Self-contained compression device with cam-movable housing members and method

Abstract

A self-contained compression device and related method for cyclically compressing the limb of a patient to improve blood flow in the limb are disclosed. In one embodiment, the compression device includes a compressive section sized and shaped for extending around a portion of the limb for applying compressive pressure and a housing operatively connected to the compressive section. The housing includes first and second housing members movable relative to each other between contracted and expanded positions. A non-pneumatic mechanical actuator is provided in the housing for cyclically moving the first and second housing members from their contracted position to their expanded position. In one embodiment, the actuator comprises a prime mover and at least one cam movable by the prime mover for effecting relative movement between the first and second housing members.

1 . A self-contained compression device for cyclically compressing the limb of a patient to improve blood flow in the limb, the compression device comprising:
 a compressive section sized and shaped for extending generally circumferentially around a portion of the limb for applying compressive pressure to the limb portion;   a housing operatively connected to the compressive section, said housing including first and second housing members movable relative to each other between a contracted position in which the housing has a first dimension for relaxing pressure on said limb portion, and an expanded position in which the housing has a second dimension greater than said first dimension for compressing the limb portion; and   a non-pneumatic mechanical actuator in the housing for cyclically moving the first and second housing members from said contracted position to said expanded position;   said actuator comprising a prime mover and at least one cam movable by the prime mover for effecting relative movement between the first and second housing members.   
   
   
       2 . The compression device set forth in  claim 1 , wherein the actuator is located in an interior housing space defined by the housing members. 
   
   
       3 . The compression device set forth in  claim 2 , wherein the cam is movable by the prime mover to contact an interior surface of one of the housing members to effect relative movement between the housing members. 
   
   
       4 . The compression device set forth in  claim 3 , wherein the cam is rotatable by the prime mover. 
   
   
       5 . The compression device set forth in  claim 4 , wherein the prime mover is an electric motor, and wherein a gear train connects an output of the electric motor to the cam for rotating the cam. 
   
   
       6 . The compression device set forth in  claim 3 , wherein the actuator comprises a first pair of cams mounted on a first cam shaft rotatable by the prime mover. 
   
   
       7 . The compression device set forth in  claim 6 , wherein the prime mover is an electric motor, and wherein a gear train connects an output of the electric motor to the first cam shaft for rotating the cam shaft and the first pair of cams. 
   
   
       8 . The compression device set forth in  claim 6 , wherein said actuator further comprises a second pair of cams mounted on a second cam shaft rotatable by said prime mover. 
   
   
       9 . The compression device set forth in  claim 8 , further comprising a gear train connecting an output of the prime mover to the first and second cam shafts for rotating the cam shafts and said first and second pairs of cams. 
   
   
       10 . The compression device set forth in  claim 1 , wherein the compressive section comprises an annular band having a pocket for receiving the housing and the actuator, and wherein the compression device further comprises a force-distributing device in the pocket for distributing compressive pressure over the limb portion. 
   
   
       11 . The compression device set forth in  claim 10 , wherein said force-distributing device comprises a cushion. 
   
   
       12 . The compression device set forth in  claim 10 , wherein the housing and actuator are removable from the pocket whereby on termination of a compression therapy the band can be disposed and the housing and actuator re-used with a different disposable band. 
   
   
       13 . The compression device set forth in  claim 1 , further comprising a control system for controlling the operation of said compression device, said control system comprising a device for indicating the amount of compressive pressure applied to the limb portion. 
   
   
       14 . The compression device set forth in  claim 13 , wherein the control system is responsive to the applied compressive pressure reaching a predetermined pressure to cause the actuator to cease further expansion of the first and second housing members. 
   
   
       15 . A method of using a self-contained compression device to cyclically compress the limb of a patient to improve blood flow in the limb, said compression device comprising a compressive section sized and shaped for extending generally circumferentially around a portion of the limb for applying compressive pressure to the limb portion, and a housing operatively connected to the compressive section, said housing including first and second housing members movable relative to each other between a contracted position in which the housing has a first dimension and an expanded position in which the housing has a second dimension greater than said first dimension, said method comprising the steps of:
 applying said compression device to said limb such that said compressive section extends circumferentially around said limb portion;   cyclically activating a mechanical non-pneumatic actuator in the housing to move the housing members from said contracted position to said expanded position in a series of cycles to cyclically compress said limb portion; and   wherein the cyclically activating step comprises moving at least one cam to move the housing members from said contracted position to said expanded position during each of said cycles.   
   
   
       16 . The method set forth in  claim 15 , wherein the cyclically activating step further comprises spring biasing the housing members from said expanded position to said contracted position during each of said cycles. 
   
   
       17 . A method as set forth in  claim 15  further comprising removing the housing from the compressive section after use of the compression device for disposition of the compressive section and re-use of the housing with a different compressive section. 
   
   
       18 . A method as set forth in  claim 15  further comprising sensing a characteristic indicative of the pressure applied by said compression device to the limb. 
   
   
       19 . A method as set forth in  claim 18  wherein said actuator comprises an electric motor, and wherein said sensed characteristic is an amount of electrical current or voltage to said motor. 
   
   
       20 . A method as set forth in  claim 18  wherein said compression device comprises a cushion positioned for location between the limb and the housing, and wherein the sensed characteristic is a pressure in an air chamber in the cushion.