Medical devices and pumps therefor

Abstract

A microwave applicator device comprising a probe (11) for ablating the body of a human or animal, a cooling passage (20,21) extending through the probe (11) and arranged to carry a cooling fluid, a pump (71) for pumping the fluid through the probe (11), and an elongate flexible duct (104) extending between the pump (71) and one end of the cooling passage (20,21), the pump comprising a pump body (73) including a motor (120) and a pump head (72) detachably mounted to the pump body (73), the pump head (72) comprising a first port (86) connected to a proximal end of the elongate flow duct (104), a second port (85) and fluid propulsion means (84,92) for creating a flow of fluid between the ports (85,86) and along the elongate flow duct 104 upon energisation of the motor (120), the pump head (72) being arranged to sealingly contain the fluid. The pump head (72), the elongate flexible duct (104) and the probe (11) form a replaceable assembly that can be detached from the pump body (73) and discarded following use.

1 . A medical device comprising a distal head portion for contacting the body of a human or animal, a cooling passage extending through the head portion and arranged to carry a fluid for cooling the head portion, a pump for pumping said fluid through the head portion, and an elongate flexible duct extending between the pump and one end of the cooling passage, said pump comprising a pump body including a motor and a pump head detachably mounted to the pump body, the pump head comprising a first port connected to a proximal end of said elongate flow duct, a second port and fluid propulsion means for creating a flow of said fluid between said ports and along said elongate flow duct upon energisation of said motor, said pump head being arranged to sealingly contain said fluid, wherein the pump head, the elongate flexible duct and the head portion form replaceable assembly that can be detached from the pump body following use. 
     
     
         2 . A medical device as claimed in  claim 1 , in which the assembly comprises a further elongate flexible duct having a distal end extending from the other end of the cooling passage of the head portion, said further elongate flexible duct being arranged to carry fluid in the opposite direction to the first-mentioned elongate flexible duct. 
     
     
         3 . A medical device as claimed in  claim 2 , in which said further elongate flexible duct is arranged to connect to a fluid drain. 
     
     
         4 . A medical device as claimed in  claim 2  or  3 , in which said further elongate flexible duct forms part of the disposable assembly. 
     
     
         5 . A medical device as claimed in any preceding claim, in which an electrical cable extends to said head portion of the device. 
     
     
         6 . A medical device as claimed in  claim 5 , in which the cable forms part of said replaceable assembly. 
     
     
         7 . A medical device as claimed in  claim 5  or  6 , in which the pump comprises a pump housing. 
     
     
         8 . A medical device as claimed in  claim 7 , in which said cable extends from said pump housing. 
     
     
         9 . A medical device as claimed in  claim 8 , in which said cable is connected to said pump housing by means of a connector provided on the pump housing. 
     
     
         10 . A medical device as claimed in  claim 8  or  9 , in which a further cable extends from the pump housing to a main unit of the device, means being provided in said pump housing for connecting said further cable to the aforementioned cable which extends to said head portion of the device. 
     
     
         11 . A medical device as claimed in  claim 10 , in which the head portion comprises a microwave antenna for performing ablation of the human or animal body, the main unit comprising a magnetron or other source of microwave radiation. 
     
     
         12 . A medical device as claimed in any of  claims 1  to  11 , in which the head portion comprises a microwave antenna for performing ablation of the human or animal body. 
     
     
         13 . A medical device as claimed in any of  claims 5  to  11 , in which the cable is also arranged to be cooled by said fluid as it flows along a said elongate flexible duct. 
     
     
         14 . A medical device as claimed in  claim 13 , in which the cable forms a wall of said elongate flexible duct. 
     
     
         15 . A medical device as claimed in  claim 14 , in which the duct defines a cooling jacket which surrounds the cable. 
     
     
         16 . A medical device as claimed in any of  claims 13  to  15  as appended to  claim 2 , in which the cable is arranged to be cooled by said fluid as it flows along said further elongate flexible duct. 
     
     
         17 . A medical device as claimed in  claim 16 , in which said further elongate flexible duct comprises a first portion having a distal end connected to said head portion of the device and a proximal end connected a first port of a manifold, the first portion of said further elongate flexible duct being arranged to cool said cable, said further elongate flexible duct further comprising a second portion which extends from a second port of the manifold, the manifold having a third port for entry of the cable, the manifold being sealed and arranged such that the cable entering the manifold extends inside said first portion of said further elongate flexible duct and is cooled by fluid flowing via the first and second ports of the manifold, said manifold forming part of the disposable assembly. 
     
     
         18 . A medical device as claimed in  claim 17 , in which the manifold comprises a further port to allow another cable to extend inside said first portion of said further elongate flexible duct. 
     
     
         19 . A medical device as claimed in  claim 18 , in said further cable may carry signals from a sensor disposed in said head portion of the device. 
     
     
         20 . A medical device as claimed in any of  claims 17  to  19 , in which the manifold is disposed adjacent the pump. 
     
     
         21 . A medical device as claimed in any preceding claim, in which the assembly comprises another elongate flexible duct connected to said second port of the pump head. 
     
     
         22 . A medical device as claimed in  claim 21 , in which the distal end of said other elongate flexible duct is arranged for connecting to a fluid source. 
     
     
         23 . A medical device as claimed in  claim 21  or  22 , in which said other elongate flexible duct forms part of the disposable assembly. 
     
     
         24 . A medical device as claimed in any preceding claim, in which the pump comprises an actuator which is driven by said motor, said fluid propulsion means being arranged to detachably engage the pump actuator. 
     
     
         25 . A medical device as claimed in  claim 24 , in which said fluid propulsion means is arranged to magnetically couple with the pump actuator. 
     
     
         26 . A medical device as claimed in any preceding claim, in which said fluid propulsion means comprises a piston. 
     
     
         27 . A medical device as claimed in any preceding claim, in which the pump actuator comprises a reciprocating shaft having one end arranged to couple with said propulsion means. 
     
     
         28 . A medical device as claimed in  claim 27 , in which the shaft reciprocates along an axis, said end of the shaft extending through an aperture in an outer wall of the pump body, the wall lying normal to said axis. 
     
     
         29 . A medical device as claimed in  claim 28 , in which the pump comprises means for positioning the shaft in a position in which said end thereof is substantially in the same plane as the outer surface of said pump wall when stopped. 
     
     
         30 . A medical device as claimed in  claim 29 , in which the pump head is arranged to slide into a position on said outer surface of said pump wall in which said fluid propulsion means couples with the pump actuator. 
     
     
         31 . A medical device as claimed in  claim 30 , in which the pump head is arranged to slidably rotate into a position on said outer surface of said pump wall in which said fluid propulsion means couples with the pump actuator. 
     
     
         32 . A medical device as claimed in  claim 31 , in which the pump head is arranged to slidably rotate about an axis which extends normal to the plane of said outer surface of said pump wall, means being provided for rotationally coupling the pump head to the pump body for rotation about said axis. 
     
     
         33 . A medical device as claimed in  claim 32  as appended to  claim 9 , in which the said means for rotationally coupling the pump head to the pump body comprises said electrical connector for coupling the cable to the pump body. 
     
     
         34 . A medical device as claimed in  claim 33 , in which the electrical connector comprises a coaxial connector. 
     
     
         35 . A medical device as claimed in any of  claims 30  to  34 , in which the pump head comprises one or more electrical terminals which engage corresponding electrical terminals on the pump body when the pump head is slid into said position on the pump body. 
     
     
         36 . A medical device as claimed in  claim 35 , in which the or each terminal carries signals from a sensor in the head of the device. 
     
     
         37 . A medical device as claimed in any preceding claim, in which means are provided for locking the pump head to the pump body when the motor is running. 
     
     
         38 . A pump comprising pump body having a pump motor arranged to drive an actuator, and a pump head detachably mounted to the pump body and having a first port, a second port and fluid propulsion means for creating a flow of said fluid between said ports upon energisation of said pump motor, said pump head being arranged to sealingly contain said fluid when detached from the pump body. 
     
     
         39 . A pump comprising pump body having a pump motor arranged to drive an actuator, and a pump head detachably mounted to the pump body and having fluid propulsion means for creating a flow of fluid between first and second ports of the pump head, the propulsion means being magnetically coupled to the pump actuator. 
     
     
         40 . A motor having a body, a stator shaft fixed to the body and a rotor arranged to rotate around the shaft, the rotor having an axially extending circumferential formation on its external surface, means being provided on the body for engaging the formation to impart linear movement to an actuator upon rotation of the rotor. 
     
     
         41 . A motor as claimed in  claim 40 , in which the actuator comprises a reciprocating shaft which reciprocates along an axis, said axis extending parallel to the axis of motor rotation. 
     
     
         42 . A motor as claimed in  claim 41 , in which the actuator comprises an arm which extends radially from the shaft and engages the formation at the outer end thereof. 
     
     
         43 . A motor as claimed in any of  claims 40  to  42 , in which the formation comprises a groove. 
     
     
         44 . A motor as claimed in any of  claims 40  to  43 , in which the formation is arranged to move the actuator in a one direction at a different speed and/or for a different time than the actuator is moved in the opposite direction. 
     
     
         45 . A pump comprising a motor as claimed in any of  claims 40  to  44 .