Abstract:
A conditioning sleeve for a medical or an industrial diagnostic sensing instrument, in which the instrument has a support for supporting at least one chemical sensing element capable of detecting at least one chemical component of a fluid and producing an electrical signal when said at least one chemical component is detected. The sleeve includes an interior sized for enclosing at least a portion of the support including the at least one chemical sensing element and for producing environmental conditions within the sleeve interior which approximate those of an intended target area. Preferably, at least one heater or cooler and a humidifier approximate the environmental conditions of the target area in order to acclimate the sensing elements of the diagnostic instrument prior to actual use.

Description:
FIELD OF THE INVENTION 
     The invention relates to the field of diagnostic fluid or vapor measurement and more particularly to a sleeve for conditioning a medical or industrial diagnostic chemical sensing instrument prior to use of the instrument. 
     BACKGROUND OF THE INVENTION 
     Chemical sensing devices are commonly known for detecting the presence of certain vapors, such as carbon monoxide and/or carbon dioxide, in either an industrial or home environment. Likewise, further applications of chemical sensing technology are found in the food processing industry. 
     To date, there are very few known chemical sensing devices which are utilized for medical applications or purposes. In addition most known devices of this type, regardless of the field of use, require a housing which retains at least one chemical sensor. These devices further include means, such as a pump or other similar device, for inputting a portion of the atmosphere of an intended target area into the housing for evaluation by the chemical sensor(s). Such devices are described, for example, in U.S. Pat. No. 5,799,102 to Leong which determines the authenticity of a bank note, and U.S. Pat. No. 5,675,070 to Gelperin in which an array of gas sensors are disposed in an interior testing chamber. The gas sensors of the array can detect the levels of specified gases in a gas mixture and then produce a sensor pattern which can subsequently be analyzed. 
     Among the problems encountered in using known electronic sensors, such as polymer gas sensors, as described by U.S. Pat. No. 5,571,401 to Lewis et al, U.S. Pat. No. 5,882,497 to Persaud et al, U.S. Pat. No. 6,033,601 to Persaud et al, U.S. Pat. No. 6,013,229 to Lewis, and U.S. Pat. No. 6,093,308, to Lewis, among others, are those relating to stability. Utilizing these sensors in a medical environment; for example, to identify specific vapors indicative of a disease process by exposing the sensors to the interior of the mouth of a patient, could require that the sensors will be subjected to exposure of large changes in both temperature and humidity, as compared to those present in an ambient environment. Therefore and with present sensor technology, substantial and undesirable equalization time periods would be required. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to overcome the above noted deficiencies of the prior art. 
     Another primary object of the present invention is to provide a diagnostic testing or detecting device which can be environmentally calibrated prior to insertion into a target atmosphere in order to suitably and efficiently acclimate the device. 
     Therefore and according to a preferred aspect of the present invention, there is described a conditioning apparatus for a diagnostic instrument, said instrument comprising a support having at least one chemical sensing element capable of detecting at least one chemical component of a fluid and producing an electrical signal when said at least one chemical component is detected, said conditioning apparatus including: 
     a sleeve sized for enclosing at least a portion of said support including said at least one chemical sensing element; and 
     means for producing environmental conditions within said sleeve which approximate those of an intended target to be used by said diagnostic instrument. 
     Preferably, the sleeve includes at least one heating element which selectively heats or cools the interior of the sleeve to a predetermined temperature and/or a humidification chamber to pre-expose the chemical sensing element(s) to an environment approximately equivalent to that of the target atmosphere, such as the interior of the mouth or other suitable medical or industrial target. 
     According to another preferred aspect of the invention, a method is described for conditioning a diagnostic instrument, the instrument comprising a support for supporting at least one chemical sensing element capable of detecting at least one chemical component of a fluid, said method comprising the steps of: 
     placing a portion of said support including said at least one chemical sensing element into the interior of a sleeve; 
     conditioning said at least one chemical sensing element by providing an environment within the interior of said sleeve approximating that of a target; 
     removing said support from said sleeve; and 
     immediately positioning said support including said at least one chemical sensing element at the target. 
     Preferably, the target can be a medical and/or an industrial target. 
     An advantage of the present invention is that the environmental conditions of a target atmosphere can be applied to a chemical sensing element array prior to insertion therein, increasing the efficiency and also improving the reliability of the device. 
     A further advantage of the present invention is that a conditioning sleeve as described by the present invention can easily be attached and removed from a diagnostic sensing device which includes at least one chemical sensing element capable of detecting at least one chemical component of a fluid or fluids. 
     These and other objects, features, and advantages will be readily apparent form the following Detailed Description which should be read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top perspective view of a diagnostic device including a plurality of electronic fluid sensing elements; 
     FIG. 2 is an electrical schematic diagram of the diagnostic device of FIG. 1; 
     FIG. 3 is a sectional view of the diagnostic device of FIG. 1, including a conditioning sleeve in accordance with a first embodiment of the invention; and 
     FIG. 4 is a perspective view of an electronic diagnostic device including a conditioning sleeve manufactured in accordance with a second embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     The following description relates to a preferred diagnostic chemical sensing apparatus having an environmental conditioning sleeve made in accordance with certain preferred embodiments. For purposes of the discussion which follows, “fluid” is defined as anyone of a liquid, gas or vapor. The description further includes a related method of pre-exposing at least one or a plurality of chemical sensing elements of the chemical sensing apparatus to environmental conditions replicating those of a target environment, in which the target environment, such as an anatomical body cavity, e.g., the mouth of a patient, has environmental conditions that are considerably different than those found in ambient surroundings. It should be readily apparent, however, that other modifications and variations are possible within the spirit and scope of the inventive concepts described herein. In addition, certain terms are used throughout this discussion, such as “inner”, “outer”, “top”, “bottom”, “distal”, “proximal”, and the like which are used to provide a frame of reference with regard to the accompanying drawings. These terms, however, are not intended to be limiting of the present invention. 
     Referring to FIG. 1, there is first depicted a diagnostic chemical sensing device  10  comprising an elongated substantially planar substrate  14 , made from any suitable biocompatible material such as composite, wood, ceramic or plastic, among others . The elongated substrate  14  according to the present embodiment has a shape and size which closely resembles that of a tongue depressor, for a specific application/use in conjunction with the mouth of a patient (not shown). Other shapes or geometries, however, can easily be imagined. 
     The elongated substrate  14  includes an exterior surface  18  as well as opposing distal and proximal ends  22 ,  26 , respectively. A plurality or array  30  of chemical sensing elements are disposed on the exterior surface  18  of the elongated substrate  14  in the vicinity of the distal end  22 . According to the present embodiment, the chemical sensing elements of the array  30  are miniature polymer gas sensors, such as those manufactured by Cyrano Sciences, Inc. of Pasadena, Calif. or as described in U.S. Pat. No. 5,571,401 to Lewis et al, U.S. Pat. No. 5,882,497 to Persaud et al, U.S. Pat. No. 6,033,601 to Persuad et al, U.S. Pat. No. 6,013,229 to Lewis, and U.S. Pat. No. 6,093,308, to Lewis, the entire contents of each which are herein incorporated by reference. It will be readily apparent, however, that other known chemical sensing elements such as organic gas sensors, conductive composites, metal oxide field effect transistors, surface acoustic wave (SAW) sensors, piezoelectric sensors, catalytic gas sensors, quartz microbalance sensors, and others, can easily be substituted. Each of the sensing elements of the array  30  are capable of detecting a specific fluid, (e.g. gas, liquid or vapor), the presence of which produces an electrical change. The electrical change can be resistance, capacitance, transconductance, conductance, voltage, impedance, resonant frequency, or other perceivable electrical change. 
     The chemical sensing elements of the array  30  are attached e.g., by epoxy, glass frit, adhesive, or other means to the substrate  14 . Alternately, the sensing element array  30  can be provided as part of a plug-in electrical module (not shown) having connectors (not shown) at the distal end  22  of the elongated substrate  14 . 
     Referring to FIGS. 1 and 2, a series of electrical traces  32  from each of the sensing elements of the array  30  are interconnected to provide an electrical path to a microprocessor  38 , having suitable store memory  40 , which according to this embodiment is also provided on the exterior surface  18  of the substrate  14 . Preferably, the microprocessor  38  includes certain processing electronics  42  including an A/D converter  36  and timing and control circuitry  43  used in conjunction with a reference crystal (not shown) as is known. Batteries (not shown in FIG. 1) or other power supply  45  are electrically connected to each of the above components for powering the device  10 . Each of the above convert an electrical signal generated from the sensing elements of the array  30  into a processed output signal. The storage memory  40  of the microprocessor  38  according to this embodiment includes a look-up table (not shown) which compares incoming signals to reference values in order to provide an analysis. The results are outputted to a compact LCD  46  provided on the exterior surface  18  of the elongated substrate  14 . Alternately, an algorithm or other analytical means for providing a chemical analysis can be provided. 
     Still referring to FIGS. 1 and 2 and according to a typical procedure such as described in copending USSN 09/663,698, the device  10  is inserted, for example, by placing the distal end  22  of the elongated substrate  14  directly into the mouth (not shown) of a patient, with the array  30  of chemical sensing elements being positioned in substantial immediate proximity with a target environment. This environment can include that contained within the mouth itself and also can include those vapors which are present in the esophagus, stomach, throat, ear, nose, sinus, colon, urinary tract, peritoneum, vagina, lungs, and an in vivo portion of the skin etc. As noted previously, each of the sensing elements of the array  30  are manufactured so as to produce an electrical change when at least one chemical component of a particular fluid is detected. The electrical changes are then transmitted along the traces  32  to the microprocessor  38  where the processing electronics  42  compares the transmitted electrical signals with those of the stored lookup table and then displays the results of those chemical components present in the target environment. 
     Due to the overall sensitivity of the miniature sensing elements of the array  30  utilized in this embodiment, at least one temperature sensor and/or humidity sensor and/or pH sensor  44 ,  47 ,  48 , respectively, are also attached to the exterior surface  18  of the elongated substrate  14 . Signals from each of the sensors  44 ,  47 ,  48  are also transmitted to the microprocessor  38  for processing thereof. 
     Referring to FIG. 3, there is shown a conditioning sleeve  60  made in accordance with a first preferred embodiment of the present invention and used with the described compact diagnostic device  10 . The conditioning sleeve  60  is defined by a sleeve housing  62 , made from tetrafluroethylene (teflon) or other suitable material which does not outgas or collect chemical components, and having a narrow input slot  64  that extends into an interior volume  68 , the slot being sized to receive the distal end  22  of the elongated substrate  14 . A pair of conduits  72 ,  76  fluidly interconnect the interior volume  68  with a temperature/relative humidity controller  80 , which according to this embodiment provides warm moist air to the interior volume to replicate that of the intended target area (e.g., the mouth), which has a considerably higher temperature and relative humidity than ambient conditions. The controller  80  permits the temperature and relative humidity to be maintained specifically otherwise or in lieu of a control mechanism the temperature and humidity sensors  44 ,  47 , of the device  10  can be utilized to monitor the conditions of the interior volume  68  until the temperature and humidity that the sensing element array  30  is exposed to approximates that of the intended target environment shown herein, though not specifically, it should be noted that the temperature/humidity controller  80  can also include a cooler element given that some conditioning of a sensing element array may involve acclimating the array to a cooler target environment. 
     Referring to FIG. 4, a conditioning sleeve made in accordance with a second preferred embodiment is herein described. For the sake of clarity, similar part numbers are herein labeled with the same reference numerals. The sleeve  90  is also defined by a sleeve housing  92 , made from tetrafluroethylene or other suitable material and having a narrow input slot  94  extending into an interior volume  96 , the slot again being sized to receive the distal end  22  of the elongated substrate  14  of the device  10 . In this instance, a heater element  100  is disposed within the interior volume  96  of the sleeve  90  wherein the sleeve is constructed to conform substantially to the shape of the substrate  14 . Similarly, the sensors  44 ,  47  can be used to monitor the temperature and relative humidity of the interior volume  96  of the sleeve  90 , or these environmental conditions can be controlled using the controller  80  through conduits  72 , 76 . 
     PARTS LIST FOR FIGS.  1 - 4   
       10  diagnostic device 
       14  substrate 
       18  exterior surface 
       22  distal end 
       26  proximal end 
       30  sensing element array 
       32  electrical traces 
       36  A/D converter 
       38  microprocessor 
       40  storage memory 
       42  processing electronics 
       43  timing and control circuitry 
       44  temperature sensor 
       45  power supply 
       46  display 
       47  humidity sensor 
       48  pH sensor 
       60  conditioning sleeve 
       62  sleeve housing 
       64  input slot 
       68  interior volume 
       72  conduit 
       76  conduit 
       80  heater/humidity controller 
       90  conditioning sleeve 
       92  sleeve housing 
       94  input slot 
       96  interior volume 
       100  heating element