Hemoglobinometers and the like for measuring the metabolic condition of a subject

Abstract

The present invention discloses a novel, user-wearable system for monitoring the oxygen concentration, or oxygenation trend, in the tissue of a subject undergoing aerobic stress. The system comprises a lightweight detector, worn against the skin surface of the subject, at the site being monitored. The system further includes wearable power pack and display means for displaying information indicative of the metabolic condition of the region being monitored. The detector preferably employs a continuous wave spectrophotometer having one or more sources of electromagnetic radiation with wavelengths between about 760 and 800 nanometers directed into the tissue of the subject. The detector utilizes photon migration to detect the portion of the transmitted radiation arriving at an adjacent skin region. The present invention also discloses methods for displaying the aerobic metabolic condition of a subject.

1 - 39 . (canceled)  
     
     
         40 . A tissue oximeter comprising a support, a detector fixed to the support and a light source mounted in an adjustable manner to the support to enable selection of the spacing between light source and detector for adjusting the mean depth of tissue to which the oximeter responds.  
     
     
         41 . A tissue oximeter in combination with means connected to receive tissue oxygen readings from the oximeter, determine the rate of change of said readings, said rate of change serving as a quantifiable indication of the state of the metabolic process of the tissue.  
     
     
         42 . The oximeter of  claim 41  including electronic control circuitry comprised of entirely nonmagnetic components enabling use of the device in conjunction with nuclear magnetic resonance imaging.  
     
     
         43 . An oximeter disposed on an endoscope, catheter, guidewire or the like for insertion via a body passage to internal tissue, and including means such as an inflatable balloon to press the oximeter sensor against the localized tissue of interest.  
     
     
         44 . The oximeter of  claim 43  including a water impermeable coating about said device for applications in the presence of water.  
     
     
         45 . The oximeter of  claim 41  wherein said light source comprises a light emitting diode.  
     
     
         46 . The oximeter of  claim 41  wherein said detector comprises a silicon diode.  
     
     
         47 . The oximeter of  claim 41  wherein said detector comprises a silicon diode and an interference filter.  
     
     
         48 . The oximeter of  claim 41  including electronic control circuitry for said light source and said detector, said circuitry being adapted to correct for a noise signal not attributable to detected light that migrated through said localized tissue of interest.  
     
     
         49 . The oximeter of  claim 48  wherein correction of a noise signal is achieved by charging a capacitor of an integrator for said detector with current of one polarity during a light off cycle and subsequently charging said capacitor with current of opposite polarity during a light on cycle, whereby subtracting said noise signal occurring during said light off cycle from the total signal occurring during said light on cycle.  
     
     
         49 - 101 . (canceled)