Patent ID: 8798705

Claim:
An instrument 10 for delivering a high voltage pulse, comprising: an outer support member 12 comprising a liquid reservoir 14 comprising: a liquid-contacting interior surface 16 , an opening 18 at a distal end 20 of said outer support member 12 , and a ground electrode 22 extending in a longitudinal direction and having a lower surface 23 proximate said opening 18 ; a working electrode 26 extending longitudinally from said liquid-contacting interior surface 16 and having a needle-shaped distal portion 28 proximate said distal end 20 ; and an inlet port 31 and an outlet port 34 in liquid communication with said liquid reservoir 14 , wherein said working electrode 26 is electrically isolated from said ground electrode 22 by an insulating portion 30 of said outer support member 12 , wherein a direct path exists through said liquid reservoir 14 between said ground electrode 22 and said working electrode 26 .