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Erschienen in:

01.11.2014 | original article

How do temperature variations influence the signal in the Triggerfish contact lens sensor?

verfasst von: Univ.-Prof. Dr. Christoph Wolfgang Faschinger, PhD, MD, Dieter Franz Rabensteiner, MD, Georg Mossböck, MD, PhD

Erschienen in: Spektrum der Augenheilkunde | Ausgabe 5/2014

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Summary

Background

Variations in the shape of the profile of a 24-h continuous, indirect measurement of intraocular pressure with a contact lens sensor may possibly be influenced by artifacts. We examined the sensitivity of a contact lens sensor to changes in temperature that patients may experience during the measurement period.

Material and methods

Three Triggerfish contact lens sensors (Sensimed, Lausanne, Switzerland) were placed in a container with 0.9 % physiological saline solution. The temperature of the solution was either raised with a thermostat over a period of hours, rapidly cooled with crushed ice, or allowed to cool slowly to room temperature. The temperatures were recorded with two probes; the Triggerfish profiles were shown in millivolt equivalents (mV eq).

Results

All three profiles mainly showed that the mV eq fell when the temperature increased, and rose when the temperature decreased, with a few deviations from this behavior. Rapid temperature change with ice produced pronounced spikes in the profile. The extent of change in mV eq was not uniform with slow changes in temperature but was always slight (between 0.5 and 3 mV eq per degree centigrade), though it was high with rapid cooling.

Conclusions

Our studies with the Triggerfish contact lens sensor showed that the sensor is sensitive to temperature changes. This is not surprising because the gauge that measures strain is made of platinum and titanium, and metals possess electrical and thermal conductivity. Apparently, the temperature sensitivity is not adequately compensated by the Wheatstone bridge used. The possible temperature sensitivity should be taken into consideration in evaluating the pressure profiles.
Literatur
1.
Zurück zum Zitat Faschinger C, Mossböck G. Kontinuierliche 24-h-Aufzeichnung von Augendruckschwankungen mittels drahtlosem Kontaktlinsensensor Triggerfish. Erste Ergebnisse an Patienten. Ophthalmologe. 2010;107:918–22.PubMedCrossRef Faschinger C, Mossböck G. Kontinuierliche 24-h-Aufzeichnung von Augendruckschwankungen mittels drahtlosem Kontaktlinsensensor Triggerfish. Erste Ergebnisse an Patienten. Ophthalmologe. 2010;107:918–22.PubMedCrossRef
2.
Zurück zum Zitat De Smet S, Mermoud A, Schnyder C. 24-hour intraocular pressure fluctuation monitoring using an ocular telemetry sensor: tolerability and functionality in healthy subjects. J Glaucoma. 2011;21:539–44.CrossRef De Smet S, Mermoud A, Schnyder C. 24-hour intraocular pressure fluctuation monitoring using an ocular telemetry sensor: tolerability and functionality in healthy subjects. J Glaucoma. 2011;21:539–44.CrossRef
3.
Zurück zum Zitat Mansouri K, Shaarawy T. Continuous intraocular pressure monitoring with a wireless ocular telemetry sensor: initial clinical experience in patients with open angle glaucoma. Br J Ophthalmol. 2011;95:627–9.PubMedCrossRef Mansouri K, Shaarawy T. Continuous intraocular pressure monitoring with a wireless ocular telemetry sensor: initial clinical experience in patients with open angle glaucoma. Br J Ophthalmol. 2011;95:627–9.PubMedCrossRef
4.
Zurück zum Zitat Lorenz K, Korb C, Herzog N, et al. Tolerability of 24-hour intraocular pressure monitoring of a pressure-sensitive contact lens. J Glaucoma. 2013;22:311–6.PubMedCrossRef Lorenz K, Korb C, Herzog N, et al. Tolerability of 24-hour intraocular pressure monitoring of a pressure-sensitive contact lens. J Glaucoma. 2013;22:311–6.PubMedCrossRef
5.
Zurück zum Zitat Mansouri K, Liu JHK, Weinreb RN, et al. Analysis of continuous 24-hour intraocular pressure patterns in glaucoma. Invest Ophthalmol Vis Sci. 2012;53:8050–6.PubMedCentralPubMedCrossRef Mansouri K, Liu JHK, Weinreb RN, et al. Analysis of continuous 24-hour intraocular pressure patterns in glaucoma. Invest Ophthalmol Vis Sci. 2012;53:8050–6.PubMedCentralPubMedCrossRef
6.
Zurück zum Zitat Faschinger C, Mossböck G, Krainz S. Validität und Reproduzierbarkeit von Sensorkontaktlinsen-Profilen im Vergleich zur Applanationstonometrie bei gesunden Augen. Klin Monatsbl Augenheilkd. 2012;229:1209–14.PubMedCrossRef Faschinger C, Mossböck G, Krainz S. Validität und Reproduzierbarkeit von Sensorkontaktlinsen-Profilen im Vergleich zur Applanationstonometrie bei gesunden Augen. Klin Monatsbl Augenheilkd. 2012;229:1209–14.PubMedCrossRef
7.
Zurück zum Zitat Hollo G, Kothy P, Vargha P. Evaluation of continuous 24-hour intraocular pressure monitoring for assessment of prostaglandin-induced pressure reduction in glaucoma. J Glaucoma. 2013. doi: 10.1097/IJG.0b013e31829e5635. Hollo G, Kothy P, Vargha P. Evaluation of continuous 24-hour intraocular pressure monitoring for assessment of prostaglandin-induced pressure reduction in glaucoma. J Glaucoma. 2013. doi: 10.1097/IJG.0b013e31829e5635.
8.
Zurück zum Zitat Pajic B, Pajic-Eggspuchler B, Haefliger I. Continuous IOP fluctuation recording in normal tension glaucoma patients. Curr Eye Res. 2011;36:1129–38.PubMedCrossRef Pajic B, Pajic-Eggspuchler B, Haefliger I. Continuous IOP fluctuation recording in normal tension glaucoma patients. Curr Eye Res. 2011;36:1129–38.PubMedCrossRef
9.
Zurück zum Zitat Leonardi M, Leuenberger P, Bertrand D, et al. First steps toward noninvasive intraocular pressure monitoring with a sensing contact lens. Invest Ophthalmol Vis Sci. 2004;45:3113–7.PubMedCrossRef Leonardi M, Leuenberger P, Bertrand D, et al. First steps toward noninvasive intraocular pressure monitoring with a sensing contact lens. Invest Ophthalmol Vis Sci. 2004;45:3113–7.PubMedCrossRef
10.
Zurück zum Zitat Leonardi M, Pitchon EM, Bertsch A, et al. Wireless contact lens sensor for intraocular pressure monitoring: assessment on enucleated pig eyes. Acta Ophthalmol. 2009;87:433–7.PubMedCrossRef Leonardi M, Pitchon EM, Bertsch A, et al. Wireless contact lens sensor for intraocular pressure monitoring: assessment on enucleated pig eyes. Acta Ophthalmol. 2009;87:433–7.PubMedCrossRef
11.
Zurück zum Zitat Mansouri K, Medeiros FA, Tafreshi A, et al. Continuous 24-hour monitoring of intraocular pressure patterns with a contact lens sensor. Arch Ophthalmol. 2012;130:1534–9.CrossRef Mansouri K, Medeiros FA, Tafreshi A, et al. Continuous 24-hour monitoring of intraocular pressure patterns with a contact lens sensor. Arch Ophthalmol. 2012;130:1534–9.CrossRef
12.
Zurück zum Zitat Leonardi M. Microfabricated thin film strain gage sensor with telemetry microprocessor embedded in a soft contact lens for minimally invasive intraocular pressure monitoring [dissertation]. Lausanne: Swiss Federal Institute of Technology Lausanne; 2007. Leonardi M. Microfabricated thin film strain gage sensor with telemetry microprocessor embedded in a soft contact lens for minimally invasive intraocular pressure monitoring [dissertation]. Lausanne: Swiss Federal Institute of Technology Lausanne; 2007.
13.
Zurück zum Zitat Rysä P, Sarvaranta J. Thermography of the eye during cold stress. Acta Ophthalmol Suppl. 1973;123:234–9. Rysä P, Sarvaranta J. Thermography of the eye during cold stress. Acta Ophthalmol Suppl. 1973;123:234–9.
14.
Zurück zum Zitat Mori A, Oguchi Y, Okusawa Y, et al. Use of high-speed, high-resolution thermography to evaluate the tear film layer. Am J Ophthalmol. 1997;124:729–35.PubMedCrossRef Mori A, Oguchi Y, Okusawa Y, et al. Use of high-speed, high-resolution thermography to evaluate the tear film layer. Am J Ophthalmol. 1997;124:729–35.PubMedCrossRef
15.
Zurück zum Zitat Alio J, Padron M. Influence of age on the temperature of the anterior segment of the eye. Ophthalmic Res. 1982;14:153–9.PubMedCrossRef Alio J, Padron M. Influence of age on the temperature of the anterior segment of the eye. Ophthalmic Res. 1982;14:153–9.PubMedCrossRef
16.
Zurück zum Zitat Girardin F, Orgül S, Erb C, et al. Relationship between corneal temperature and finger temperature. Arch Ophthalmol. 1999;117:166–9.PubMedCrossRef Girardin F, Orgül S, Erb C, et al. Relationship between corneal temperature and finger temperature. Arch Ophthalmol. 1999;117:166–9.PubMedCrossRef
17.
Zurück zum Zitat Efron N, Young G, Brennan NA. Ocular surface temperature. Curr Eye Res. 1989;8:901–6.PubMed Efron N, Young G, Brennan NA. Ocular surface temperature. Curr Eye Res. 1989;8:901–6.PubMed
18.
Zurück zum Zitat Rysä P, Sarvaranta J. Corneal temperature in man and rabbit. Acta Ophthalmol. 1974;52:810–16.CrossRef Rysä P, Sarvaranta J. Corneal temperature in man and rabbit. Acta Ophthalmol. 1974;52:810–16.CrossRef
Metadaten
Titel
How do temperature variations influence the signal in the Triggerfish contact lens sensor?
verfasst von
Univ.-Prof. Dr. Christoph Wolfgang Faschinger, PhD, MD
Dieter Franz Rabensteiner, MD
Georg Mossböck, MD, PhD
Publikationsdatum
01.11.2014
Verlag
Springer Vienna
Erschienen in
Spektrum der Augenheilkunde / Ausgabe 5/2014
Print ISSN: 0930-4282
Elektronische ISSN: 1613-7523
DOI
https://doi.org/10.1007/s00717-014-0228-3