# US 8,465,487 B2 · Plasma-generating device having a throttling portion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,465,487 B2 - Document ID: US8465487B2 - Status: Granted - Kind: B2 - Application number: 13/357,895 - Filed: 2012-01-25 - Published: 2012-06-07 - Granted: 2013-06-18 - Earliest claimed: 2005-07-08 - Assignees: Plasma Surgical Investments Limited - Applicants: Nikolay Suslov - Inventors: Nikolay Suslov - Web page: https://patentgrep.com/patent/US8465487B2 ## CPC - H05H 1/34: Details, e.g. electrodes, nozzles - H05H 1/3452: {Supplementary electrodes between cathode and anode, e.g. cascade} - H05H 1/3484: {Convergent-divergent nozzles} - H05H: PLASMA TECHNIQUE (apparatus or processes specially adapted for producing X-rays H05G2/00); PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS ## Abstract The present invention relates to a plasma-generating device comprising an anode, a cathode, and intermediate electrodes. The intermediate electrodes and the anode form an elongate plasma channel that extends from a point between the cathode and the anode and through the anode. The plasma channel has a throttling portion with a throat having the smallest cross-sectional area of the entire plasma channel. As a plasma flow passes through the throttling portion, the plasma flow's speed is increased while its pressure is decreased. By varying the position of the throttling portion in the plasma channel properties of the discharged plasma can be changed. Plasma flows with different properties can be used for various applications, especially, medical procedures. ## Claims ### Claim 1 A plasma-generating device comprising: a. an anode at a distal end of the device, the anode having a hole therethrough; b. a plurality of intermediate electrodes electrically insulated from each other and from the anode, each of the intermediate electrodes having a hole therethrough, wherein the holes in the intermediate electrodes and the hole in the anode, at least in part, form a hollow space having i. a first portion having a throat, the throat having a first cross-sectional area, ii. a second portion, which over a substantial length of this portion has a uniform second cross-sectional area larger than the first cross-sectional area, the second portion being formed by two or more of the intermediate electrodes, the second portion being upstream of the first portion, iii. a third portion, which over a substantial length of this portion has a uniform third cross-sectional area larger than the first cross-sectional area, the third portion, at least in part, being formed by the anode, the third portion being downstream of the first portion; c. a cathode having a tapered portion; and d. an insulator sleeve extending along and surrounding a substantial portion of the cathode, wherein an inside surface of the insulator sleeve and an outside surface of the cathode form a gap, the gap being in communication with the hollow space. ### Claim 2 (depends on 1) The plasma-generating device of claim 1 further comprising an outer sleeve. ### Claim 3 (depends on 2) The plasma-generating device of claim 2, wherein the outer sleeve and the anode are parts of an integral structure. ### Claim 4 (depends on 1) The plasma-generating device of claim 1 further comprising an insulator positioned between a pair of adjacent intermediate electrodes of the plurality of intermediate electrodes, and an insulator positioned between a distal-most intermediate electrode and the anode. ### Claim 5 (depends on 1) The plasma-generating device of claim 1, wherein a distal portion of the cathode is tapered, and the tapered portion partially projects beyond a distal end of the insulator sleeve. ### Claim 6 (depends on 1) The plasma-generating device of claim 1, wherein the first portion of the hollow space is formed by one of the intermediate electrodes. ### Claim 7 (depends on 1) The plasma-generating device of claim 1, wherein the first portion of the hollow space is a supersonic nozzle. ### Claim 8 (depends on 7) The plasma-generating device of claim 7, wherein the hollow space has a fourth portion, which over a substantial length of this portion has a uniform fourth cross-sectional area, the fourth cross-sectional area being larger than the second cross-sectional area and the third cross-sectional area, the fourth portion being upstream of the second portion of the hollow space. ### Claim 9 (depends on 8) The plasma-generating device of claim 8, wherein the fourth portion is formed by a proximal-most of the intermediate electrodes. ### Claim 10 (depends on 9) The plasma-generating device of claim 9, wherein a distal end of the cathode is positioned inside the fourth portion of the hollow space. ### Claim 11 (depends on 8) The plasma-generating device of claim 8, wherein the fourth and second portions of the hollow space are connected through a transitional fifth portion of the hollow space tapering toward the anode. ### Claim 12 (depends on 8) The plasma-generating device of claim 8, wherein the fourth portion of the hollow space extends from a distal end of the insulator sleeve to a proximal end of the second portion of the hollow space. ### Claim 13 (depends on 1) A plasma surgical instrument comprising the plasma-generating device of claim 1. ### Claim 14 (depends on 13) The plasma surgical instrument of claim 13 adapted for laparoscopic surgery. ### Claim 15 (depends on 14) The plasma surgical instrument of claim 14 having an outer cross-sectional width of under 10 mm. ### Claim 16 (depends on 15) The plasma surgical instrument of claim 15 having an outer cross-sectional width of under 5 mm. ### Claim 17 (depends on 13) A method of using the plasma surgical instrument of claim 13 comprising a step of discharging plasma from a distal end of the plasma surgical instrument on a biological tissue. ### Claim 18 (depends on 17) The method of claim 17 further comprising one or more steps of: cutting, vaporizing, and coagulating the biological tissue. ### Claim 19 (depends on 17) The method of claim 17, wherein the discharged plasma is substantially free of impurities. ### Claim 20 (depends on 17) The method of claim 17, wherein the biological tissue is one of liver, spleen, heart, brain, kidney, or bone. ### Claim 21 (depends on 1) A method of generating plasma comprising a step of supplying to the plasma-generating device of claim 1 a plasma-generating gas at a rate of 0.05 to 1.00 1/min and establishing an electric arc of 4 to 10 Amperes between the cathode and the anode. ### Claim 22 (depends on 21) The method of claim 21, wherein the plasma-generating gas is an inert gas.