liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
In-vivo reflection spectroscopy measurements in pig brain during stereotactic surgery
Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, The Institute of Technology.
Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, The Institute of Technology.
Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, The Institute of Technology. (MINT)
2003 (English)In: Biophotonics West: Biomedical Optics, 2003, Vol. 4958, 242-250 p.Conference paper, Published paper (Refereed)
Abstract [en]

Radiofrequency (RF) lesioning in the human brain is a commonsurgical therapy for relieving severe pain as well as formovement disorders such as Parkinsonia. During the procedure a smallelectrode is introduced by stereotactic means towards a target arealocalized by CT or MRI. An RF-current is applied throughthe electrode tip when positioned in the target area. Thetissue in the proximity of the tip is heated bythe current and finally coagulated.The overall aim of this studywas to improve the RF-technique and its ability to estimatelesion size by means of optical methods. Therefore, the opticaldifferences between white and gray matter, as well as lesionedand unlesioned tissue were investigated. Reflection spectroscopy measurements in therange of 450-800 nm were conducted on fully anesthetized pigsduring stereotactic RF-lesioning (n=6). Light from a tungsten lamp wasguided to the electrode tip through optical fibers, inserted alonga 2 mm in diameter monopolar RF-electrode. Measurements were performedin steps of 0-10 mm from the target in eachhemisphere towards the entry point of the skull. In thecentral gray of the porcine brain measurements were performed bothbefore and after the creation of a lesion. A totalof 55 spectra were collected during this study. Correlation totissue type was done using post-operative MR-images. The spectral signaturefor white and gray matter differs significantly for the entirespectral range of 450-800 nm. Pre- and post-lesioning reflection spectroscopyshowed the largest differences below 600 and above 620 nm,which implies that lasers within this wavelength range may beuseful for in-vivo measurements of tissue optical changes during RF-lesioning.

Place, publisher, year, edition, pages
2003. Vol. 4958, 242-250 p.
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:liu:diva-14234DOI: 10.1117/12.476131OAI: oai:DiVA.org:liu-14234DiVA: diva2:22961
Available from: 2007-01-26 Created: 2007-01-26 Last updated: 2017-02-22Bibliographically approved
In thesis
1. On optical methods for intracerebral measurements during stereotactic and functional neurosurgery: Experimental studies
Open this publication in new window or tab >>On optical methods for intracerebral measurements during stereotactic and functional neurosurgery: Experimental studies
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Radio frequency (RF) lesioning and deep brain stimulation (DBS) are the two prevailing surgical treatments for movement disorders within the field of stereotactic and functional neurosurgery. For RF-lesioning, a small volume of brain tissue is coagulated and knowledge of the lesion size and growth is of great importance for the safety and outcome of the procedure. This thesis deals with adapting the laser Doppler perfusion monitoring (LDPM) technique for measurements in brain tissue during RF-lesioning. The relation between LDPM signal changes and developed lesion size was investigated. LDPM measurements were evaluated both in vitro (albumin protein solution) and in vivo in the porcine brain during RF-lesioning corresponding to a bilateral thalamotomy in man. The investigated signals from the LDPI measurements can be used for following the lesioning time course and to detect if a lesion was created, both in vitro and in the animal model. For the albumin model, both the total backscattered light intensity and the perfusion signal can be used as markers for estimating the final coagulation size, while in the animal model this conclusion was not statistical verified.

Independent on surgical method, RF-lesioning or DBS, intracerebral guidance is an important aspect within stereotactic and functional neurosurgery. To increase the accuracy and precision of reaching the correct target, different methods for intracerebral guidance exist, such as microelectrode recording and impedance methods. In this thesis, the possibility of developing an optical intracerebral guidance method has been investigated. Diffuse reflectance spectroscopy served as technology and all measurements were performed stereotactically in both porcine and human brain. Measurements of white and gray matter showed large differences, with higher reflectivity for white brain matter, both in porcine and in human brain. For the human measurements during DBS-implants, large differences between white matter and functional targets were found. Additionally, differences between native and lesioned porcine brain matter were detected. Both studies support the idea of using diffuse reflectance spectroscopy for developing an intracerebral guidance method.

Place, publisher, year, edition, pages
Institutionen för medicinsk teknik, 2007
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1070
Keyword
Laser Doppler perfusion monitoring, Diffuse reflectance spectroscopy, Functional and stereotactic neurosurgery
National Category
Medical Laboratory and Measurements Technologies
Identifiers
urn:nbn:se:liu:diva-8081 (URN)978-91-85715-91-6 (ISBN)
Public defence
2007-02-02, Elsa Brändströms sal, Södra Entreén, Universitetssjukhuset, Linköping, 09:15 (English)
Opponent
Supervisors
Available from: 2007-01-26 Created: 2007-01-26 Last updated: 2016-05-04
2. Optical measurements in brain tissue during radio frequency lesioning
Open this publication in new window or tab >>Optical measurements in brain tissue during radio frequency lesioning
2004 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Radio frequency (RF) lesioning is a well well-known procedure within the field of stereotactic neurosurgery, commonly used for the treatment of movement disorders. During the intervention, an RF-electrode is inserted into the deeper parts of the brain, where a small volume of malfunctioning brain tissue will be coagulated. This procedure is irreversible, as a result, the size and position of the created lesion is crucial in order to avoid unwanted side effects. In this thesis a further development of the RF-technology is presented in order to follow a lesioning process and to estimate the created lesion size. Software, electronics, fiber optics and an RF-electrode equipped with optical fibers was developed and evaluated.

Diffuse reflectance spectroscopy measurements at 450-800 nm in the central gray of porcine brain have been performed with the developed RF-electrode. Measurements of white and gray brain matter showed a large reflectance difference in the investigated wavelength interval, with higher reflectivity for white brain matter. Reflectance differences between native and coagulated, white and gray brain matter were also found .

In-vitro laser Doppler perfusion monitoring measurements at 633 nm have also been performed in a newly designed flow model. An albumin solution with added glass microspheres was placed on top of a revolving disc. The motion of the liquid surrounding the electrode tip simulated a perfusion situation. Changes in both laser Doppler perfusion and total backscattered light intensity signals were collected during the creation of different sized coagulations. The volume, width and length of the created coagulations are correlated to the measured signal changes in-vitro, where larger coagulations displayed larger signal changes. The laser Doppler perfusion and backscattered light intensity signals can be used to follow the lesioning time course and estimate the developed lesion size in-vitro.

Place, publisher, year, edition, pages
Linköping: Linköpings universitet, 2004. 33 p.
Series
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1114
Series
LiU-TEK-LIC, 43
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-22099 (URN)1192 (Local ID)91-85295-29-9 (ISBN)1192 (Archive number)1192 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2013-11-13

Open Access in DiVA

No full text

Other links

Publisher's full textLink to Ph.D. thesis

Authority records BETA

Antonsson, JohanEriksson, OlaWårdell, Karin

Search in DiVA

By author/editor
Antonsson, JohanEriksson, OlaWårdell, Karin
By organisation
Biomedical InstrumentationThe Institute of Technology
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 572 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf