Patent GB-618528-A (GB)
Title: Improvements in or relating to electrosurgical resecting instrument
IPC: A61B18/14
Filed: 1946-07-09
Abstract: 618,528. Diathermic cutting endoscopes. AMERICAN CYSTOSCOPE MAKERS, Inc. July 9, 1946, No.. 20460. Convention date, July 10, 1945. [Class 81 (ii)] A surgical instrument for removing protrusions, tissue growths &c. with the aid of a highfrequency electric current, comprises at least one high-frequency cutting electrode rotatably supported within a tubular member and positioned at least in part within a fenestra formed in the tubular member, a portion of the electrode intermediate the ends thereof being substantially helical in form, and a motor, such as an electric or fluid actuated motor, for imparting continuous rotation to the electrode. An endoscopic tubular member 15 is provided at its forward end with a beak 16 and a lateral fenestra 18, and is screwed at its rearward end into a collar 19 provided with a recess 20 and passage 21 in fluid communication with a conduit 22 and the interior of the tube 15. A removable device in tube 15 comprises a unitary bundle of four tubes, of which one (24) accommodates a telescope. Two others are used for introducing and withdrawing an irrigating fluid, and tube 27 having a longitudinal slot supports an electrode shaft. A depending support 29 is spaced apart from the forward ends of the tubes which are secured at their rearward ends to a collar 32 which is in fluid tight connection with collar 19, the former having a flange 33 with circumferentially spaced tapped openings communicating with the irrigation tubes. The collar 32 and associated parts are mounted on a support which includes a pistol grip handle 45 having a top wall 46 containing a compartment 49 housing a motor P and speed-reducing gear R. Above the compartment 49 is a block of insulating material 51 to which is attached a bridge 52 having a depending arm 58 through an opening in which passes a telescope 65 fitted with an electric lamp 67, eye-piece 70 and electric plug 72. Within tube 27 is disposed a hollow rotatable shaft 75 containing an electrically conductive rod 77 insulated by a sheath 76. A preferred form of cutting electrode consists of two wires 78 each of a helical configuration, the ends of which are embedded in the end of rod 77 and a shaft-like element of insulating material 79 rotatably supported in the beak 16 ; other forms of electrodes include a helical wire as such or secured at its ends to a co-axial rod; and a transparent core member, e.g. of glass, having a rounded end portion to fit rotatably in support 29 and a recessed rearward end to engage end of rod 77, the core being shaped with two helical grooves one of which carries the electrode wire. The rearward end of rod 77 communicates through a bearing 82 and terminal 84 with a source of high frequency current. A collar 80 mounted on rod 77 bears against a bush 82 to restrain rod 77 and shaft 75 against rearward movement and to prevent forward movement a spring biased detent 86 extends beneath the rod and against the collar 80. The Specification as open to inspection under Sect. 91 describes also an electrode consisting of a wire having a central longitudinal portion parallel with the axis of the shaft, and a forward and rearward crank portion. This subject-matter does not appear in the Specification as accepted.