Pneumatic circuit

Abstract

A pneumatic circuit and other components are provided for the operation of a medical device. The pneumatic circuit provides controlled pressurized air to a medical device for use during a medical procedure.

1 . A medical device comprising: 
 a biopsy device comprising 
 a cannula with an orifice, the cannula being configured for insertion into a body to a point such that the orifice is adjacent to a tissue mass to be biopsied,  
 a cutter housed within the cannula and configured to move relative to the orifice to selectively cut tissue from the mass, and  
 a pneumatic cylinder coupled to the cutter for moving the cutter relative to the orifice; and  
 a pneumatic circuit coupled to the biopsy device for controlling the pneumatic cylinder, the pneumatic circuit comprising a sensor configured to sense back pressure in the pneumatic cylinder.  
   
   
   
       2 . The medical device of  claim 1 , wherein the cannula defines an axis and the cutter is aligned coaxially with the cannula.  
   
   
       3 . The medical device of  claim 2 , wherein the cutter rotates about the axis.  
   
   
       4 . The medical device of  claim 2 , further comprising a pneumatic motor controlled by the pneumatic circuit, the pneumatic motor actuating rotational movement of the cutter.  
   
   
       5 . The medical device of  claim 2 , wherein the pneumatic circuit selectively causes the cutter to rotate relative to the cannula as the cutter approaches and closes the orifice and the pneumatic circuit further selectively causes the cutter to retract to a retracted position without rotating.  
   
   
       6 . The medical device of  claim 5 , wherein the pneumatic circuit provides a signal to the operator when the cutter has completed one cycle of moving between the closed-orifice position and the retracted position and back.  
   
   
       7 . The medical device of  claim 2 , wherein the pneumatic cylinder causes the cutter to move axially relative to the cannula.  
   
   
       8 . The medical device of  claim 1 , wherein the pneumatic circuit directs the retraction of the cutter relative to the orifice when a predetermined back pressure is sensed in the pneumatic cylinder.  
   
   
       9 . The medical device of  claim 7 , wherein the predetermined back pressure is approximately 24 pounds per square inch.  
   
   
       10 . The medical device of  claim 1 , further comprising a pneumatic switch configured to permit an operator to selectively operate the cutter by actuating the pneumatic switch.  
   
   
       11 . The medical device of  claim 1 , wherein the biopsy device is substantially free of magnetically sensitive objects such that it can be operated in conjunction with a Magnetic Resonance Imaging device.  
   
   
       12 . The medical device of  claim 1 , further comprising a saline supply coupled to the biopsy device, the saline supply dispensing saline in a manner controlled by the pneumatic circuit.  
   
   
       13 . The medical device of  claim 12 , wherein the saline is directed between the cutter and the cannula.  
   
   
       14 . The medical device of  claim 12 , further comprising a vacuum coupled to the biopsy device for creating a suction and drawing the saline through the cannula.  
   
   
       15 . A medical device comprising: 
 a cutter configured to selectively cut tissue from a body;    a pneumatic cylinder coupled to the cutter for moving the cutter relative to the body; and    a pneumatic circuit coupled to the pneumatic cylinder for controlling the pneumatic cylinder, the pneumatic circuit sensing the back pressure in the pneumatic cylinder and responsively controlling the pneumatic cylinder.    
   
   
       16 . The medical device of  claim 15 , further comprising a pneumatic motor, wherein the cutter defines an axis and the pneumatic motor causes the cutter to rotate about its axis as the cutter is cutting tissue from the body.  
   
   
       17 . The medical device of  claim 15 , wherein the pneumatic circuit provides a signal to the operator when the cutter has completed one cycle of cutting tissue from the body.  
   
   
       18 . The medical device of  claim 15 , wherein the pneumatic circuit directs the retraction of the cutter relative to the body when a predetermined back pressure is sensed in the pneumatic cylinder.  
   
   
       19 . The medical device of  claim 18 , wherein the predetermined back pressure is approximately 24 pounds per square inch.  
   
   
       20 . The medical device of  claim 15 , further comprising a pneumatic switch coupled to the cutter for selectively operating the cutter.  
   
   
       21 . The medical device of  claim 20 , wherein the pneumatic switch is foot pedal operated.  
   
   
       22 . The medical device of  claim 20 , wherein the pneumatic circuit uses the pneumatic switch as an indication of whether to initiate another cutting cycle.  
   
   
       23 . The medical device of  claim 15 , further comprising a saline supply for dispensing saline in a manner controlled by the pneumatic circuit.  
   
   
       24 . The medical device of  claim 23 , wherein the saline is directed to flow around the cutter, providing lubrication to the cutter and providing a flush for tissue cut from the body by the cutter.  
   
   
       25 . The medical device of  claim 15 , further comprising a vacuum coupled to the biopsy device, the vacuum being controlled by the pneumatic circuit.  
   
   
       26 . The medical device of  claim 25 , wherein the vacuum is used to facilitate the removal of tissue after the tissue has been cut from the body.  
   
   
       27 . The medical device of  claim 15 , wherein the tissue is breast tissue.  
   
   
       28 . A method of removing a tissue mass from a body, the method comprising the steps of: 
 inserting a hollow cannula having an aperture into the body such that the aperture is positioned adjacent to the tissue mass, the hollow cannula housing a cutter therein;    providing suction to the cannula such that a portion of the tissue mass is pulled inside the cannula through the aperture;    pneumatically moving the cutter relative to the aperture so that the cutter cuts the portion of tissue mass from the remainder of the tissue mass; and    transporting the cut portion of tissue mass through the cannula with the provided suction, wherein the pneumatic movement of the cutter is controlled by a pneumatic circuit comprising a pressure sensor.    
   
   
       29 . The method of  claim 28 , wherein the step of moving the cutter across the aperture is repeated such that additional portions of the tissue mass are removed.  
   
   
       30 . The method of  claim 28 , wherein the cutter is rotating as it cuts the portion of tissue mass.  
   
   
       31 . The method of  claim 30 , wherein the rotation of the cutter is pneumatically actuated by a pneumatic motor.  
   
   
       32 . The method of  claim 28 , wherein the movement of the cutter is pneumatically actuated by a pneumatic cylinder.  
   
   
       33 . The method of  claim 28 , wherein the pneumatic circuit controls the provision of suction and controls the movement of the cutter.  
   
   
       34 . A biopsy device comprising 
 a cannula with an orifice, the cannula being configured for insertion into a body to a point such that the orifice is adjacent to a tissue mass to be biopsied;    a cutter housed within the cannula and configured to move relative to the orifice to selectively cut tissue from the mass;    a pneumatic cylinder coupled to the cutter for moving the cutter relative to the orifice, the pneumatic cylinder being controlled by a controller responsive to back pressure in the cylinder; and    a pneumatic motor coupled to the cutter for rotating the cutter relative to the orifice.    
   
   
       35 . The biopsy device of  claim 34 , wherein the pneumatic motor comprises six pneumatic vanes.  
   
   
       36 . The biopsy device of  claim 34 , wherein the controller is a pneumatic circuit.  
   
   
       37 . The biopsy device of  claim 34 , wherein the controller responds to a back pressure of approximately 24 pounds per square inch.  
   
   
       38 . The biopsy device of  claim 34 , wherein the controller directs the cutter to retract relative to the cannula when a predetermined back pressure is sensed in the pneumatic cylinder.  
   
   
       39 . The biopsy device of  claim 38 , wherein the predetermined back pressure is approximately 24 pounds per square inch.