Detection of conditions by analysis of gases or vapors

#This invention relates to the detection of conditions, in particular to the detection of conditions in a patient and the detection of microorganisms by analysis of gases or vapors emitted therefrom.

#It is known that many gaseous or volatile species can be detected and identified by so-called “electronic noses”, which are usually devices comprising an array of individual gas sensing elements. For example, the present applicants produce such an instrument having up to thirty two gas sensing elements, each element having a different semiconducting polymer. The semiconducting polymers typically display broad and overlapping responses towards gaseous species. However, this is turned to advantage when an array of such polymers is employed. On exposure to a gas or volatile species, the resistances of the semiconducting organic polymer vary—but to different extents. Thus the pattern of resistance variation across the array of sensors is indicative of the species being detected. Further information concerning polymers and the techniques used to interrogate them may be found in International Publication No. WO 96/00384 and references therein.

#International Publication No. WO 95/33848 describes a method for detecting bacteria via detection of the characteristic vapors emanating therefrom as a result of bacterial metabolism by an array of gas sensors, in particular an array of semiconducting organic polymers of the type described above. The technique is of potentially wide and significant use in the medical area. However, to date, methods and apparatus suitable for practical, day to day use in a clinical environment have not been available. Furthermore, it would be desirable to detect and monitor a whole range of clinical conditions, which might include bacterial infections, but which might also include other conditions, such as viral or fungal infection.

#Methods and apparatus in accordance with the invention will now be described with reference to the accompanying drawings, in which:

#FIG. 1 depicts schematically apparatus for performing an improved method for identifying bacteria;

#FIG. 2 shows response as a function of time for patient one;

#The invention comprises, in one aspect, a method for monitoring at least one condition in a patient comprising the steps of:

#obtaining samples from the patient over a period of time;

#flowing the samples, or gases and/or vapors associated with or produced by the samples, over at least one gas sensor;