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Miniature Vapor Sensor Device for Implantation in the Respiratory Tract

IP.com Disclosure Number: IPCOM000032827D
Publication Date: 2004-Nov-13
Document File: 10 page(s) / 95K

Publishing Venue

The IP.com Prior Art Database

Abstract

The present disclosure generally relates to implantable sensors, and more particularly relates to implantable miniature sensor systems and methods utilizing one or more vapor sensors for implantation in the respiratory tract.

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Miniature Vapor Sensor Device for Implantation in the Respiratory Tract

Background

                    The present disclosure generally relates to implantable sensors, and more particularly relates to implantable miniature sensor systems and methods utilizing one or more vapor sensors for implantation in the respiratory tract.

Patients suffering from expired breath may be exposed to a number of trace compounds found in the respiratory that may indicate the presence or the extent of a pathological condition.  These include compounds that may indicate the presence and level of blood ketones (elevated in diabetic ketoacidosis) [Zellers, et al., "Optimal Coating Selection for the Analysis of Organic Vapor Mixtures with Polymer-Coated Surface Acoustic Wave Sensor Arrays."  Anal Chem 1995 Mar 15; 67(6): pages 1092-106.], the presence and level of blood alcohol, the presence of H. pylori (responsible for most ulcers) [Kelly DJ., "The Physiology and Metabolism of the Human Gastric Pathogen Helicobacter Pylori."  Adv Microb Physiol 1998; 40: pages 137-89.], and the presence of inflammation (indicative of asthma, among many other conditions) [Robinson, et al.,  "Luminol/H2O2 Chemiluminescence Detector for the Analysis of Nitric Oxide in Exhaled Breath."  Anal Chem 1999 Nov 15;71(22):5131-6.]. 

A vapor sensor (or combination of sensors) may also provide selective multivapor monitoring of personal exposures in workplace environments.  Sensors are also able to detect levels of oxygen and of carbon dioxide, the levels of which may be altered in chronic respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD).  For example, [VanderGheynst, et al.,  "Development and Analysis of Oxygen-Sensing Probes for in situ Monitoring of Unsaturated Solid-State Biodegradation Processes."  J Air Waste Manag Assoc 1997 Oct; 47(10): pages1041-50.] and [Yim, et al., "Reversible Potentiometric Oxygen Sensors Based on Polymeric and Metallic Film Electrodes."  Anal Chem 1992 Sep 1; 64(17): pages 1777-84.] both discuss test results of a long-lasting oxygen sensor.  Sensors may also be able to detect peak airflow rate, which may be altered in chronic respiratory diseases such as asthma and COPD [Henneberger, et al., "The Use of Portable Peak Flowmeters in the Surveillance of Occupational Asthma."  Chest 1991 Dec; 100(6): pages 1515-21].

Miniature sensors have been developed that, when combined with appropriate signal processing circuitry, may detect the presence and the levels of some of these trace compounds.  For example, a surface acoustic wave (SAW) vapor sensor with a polymeric adsorbent layer can respond to vapors on the basis of mass loading and modulus decreases of the polymer film.  The modulus changes are associated with volume changes that occur as vapor is adsorbed by the film.  The (SAW) resonator may then identify different analytes by exhibiting a characteristic change in output frequencies, for example.  Another type...