Cryosurgical instrument
OwnerJohn D. Dobak, IIIinventor
Life of this patent
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Abstract
A closed cycle cryosurgical instrument having a mixed gas assembly that is mounted in a housing and also having a cryosurgical probe unit. By using special (or certain) gas mixtures as opposed to pure gasses, pressure reductions to .perspectiveto. or 1/4 of that required by pure gasses can be obtained. The use of gas mixtures with their attendant lower pressures allows for a closed cycle system since expensive and complex multi-stage compressors are not required. With the gas mixtures it is possible to obtain temperatures in the range of liquid nitrogen using a Joule-Thomson based system.
Claims9
A cryosurgical instrument comprising:
- a mixed gas assembly having a compressor connected to an inlet valve and an outlet valve, a mixed gas mixture having a temperature colder than -90 degrees C. at a pressure less than 740 psi;
- a cryosurgical probe unit comprising an inlet port and an outlet port, a Joule-Thomson valve having an inlet end and an outlet end, a cryosurgical probe tip, a first connecting means for connecting said inlet port to said inlet end of said Joule-Thomson valve, a second connecting means for connecting the outlet end of said Joule-Thomson valve to the inlet end of salad cryosurgical probe tip, a third connecting means for connecting the outlet end of said cryosurgical probe tip to the outlet end of said cryosurgical probe unit;
- a fourth connecting means for connecting the outlet valve of said compressor to the inlet port of said cryosurgical probe unit;
- and
- a fifth connecting means for connecting the outlet port of said cryosurgical probe unit to the inlet valve of said gas compressor.
A cryosurgical instrument comprising:
- a source of mixed gases in a housing having an inlet valve and an outlet valve, a mixed gas mixture having a temperature colder than -90 at degrees C. at a pressure less than 740 psi;
- a cryosurgical probe unit comprising an inlet port and an outlet, means for allowing the mixed gases to expand across a primary structure having an inlet end and an outlet end, a cryosurgical probe tip, a first connecting means for connecting said inlet port to said inlet end of said primary structure, a second connecting means for connecting the outlet end of said primary structure to the inlet end of said cryosurgical probe tip, a third connecting means for connecting the outlet end of said cryosurgical probe tip to the outlet end of said cryosurgical probe unit;
- a fourth connecting means for connecting the outlet valve of said compressor to the inlet port of said cryosurgical probe unit;
- and
- a fifth connecting means connected to the outlet port of said cryosurgical probe unit.
A method comprising the step of using mixed gas a mixture having a temperature colder than -90 degrees C. at a pressure less than 740 psi cooling in a cryosurgical unit for medical purposes that require cold temperatures to alter tissue.
Dependencies are inferred from the claim text.