Method for Studying Gas Composition in the Human Mastoid Cavity by Use of Laser Spectroscopy
(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:
https://lup.lub.lu.se/record/2571061
- author
- Lindberg, Sven LU ; Lewander, Märta LU ; Svensson, Tomas LU ; Siemund, Roger LU ; Svanberg, Katarina LU and Svanberg, Sune LU
- organization
- publishing date
- 2012
- 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
- 2016-04-01 13:50:55
- date last changed
- 2022-02-11 23:27:12
@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}},
keywords = {{* 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}},
url = {{http://www.ncbi.nlm.nih.gov/pubmed/22606924?dopt=Abstract}},
volume = {{121}},
year = {{2012}},
}