Medical sensor and technique for using the same

Abstract

A sensor is provided that is appropriate for transcutaneous detection of tissue or blood constituents. A sensor for tissue constituent detection may include a gas collection chamber with a conduit to a sensing component and a conduit from the sensing component to the chamber. A sensor as provided may also include a barrier layer to prevent water from infiltrating the sensor.

1 . A sensing system component comprising: 
 at least one gas collection chamber into which a tissue constituent is able to diffuse, wherein the gas collection chamber is adapted to be placed proximate to a tissue;    a first conduit in communication with the gas collection chamber comprising a connector located distally from the gas collection chamber; and    a second conduit in communication with the gas collection chamber comprising a connector located distally from the gas collection chamber.    
   
   
       2 . The sensing system component, as set forth in  claim 1 , wherein the tissue constituent comprises carbon dioxide, oxygen, ethanol, or carbon monoxide.  
   
   
       3 . The sensing system component, as set forth in  claim 1 , wherein the tissue constituent comprises a volatile anesthetic agent, a volatile product of metabolism, or a volatile xenobiotic.  
   
   
       4 . The sensing system component, as set forth in  claim 1 , comprising a calibration element adapted to provide at least one signal related to at least one physical characteristic of the gas collection chamber.  
   
   
       5 . The sensing system component, as set forth in  claim 4 , wherein the calibration element comprises a coded resistor or an electrically erasable programmable read-only memory.  
   
   
       6 . The sensing system component, as set forth in  claim 1 , comprising a barrier layer defining at least part of a surface of the gas collection structure, wherein the barrier layer is substantially impermeable to water.  
   
   
       7 . The sensing system component, as set forth in  claim 1 , comprising a barrier layer defining at least part of a surface of the gas collection structure, wherein the barrier layer is selectively permeable to the tissue constituent.  
   
   
       8 . The sensing system component, as set forth in  claim 1 , comprising a water-permeable conduit that is impermeable to the tissue constituent, wherein the water-permeable conduit is adapted to direct water away from gas collection structure.  
   
   
       9 . The sensing system component, as set forth in  claim 1 , wherein the gas collection structure comprises a tube, wherein at least a portion of the tube adapted to be placed proximate to the tissue is permeable to the tissue constituent.  
   
   
       10 . The sensing system component, as set forth in  claim 1 , comprising an agent adapted to be placed proximate to the tissue, wherein the agent is adapted to increase blood flow to the tissue or wherein the agent is adapted to increase the tissue's permeability to the tissue constituent.  
   
   
       11 . The sensing system component, as set forth in  claim 10 , wherein the agent comprises an electrical heating element, a chemical heating element, nicotinic acid, or salicylic acid.  
   
   
       12 . A method of manufacturing a sensing system component, comprising: 
 providing at least one gas collection chamber into which a tissue constituent is able to diffuse, wherein the gas collection chamber is adapted to be placed proximate to a tissue;    providing a first conduit in communication with the gas collection chamber comprising a connector located distally from the gas collection; and    providing a second conduit in communication with the gas collection chamber comprising a connector located distally from the gas collection chamber.    
   
   
       13 . The method, as set forth in  claim 12 , comprising: 
 providing a barrier layer defining at least part of a surface of the gas collection structure, wherein the barrier layer is substantially impermeable to water.    
   
   
       14 . The method, as set forth in  claim 12 , comprising: 
 providing a water-permeable conduit that is impermeable to the tissue constituent, wherein the water-permeable structure is adapted to direct water away from gas collection structure.    
   
   
       15 . The method, as set forth in  claim 12 , comprising: 
 providing a calibration element adapted to provide a signal related to calibration characteristics of the gas collection structure.    
   
   
       16 . The method, as set forth in  claim 12 , wherein the gas collection chamber comprises a tube, wherein at least a portion of the tube adapted to be placed proximate to the tissue is permeable to the tissue constituent.  
   
   
       17 . A sensor comprising: 
 a sensor body comprising at least one gas collection chamber adapted to be placed proximate to a tissue;    a sensing component disposed on the sensor body adapted to provide a signal related to a tissue constituent; and    a barrier layer defining at least part of a surface of the gas collection chamber, wherein the barrier layer is substantially impermeable to water.    
   
   
       18 . The sensor, as set forth in  claim 17 , wherein the tissue constituent comprises carbon dioxide, carbon monoxide or oxygen.  
   
   
       19 . The sensor, as set forth in  claim 17 , wherein the barrier layer has a ratio of water permeability to carbon dioxide permeability of less than 1:1.  
   
   
       20 . The sensor, as set forth in  claim 17 , wherein the sensing component comprises a non-optical transducer, an optical transducer, a chemical indicator, or an electrochemical transducer.  
   
   
       21 . The sensor, as set forth in  claim 17 , wherein the gas collection chamber comprises a tube, wherein at least a portion of the tube adapted to be placed proximate to the tissue is permeable to the tissue constituent.  
   
   
       22 . A system comprising: 
 a monitor; and    a sensor adapted to be coupled to the monitor, the sensor comprising:    a sensor body comprising a gas collection chamber adapted to be placed proximate to a tissue;    a sensing component disposed on the sensor body adapted to provide a signal to the monitor related to a tissue constituent; and    a barrier layer defining at least part of a surface of the gas collection chamber, wherein the barrier layer is substantially impermeable to water.    
   
   
       23 . The system, as set forth in  claim 22 , wherein the tissue constituent comprises carbon dioxide, carbon monoxide, or oxygen.  
   
   
       24 . The system, as set forth in  claim 22 , wherein the barrier layer has a ratio of water permeability to carbon dioxide permeability of less than 1:1.  
   
   
       25 . The system, as set forth in  claim 22 , wherein the sensing component comprises a non-optical transducer, an optical transducer, a chemical indicator, or an electrochemical transducer.  
   
   
       26 . The system, as set forth in  claim 22 , wherein the gas collection structure comprises a tube, wherein at least a portion of the tube adapted to be placed proximate to the tissue is permeable to the tissue constituent.  
   
   
       27 . The system, as set forth in  claim 22 , comprising a multi-parameter monitor.  
   
   
       28 . A method of measuring a tissue constituent comprising: 
 diffusing a tissue constituent through a barrier layer that is substantially impermeable to water, wherein the barrier layer defines at least part of a surface of a gas collection chamber; and    providing a signal related to the tissue constituent with a sensing element disposed on the gas collection chamber.    
   
   
       29 . The method, as set forth in  claim 28 , wherein providing a signal comprises providing an optical or a non-optical signal.  
   
   
       30 . The method, as set forth in  claim 28 , wherein providing a signal comprises providing a chemical signal.  
   
   
       31 . The method, as set forth in  claim 28 , wherein providing a signal comprises providing an electrochemical signal.  
   
   
       32 . The method, as set forth in  claim 28 , wherein providing a signal comprises providing a quantum-restricted signal.  
   
   
       33 . A method of manufacturing a sensor, comprising: 
 providing a sensor body comprising a gas collection chamber adapted to be placed proximate to a tissue;    providing a sensing component disposed on the sensor body adapted to provide a signal related to a tissue constituent; and    providing a barrier layer defining at least part of a surface of the gas collection chamber, wherein the barrier layer is substantially impermeable to water.    
   
   
       34 . The method, as set forth in  claim 33 , wherein the tissue constituent comprises carbon dioxide, carbon monoxide, or oxygen.  
   
   
       35 . The method, as set forth in  claim 33 , wherein the barrier layer has a ratio of water permeability to carbon dioxide permeability of less than 1:1.  
   
   
       36 . The method, as set forth in  claim 33 , wherein the sensing component comprises a non-optical transducer, an optical transducer, a chemical indicator, or an electrochemical transducer.  
   
   
       37 . The method, as set forth in  claim 33 , wherein the gas collection structure comprises a tube, wherein at least a portion of the tube adapted to be placed proximate to the tissue is permeable to the tissue constituent.