Monitoring compliance using venous refill detection

Abstract

Monitoring patient compliance with a compression therapy regimen. Venous Refill Time (VRT) is monitored via a pressure sensor in a bladder of a compression system. A controller of the compression system correlates the monitored VRT to a predetermined threshold to determine whether the patient is using the compression system.

What is claimed is: 
     
         1 . A method of monitoring patient compliance with a compression therapy regimen, said method comprising:
 receiving a signal from a pressure sensor coupled to a compression garment, wherein the garment is sized and shaped to be wrapped around substantially a limb of a wearer and comprises one or more selectively inflatable bladders for applying compression to the limb upon inflation, said signal being indicative of a change of girth of the limb;   determining a venous refill time of the limb as a function of the received signal;   monitoring the determined venous refill time; and   incrementing a patient compliance timer in response to the monitored venous refill time exceeding a predetermined threshold.   
     
     
         2 . The method of  claim 1 , further comprising indicating an alarm condition when the monitored venous refill time falls below the predetermined threshold. 
     
     
         3 . The method of  claim 2 , further comprising overriding the indicated alarm condition, by a user, to continue said incrementing of the patient compliance timer. 
     
     
         4 . The method of  claim 3 , further comprising resetting the predetermined threshold to the monitored venous refill time when the indicated alarm condition was overridden. 
     
     
         5 . The method of  claim 2 , wherein the alarm condition is one or more of an audio alarm and a visual alarm. 
     
     
         6 . The method of  claim 1 , further comprising providing a display representative of the patient compliance timer to a user. 
     
     
         7 . The method of  claim 1 , further comprising changing a compression profile of the garment as a function of the determined venous refill time. 
     
     
         8 . A system for monitoring patient compliance with a compression therapy regimen, said system comprising:
 a compression garment sized and shaped to be wrapped around substantially a body part of a wearer, said garment comprising one or more selectively inflatable bladders for applying compression to the body part upon inflation;   one or more fasteners for securing the garment in a self-retaining wrapped configuration around the body part;   a pressure sensor coupled to at least one of the bladders, said sensor generating a signal indicative of a change of girth of the body part when the garment is in the wrapped configuration; and
 a compression control unit, said control unit comprising: 
 a pump for pressurizing fluid; 
 an outlet port in fluid communication with the pump, said outlet port having fluid tubing connected thereto for selectively delivering pressurized fluid to at least one of the inflatable bladders; and 
 one or more processors receiving and responsive to the signal generated by the pressure sensor for:
 determining a venous refill time of the body part as a function of the received signal; 
 monitoring the determined venous refill time; and 
 incrementing a patient compliance timer in response to the monitored venous refill time exceeding a predetermined threshold. 
 
   
     
     
         9 . The system of  claim 8 , wherein the compression control unit comprises an alarm indicating when the monitored venous refill time falls below the predetermined threshold. 
     
     
         10 . The system of  claim 9 , wherein the compression control unit is responsive to user input for overriding the alarm to continue incrementing the patient compliance timer. 
     
     
         11 . The system of  claim 10 , wherein the one or more processors is configured for resetting the predetermined threshold to a value corresponding to the monitored venous refill time when the alarm was overridden. 
     
     
         12 . The system of  claim 9 , wherein the alarm is one or more of an audio alarm and a visual alarm. 
     
     
         13 . The system of  claim 9 , wherein the compression control unit comprises a display representative of the patient compliance timer. 
     
     
         14 . The system of  claim 9 , wherein the one or more processors increment the patient compliance timer when the monitored venous refill time is in a range of about 30-60 seconds. 
     
     
         15 . The system of  claim 14 , wherein the predetermined threshold is approximately 30 seconds. 
     
     
         16 . A method of monitoring patient compliance with a compression therapy regimen, said method comprising:
 receiving a signal from a pressure sensor coupled to a compression garment, wherein the garment is sized and shaped to be wrapped around substantially a limb of a wearer and comprises one or more selectively inflatable bladders for applying compression to the limb upon inflation, said signal being indicative of a change of girth of the limb when the compression garment is wrapped substantially around the limb of the wearer;   determining a venous refill time of the limb as a function of the received signal;   monitoring the determined venous refill time;   comparing the monitored venous refill time to a predetermined range of normal venous refill times; and   correlating the monitored venous refill time to patient compliance as a function of said comparing.   
     
     
         17 . The method of  claim 16 , said comparing further comprising indicating an alarm condition when the monitored venous refill time falls outside the range of normal venous refill times. 
     
     
         18 . The method of  claim 17 , further comprising permitting manual overriding of the indicated alarm condition and resetting the range of normal venous refill times based on the determined venous refill time upon said manual overriding. 
     
     
         19 . The method of  claim 16 , further comprising providing a display representative of said correlated patient compliance. 
     
     
         20 . The method of  claim 17 , wherein the alarm condition is one or more of an audio alarm and a visual alarm. 
     
     
         21 . The method of  claim 16 , wherein the range of normal venous refill times is about 30 seconds to about 60 seconds.