System and Method For Determining A Measure Of The Resistance Of Peripheral Vasculature

Abstract

A system for determining the resistance of peripheral vasculature including a a sensor configured to generate output signals proportional to the amount of blood in the peripheral vasculature over time, and a computer subsystem configured to determine the resistance of the peripheral vasculature in response to the output signals.

What is claimed is: 
     
         1 . A system for determining the resistance of peripheral vasculature comprising:
 a sensor configured to generate output signals proportional to the amount of blood in the peripheral vasculature of a predetermined body part over time; and   a computer subsystem configured to determine the resistance of the peripheral vasculature in response to the output signals.   
     
     
         2 . The system of  claim 1  in which the sensor is configured to emit light in the near-infrared or infrared spectra to peripheral vasculature in the predetermined body part and measure the light absorbed by the peripheral vasculature to generate the output signal proportional to the amount of blood in the peripheral vasculature over time. 
     
     
         3 . The system of  claim 1  in which the sensor is configured to measure the pressure in the predetermined body part by generating the output signals proportional to the amount of blood in the peripheral vasculature. 
     
     
         4 . The system of  claim 1  in which the predetermined body part includes a finger, thumb, hand, arm, abdomen, foot, or a body part directly associated with the peripheral vasculature. 
     
     
         5 . The system of  claim 1  in which the computer subsystem includes an algorithm configured to calculate the resistance of the peripheral vasculature. 
     
     
         6 . The system of  claim 5  in which the algorithm is configured to round the calculated resistance of peripheral vasculature to an integer between 0 and 10. 
     
     
         7 . The system of  claim 1  further including a display device coupled to the computer system configured to display the resistance of the peripheral vasculature. 
     
     
         8 . The system of  claim 7  in which the display device is configured to display an integer rounded from the calculated value to provide a digit indication of the measured resistance to the peripheral vasculature. 
     
     
         9 . The system of  claim 8  in which the display device is configured to display the resistance of the peripheral vasculature as a bar graph. 
     
     
         10 . The system of  claim 5  in which the algorithm is configured to calculate the resistance of the peripheral vasculature using a transfer function. 
     
     
         11 . The system of  claim 10  in which the transfer function is configured to calculate the resistance of the peripheral vasculature using time content of the output signals. 
     
     
         12 . The system of  claim 10  in which the algorithm is configured to calculate the resistance of the peripheral vasculature using the frequency content of the output signals. 
     
     
         13 . The system of  claim 12  in which the algorithm includes a Fourier transform. 
     
     
         14 . The system of  claim 1  in which the resistance of the peripheral vasculature includes an anti-G straining maneuver (AGSM) index. 
     
     
         15 . A method for determining a measure of the resistance of peripheral vasculature, the method comprising:
 generating and monitoring output signals proportional to the amount of blood in the peripheral vasculature of a predetermined body part over time; and   determining the resistance of the peripheral vasculature in response to the output signals.   
     
     
         16 . The method of  claim 15  in which the output signals are generated by emitting light in near red or infrared spectra to peripheral vasculature in a predetermined body part and measuring the light absorbed by the peripheral vasculature. 
     
     
         17 . The method of  claim 15  in which the output signals are generated by measuring the pressure in the predetermined body part. 
     
     
         18 . The method of  claim 15  further including the step of displaying the resistance of the peripheral vasculature. 
     
     
         19 . The method of  claim 18  further including the step of displaying the resistance of the peripheral vasculature as an integer ranging from 0 to 10. 
     
     
         20 . The method of  claim 18  further including the step of displaying the resistance of the peripheral vasculature as a bar graph. 
     
     
         21 . The method of  claim 15  in which determining the resistance of the peripheral vasculature includes calculating the resistance of the peripheral vasculature using a transfer function. 
     
     
         22 . The method of  claim 21  in which the calculating includes using the time content of the output signals. 
     
     
         23 . The method of  claim 21  in which the calculating includes using the frequency content of the output signals.