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Karlsson, Daniel M. G.
Alternative names
Publications (10 of 14) Show all publications
Lyth, J., Lind, L., Karlsson, D., Persson, L. H. & Wiréhn, A.-B. (2018). Can a telemonitoring system lead to decreased hospital admissions in elderly patients?. In: : . Paper presented at ERS International Congress 2018, Paris, France, 15-19 September, 2018.
Open this publication in new window or tab >>Can a telemonitoring system lead to decreased hospital admissions in elderly patients?
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2018 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Background: Populations of elderly patients with chronic obstructive pulmonary disease (COPD) or heart failure (HF) are growing. To prevent exacerbations leading to inpatient care, a 4 year (2013-2017) telehealth intervention non-randomized single-centre clinical study was performed. We hypothesized that the patients, grouped by advanced COPD or HF, would exhibit decreased need of hospital admissions.

Objective: To study hospital admissions in patients with COPD or HF using a telemonitoring system, the Health Diary.

Methods: A telemonitoring system, the Health Diary, based on digital pen technology, was employed. Patients with COPD or HF treated at the University Hospital in Linköping were included if they had at least 2 hospital admissions the previous year. Data on hospital admissions was obtained from the administrative healthcare database. Expected number of hospital admissions for the study year was calculated using 5-year data for a group of patients with matching diagnosis and history of hospital admissions and was compared to the actual value in the intervention group using Poisson regression.

Results: Together with the included patients, 159 HF and 136 COPD non-intervention patients was used to calculate the expected values for hospital admissions. For the 58 included HF patients, the average number of hospital admissions of 0.81 was 32.8 percent (p=0.04) lower than expected. For the 36 included COPD patients, the average number of hospital admissions of 1.44 was 37.0 percent (p=0.02) lower than expected.

Conclusions: Use of the telemonitoring system, the Health Diary, decreases hospital admissions in elderly with COPD and HF.

National Category
Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:liu:diva-153784 (URN)10.1183/13993003.congress-2018.PA1998 (DOI)
Conference
ERS International Congress 2018, Paris, France, 15-19 September, 2018
Available from: 2019-01-10 Created: 2019-01-10 Last updated: 2019-01-17Bibliographically approved
Lind, L., Lyth, J., Karlsson, D. M. G., Wiréhn, A.-B. & Persson, L. (2018). COPD patients require more health care than heart failure patients. In: ERS International Congress 2018: . Paper presented at ERS International Congress 2018, Paris, France, 15-19 September, 2018.
Open this publication in new window or tab >>COPD patients require more health care than heart failure patients
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2018 (English)In: ERS International Congress 2018, 2018Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Background: Populations of elderly patients with advanced stages of chronic obstructive pulmonary disease (COPD) or heart failure (HF) are growing, urging the need for specialized health care in the patients’ home. A 4 year (2013-2017) telehealth intervention single-centre clinical study has been completed. We hypothesized that the two groups of patients, advanced COPD or HF, would exhibit differences regarding exacerbations and the need of health care.

Objective: To study exacerbations of COPD or HF, and patients’ need of health care.

Methods: A telemonitoring system, the Health Diary, which is based on digital pen technology, was employed. Patients with at least 2 hospital admissions the previous year were included. Responsible nurses and physicians at a specialized home care unit at a university hospital checked all daily patient reports. Physicians identified exacerbations using information provided through the telemonitoring system and patient contacts. Consumed health care was assessed as the number of patient contacts (home visits or telephone consultations).

Results: Totally, 94 patients with advanced disease were enrolled (36 COPD and 58 HF patients) of which 53 patients (19 COPD and 34 HF patients) completed the 1-yr study period. The major reason for not completing the study was death (13 COPD, 15 HF patients). Average numbers of exacerbations were 3.1 and 0.8 and patient contacts were 94 and 67 per COPD and HF patient, respectively.

Conclusions: Compared to HF patients, COPD patients exhibit exacerbations more frequently and demand much more home health care. This difference of health care consumption is mainly due to disease characteristics.

National Category
Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:liu:diva-153785 (URN)10.1183/13993003.congress-2018.PA743 (DOI)
Conference
ERS International Congress 2018, Paris, France, 15-19 September, 2018
Available from: 2019-01-10 Created: 2019-01-10 Last updated: 2019-01-17
Lindbergh, T., Häggblad, E., Karlsson, D. M., Ahn, H. C., Salerud, G. & Strömberg, T. (2005). Hjärtmuskelns syresättning mätt med diffus reflektansspektroskopi under by-passkirurgi på människa. In: Medicinteknikdagar MTF,2005.
Open this publication in new window or tab >>Hjärtmuskelns syresättning mätt med diffus reflektansspektroskopi under by-passkirurgi på människa
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2005 (Swedish)In: Medicinteknikdagar MTF,2005, 2005Conference paper, Published paper (Other academic)
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-30201 (URN)15695 (Local ID)15695 (Archive number)15695 (OAI)
Available from: 2009-10-09 Created: 2009-10-09
Karlsson, M. D. (2005). Movement artifact reduction in laser Doppler blood flowmetry: myocardial perfusion applications. (Doctoral dissertation). Linköping: Linköpings universitet
Open this publication in new window or tab >>Movement artifact reduction in laser Doppler blood flowmetry: myocardial perfusion applications
2005 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Laser Doppler perfusion monitoring (LDPM) and imaging (LDPI) enable assessment of tissue microvascular perfusion. The techniques are based on the Doppler broadening of the optical spectrum occurring when coherent laser light is scattered by moving red blood cells (RBC). However, if tissue motion not related to moving RBCs is present, artifacts arise in the derived perfusion estimate. The aim of this thesis was to develop and evaluate methods to reduce tissue motion influence on the perfusion estimate in general and for the specific purpose of enabling myocardial perfusion monitoring in the beating heart.

An LDPM system, based on digital signal processing, was developed for myocardial perfusion assessment. To achieve an accurate estimate of the local microvascular perfusion, the varying myocardial tissue motion during the cardiac cycle is taken into account. By means of ECG-triggering, periods of minimum myocardial tissue motion can be pinpointed. The system and proposed methods were successfully evaluated both in an animal model (3 calves) and during coronary artery bypass grafting (CABG) on 13 humans. Animal studies showed the importance of processing during minimum tissue motion, at late diastole and/or late systole, to reduce movement artifacts. The human evaluation confirmed earlier animal findings and revealed low flow situations in the intraoperative phase. Influence of mechanical ventilation on the myocardial blood flow was found. The results justify investigation postoperative of CABG, where myocardial perfusion monitoring may give a rapid response to potential ischemia.

The influence of tissue motion on LDPI was studied in model measurements and on the skin. A relatively large tissue velocity, compared to microvascular flow velocities, was needed to significantly influence the perfusion signal. Movement artifact magnitude depended on the movement direction and the surface structure. An LDPI system utilizing a polarization technique that blocks specularly reflected light is proposed. The method was evaluated in a flow model and on the skin of 12 subjects and was found to significantly reduce influence from tissue motion. Finally, a theoretical explanation of the origin of LDPI movement artifacts is proposed. Reduction of movement artifacts makes measurements more reliable and increases the potential of LDPI as a clinical tool.

Place, publisher, year, edition, pages
Linköping: Linköpings universitet, 2005. p. 84
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 935
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-28804 (URN)13992 (Local ID)91-85297-73-9 (ISBN)13992 (Archive number)13992 (OAI)
Public defence
2005-04-29, Linden, ingång 65, Campus US, Linköpings universitet, Linköping, 09:15 (English)
Opponent
Supervisors
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2018-01-08Bibliographically approved
Fors, C., Karlsson, D. M., Ahn, H. C. & Wårdell, K. (2005). Myocardial perfusion assessment using an ECG triggered laser doppler technique. In: 13th Nordic Baltic Conference Biomedical Engineering and Medical Physics,2005: (pp. 83-84). Umeå: IFMBE
Open this publication in new window or tab >>Myocardial perfusion assessment using an ECG triggered laser doppler technique
2005 (English)In: 13th Nordic Baltic Conference Biomedical Engineering and Medical Physics,2005, Umeå: IFMBE , 2005, p. 83-84Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Umeå: IFMBE, 2005
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-28744 (URN)13918 (Local ID)13918 (Archive number)13918 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-02-21Bibliographically approved
Karlsson, D. M. G., Fors, C., Wårdell, K. & Casimir-Ahn, H. (2005). Myocardial perfusion monitoring during coronary artery bypass using an electrocardiogram-triggered laser Doppler technique. Medical and Biological Engineering and Computing, 43(5), 582-588
Open this publication in new window or tab >>Myocardial perfusion monitoring during coronary artery bypass using an electrocardiogram-triggered laser Doppler technique
2005 (English)In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 43, no 5, p. 582-588Article in journal (Refereed) Published
Abstract [en]

Electrocardiogram (ECG)—triggered laser Doppler perfusion monitoring (LDPM) was used to assess myocardial perfusion, with minimum myocardial tissue motion influence, during coronary artery bypass grafting (CABG). Thirteen subjects were investigated at six phases: pre- and post-CABG; post aorta cross-clamping; pre and post left internal mammary artery (LIMA) graft declamping; and post aorta declamping. The perfusion signal was calculated in late systole and late diastole, with expected minimum tissue motion, and compared with arrested heart measurements. Patient conditions or artifacts caused by surgical activity made it impossible to perform and analyse data in all six phases for some patients. No significant (n=5) difference between perfusion signals pre- and post-CABG was found. Diastolic perfusion signal levels were significantly (p<0.02) lower compared with systolic levels. After aorta cross-clamping, the signal level was almost zero. A distinct perfusion signal increase after LIMA and aorta declamping, compared with pre-LIMA declamping, was found in ten cases out of 13. A significantly (p<0.04) lower perfusion signal in the arrested heart compared with in the beating heart was registered. Influence from mechanical ventilation was observed in 14 measurements out of 17. In conclusion, ECG-triggered LDPM can be used to assess myocardial perfusion during CABG. Perfusion signals were lower in the arrested heart compared with in the beating heart and in late diastole compared with late systole. No significant difference between pre- and post-CABG was found.

Place, publisher, year, edition, pages
Springer, 2005
Keywords
Laser Doppler perfusion monitoring, Coronary artery bypass grafting, Beating heart, Myocardial microcirculation, Movement artifacts, Electrocardiography
National Category
Medical Laboratory and Measurements Technologies
Identifiers
urn:nbn:se:liu:diva-14612 (URN)10.1007/BF02351031 (DOI)000234262300007 ()2-s2.0-29244438810 (Scopus ID)
Available from: 2007-08-27 Created: 2007-08-27 Last updated: 2017-12-13Bibliographically approved
Karlsson, D. M. & Wårdell, K. (2005). Polarized laser Doppler perfusion imaging—reduction of movement-induced artifacts. Journal of Biomedical Optics, 10(6)
Open this publication in new window or tab >>Polarized laser Doppler perfusion imaging—reduction of movement-induced artifacts
2005 (English)In: Journal of Biomedical Optics, ISSN 1083-3668, E-ISSN 1560-2281, Vol. 10, no 6Article in journal (Refereed) Published
Abstract [en]

Laser Doppler perfusion imaging (LDPI) enables superficial tissue perfusion assessment, but is sensitive to tissue motion not related to blood cells. The aim was to investigate if a polarization technique could reduce movement-induced artifacts. A linearly polarized laser and a cross-polarized filter, placed in front of the detectors, were used to block specular reflection. Measurements were performed with, and without, the polarization filter, at a single site during horizontal and vertical movement of skin tissue (index finger, twelve subjects, n=112) and of a flow model (n=432), with varying surface structures. Measurements were repeated during different flow conditions and at increased skin specular reflection. Statistical analysis was performed using ANOVA models. The perfusion signal was lower (p<0.001, skin and p<0.05, flow model) using the polarization filter, due to movement artifact reduction. No significant influence from surface structure was found when using the polarization filter. Movement artifacts were lower (p<0.05) in the vertical movement direction, however, depending on flow conditions for skin measurements. Increased skin specular reflection gave rise to large movement artifacts without the polarization filter. In conclusion, the polarized LDPI technique reduces movement artifacts and is particularly appropriate when assessing, e.g., ulcers and burns, where specular reflection is high.

Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2005
National Category
Medical Laboratory and Measurements Technologies
Identifiers
urn:nbn:se:liu:diva-30112 (URN)10.1117/1.2120467 (DOI)000234859400005 ()16409068 (PubMedID)2-s2.0-33645238951 (Scopus ID)15582 (Local ID)15582 (Archive number)15582 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13Bibliographically approved
Fors, C., Karlsson, M. G., Ahn, H. C. & Wårdell, K. (2004). A system for on-line laser Doppler monitoring of ECG-traced myocardial perfusion. In: IEEE EMBS,2004: (pp. 3796). Piscataway, NJ, USA: IEEE
Open this publication in new window or tab >>A system for on-line laser Doppler monitoring of ECG-traced myocardial perfusion
2004 (English)In: IEEE EMBS,2004, Piscataway, NJ, USA: IEEE , 2004, p. 3796-Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Piscataway, NJ, USA: IEEE, 2004
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-22105 (URN)1201 (Local ID)1201 (Archive number)1201 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-02-22Bibliographically approved
Karlsson, M. G., Hübbert, L., Lönn, U., Janerot-Sjöberg, B., Ahn, H. C. & Wårdell, K. (2004). Myocardial tissue motion influence on laser Doppler perfusion monitoring using tissue Doppler imaging. Medical and Biological Engineering and Computing, 42(6), 770-776
Open this publication in new window or tab >>Myocardial tissue motion influence on laser Doppler perfusion monitoring using tissue Doppler imaging
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2004 (English)In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 42, no 6, p. 770-776Article in journal (Refereed) Published
Abstract [en]

Tissue motion of the beating heart generates large movement artifacts in the laser Doppler perfusion monitoring (LDPM) signal. The aim of the study was to use tissue Doppler imaging (TDI) to localise intervals during the cardiac cycle where the influence of movement artifacts on the LDPM signal is minimum. TDI velocities and LDPM signals were investigated on three calves, for normal heartbeat and during occlusion of the left anterior descending coronary artery. Intervals of low tissue velocity (TDIint<1 cm s−1) during the cardiac cycle were identified. During occlusion, these intervals were compared with low LDPM signal intervals (LDPMint<50% compared with baseline). Low-velocity intervals were found in late systole (normal and occlusion) and late diastole (normal). Systolic intervals were longer and less sensitive to heart rate variation compared with diastolic ones. The overlap between LDPMint and TDIint in relation to TDIint length was 84±27% (n=14). The LDPM signal was significantly (p<0.001, n=14) lower during occlusion if calculated during minimum tissue motion inside TDIint), compared with averaging over the entire cardiac cycle without taking tissue motion into consideration. In conclusion, movement artifacts are reduced if the LDPM signal is correlated to the ECG and investigated during minimum wall motion. The optimum interval depends on the application; late systole and late diastole can be used.

Place, publisher, year, edition, pages
Springer, 2004
National Category
Medical Laboratory and Measurements Technologies
Identifiers
urn:nbn:se:liu:diva-22150 (URN)10.1007/BF02345210 (DOI)000225543500006 ()2-s2.0-10244245509 (Scopus ID)1260 (Local ID)1260 (Archive number)1260 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13Bibliographically approved
Karlsson, D. M., Ahn, H. C., Lönn, U. & Wårdell, K. (2003). Analysis and processing of laser Doppler perfusion monitoring signals recorded from the beating heart. Medical and Biological Engineering and Computing, 41(3), 255-262
Open this publication in new window or tab >>Analysis and processing of laser Doppler perfusion monitoring signals recorded from the beating heart
2003 (English)In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 41, no 3, p. 255-262Article in journal (Refereed) Published
Abstract [en]

Laser Doppler perfusion monitoring (LDPM) can be used for monitoring myocardial perfusion in the non-beating heart. However, the movement of the beating heart generates large artifacts. Therefore the aim of the study was to develop an LDPM system capable of correlating the laser Doppler signals to the cardiac cycle and to process the signals to reduce the movement artifacts. Measurements were performed on three calves, both on the normal beating heart and during occlusion of the left anterior descending coronary artery (LAD). The recorded LDPM signals were digitally processed and correlated to the sampled ECG. Large variations in the output (perfusion) and DC signals during the cardiac cycle were found, with average coefficients of variation of 0.36 and 0.14 (n-14), respectively. However, sections with a relatively low, stable output signal were found in late diastole, where the movement of the heart is at a minimum. Occlusion of the LAD showed the importance of recording the laser Doppler signals at an appropriate point in the cardiac cycle, in this case late systole, to minimise movement artifacts. It is possible to further reduce movement artifacts by increasing the lower cutoff frequency when calculating the output signal.

Place, publisher, year, edition, pages
Springer, 2003
National Category
Medical Laboratory and Measurements Technologies
Identifiers
urn:nbn:se:liu:diva-24478 (URN)10.1007/BF02348429 (DOI)000183399600004 ()2-s2.0-0037842891 (Scopus ID)6594 (Local ID)6594 (Archive number)6594 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13Bibliographically approved
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