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Method for Studying Gas Composition in the Human Mastoid Cavity by Use of Laser Spectroscopy

Lindberg, Sven LU ; Lewander, Märta LU ; Svensson, Tomas LU ; Siemund, Roger LU ; Svanberg, Katarina LU and Svanberg, Sune LU (2012) In Annals of Otology, Rhinology & Laryngology 121(4). p.217-223
Abstract
Objectives:

We evaluated a method for gas monitoring in the mastoid cavity using tunable diode laser spectroscopy by comparing it to simultaneously obtained computed tomographic (CT) scans.



Methods:

The presented optical technique measures free gases, oxygen (O2), and water vapor (H2O) within human tissue by use of low-power diode lasers. Laser light was sent into the tip of the mastoid process, and the emerging light at the level of the antrum was captured with a detector placed on the skin. The absorption of H2O was used to monitor the probed gas volume of the mastoid cavity, and it was compared to the CT scan measured volume. The ratio between O2 absorption and H2O absorption estimated the O2... (More)
Objectives:

We evaluated a method for gas monitoring in the mastoid cavity using tunable diode laser spectroscopy by comparing it to simultaneously obtained computed tomographic (CT) scans.



Methods:

The presented optical technique measures free gases, oxygen (O2), and water vapor (H2O) within human tissue by use of low-power diode lasers. Laser light was sent into the tip of the mastoid process, and the emerging light at the level of the antrum was captured with a detector placed on the skin. The absorption of H2O was used to monitor the probed gas volume of the mastoid cavity, and it was compared to the CT scan measured volume. The ratio between O2 absorption and H2O absorption estimated the O2 content in the mastoid cavity and thus the ventilation. The parameters were compared to the grading of mastoid cavities based on the CT scans (n = 31). The reproducibility of the technique was investigated by measuring each mastoid cavity 4 times.



Results:

Both O2 and H2O were detected with good reproducibility. The H2O absorption and the CT volume correlated (r = 0.69). The average ratio between the normalized O2 absorption and the H2O absorption signals was 0.7, indicating a lower O2 content than in surrounding air (expected ratio, 1.0), which is consistent with previous findings made by invasive techniques. All mastoid cavities with radiologic signs of disease were detected.



Conclusions:

Laser spectroscopy monitoring appears to be a usable tool for noninvasive investigations of gas composition in the mastoid cavity, providing important clinical information regarding size and ventilation. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
* mastoid cavity * laser spectroscopy * oxygen * water vapor
in
Annals of Otology, Rhinology & Laryngology
volume
121
issue
4
pages
217 - 223
publisher
Annals Publishing Company
external identifiers
  • wos:000302882300001
  • scopus:84858270185
ISSN
0003-4894
language
English
LU publication?
yes
id
0ba0d867-40ed-4f3c-977c-df05d0117436 (old id 2571061)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/22606924?dopt=Abstract
date added to LUP
2012-05-30 20:14:15
date last changed
2017-08-06 04:05:23
@article{0ba0d867-40ed-4f3c-977c-df05d0117436,
  abstract     = {Objectives: <br/><br>
We evaluated a method for gas monitoring in the mastoid cavity using tunable diode laser spectroscopy by comparing it to simultaneously obtained computed tomographic (CT) scans. <br/><br>
<br/><br>
Methods:<br/><br>
The presented optical technique measures free gases, oxygen (O2), and water vapor (H2O) within human tissue by use of low-power diode lasers. Laser light was sent into the tip of the mastoid process, and the emerging light at the level of the antrum was captured with a detector placed on the skin. The absorption of H2O was used to monitor the probed gas volume of the mastoid cavity, and it was compared to the CT scan measured volume. The ratio between O2 absorption and H2O absorption estimated the O2 content in the mastoid cavity and thus the ventilation. The parameters were compared to the grading of mastoid cavities based on the CT scans (n = 31). The reproducibility of the technique was investigated by measuring each mastoid cavity 4 times. <br/><br>
<br/><br>
Results: <br/><br>
Both O2 and H2O were detected with good reproducibility. The H2O absorption and the CT volume correlated (r = 0.69). The average ratio between the normalized O2 absorption and the H2O absorption signals was 0.7, indicating a lower O2 content than in surrounding air (expected ratio, 1.0), which is consistent with previous findings made by invasive techniques. All mastoid cavities with radiologic signs of disease were detected. <br/><br>
<br/><br>
Conclusions: <br/><br>
Laser spectroscopy monitoring appears to be a usable tool for noninvasive investigations of gas composition in the mastoid cavity, providing important clinical information regarding size and ventilation.},
  author       = {Lindberg, Sven and Lewander, Märta and Svensson, Tomas and Siemund, Roger and Svanberg, Katarina and Svanberg, Sune},
  issn         = {0003-4894},
  keyword      = {* mastoid cavity * laser spectroscopy * oxygen * water vapor},
  language     = {eng},
  number       = {4},
  pages        = {217--223},
  publisher    = {Annals Publishing Company},
  series       = {Annals of Otology, Rhinology & Laryngology},
  title        = {Method for Studying Gas Composition in the Human Mastoid Cavity by Use of Laser Spectroscopy},
  volume       = {121},
  year         = {2012},
}