Vibrating patient support apparatus with a resonant referencing percussion device

Abstract

A vibrating patient support apparatus has a resonant referencing percussion device preferably located internally to a cover of a mattress of the apparatus. The percussion device delivers a percussion or vibration at a controlled operating frequency that is preferably slightly less than a resonant frequency located internal to the mattress of the apparatus. With the various weight distributions of a patient, the device is capable of determining the ever shifting resonant frequency via control signals received by a controller from a pressure sensor or accelerometer of the device. Because the operating frequency is slightly less than the natural resonating frequency, energy of the system is conserved. Because the operating frequency is not the controller calculated resonant frequency, wear on the device and potential damage is minimized.

1 . A patient support apparatus for providing therapeutic treatment to a patient, the patient support apparatus comprising: 
 a loaded state wherein at least a portion of the patient is supported by the patient support apparatus;    an unloaded state wherein the patient is not being supported by the patient support apparatus;    a percussion device for producing a variable oscillating displacement at an operating frequency;    a resonating pad having at least one natural resonant frequency when in the unloaded state and at least one shifted resonant frequency when in the loaded state and wherein each one of the at least one shifted resonant frequency corresponds to a respective one of the natural resonant frequency;    a controller for electrically operating the percussion device; and    a sensor for communicating a control signal that corresponds to an amplitude of vibration processed by the controller.    
   
   
       2 . The patient support apparatus set forth in  claim 1  further comprising at least one shifted operating frequency wherein each one of the shifted operating frequency is slightly less than a respective one of the at least one shifted resonant frequency.  
   
   
       3 . The patient support apparatus set forth in  claim 1  wherein the sensor is an accelerometer.  
   
   
       4 . The patient support apparatus set forth in  claim 3  wherein the accelerometer is in contact with the resonating pad.  
   
   
       5 . The patient support apparatus set forth in  claim 1  further comprising the percussion device having at least one bladder constructed and arranged to inflate and deflate at the shifted operating frequency.  
   
   
       6 . The patient support apparatus set forth in  claim 1  wherein the sensor is at least one pressure sensor located in at least one of the at least one bladder.  
   
   
       7 . The patient support apparatus set forth in  claim 6  further comprising a variable speed pump controlled by the controller for inflating and deflating the at least one bladder.  
   
   
       8 . The patient support apparatus set forth in  claim 7  wherein the variable speed pump is an air pump.  
   
   
       9 . The patient support apparatus set forth in  claim 7  wherein the variable speed pump is a fluid pump.  
   
   
       10 . The patient support apparatus set forth in  claim 1  further comprising a percussion mode wherein the shifted operating frequency is between one beat per second and seven beats per second.  
   
   
       11 . The patient support apparatus set forth in  claim 10  further comprising a vibration mode wherein the operating frequency is between seven beats per second and twenty five beats per second.  
   
   
       12 . A patient support apparatus for providing therapeutic treatment to a patient, the patient support apparatus comprising: 
 a cushioning member;    a percussion device having a plurality of bladders located below the cushioning member and a sensor;    a variable speed pump for flowing a pressurized medium into the plurality of bladders;    a valve system for controlling flow to and from the bladders for inflation and deflation at a controlled operating frequency;    a controller for controlling the valve system and the variable speed pump based in-part on a signal received from the sensor.    
   
   
       13 . The patient support apparatus set forth in  claim 12  wherein the cushioning member is a main bladder inflated by the variable speed pump at a pressure controlled by the controller.  
   
   
       14 . The patient support apparatus set forth in  claim 13  further comprising a resonating pad of the percussion device located vertically between the main bladder and the plurality of bladders.  
   
   
       15 . The patient support apparatus set forth in  claim 14  wherein the resonating pad has at least one known natural resonating frequency located within a range producible by the controller, variable speed pump and valve system.  
   
   
       16 . The patient support apparatus set forth in  claim 14  wherein the sensor is an accelerometer being in contact with the resonating pad.  
   
   
       17 . The patient support apparatus set forth in  claim 12  wherein the sensor is an accelerometer being in contact with the cushioning member.  
   
   
       18 . The patient support apparatus set forth in  claim 12  wherein the sensor is at least one pressure sensor located in at least one of the plurality of bladders of the percussion device.  
   
   
       19 . The patient support apparatus set forth in  claim 12  further comprising: 
 the flow medium of the pump being pressurized air; and    the cushioning member being a main bladder of a firmness setting device that receives controlled pressurized air from the pump.    
   
   
       20 . The patient support apparatus set forth in  claim 19  further comprising a rotation device having two rotation bladders located below the plurality of bladders of the percussion device, and wherein the two rotation bladders are independently inflated and deflated by the controller and receive pressurized air from the pump.