§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
US3903891A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for generating plasma

Assignee: HOGLE KEARNS INT
•
Filing: 1970-10-12
•
Granted: 1975-09-09
•
Expires: 1990-10-12
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Apparatus for producing an electric-field plasma is constructed with a hollow, electrically-conductive conduit connected in series with a radio frequency resonant circuit. The spatial relationship of the hollow conduit and the inductance of the resonant circuit is selected to avoid transformer action. The components of the generator (including the plasma) interact to effect a high Q under unloaded conditions and a low Q under loaded conditions. Flowable material, usually including a carrier gas, is displaced through the conduit while RF energy is applied to the resonant circuit. By proper adjustment of the process parameters, the gas may be excited to and maintained at preselected energization levels. Plasmas may be initiated by the application of RF energy alone without auxiliary initiation techniques. Plasmas generated at ambient pressures may optionally be either at close to thermal equilibrium or at substantial thermal nonequilibrium. Plasmas at thermal nonequilibrium may comprise noble gases (or other substances susceptible to excitation to a mestastable state) in a metastable state.

Inventors

  • 👤 Forrest G Brayshaw

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 07:58
CPC Classifications
A; A61; A61B; A61B18/00; A61B18/04; A61B18/042; H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/30

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 41 words
A method for performing surgery which comprises: establishing and maintaining a cold plasma of a sufficiently small cross section to permit a narrow region of contact between the plasma and tissue; and applying said plasma to tissue to produce an incision.
Claim 2
Independent Claim 41 words
A method for performing surgery which comprises: establishing and maintaining a cold plasma of a sufficiently small cross section to permit a narrow region of contact between the plasma and tissue; and applying said plasma to tissue to produce an incision.
Claim 3
Dependent Claim 19 words
A method according to claim 1, wherein the plasma is produced by applying RF energy to a noble gas.
Claim 4
Dependent Claim 28 words
A method according to claim 2, wherein the noble gas is Argon and sufficient RF energy is applied to said gas to excite it to a metastable state.
Claim 5
Dependent Claim 34 words
A method according to claim 2, wherein the noble gas is displaced through a hollow electrode terminating in an effluent nozzle and RF energy is applIed conductively to said electrode through a parallel-resonant circuit.
Claim 6
Dependent Claim 29 words
A method according to claim 4, wherein RF energy is applied to said parallel-resonant circuit at a frequency close to, but different from, the resonant frequency of said circuit.
Claim 7
Dependent Claim 31 words
A method according to claim 5, wherein RF energy is applied to said parallel-resonant circuit at a frequency up to about 5 percent higher than the resonant frequency of said circuit.
Claim 8
Dependent Claim 41 words
A method according to claim 6, wherein the noble gas is Argon, the diameter of the plasma is between about 0.005 and about 0.015 inches, and the resonant frequency of the parallel-resonant circuit is between about 30 and about 200 megahertz.
Claim 9
Dependent Claim 38 words
A method according to claim 7, wherein the resonant frequency of the parallel-resonant circuit is between about 80 and about 100 megahertz, and the flow rate of the Argon gas is below about 5 cubic feet per hour.
Claim 10
Dependent Claim 60 words
A method according to claim 8, wherein the flow rate of the Argon gas is between about 1/10 and about 2 cubic feet per hour, the unloaded Q of the parallel-resonant circuit is above about 100, and RF energy is applied to said circuit at between about 30 and about 300 watts and between about 50 and about 300 volts.
Claim 11
Dependent Claim 19 words
A method according to claim 1, wherein the plasma is produced by applying electrical energy to a noble gas.
Claim 12
Dependent Claim 22 words
A method according to claim 10, wherein the diameter of the plasma is adjusted to between about 0.005 and about 0.015 inches.
Claim 13
Dependent Claim 27 words
A method according to claim 10, wherein the noble gas is Argon and said gas is excited to a metastable state by the application of electrical energy.
Claim 14
Dependent Claim 22 words
A method according to claim 12, wherein the diameter of the plasma is adjusted to between about 0.005 and about 0.015 inches.
Claim 15
Dependent Claim 26 words
A method according to claim 13, wherein the Argon is displaced through an effluent nozzle at a flow rate below about 5 cubic feet per hour.
Claim 16
Dependent Claim 25 words
A method according to claim 14, wherein the flow rate of the Argon is held between about 1/10 and about 2 cubic feet per hour.

References Cited (Backward Citations)

US3566184A Cited
US3434476A Cited
US3483107A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-09-08 1979-03-10 1979-09-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-09-08 1983-03-10 1983-09-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-09-08 1987-03-10 1987-09-09 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag