Breath test analyzer

Abstract

A breath test analyzer, which analyzes exhaled breadths of a patient for isotope labeled products generated in the patient's body after ingestion by the patient of an isotope labeled substance, where the presence of these isotope labeled products provide an indication of a medical condition in the patient. The analyzer uses a very sensitive infra-red spectrophotometer, which enables it to continuously collect and analyze multiple samples of the patient's breath, and process the outputs in real time, while the patient is still connected to the analyzer, such that a definitive result is obtained within a short time, such as the order of a few minutes. The breath test analyzer is sufficiently small in that it can be easily accommodated in the office of a physician. The breath test analyzer can be utilized for a number of diagnostic breath tests, according to the isotope labeled substance ingested by the patient and the gases detected in the patient's breath.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This is a continuation-in-part of commonly-assigned U.S. patent application Ser. No. 08 / 805,415, filed Feb. 26, 1997 now U.S. Pat. No. 6,067,989.FIELD OF THE INVENTION[0002]The invention relates to the field of analyzers of the breath of patients to detect the gastric by-products of various diseases and infections.BACKGROUND OF THE INVENTION[0003]Since the early 1950's, it has been known that the presence of bacterial organisms in the gastro-intestinal tract is accompanied by a high concentration of urease, which hydrolyses urea to form carbon dioxide and ammonia. These gases are detected in the subject's blood stream and ultimately, in the subject's breath, if he had been administered isotopically labeled urea. Such early results appear in reviews published by R. W. VonKorff et al. in Am. J. Physiol., Vol. 165, pp. 688-694, 1951, and by H. L. Kornberg and R. E. Davies in Physiol. Rev., Vol. 35, pp. 169-177, 1955.[0004]Since these early ex...

AI Technical Summary

Benefits of technology

[0039]The present invention seeks to provide an improved breath test analyzer which overcomes disadvantages and drawbacks of existing analyzers, which provides accurate results on-site in times of the order of minutes, and which is capable of implementation as a low cost, low volume and weight, portable instrument. The breath analyzer of the present invention is sufficiently sensitive to enable it to continuously collect and analyze multiple samples of the patient's breath from the beginning of the test, and process the outputs in real time, such that a definitive result is obtained within a short period of time, such as of the order of a few minutes.

[0042]The breath test analyzer is also sufficiently small that it can easily be accommodated in the office of a physician, such as a gastro-enterologist, and its cost is also sufficiently low that its use in such an environment can be economically justified.

[0045]There are also two modes of analyzing the breath samples. The analyser can either perform its analysis on individual exhaled breaths, or, as stated above, it can perform its analysis on multiple samples of the patient's breath, continuously collected from the patient. The method of collection and subsequent analysis of multiple samples of the patient's breath has been described in co-pending Isreal Patent Application No. 121793, which is hereby incorporated by reference. That application described an analyzer wherein the patient's breaths are exhaled into a reservoir for collection, in this application called a breath collection chamber, and transferred from there by one of various methods to the sample measurement chamber. One of the advantages of the method described therein, is that the analyzer draws an averaged sample of breath for measurement, instead of individual breaths, thereby increasing accuracy. Another advantage is that it is possible, by suitable valving means, to collect only the plateau parts of multiple breaths for analysis.

Problems solved by technology

In addition, carbon-14 is still used in some procedures, but being radioactive, there are severe disadvantages both to its ingestion by the patient, and because of the storage, handling and disposal precautions required at the test site.

Previously available tests for these illnesses generally involve drastically more invasive procedures, and are therefore much less patient compliant than the simple breath tests described above.

Furthermore, there are other disadvantages to the previously used tests, such as the fact that they rarely give real time information about the organ function or status being observed.

However, in spite of the advantages of isotopically labeled breath tests, current instrumentation and procedures for performing it sill have a number of serious drawbacks, which continue to limit its usefulness.

The major disadvantage, which becomes apparent when a review of prior art breath test performance techniques and instrumentation is performed, is that none of the currently used techniques are sufficiently rapid to permit immediate measurement of the requested parameter, allowing a diagnosis for the patient in a single short visit to the physicians office.

Clearly this method cannot be used to provide the results of the test within the context of a single visit to the office of the physician.

Such a long delay to obtain breath samples, as well as the long wait between samples, is inconvenient and potentially reduces patient compliance.

Furthermore, as in the previously mentioned prior art, the sample or samples are collected from the patient and then sent to a laboratory for analysis, causing a delay in the determination of the results and forcing the subject to return to the office of the physician to obtain the results.

The requirement for multiple office visits potentially further reduces patient compliance.

The potential reduction in patient compliance can have serious consequences, since Helicobacter pylori is implicated by the World Health Organisation as a possible cause of stomach cancer, in addition to its role in gastric and duodenal ulcers.

This test thus has all the disadvantages of the use of radioactive materials.

Not only is the ingestion of radioactive materials potentially hazardous, but it also restricts the test to large testing centers which can handle such materials.

Thus, the test cannot be performed in the office of the average physician, so that multiple office visits are again required.

Because of the need to provide high sensitivity and good mass discrimination, all of the above described analysis systems are complex in nature.

They are therefore, costly to manufacture and generally of large dimensions, making them suitable for commercial exploitation only for large and high sample volume installations.

Because of the complexity of the LARA™ System, it is a large piece of equipment, weighing over 300 kg, and very costly.

Consequently, this system too is only feasible for very large institutions and central laboratories, where the large number of tests performed can justify the cost.

In this system too, the analyzer unit is large, costly and sophisticated, and therefore is usually located remote from the collection point.

No details of such a connection tube accessory are however given in the technical manual accompanying the analyzer, nor does the manufacturer provide any programs with the system's operational software to enable such an accessory to be used for performing on-line analyses.

Though smaller and less costly than those mentioned above, it is still too large and heavy to be described as a truly portable device.

Furthermore, its reported cost of several tens of thousands of U.S. Dollars, though considerably less than that of the two above-mentioned commercial systems, still makes it unsuitable for point-of-care or physician's office use.

However, such a single point determination potentially decreases the accuracy of the test, as well as increasing the risk of ambiguous results.

To the best of our knowledge, no breath test analyzer system has been described in the prior art which is sufficiently small, fast in producing reliable results, low in production cost, portable and sensitive, to enable it to be used as for executing tests in real time in the physician's office or at another point of care.

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