method to extract brain tissues from T1-weighted MR images of the head. The method should be automatic to be suitable for patient individual modeling.

    A summary of the most common segmentation methods is presented and one of the methods is implemented. The implemented method is based on the assumption that the probability density function (pdf) of an MR image can be described by parametric models. The intensity distribution of each tissue class is modeled as a Gaussian distribution. Thus, the total pdf is a sum of Gaussians. However, the voxel values are also influenced by intensity inhomogeneities, which affect the pdf. The implemented method is based on the expectation-maximization algorithm and it corrects for intensity inhomogeneities. The result from the algorithm is a classification of the voxels. The brain is extracted from the classified voxels using morphological operations.

  • 312.
    Cai, Hongming
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Ortopedi. Linköpings universitet, Tekniska högskolan.
    Single fibre laser Doppler flowmetry for skeletal muscle perfusion measurements: methodological developments and clinical applications1997Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Measurements of microvascular blood flow in skeletal muscle by using the laser Doppler flowmetry (LDF) technique were first reported in 1979. The introduction of the single fibre technique in 1987 increased the possibilities of studying muscle perfusion under various physiological conditions without causing major tissue trauma.

    On-line processing of the LDF- and rms-EMG-signals made possible interpretation of the relationship between the perfusion and the activity of the muscle. Percutaneous single fibre LDF and bipolar surface electromyography (EMG) of the upper portion of trapezius muscle were performed continuously during a 10-minute long series of alternating periods of static contractions and rest, each of a one-minute duration. Regression analyses showed positive correlation between LDF and rms-EMG, as well as LDF and degree of arm elevation. Microcirculation in the trapezius muscle and the supraspinatus were measured simultaneously by continuous LDF during stepwise increased contractions related to the EMG too. Blood flow increased significantly in both muscles during increased shoulder torque. The blood flow in the trapezius muscle increased significantly at increased rms-EMG. But, no significant increase in muscle blood flow occurred in the supraspinatus muscle which thus seems to be more prone to develop ischemia during strenuous static work.

    A PC-based signal processor with a digital signal processing board was developed for evaluation of the different fibre tips' optic characters and laser Doppler algorithm, as well as for presentation of the laser Doppler measurement results. The Doppler signal power spectral density and corresponding flux values were visualized on the computer screen continuously in real-time. The single fibre technique has been further developed with the aim of improving the signal quality by modifying the geometry of the fibre tip and increasing the light wavelength, since the small monitored tissue volume in the muscle tissue by single fibre LDF is its drawback. The modified fibre tips, sphere and "pear" type, probes showed a higher flow sensitivity than did the flat end type. An infrared  laser diode with the wavelength of 750 nm was used in the new optical module. These improvements were interpreted as being related mostly to a larger, strongly irradiated tissue volume in front of the fibre. The results were evaluated theoretically with ray tracing simulations and experimentally with the mechanical and flow models. The modified fibre with the new signal processor for monitoring blood flow has been successfully used in intramuscular measurements.

  • 313.
    Cai, Hongming
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Rohman, Håkan
    Linköpings universitet, Institutionen för medicinsk teknik.
    Pettersson, Hans
    IMT LiU.
    Larsson, Sven-Erik
    Öberg, Åke
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    A new single fibre laser Doppler flowmeter based on digital signal processing1996Inngår i: Medical Engineering and Physics, ISSN 1350-4533, E-ISSN 1873-4030, Vol. 18, s. 523-528Artikkel i tidsskrift (Fagfellevurdert)
  • 314.
    Cai, Hongming
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Rohman, Håkan
    Linköpings universitet, Institutionen för medicinsk teknik.
    Pettersson, Hans
    IMT .
    Larsson, Sven-Erik
    Öberg, Åke
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Laser Doppler flowmetry: Charactersistics of a modified single fibre technique1996Inngår i: Medical Engineering and Physics, ISSN 1350-4533, E-ISSN 1873-4030, Vol. 34Artikkel i tidsskrift (Fagfellevurdert)
  • 315.
    Cammoun, L.
    et al.
    Signal Processing Institute Ecole Polytechnigue Fédérale de Lausanne Switserland.
    Castano-Moraga, C.A.
    University of Las Palmas de Gran Canaria.
    Munoz-Moreno, E.
    Univ. de Valladolid, Spain.
    Sosa-Cabrera, D.
    University of Las Palmas de Gran Canaria.
    Acar, B.
    University Istanbul.
    Rodriguez-Florido, M.A.
    University of Las Palmas de Gran Canaria.
    Brun, Anders
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Thiran, J.P.
    Signal Processing Institute Ecole Polytechnigue Fédérale de Lausanne Switserland.
    A Review of Tensors and Tensor Signal Processing2009Inngår i: Tensors in Image Processing and Computer Vision / [ed] S. Aja-Fernandez, R. de Luis Garcia, D. Tao, and X. Li, Springer London, 2009, s. 1-32Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Tensors have been broadly used in mathematics and physics, since they are a generalization of scalars or vectors and allow to represent more complex properties. In this chapter we present an overview of some tensor applications, especially those focused on the image processing field. From a mathematical point of view, a lot of work has been developed about tensor calculus, which obviously is more complex than scalar or vectorial calculus. Moreover, tensors can represent the metric of a vector space, which is very useful in the field of differential geometry. In physics, tensors have been used to describe several magnitudes, such as the strain or stress of materials. In solid mechanics, tensors are used to define the generalized Hooke’s law, where a fourth order tensor relates the strain and stress tensors. In fluid dynamics, the velocity gradient tensor provides information about the vorticity and the strain of the fluids. Also an electromagnetic tensor is defined, that simplifies the notation of the Maxwell equations. But tensors are not constrained to physics and mathematics. They have been used, for instance, in medical imaging, where we can highlight two applications: the diffusion tensor image, which represents how molecules diffuse inside the tissues and is broadly used for brain imaging; and the tensorial elastography, which computes the strain and vorticity tensor to analyze the tissues properties. Tensors have also been used in computer vision to provide information about the local structure or to define anisotropic image filters.

  • 316.
    Campbell, James R.
    et al.
    University of Nebraska Medical Center, Omaha NE USA.
    Talmon, Geoffrey
    University of Nebraska Medical Center, Omaha NE USA.
    Cushman-Vokoun, Allison
    University of Nebraska Medical Center, Omaha NE USA.
    Karlsson, Daniel
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Campbell, Scott W.
    University of Nebraska Medical Center, Omaha NE USA.
    An Extended SNOMED CT Concept Model for Observations in Molecular Genetics2016Inngår i: AMIA Annual Symposium Proceedings, 2016, s. 352-360Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Molecular genetics laboratory reports are multiplying and increasingly of clinical importance in diagnosis and treatment of cancer, infectious disease and managing of public health. Little of this data is structured or maintained in the EHR in format useful for decision support or research. Structured, computable reporting is limited by non-availability of a domain ontology for these data. The IHTSDO and Regenstrief Institute(RI) have been collaborating since 2008 to develop a unified concept model and ontology of observable entities - concepts which represent the results of laboratory and clinical observations. In this paper we report the progress we have made to apply that unified concept model to the structured recording of observations in clinical molecular genetic pathology including immunohistochemistry and sequence variant findings. The primary use case for deployment is the structured and coded reporting of Cancer checklist

  • 317.
    Campbell, Walter S.
    et al.
    Univ Nebraska Med Ctr, NE 68198 USA.
    Karlsson, Daniel
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Vreeman, Daniel J.
    Indiana Univ Sch Med, IN 46202 USA.
    Lazenby, Audrey J.
    Univ Nebraska Med Ctr, NE 68198 USA.
    Talmon, Geoffrey A.
    Univ Nebraska Med Ctr, NE 68198 USA.
    Campbell, James R.
    Univ Nebraska Med Ctr, NE USA.
    A computable pathology report for precision medicine: extending an observables ontology unifying SNOMED CT and LOINC2018Inngår i: JAMIA Journal of the American Medical Informatics Association, ISSN 1067-5027, E-ISSN 1527-974X, Vol. 25, nr 3, s. 259-266Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The College of American Pathologists (CAP) introduced the first cancer synoptic reporting protocols in 1998. However, the objective of a fully computable and machine-readable cancer synoptic report remains elusive due to insufficient definitional content in Systematized Nomenclature of Medicine - Clinical Terms (SNOMED CT) and Logical Observation Identifiers Names and Codes (LOINC). To address this terminology gap, investigators at the University of Nebraska Medical Center (UNMC) are developing, authoring, and testing a SNOMED CT observable ontology to represent the data elements identified by the synoptic worksheets of CAP. Investigators along with collaborators from the US National Library of Medicine, CAP, the International Health Terminology Standards Development Organization, and the UK Health and Social Care Information Centre analyzed and assessed required data elements for colorectal cancer and invasive breast cancer synoptic reporting. SNOMED CT concept expressions were developed at UNMC in the Nebraska LexiconA (c) SNOMED CT namespace. LOINC codes for each SNOMED CT expression were issued by the Regenstrief Institute. SNOMED CT concepts represented observation answer value sets. UNMC investigators created a total of 194 SNOMED CT observable entity concept definitions to represent required data elements for CAP colorectal and breast cancer synoptic worksheets, including biomarkers. Concepts were bound to colorectal and invasive breast cancer reports in the UNMC pathology system and successfully used to populate a UNMC biobank. The absence of a robust observables ontology represents a barrier to data capture and reuse in clinical areas founded upon observational information. Terminology developed in this project establishes the model to characterize pathology data for information exchange, public health, and research analytics.

  • 318. Carlhall, C.
    et al.
    Wigström, Lars
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Heiberg, Einar
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Karlsson, Matts
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk modellering och simulering.
    Bolger, A.F.
    Department of Medicine, Division of Cardiology, University of California, San Francisco, CA, United States.
    Nylander, Eva
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Reply [2]2006Inngår i: American Journal of Physiology. Heart and Circulatory Physiology, ISSN 0363-6135, E-ISSN 1522-1539, Vol. 291, nr 5Annet (Annet vitenskapelig)
    Abstract [en]

    [No abstract available]

  • 319.
    Carlhäll, Carljohan
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Kindberg, Katarina
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk modellering och simulering.
    Karlsson, Matts
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk modellering och simulering.
    Daughters, GT
    Miller, DC
    Ingels, NB
    Regional contribution of mitral annular dynamics to LV filling2006Inngår i: Experimental Biology,2006, 2006, s. A1194-A1194Konferansepaper (Annet vitenskapelig)
  • 320.
    Carlhäll, Carljohan
    et al.
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Kindberg, Katarina
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Wigström, Lars
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Daughters, G. T.
    Linköpings universitet, Hälsouniversitetet.
    Millers, D. C.
    Linköpings universitet, Hälsouniversitetet.
    Karlsson, Matts
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Ingels Jr, N. B.
    Linköpings universitet, Hälsouniversitetet.
    Contribution of mitral annular dynamics to LV diastolic filling with alteration in preload and inotropic state2007Inngår i: American Journal of Physiology. Heart and Circulatory Physiology, ISSN 0363-6135, E-ISSN 1522-1539, Vol. 293, nr 3, s. G1473-H1479Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mitral annular (MA) excursion during diastole encompasses a volume that is part of total left ventricular (LV) filling volume (LVFV). Altered excursion or area variation of the MA due to changes in preload or inotropic state could affect LV filling. We hypothesized that changes in LV preload and inotropic state would not alter the contribution of MA dynamics to LVFV. Six sheep underwent marker implantation in the LV wall and around the MA. After 7–10 days, biplane fluoroscopy was used to obtain three-dimensional marker dynamics from sedated, closed-chest animals during control conditions, inotropic augmentation with calcium (Ca), preload reduction with nitroprusside (N), and vena caval occlusion (VCO). The contribution of MA dynamics to total LVFV was assessed using volume estimates based on multiple tetrahedra defined by the three-dimensional marker positions. Neither the absolute nor the relative contribution of MA dynamics to LVFV changed with Ca or N, although MA area decreased (Ca, P < 0.01; and N, P < 0.05) and excursion increased (Ca, P < 0.01). During VCO, the absolute contribution of MA dynamics to LVFV decreased (P < 0.001), based on a reduction in both area (P < 0.001) and excursion (P < 0.01), but the relative contribution to LVFV increased from 18 ± 4 to 45 ± 13% (P < 0.001). Thus MA dynamics contribute substantially to LV diastolic filling. Although MA excursion and mean area change with moderate preload reduction and inotropic augmentation, the contribution of MA dynamics to total LVFV is constant with sizeable magnitude. With marked preload reduction (VCO), the contribution of MA dynamics to LVFV becomes even more important.

  • 321.
    Carlhäll, Carljohan
    et al.
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Institutionen för medicin och vård, Centrum för medicinsk bildvetenskap och visualisering. Linköpings universitet, Hälsouniversitetet.
    Wigström, Lars
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Institutionen för medicin och vård, Centrum för medicinsk bildvetenskap och visualisering. Linköpings universitet, Hälsouniversitetet.
    Heiberg, Einar
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Institutionen för medicin och vård, Centrum för medicinsk bildvetenskap och visualisering. Linköpings universitet, Hälsouniversitetet.
    Karlsson, Matts
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Institutionen för medicin och vård, Centrum för medicinsk bildvetenskap och visualisering. Linköpings universitet, Hälsouniversitetet.
    Bolger, A. F.
    Department of Medicine/Cardiology, University of California, San Francisco, California.
    Nylander, Eva
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Institutionen för medicin och vård, Centrum för medicinsk bildvetenskap och visualisering. Linköpings universitet, Hälsouniversitetet.
    Contribution of mitral annular excursion and shape dynamics to total left ventricular volume change2004Inngår i: American Journal of Physiology. Heart and Circulatory Physiology, ISSN 0363-6135, E-ISSN 1522-1539, Vol. 287, nr 4, s. H1836-H1841Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The mitral annulus (MA) has a complex shape and motion, and its excursion has been correlated to left ventricular (LV) function. During the cardiac cycle the annulus’ excursion encompasses a volume that is part of the total LV volume change during both filling and emptying. Our objective was to evaluate the contribution of MA excursion and shape variation to total LV volume change. Nine healthy subjects aged 56 ± 11 (means ± SD) years underwent transesophageal echocardiography (TEE). The MA was outlined in all time frames, and a four-dimensional (4-D) Fourier series was fitted to the MA coordinates (3-D+time) and divided into segments. The annular excursion volume (AEV) was calculated based on the temporally integrated product of the segments’ area and their incremental excursion. The 3-D LV volumes were calculated by tracing the endocardial border in six coaxial planes. The AEV (10 ± 2 ml) represented 19 ± 3% of the total LV stroke volume (52 ± 12 ml). The AEV correlated strongly with LV stroke volume (r = 0.73; P < 0.05). Peak MA area occurred during middiastole, and 91 ± 7% of reduction in area from peak to minimum occurred before the onset of LV systole. The excursion of the MA accounts for an important portion of the total LV filling and emptying in humans. These data suggest an atriogenic influence on MA physiology and also a sphincter-like action of the MA that may facilitate ventricular filling and aid competent valve closure. This 4-D TEE method is the first to allow noninvasive measurement of AEV and may be used to investigate the impact of physiological and pathological conditions on this important aspect of LV performance.

  • 322.
    Carlsson, Mats
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Methods and computer based tools for handling medical terminologies and classifications2000Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Classifications, terminology and terminology services are important in the field of medical informatics. They are needed when building applications such as Computer based Patient Record systems (CPRs). Even though many classifications, nomenclatures and terminology systems have been constructed to this end, e .g. ICD, MeSH and SNOMED, no single system has, so far, covered medicine in its entirety. Several of the aforementioned constructs have grown to the extent that manual maintenance can no longer cope, thus computer based tools are needed for this task.

    The main objective of this thesis is to present some computer based terminology tools that have been constructed to facilitate part of the work of building sound terminologies and application systems. The usefulness of such terminologies, terminology tools as well as the importance of being able to integrate the terminology have been reviewed and are discussed. Moreover tools (from GALEN) for maintenance and developme nt of classilications are evaluated.

    Two terminology tools are presented that aim to facilitate the access to and the use of terminology and terminology services. One tool is built on a proposal for a concept oriented Swedish national terminology data base model (Spriterm). The other tool is a dedicated client (KOMANTIS) to the GALEN terminology server (TeS) developed as a deliverable within the European GALEN project. It will facilitate the integration of terminologies between the information system and the knowledge base when building Decision Support Systems (DSS).

    Delarbeid
    1. Development of a terminology management system for the Swedish healthcare sector
    Åpne denne publikasjonen i ny fane eller vindu >>Development of a terminology management system for the Swedish healthcare sector
    1996 (engelsk)Inngår i: Studies in Health Technology and Informatics, Volume 34: Medical Informatics Europe ’96, Amsterdam: IOS Press , 1996, s. 232-235Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    This paper describes the ongoing work of creating and building a Swedish national terminology database. The terminology management system herein is a prototype, built in ACCESS™. Still it addresses some important issues concerning terminology management such as the data model used for representing concepts and terms, and multiple inheritance is discussed in relation to relational databases.

    sted, utgiver, år, opplag, sider
    Amsterdam: IOS Press, 1996
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-31352 (URN)10.3233/978-1-60750-878-6-232 (DOI)17118 (Lokal ID)17118 (Arkivnummer)17118 (OAI)
    Konferanse
    MIE 96, Thirteenth International Congress, August 19-22 1996 Copenhagen Denmark
    Tilgjengelig fra: 2009-10-09 Laget: 2009-10-09 Sist oppdatert: 2013-02-25
    2. Design and application of a terminology management system
    Åpne denne publikasjonen i ny fane eller vindu >>Design and application of a terminology management system
    1998 (engelsk)Inngår i: Studies in Health Technology and Informatics, Volume 52: MEDINFO '98 / [ed] Cesnik, B., McCray, A.T., Scherrer, J.R., Australia: IOS Press , 1998, s. 207-211Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    A Swedish data model for handling terminology, Spriterm, is presented in this paper. A prototype terminology management system, using the Spriterm data model in also described. This prototype is implemented is Microsoft ACCESS. Furthermore, two other applications using this prototype as a base are introduced. One World Wide Web based application, and a data dictionary.

    sted, utgiver, år, opplag, sider
    Australia: IOS Press, 1998
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-29899 (URN)10.3233/978-1-60750-896-0-207 (DOI)15320 (Lokal ID)978-90-5199-407-0 (ISBN)15320 (Arkivnummer)15320 (OAI)
    Konferanse
    MEDINFO '98, Aug 14-21, Seoul, South Korea
    Tilgjengelig fra: 2009-10-09 Laget: 2009-10-09 Sist oppdatert: 2013-02-25
    3. Terminology support for development of sharable knowledge modules
    Åpne denne publikasjonen i ny fane eller vindu >>Terminology support for development of sharable knowledge modules
    1996 (engelsk)Inngår i: Informatics for Health and Social Care, ISSN 1753-8157, E-ISSN 1753-8165, Vol. 21, nr 3, s. 207-214Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Lack of an agreed infrastructure for terminology is identified as one of the major barriers to interchange of knowledge modules and integration of knowledge bases with other clinical information systems. The goal of the GALEN project is to bridge this gap between different terminology systems through the construction of a terminology server, which is based on a rich conceptual model with mapping facilities to natural language expressions and coding schemas. The long term goal is to support communication between medical information systems. Arden Syntax is a standard format for the creation of knowledge modules, with sharability as one of the main objectives. Since Arden Syntax is based on a data-driven approach, the data items used need to be adapted to locally available terminology. The GALEN approach appears to be complementary to Arden Syntax and to the development of sharable knowledge modules. The major theme of this paper is utilization of the GALEN terminology server for knowledge module authoring. Two systems are presented, a knowledge base manager and a client to the terminology server, allowing the user to navigate in the semantic network and to import concept definitions and terms into the knowledge modules. The benefit of the terminology services is discussed.

    Emneord
    Terminology services, Knowledge authoring, Knowledge sharing, Arden Syntax
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-31359 (URN)10.3109/14639239609025358 (DOI)17125 (Lokal ID)17125 (Arkivnummer)17125 (OAI)
    Tilgjengelig fra: 2009-10-09 Laget: 2009-10-09 Sist oppdatert: 2017-12-13
    4. Modelling and reclassification of surgical procedures: experiences from the use of GALEN methods in the domain of thoracic surgery
    Åpne denne publikasjonen i ny fane eller vindu >>Modelling and reclassification of surgical procedures: experiences from the use of GALEN methods in the domain of thoracic surgery
    2000 (engelsk)Inngår i: Medical informatics and the Internet in medicine (Print), ISSN 1463-9238, E-ISSN 1464-5238, Vol. 25, nr 2, s. 109-122Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    This paper reports on experiences fromthe evaluation of GALEN methods for mapping of follow-up categories in the domain of thoracic surgery to an existing classification of surgical procedures. The mapping of the aggregated levels or groups of thoracic procedures presents a genuine problem in relation to strict hierarchical classifications, since the follow-up categories do not necessarily fit in the pre-set structure of the classification. Experiences from modelling of the traditional classification and of the follow-up categories are reported, and an analysis of the results is presented along with a discussion of opportunities and potential problems and pitfalls when applying GALEN models and tools.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-29754 (URN)10.1080/14639230050058293 (DOI)15159 (Lokal ID)15159 (Arkivnummer)15159 (OAI)
    Tilgjengelig fra: 2009-10-09 Laget: 2009-10-09 Sist oppdatert: 2017-12-13
    5. Classification of procedures in the domain of thoracic surgery: a study of relibility in coding
    Åpne denne publikasjonen i ny fane eller vindu >>Classification of procedures in the domain of thoracic surgery: a study of relibility in coding
    2001 (engelsk)Inngår i: Journal of medical systems, ISSN 0148-5598, E-ISSN 1573-689X, Vol. 25, nr 1, s. 47-61Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    This paper relates a study of reliability of coding of surgical procedures in the domain of thoracic surgery. The reliability measured is inter-coder variability in form of agreement. Four classifications were used by four physicians on 100 patient cases. The classifications, having differing granularity and structure, were analyzed using a statistical method (kappa). These results are discussed and related to the differences between the classifications. One of the topics for discussion is how the granularity affects the degree of agreement, coupled to the usefulness of the classification. Also the concept of using formal methods for representing classifications is discussed, how this will affect how classifications are designed and used.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-29560 (URN)10.1023/A:1005636432502 (DOI)14934 (Lokal ID)14934 (Arkivnummer)14934 (OAI)
    Tilgjengelig fra: 2009-10-09 Laget: 2009-10-09 Sist oppdatert: 2017-12-13
  • 323.
    Carlsson, Mats
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Tools for providing terminology services in health care computing1997Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Terminology and terminology services are increasingly important in building medical informatics applications like Computerbased Patient Record systems (CPR). Many classifications, nomenclatures and terminology systems have been constructed to this end i. a. ICD, MeSH and SNOMED. So far no single system has covered medicine in its entirety and particularly have they not been suitable for building computerbased applications and handling.

    The arrival of computer technology has led to new, more advanced terminology systems. The combination of these new terminology systems with knowledge representation vehicles such as Arden Syntax constitutes an important part of the process of developing efficient methods and systems for information handling including decision support and communication of meaning within health care.

    The main objective of the thesis is to present some computer based terminology tools that have been constructed to facilitate part of the work of building sound terminologies and application systems. The usefulness of such terminologies, terminology tools and the importance of being able to integrate the terminology have been reviewed and are discussed.

    Two terminology tools are presented that aims at facilitating the access to and the use of terminology and terminology services. One tool is built on the concept oriented Swedish national terminology data base model SpriTerm and provides browsing and editing facilities of concepts and concept spaces of vocabularies. Also the motivations behind the SpriTerm model are discussed.

    The other tool is a dedicated client (KOMANTIS) to the GALEN terminology server (TeS) developed as a deliverable within the European GALEN project. It will facilitate the integration of terminologies between an information system, and the knowledge base when building Decision Support Systems (DSS). The user can navigate through KOMANTIS and select the pertinent attributes for integrating, for example the DSS and the CPR.

  • 324.
    Carlsson, Mats
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Karlsson, Daniel
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Åhlfeldt, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Wigertz, Ove
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Design and application of a terminology management system1998Inngår i: Studies in Health Technology and Informatics, Volume 52: MEDINFO '98 / [ed] Cesnik, B., McCray, A.T., Scherrer, J.R., Australia: IOS Press , 1998, s. 207-211Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A Swedish data model for handling terminology, Spriterm, is presented in this paper. A prototype terminology management system, using the Spriterm data model in also described. This prototype is implemented is Microsoft ACCESS. Furthermore, two other applications using this prototype as a base are introduced. One World Wide Web based application, and a data dictionary.

  • 325.
    Carlsson, Mats
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Löfström, Lars
    Linköpings universitet, Hälsouniversitetet.
    Rogers, Jeremy
    Medical Informatics Group, Department of Computer Science, University of Manchester, UK.
    Åhlfeldt, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Modelling and reclassification of surgical procedures: experiences from the use of GALEN methods in the domain of thoracic surgery2000Inngår i: Medical informatics and the Internet in medicine (Print), ISSN 1463-9238, E-ISSN 1464-5238, Vol. 25, nr 2, s. 109-122Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper reports on experiences fromthe evaluation of GALEN methods for mapping of follow-up categories in the domain of thoracic surgery to an existing classification of surgical procedures. The mapping of the aggregated levels or groups of thoracic procedures presents a genuine problem in relation to strict hierarchical classifications, since the follow-up categories do not necessarily fit in the pre-set structure of the classification. Experiences from modelling of the traditional classification and of the follow-up categories are reported, and an analysis of the results is presented along with a discussion of opportunities and potential problems and pitfalls when applying GALEN models and tools.

  • 326.
    Carlsson, Mats
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Löfström, Lars
    Linköpings universitet, Hälsouniversitetet.
    Åhlfeldt, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Classification of procedures in the domain of thoracic surgery: a study of relibility in coding2001Inngår i: Journal of medical systems, ISSN 0148-5598, E-ISSN 1573-689X, Vol. 25, nr 1, s. 47-61Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper relates a study of reliability of coding of surgical procedures in the domain of thoracic surgery. The reliability measured is inter-coder variability in form of agreement. Four classifications were used by four physicians on 100 patient cases. The classifications, having differing granularity and structure, were analyzed using a statistical method (kappa). These results are discussed and related to the differences between the classifications. One of the topics for discussion is how the granularity affects the degree of agreement, coupled to the usefulness of the classification. Also the concept of using formal methods for representing classifications is discussed, how this will affect how classifications are designed and used.

  • 327.
    Carlsson, Mats
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik.
    Rogers, Jeremy
    University of Manchester, UK .
    Åhlfeldt, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik.
    Aggregation and reclassification - Assessment of GALEN methods in the domain of thoracic surgery1999Inngår i: AIA99,1999, Philadelphia: Hanley & Belfus Inc , 1999, s. 32-Konferansepaper (Fagfellevurdert)
  • 328.
    Carlsson, Mats
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Wigertz, Ove
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Junford, A.
    Swedish Institute for Health Services Development, Stockholm, Sweden.
    Wallin, S-B.
    Swedish Institute for Health Services Development, Stockholm, Sweden.
    Development of a terminology management system for the Swedish healthcare sector1996Inngår i: Studies in Health Technology and Informatics, Volume 34: Medical Informatics Europe ’96, Amsterdam: IOS Press , 1996, s. 232-235Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper describes the ongoing work of creating and building a Swedish national terminology database. The terminology management system herein is a prototype, built in ACCESS™. Still it addresses some important issues concerning terminology management such as the data model used for representing concepts and terms, and multiple inheritance is discussed in relation to relational databases.

  • 329.
    Carlsson, Mats
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik.
    Åhlfeldt, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik.
    Thurin, Anders
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik.
    Wigertz, Ove
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik.
    Knowledge module authoring with terminolgy support1995Inngår i: AMIA Symposium on Coputer Applications in Medical Care,1995, Hanley & belfus , 1995, s. 969-Konferansepaper (Fagfellevurdert)
  • 330.
    Carlsson, Mats
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Åhlfeldt, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Thurin, Anders
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Wigertz, Ove
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Terminology support for development of sharable knowledge modules1996Inngår i: Informatics for Health and Social Care, ISSN 1753-8157, E-ISSN 1753-8165, Vol. 21, nr 3, s. 207-214Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lack of an agreed infrastructure for terminology is identified as one of the major barriers to interchange of knowledge modules and integration of knowledge bases with other clinical information systems. The goal of the GALEN project is to bridge this gap between different terminology systems through the construction of a terminology server, which is based on a rich conceptual model with mapping facilities to natural language expressions and coding schemas. The long term goal is to support communication between medical information systems. Arden Syntax is a standard format for the creation of knowledge modules, with sharability as one of the main objectives. Since Arden Syntax is based on a data-driven approach, the data items used need to be adapted to locally available terminology. The GALEN approach appears to be complementary to Arden Syntax and to the development of sharable knowledge modules. The major theme of this paper is utilization of the GALEN terminology server for knowledge module authoring. Two systems are presented, a knowledge base manager and a client to the terminology server, allowing the user to navigate in the semantic network and to import concept definitions and terms into the knowledge modules. The benefit of the terminology services is discussed.

  • 331.
    Casas Garcia, Belén
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Lantz, Jonas
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Viola, Frederica
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten.
    Cedersund, Gunnar
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Bolger, Ann F.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Fysiologiska kliniken US. University of Calif San Francisco, CA USA.
    Carlhäll, Carljohan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Karlsson, Matts
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanisk värmeteori och strömningslära. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Ebbers, Tino
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Bridging the gap between measurements and modelling: a cardiovascular functional avatar2017Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, artikkel-id 6214Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lumped parameter models of the cardiovascular system have the potential to assist researchers and clinicians to better understand cardiovascular function. The value of such models increases when they are subject specific. However, most approaches to personalize lumped parameter models have thus far required invasive measurements or fall short of being subject specific due to a lack of the necessary clinical data. Here, we propose an approach to personalize parameters in a model of the heart and the systemic circulation using exclusively non-invasive measurements. The personalized model is created using flow data from four-dimensional magnetic resonance imaging and cuff pressure measurements in the brachial artery. We term this personalized model the cardiovascular avatar. In our proof-of-concept study, we evaluated the capability of the avatar to reproduce pressures and flows in a group of eight healthy subjects. Both quantitatively and qualitatively, the model-based results agreed well with the pressure and flow measurements obtained in vivo for each subject. This non-invasive and personalized approach can synthesize medical data into clinically relevant indicators of cardiovascular function, and estimate hemodynamic variables that cannot be assessed directly from clinical measurements.

  • 332.
    Casas Garcia, Belén
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Viola, Frederica
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten.
    Cedersund, Gunnar
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Bolger, Ann F
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Univ Calif San Francisco, CA USA.
    Karlsson, Matts
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanisk värmeteori och strömningslära. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Carlhäll, Carljohan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Ebbers, Tino
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Non-invasive Assessment of Systolic and Diastolic Cardiac Function During Rest and Stress Conditions Using an Integrated Image-Modeling Approach2018Inngår i: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 9, artikkel-id 1515Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: The possibility of non-invasively assessing load-independent parameters characterizing cardiac function is of high clinical value. Typically, these parameters are assessed during resting conditions. However, for diagnostic purposes, the parameter behavior across a physiologically relevant range of heart rate and loads is more relevant than the isolated measurements performed at rest. This study sought to evaluate changes in non-invasive estimations of load-independent parameters of left-ventricular contraction and relaxation patterns at rest and during dobutamine stress. Methods: We applied a previously developed approach that combines non-invasive measurements with a physiologically-based, reduced-order model of the cardiovascular system to provide subject-specific estimates of parameters characterizing left ventricular function. In this model, the contractile state of the heart at each time point along the cardiac cycle is modeled using a time-varying elastance curve. Non-invasive data, including four-dimensional magnetic resonance imaging (4D Flow MRI) measurements, were acquired in nine subjects without a known heart disease at rest and during dobutamine stress. For each of the study subjects, we constructed two personalized models corresponding to the resting and the stress state. Results: Applying the modeling framework, we identified significant increases in the left ventricular contraction rate constant [from 1.5 +/- 0.3 to 2 +/- 0.5 (p = 0.038)] and relaxation constant [from 37.2 +/- 6.9 to 46.1 +/- 12 (p = 0.028)]. In addition, we found a significant decrease in the elastance diastolic time constant from 0.4 +/- 0.04 s to 0.3 +/- 0.03 s = 0.008). Conclusions: The integrated image-modeling approach allows the assessment of cardiovascular function given as model-based parameters. The agreement between the estimated parameter values and previously reported effects of dobutamine demonstrates the potential of the approach to assess advanced metrics of pathophysiology that are otherwise difficult to obtain non-invasively in clinical practice.

  • 333.
    Cederberg, Erik
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Adipose tissue segmentation in whole-body MRI2010Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Adipose tissue volume and distribution is related to metabolic diseases such as diabetes and atherosclerosis. This relationship is in focus for much research, much due to a worldwide increase in obesity. It is in many cases of interest to calculate the amount of adipose tissue in different compartments within the body. Commonly used methods are however prone to introduce errors due to partial volume effects.

    Previous studies have successfully segmented three adipose tissue compartments from abdominal two-point Dixon fat-water MRI volumes using Morphon registration and atlas segmentation. This thesis extends upon the previous work by enabling segmentation of whole-body MRI volumes and by improving the registration with the use of both fat and water data. Possible methods for bone marrow segmentation are also tested and evaluated.

    The methods presented seem to be sufficient for creating whole-body volumes from a set of smaller volumes. The adipose tissue segmentation was adequate for subjects with relatively small volumes of adipose tissue, whereas segmentation of subjects with large amounts of adipose tissue require further improvement. Of the evaluated methods for bone marrow segmentation one seemed to perform adequately on all the tested datasets. Due to the few datasets available for testing it was not possible to draw any general conclusions as to how well the presented methods perform.

  • 334.
    Cedersund, Gunnar
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Tekniska fakulteten.
    Prediction uncertainty estimation despite unidentifiability: an overview of recent developments2016Inngår i: Uncertainty in Biology: a computational modeling approach / [ed] Liesbet Geris and David Gomez-Cabrero, Springer, 2016, s. 449-466Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    One of the most important properties of a mathematical model is the abilityto make predictions: to predict that which has not yet been measured. Suchpredictions can sometimes be obtained from a simple simulation, but that requiresthat the parameters in the model are known from before. In biology, theparameters are usually both not known from before and not identifiable, i.e.the parameter values cannot be determined uniquely from available data. Insuch cases of unidentifiability, the space of acceptable parameters is large, ofteninfinite in certain directions. For such large spaces, sampling-based approachesthat try to characterize the entire space have difficulties. Recently, a new type ofalternative approaches that circumvent this characterization problem has beenproposed: where one only searches those directions in the space of acceptable parametersthat are relevant for the uncertainty of a particular prediction. In thisreview chapter, these recently proposed methods are compared and contrasted,both regarding theoretical properties, and regarding user experience. The focusis on methods from the field of systems biology, but also methods from biostatistics,pharmacodynamics, and biochemometrics are discussed. The hope is thatthis review will increase the usefulness and understanding of already proposedmethods, and thereby help foster a tradition where predictions only are deemedinteresting if their uncertainties have been determined.

  • 335.
    Cedersund, Gunnar
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Tekniska fakulteten.
    Oscar, Samuelsson
    Stockholm, Sweden.
    Ball, Gordon
    Stockholm, Sweden.
    Tegnér, Jesper
    Unit of Computational Medicine, Department of Medicine, Karolinska Institutet, Solna, Sweden.
    Gomez-Cabrero, David
    Center for Molecular Medicine, Stockholm, Sweden.
    Optimization in biology parameter estimation and the associated optimization problem2016Inngår i: Uncertainty in biology: a computational modeling approach / [ed] Liesbet Geris, David Gomez-Cabrero, New York: Springer, 2016, s. 177-197Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Parameter estimation – the assignment of values to the parameters in a model – is an important and time-consuming task in computational biology. Recent computational and algorithmic developments have provided novel tools to improve this estimation step. One of these improvements concerns the optimization step, where the parameter space is explored to find interesting regions. In this chapter we review the parameter estimation problem, with a special emphasis on the associated optimization methods. In relation to this, we also provide concepts and tools to help you select the appropriate methodology for a specific scenario.

  • 336.
    Chaabane, Wiem
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Hälsouniversitetet. Tunis University, Tunisia.
    Cieślar-Pobuda, Artur
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Hälsouniversitetet. Silesian University of Technology, Gliwice, Poland.
    El-Gazzah, Mohamed
    Tunis University, Tunisia.
    Jain, Mayur V.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Rzeszowska-Wolny, Joanna
    Silesian University of Technology, Gliwice, Poland.
    Rafat, Mehrdad
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Hälsouniversitetet.
    Stetefeld, Joerg
    University of Manitoba, Winnipeg, Canada.
    Ghavami, Saeid
    University of Manitoba, Winnipeg, Canada.
    Los, Marek
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Hälsouniversitetet. Pomeranian Medical University, Szczecin, Poland.
    Human-Gyrovirus-Apoptin Triggers Mitochondrial Death Pathway—Nur77 is Required for Apoptosis Triggering: 2014Inngår i: Neoplasia, ISSN 1522-8002, E-ISSN 1476-5586, Vol. 16, nr 9, s. 679-693Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The human gyrovirus derived protein Apoptin (HGV-Apoptin) a homologue of the chicken anemia virus Apoptin (CAV-Apoptin), a protein with high cancer cells selective toxicity, trigger apoptosis selectively in cancer cells. In this paper, we show that HGV-Apoptin acts independently from the death receptor pathway as it induces apoptosis in similar rates in Jurkat cells deficient in either FADD-function or caspase-8 (key players of the extrinsic pathway) and their parental clones. HGV-Apoptin induces apoptosis via the activation of the mitochondrial intrinsic pathway. It induces both mitochondrial inner and outer membrane permebilization, characterized by the loss of the mitochondrial potential and the release into cytoplasm of the pro-apoptotic molecules including apoptosis inducing factor (AIF) and cytochrome c. HGV-Apoptin acts via the apoptosome, as lack of expression of APAF1 in murine embryonic fibroblast strongly protected the cells from HGV-Apoptin-induced apoptosis. Moreover, QVD-oph a broad-spectrum caspase inhibitor delayed HGV-Apoptin-induced death. On the other hand, overexpression of the anti-apoptotic BCL-XL confers resistance to HGV-Apoptin induced cell death. In contrast, cells that lack the expression of the pro-apoptotic BAX and BAK are protected from HGV-Apoptin induced apoptosis. Furthermore, HGV-Apoptin acts independently from p53 signal but triggers the cytoplasmic translocation of Nur77. Taking together this data indicate that HGV-Apoptin acts through the mitochondrial pathway, in a caspase-dependent manner but independently from the death receptor pathway.

  • 337.
    Chan, Yung-Kuan
    et al.
    Natl Chung Hsing Univ, Taiwan.
    Chen, Yung-Fu
    Cent Taiwan Univ Sci and Technol, Taiwan.
    Pham, Tuan
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Chang, Weide
    Calif State Univ Sacramento, CA 95819 USA.
    Hsieh, Ming-Yuan
    Natl Taichung Univ Educ, Taiwan.
    Editorial Material: Artificial Intelligence in Medical Applications in JOURNAL OF HEALTHCARE ENGINEERING, vol , issue , pp2018Inngår i: Journal of Healthcare Engineering, ISSN 2040-2295, E-ISSN 2040-2309, artikkel-id 4827875Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    n/a

  • 338.
    Chellappa, Rama
    et al.
    Department of Electrical and Computer Engineering, University of Maryland, USA.
    Heyden, AndersLund University, Sweden.Laurendeau, DenisUniversité Laval, Canada.Felsberg, MichaelLinköpings universitet, Institutionen för systemteknik, Datorseende. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.Borga, MagnusLinköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Special issue on ICPR 2014 awarded papers2016Collection/Antologi (Fagfellevurdert)
    Abstract [en]

    We, the Guest Editors of this special issue of Pattern Recognition Letters are pleased to share these contributions with you. The papers included here are based on work from the 22nd International Conference on Pattern Recognition (IAPR) in Stockholm, Sweden, held August 24–28, 2014. The papers selected for this special issue were those winning one of the IAPR awards, as well as one paper by a former student of the winner of the KS Fu Prize, Prof. Jitendra Malik. Taken together, this body of work represents some of the finest research being conducted by the IAPR community worldwide, it builds on a rich legacy of accomplishment by the entire community, and it offers a view to the future, to where we are going as a scientific community.

    For each of the award-winning papers, the authors were asked to revise and extend their contributions to full journal length and to provide true added value vis-à-vis the original conference submission. In some cases, the authors elected to modify the titles slightly, and in some cases the list of authors has also been modified. The resulting manuscripts were sent out for full review by a different set of referees than those who reviewed the conference versions. The process, including required revisions, was in accordance with the standing editorial policy of Pattern Recognition Letters, resulting in the final versions accepted and appearing here. These are thoroughly vetted, high-caliber scientific contributions.

    It has been our honor to serve as Guest Editors for this special issue. We would like to thank the Editors of Pattern Recognition Letters for allowing us this opportunity. We are especially grateful to Dr. Gabriella Sanniti di Baja for her enthusiasm, support, and her willingness to keep prodding us along to bring the special issue through to completion. We would also like to thank all of those who reviewed the papers, both originally for the conference and subsequently for the journal, and those who served on the ICPR awards and KS Fu Prize committees.

    Finally, we express our heartfelt gratitude to all of the authors for taking the time to prepare these versions for our collective enlightenment, sharing their knowledge, innovation, and discoveries with the rest of us.

  • 339.
    Chen, Rong
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Towards interoperable and knowledge-based electronic health records using archetype methodology2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The use of Electronic Health Records (EHR) is wide spread in healthcare today. EHRs are not only used to support daily care but also used to support important secondary uses, e.g. clinical research, quality assurance and education. Although considered advantageous compared to paper-based records, EHRs still have a long way to go in realizing its full potential as an integral part of a safe, effective and efficient health care system.

    Making EHRs interoperable is a prerequisite to support increasingly distributed and diverse healthcare. Bringing up-to-date knowledge into EHRs for decision support is a critical step to foster evidence based care. EHR data from different sources need to be analyzed in research in order to find new evidence for improvement of the current practice. Knowledge in the form of guidelines needs to be disseminated and applied in practice through continuous education. This cyclic flow of information and knowledge between care, research and education must be facilitated in order to achieve a safer and more efficient healthcare. An interoperable EHR framework can facilitate the sharing of information and knowledge between not only human users but also participating software systems. This is the aim of this thesis, which is built upon the research in the field of semantic interoperability, in particular the pioneering work by the openEHR Foundation.

    The journey of this thesis started with a template-based supplementary EHR system - Julius, which allows clinicians to define and share record structures for care and research. The formalism behind Julius is comparable to the openEHR archetype formalism but less expressive and without the backing of international standards. This finding led to an open source implementation of the openEHR design, which in turn initiated the validation and further improvements of the archetype formalism. The software components made the archetype formalism more accessible to academic and commercial projects around the world.

    The investigation of the convertibility between a legacy EHR content model and the archetype model showed that the archetype format is more expressive and thus can be used to preserve legacy EHR content definitions. A general strategy for migration from legacy EHRs to archetype-based EHRs was formulated. A novel way of representing clinical practice guidelines using archetype formalism was proposed and tested on a lymphoma chemotherapy guideline. The implication of this study is improved interoperability between guidelines and EHRs that could facilitate both clinical decision support and guideline-compliance checking. Maintainability of guidelines could be increased through reuse of EHR content models as building blocks of guidelines. In the last part of the research, a way of expressing fully structured care plans using openEHR and CONTsys has been explored based on the requirements for elderly home care. A sharable and semantically well-defined care plan could contribute to the coordination of shared care.

    The key contribution of the thesis can be summarized as the validation and further improvement of the openEHR archetype formalism through software implementation and the explorations on clinical guidelines, shared care plans and legacy EHR content models in relation to archetypebased EHR framework.

    Delarbeid
    1. Julius--a template based supplementary electronic health record system
    Åpne denne publikasjonen i ny fane eller vindu >>Julius--a template based supplementary electronic health record system
    2007 (engelsk)Inngår i: BMC Medical Informatics and Decision Making, ISSN 1472-6947, E-ISSN 1472-6947, Vol. 7, nr 10Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background: EHR systems are widely used in hospitals and primary care centres but it is usually difficult to share information and to collect patient data for clinical research. This is partly due to the different proprietary information models and inconsistent data quality. Our objective was to provide a more flexible solution enabling the clinicians to define which data to be recorded and shared for both routine documentation and clinical studies. The data should be possible to reuse through a common set of variable definitions providing a consistent nomenclature and validation of data. Another objective was that the templates used for the data entry and presentation should be possible to use in combination with the existing EHR systems.

    Methods: We have designed and developed a template based system (called Julius) that was integrated with existing EHR systems. The system is driven by the medical domain knowledge defined by clinicians in the form of templates and variable definitions stored in a common data repository. The system architecture consists of three layers. The presentation layer is purely webbased, which facilitates integration with existing EHR products. The domain layer consists of the template design system, a variable/clinical concept definition system, the transformation and validation logic all implemented in Java. The data source layer utilizes an object relational mapping tool and a relational database.

    Results: The Julius system has been implemented, tested and deployed to three health care units in Stockholm, Sweden. The initial responses from the pilot users were positive. The template system facilitates patient data collection in many ways. The experience of using the template system suggests that enabling the clinicians to be in control of the system, is a good way to add supplementary functionality to the present EHR systems.

    Conclusion: The approach of the template system in combination with various local EHR systems can facilitate the sharing and reuse of validated clinical information from different health care units. However, future system developments for these purposes should consider using the openEHR/CEN models with shareable archetypes.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-38662 (URN)10.1186/1472-6947-7-10 (DOI)45253 (Lokal ID)45253 (Arkivnummer)45253 (OAI)
    Tilgjengelig fra: 2009-10-10 Laget: 2009-10-10 Sist oppdatert: 2017-12-13bibliografisk kontrollert
    2. The openEHR Java Reference Implementation Project
    Åpne denne publikasjonen i ny fane eller vindu >>The openEHR Java Reference Implementation Project
    2007 (engelsk)Inngår i: Proceedings of the 12th World Congress onHealth (Medical) Informatics / [ed] K.A. Kuhn, J.R. Warren and T.-Y. Leong, IOS Press , 2007, s. 58-62Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    The openEHR foundation has developed an innovative design for interoperable and future-proof Electronic Health Record (EHR) systems based on a dual model approach with a stable reference information model complemented by archetypes for specific clinical purposes.

    A team from Sweden has implemented all the stable specifications in the Java programming language and donated the source code to the openEHR foundation. It was adopted as the openEHR Java Reference Implementation in March 2005 and released under open source licenses. This encourages early EHR implementation projects around the world and a number of groups have already started to use this code.

    The early Java implementation experience has also led to the publication of the openEHR Java Implementation Technology Specification. A number of design changes to the specifications and important minor corrections have been directly initiated by the implementation project over the last two years. The Java Implementation has been important for the validation and improvement of the openEHR design specifications and provides building blocks for future EHR systems.

    sted, utgiver, år, opplag, sider
    IOS Press, 2007
    Emneord
    Electronic Health Records, Health Information Systems, openEHR, Java, open source
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-38638 (URN)45134 (Lokal ID)978-1-58603-774-1 (ISBN)45134 (Arkivnummer)45134 (OAI)
    Konferanse
    12th World Congress on Health (Medical) Informatics Brisbane Convention Centre, 20–24 August, Brisbane, Australia
    Tilgjengelig fra: 2009-10-10 Laget: 2009-10-10 Sist oppdatert: 2010-04-14bibliografisk kontrollert
    3. Archetype-based conversion of EHR content models: pilot experience with a regional EHR system
    Åpne denne publikasjonen i ny fane eller vindu >>Archetype-based conversion of EHR content models: pilot experience with a regional EHR system
    Vise andre…
    2009 (engelsk)Inngår i: BMC Medical Informatics and Decision Making, ISSN 1472-6947, E-ISSN 1472-6947, Vol. 9, nr 33Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background: Exchange of Electronic Health Record (EHR) data between systems from different suppliers is a major challenge. EHR communication based on archetype methodology has been developed by openEHR and CEN/ISO. The experience of using archetypes in deployed EHR systems is quite limited today. Currently deployed EHR systems with large user bases have their own proprietary way of representing clinical content using various models. This study was designed to investigate the feasibility of representing EHR content models from a regional EHR system as openEHR archetypes and inversely to convert archetypes to the proprietary format. Methods: The openEHR EHR Reference Model (RM) and Archetype Model (AM) specifications were used. The template model of the Cambio COSMIC, a regional EHR product from Sweden, was analyzed and compared to the openEHR RM and AM. This study was focused on the convertibility of the EHR semantic models. A semantic mapping between the openEHR RM/AM and the COSMIC template model was produced and used as the basis for developing prototype software that performs automated bidirectional conversion between openEHR archetypes and COSMIC templates. Results: Automated bi-directional conversion between openEHR archetype format and COSMIC template format has been achieved. Several archetypes from the openEHR Clinical Knowledge Repository have been imported into COSMIC, preserving most of the structural and terminology related constraints. COSMIC templates from a large regional installation were successfully converted into the openEHR archetype format. The conversion from the COSMIC templates into archetype format preserves nearly all structural and semantic definitions of the original content models. A strategy of gradually adding archetype support to legacy EHR systems was formulated in order to allow sharing of clinical content models defined using different formats. Conclusion: The openEHR RM and AM are expressive enough to represent the existing clinical content models from the template based EHR system tested and legacy content models can automatically be converted to archetype format for sharing of knowledge. With some limitations, internationally available archetypes could be converted to the legacy EHR models. Archetype support can be added to legacy EHR systems in an incremental way allowing a migration path to interoperability based on standards.

    sted, utgiver, år, opplag, sider
    BMC, 2009
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-19912 (URN)10.1186/1472-6947-9-33 (DOI)
    Merknad
    Original Publication: Rong Chen, Gunnar O Klein, Erik Sundvall, Daniel Karlsson and Hans Åhlfeldt, Archetype-based conversion of EHR content models: pilot experience with a regional EHR system, 2009, BMC MEDICAL INFORMATICS AND DECISION MAKING, (9), 33. http://dx.doi.org/10.1186/1472-6947-9-33 Licensee: BioMed Central http://www.biomedcentral.com/ Tilgjengelig fra: 2009-08-25 Laget: 2009-08-14 Sist oppdatert: 2017-12-13bibliografisk kontrollert
    4. Representing a chemotherapy guideline using openEHR and rules
    Åpne denne publikasjonen i ny fane eller vindu >>Representing a chemotherapy guideline using openEHR and rules
    2009 (engelsk)Inngår i: Medical Informatics in a United and Healthy Europe / [ed] Klaus-Peter Adlassnig, Bernd Blobel, John Mantas, Izet Masic, IOS Press, 2009, Vol. 150, s. 653-657Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Computerized guidelines can provide decision support and facilitate the use of clinical guidelines. Several computerized guideline representation models (GRMs) exist but the poor interoperability between the guideline systems and the Electronic Health Record (EHR) systems limits their clinical usefulness. In this study we analyzed the clinical use of a published lymphoma chemotherapy guideline. We found that existing GRMs have limitations that can make it difficult to meet the clinical requirements. We hypothesized that guidelines could be represented as data and logic using openEHR archetypes, templates and rules. The design was tested by implementing the lymphoma guideline. We conclude that using the openEHR models and rules to represent chemotherapy guidelines is feasible and confers several advantages both from a clinical and from an informatics perspective.

    sted, utgiver, år, opplag, sider
    IOS Press, 2009
    Serie
    Studies in Health Technology and Informatics, ISSN 0926-9630 ; 150
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-21864 (URN)10.3233/978-1-60750-044-5-653 (DOI)000326889500137 ()978-1-60750-044-5 (ISBN)
    Konferanse
    MIE 2009 – The XXIInd International Congress of the European Federation for Medical Informatics
    Tilgjengelig fra: 2009-10-06 Laget: 2009-10-06 Sist oppdatert: 2018-01-13bibliografisk kontrollert
    5. Modelling Shared Care Plans Using Contsys and OpenEHR to Support Shared Homecare of Elderly
    Åpne denne publikasjonen i ny fane eller vindu >>Modelling Shared Care Plans Using Contsys and OpenEHR to Support Shared Homecare of Elderly
    2011 (engelsk)Inngår i: JAMIA Journal of the American Medical Informatics Association, ISSN 1067-5027, E-ISSN 1527-974X, Vol. 18, nr 1, s. 66-69Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    This case report describes how two complementary standards, CONTsys (the continuity of care standard EN 13940-1) and the reference model (RM) of openEHR, were applied in modeling a shared care plan for shared homecare based on requirements from the OLD@HOME project. The OLD@HOME shared care plan conceptual model is used to verify these standards against real world requirements. Our study shows that these requirements are matched by CONTsys on a general level. However, certain attributes are not explicit in CONTsys, e.g. agents responsible for performing planned interventions, and support for monitoring outcome of interventions. We further studied how the care plan conceptual model can be implemented using the openEHR RM. The study demonstrates the

    sted, utgiver, år, opplag, sider
    B M J PUBLISHING GROUP, 2011
    Emneord
    Medical Informatics; Integrated Advanced Information Management Systems; Information Storage and Retrieval; Home Care Services; Nursing Record; Electronic Health Records, Archetypes
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-54821 (URN)10.1136/jamia.2009.000216 (DOI)000289218000011 ()
    Tilgjengelig fra: 2010-04-14 Laget: 2010-04-14 Sist oppdatert: 2017-12-12
  • 340.
    Chen, Rong
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Garde, Sebastian
    Ocean Informatics UK, London, UK.
    Beale, Thomas
    Ocean Informatics UK, London, UK.
    Nyström, Mikael
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Karlsson, Daniel
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Klein, Gunnar O.
    Karolinska Institutet, Sweden.
    Åhlfeldt, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    An Archetype-based Testing Framework2008Inngår i: EHEALTH BEYOND THE HORIZON: GET IT THERE / [ed] Andersen, SK; Klein, GO; Schulz, S; Aarts, J; Mazzoleni, MC, Amsterdam: IOS Press, 2008, Vol. 136, s. 401-406Konferansepaper (Fagfellevurdert)
    Abstract [en]

    With the introduction of EHR two-level modelling and archetype methodologies pioneered by openEHR and standardized by CEN/ISO, we are one step closer to semantic interoperability and future-proof adaptive healthcare information systems. Along with the opportunities, there are also challenges. Archetypes provide the full semantics of EHR data explicitly to surrounding systems in a platform-independent way, yet it is up to the receiving system to interpret the semantics and process the data accordingly. In this paper we propose a design of an archetype-based platform-independent testing framework for validating implementations of the openEHR archetype formalism as a means of improving quality and interoperability of EHRs.

  • 341.
    Chen, Rong
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Georgii-Hemming, Patrik
    Department of Oncology, Uppsala University, Sweden.
    Åhlfeldt, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Representing a chemotherapy guideline using openEHR and rules2009Inngår i: Medical Informatics in a United and Healthy Europe / [ed] Klaus-Peter Adlassnig, Bernd Blobel, John Mantas, Izet Masic, IOS Press, 2009, Vol. 150, s. 653-657Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Computerized guidelines can provide decision support and facilitate the use of clinical guidelines. Several computerized guideline representation models (GRMs) exist but the poor interoperability between the guideline systems and the Electronic Health Record (EHR) systems limits their clinical usefulness. In this study we analyzed the clinical use of a published lymphoma chemotherapy guideline. We found that existing GRMs have limitations that can make it difficult to meet the clinical requirements. We hypothesized that guidelines could be represented as data and logic using openEHR archetypes, templates and rules. The design was tested by implementing the lymphoma guideline. We conclude that using the openEHR models and rules to represent chemotherapy guidelines is feasible and confers several advantages both from a clinical and from an informatics perspective.

  • 342.
    Chen, Rong
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Klein, Gunnar
    Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
    The openEHR Java Reference Implementation Project2007Inngår i: Proceedings of the 12th World Congress onHealth (Medical) Informatics / [ed] K.A. Kuhn, J.R. Warren and T.-Y. Leong, IOS Press , 2007, s. 58-62Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The openEHR foundation has developed an innovative design for interoperable and future-proof Electronic Health Record (EHR) systems based on a dual model approach with a stable reference information model complemented by archetypes for specific clinical purposes.

    A team from Sweden has implemented all the stable specifications in the Java programming language and donated the source code to the openEHR foundation. It was adopted as the openEHR Java Reference Implementation in March 2005 and released under open source licenses. This encourages early EHR implementation projects around the world and a number of groups have already started to use this code.

    The early Java implementation experience has also led to the publication of the openEHR Java Implementation Technology Specification. A number of design changes to the specifications and important minor corrections have been directly initiated by the implementation project over the last two years. The Java Implementation has been important for the validation and improvement of the openEHR design specifications and provides building blocks for future EHR systems.

  • 343.
    Chen, Rong
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Klein, Gunnar O
    Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden.
    Sundvall, Erik
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Karlsson, Daniel
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Åhlfeldt, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Archetype-based conversion of EHR content models: pilot experience with a regional EHR system2009Inngår i: BMC Medical Informatics and Decision Making, ISSN 1472-6947, E-ISSN 1472-6947, Vol. 9, nr 33Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Exchange of Electronic Health Record (EHR) data between systems from different suppliers is a major challenge. EHR communication based on archetype methodology has been developed by openEHR and CEN/ISO. The experience of using archetypes in deployed EHR systems is quite limited today. Currently deployed EHR systems with large user bases have their own proprietary way of representing clinical content using various models. This study was designed to investigate the feasibility of representing EHR content models from a regional EHR system as openEHR archetypes and inversely to convert archetypes to the proprietary format. Methods: The openEHR EHR Reference Model (RM) and Archetype Model (AM) specifications were used. The template model of the Cambio COSMIC, a regional EHR product from Sweden, was analyzed and compared to the openEHR RM and AM. This study was focused on the convertibility of the EHR semantic models. A semantic mapping between the openEHR RM/AM and the COSMIC template model was produced and used as the basis for developing prototype software that performs automated bidirectional conversion between openEHR archetypes and COSMIC templates. Results: Automated bi-directional conversion between openEHR archetype format and COSMIC template format has been achieved. Several archetypes from the openEHR Clinical Knowledge Repository have been imported into COSMIC, preserving most of the structural and terminology related constraints. COSMIC templates from a large regional installation were successfully converted into the openEHR archetype format. The conversion from the COSMIC templates into archetype format preserves nearly all structural and semantic definitions of the original content models. A strategy of gradually adding archetype support to legacy EHR systems was formulated in order to allow sharing of clinical content models defined using different formats. Conclusion: The openEHR RM and AM are expressive enough to represent the existing clinical content models from the template based EHR system tested and legacy content models can automatically be converted to archetype format for sharing of knowledge. With some limitations, internationally available archetypes could be converted to the legacy EHR models. Archetype support can be added to legacy EHR systems in an incremental way allowing a migration path to interoperability based on standards.

  • 344.
    Chew, Michelle
    et al.
    Departments of Anaesthesia and Intensive Care, Institute of Experimental Clinical Research, Skejby Sygehus, Aarhus University Hospital, Denmark.
    Brandberg, Joakim
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Bjarum, Steinar
    Department of Biomerical Engineering, Trondheim University, Norway.
    Baek-Jensen, Katrine
    Institute of Experimental Clinical Research, Skejby Sygehus, Aarhus University Hospital, Denmark.
    Sloth, Erik
    Departments of Anaesthesia and Intensive Care, Skejby Sygehus, Aarhus University Hospital, Denmark.
    Ask, Per
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Hasenkam, J. Michael
    Department of Cardiothoracic Surgery, Skejby Sygehus, Aarhus University Hospital, Denmark.
    Janerot Sjöberg, Birgitta
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Pediatric cardiac output measurement using surface integration of velocity vectors: an in vivo validation study2000Inngår i: Critical Care Medicine, ISSN 0090-3493, E-ISSN 1530-0293, Vol. 28, nr 11, s. 3664-3671Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objective: To test the accuracy and reproducibility of systemic cardiac output (CO) measurements using surface integration of velocity vectors (SIVV) in a pediatric animal model with hemodynamic instability and to compare SIVV with traditional pulsed-wave Doppler measurements.

    Design: Prospective, comparative study.

    Setting: Animal research laboratory at a university medical center.

    Subjects: Eight piglets weighing 10-15 kg.

    Interventions: Hemodynamic instability was induced by using inhalation of isoflurane and infusions of colloid and dobutamine.

    Measurements: SIVV CO was measured at the left ventricular outflow tract, the aortic valve, and ascending aorta. Transit time CO was used as the reference standard.

    Results: There was good agreement between SIVV and transit time CO. At high frame rates, the mean difference ± 2 sd between the two methods was 0.01 ± 0.27 L/min for measurements at the left ventricular outflow tract, 0.08 ± 0.26 L/min for the ascending aorta, and 0.06 ± 0.25 L/min for the aortic valve. At low frame rates, measurements were 0.06 ± 0.25, 0.19 ± 0.32, and 0.14 ± 0.30 L/min for the left ventricular outflow tract, ascending aorta, and aortic valve, respectively. There were no differences between the three sites at high frame rates. Agreement between pulsed-wave Doppler and transit time CO was poorer, with a mean difference ± 2 sd of 0.09 ± 0.93 L/min. Repeated SIVV measurements taken at a period of relative hemodynamic stability differed by a mean difference ±2 sd of 0.01 ± 0.22 L/min, with a coefficient of variation = 7.6%. Intraobserver coefficients of variation were 5.7%, 4.9%, and 4.1% at the left ventricular outflow tract, ascending aorta, and aortic valve, respectively. Interobserver variability was also small, with a coefficient of variation = 8.5%.

    Conclusions: SIVV is an accurate and reproducible flow measurement technique. It is a considerable improvement over currently used methods and is applicable to pediatric critical care.

  • 345.
    Chew, Michelle
    et al.
    Departments of Anaesthesia and Intensive Care, Aarhus, Denmark.
    Brandberg, Joakim
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Canard, Peter
    Institute of Experimental Clinical Research, Skejby Sygehus, Aarhus University Hospital, Aarhus, Denmark.
    Sloth, Erik
    Departments of Anaesthesia and Intensive Care, Aarhus, Denmark.
    Ask, Per
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Hasenkam, Michael
    Department of Cardiothoracic and Vascular Surgery, Aarhus, Denmark.
    Doppler flow measurement using surface integration of velocity vectors (Sivv): in vitro validation2000Inngår i: Ultrasound in Medicine and Biology, ISSN 0301-5629, E-ISSN 1879-291X, Vol. 26, nr 2, s. 255-262Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Blood flow measurement using an improved surface integration of velocity vectors (SIVV) technique was tested in in vitro phantoms. SIVV was compared with true flow (12–116 mL/s) in a steady-state model using two angles of insonation (45° and 60°) and two vessel sizes (internal diameter = 11 and 19 mm). Repeatability of the method was tested at various flow rates for each angle of insonation and vessel. In a univentricular pulsatile model, SIVV flow measured at the mitral inlet was compared to true flow (29–61 mL/s). Correlation was excellent for the 19-mm vessel (r2= 0.99). There was a systematic bias but close limits of agreement (mean ± 2 SD = −24.1% ± 7.6% at 45 °; +16.4% ± 11.0% at 60 °). Using the 11-mm vessel, a quadratic relationship was demonstrated between between SIVV and true flow (r2 = 0.98–0.99), regardless of the angle of insonation. In the pulsatile system, good agreement and correlation were shown (r2 = 0.94, mean ± 2 SD = −4.7 ± 10.1%). The coefficients of variation for repeated SIVV measurements ranged from 0.9% to 10.3%. This method demonstrates precision and repeatability, and is potentially useful for clinical measurements.

  • 346.
    Chew, Michelle
    et al.
    Malmö University.
    Brandberg, Joakim
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Janerot Sjöberg, Birgitta
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Sloth, Erik
    Aarhus University Hospital.
    Hasenkam, J. Michael
    Aarhus University Hospital.
    Ask, Per
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Colour Doppler flow measurements using surface integration of velocity vectors (SIVV): Effect of colour flow gain, pulse repetition frequency and number of imaging planes2008Inngår i: Open medical imaging journal, ISSN 1874-3471, Vol. 2, s. 56-61Artikkel i tidsskrift (Fagfellevurdert)
  • 347.
    Chew, Michelle
    et al.
    Faculty of Health Science University of Aarhus, Denmark.
    Brandberg, Joakim
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Janerot-Sjöberg, Birgitta
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Sloth, Erik
    Aarhus University Hospital Aarhus Denmark.
    Ask, Per
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Hasenkam, Michael
    Aarhus University Hospital Aarhus Denmark.
    Noninvasive cardiac output measurement using Doppler echocardiography; current status and future perspective using Surface Integration of Velocity Vectors (SIVV)1999Inngår i: Danish Society of Anesthesiologists,1999, 1999Konferansepaper (Annet vitenskapelig)
  • 348.
    Chew, Michelle
    et al.
    University of Aarhus Denamrk.
    Brandberg, Joakim
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Sloth, Erik
    Aarhus University Hospital Aarhus Denmark.
    Ask, Per
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Janerot-Sjöberg, Birgitta
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Non-invasive cardiac output measurement using colour Doppler ultrasound - the SIVV approach1999Inngår i: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 114, s. 91-92Artikkel i tidsskrift (Fagfellevurdert)
  • 349. Chew, Michelle S
    et al.
    Brandberg, Joakim
    Canard, P
    Sloth, E
    Ask, Per
    Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik. Linköpings universitet, Tekniska högskolan.
    Hasenkam, J Michael
    Doppler flow measurement using surface integration of velocity vectors (SIVV): in vitro validation.2000Inngår i: Ultrasound in Medicine and Biology, ISSN 0301-5629, E-ISSN 1879-291X, Vol. 26, nr 2, s. 255-262Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Blood flow measurement using an improved surface integration of velocity vectors (SIVV) technique was tested in in vitro phantoms. SIVV was compared with true flow (12-116 mL/s) in a steady-state model using two angles of insonation (45 degrees and 60 degrees ) and two vessel sizes (internal diameter = 11 and 19 mm). Repeatability of the method was tested at various flow rates for each angle of insonation and vessel. In a univentricular pulsatile model, SIVV flow measured at the mitral inlet was compared to true flow (29-61 mL/s). Correlation was excellent for the 19-mm vessel (r(2)= 0.99). There was a systematic bias but close limits of agreement (mean +/- 2 SD = -24.1% +/- 7.6% at 45 degrees; +16.4% +/- 11.0% at 60 degrees ). Using the 11-mm vessel, a quadratic relationship was demonstrated between between SIVV and true flow (r(2) = 0.98-0.99), regardless of the angle of insonation. In the pulsatile system, good agreement and correlation were shown (r(2) = 0.94, mean +/- 2 SD = -4.7 +/- 10.1%). The coefficients of variation for repeated SIVV measurements ranged from 0.9% to 10.3%. This method demonstrates precision and repeatability, and is potentially useful for clinical measurements.

  • 350. Chew, MS
    et al.
    Brandberg, Joakim
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Cannard, p
    Sloth, E
    Hasenkam, JM
    Ask, Per
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Evaluation of the surface integration of velocity vectors (SIVV) method in tubular flow model1998Inngår i: European Soc for Noninvasive cardiovascular dynamics,1998, 1998, s. 161-161Konferansepaper (Annet vitenskapelig)
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