Method and means for controlling the freeze zone of a cryosurgical probe
US4015606A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1975 |
| Grant date | Apr 5, 1977 |
| Priority date | — |
| Expiry date | Sep 9, 1995 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B18/02
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A cryosurgical probe has a refrigerant supply conduit for conducting refrigerant to the hollow thermally-conductive probe tip. A refrigerant exhaust conduit extends through the probe into the tip and the end of the exhaust conduit in the tip is positioned a selected distance proximally of the end of the supply conduit. Thus, when refrigerant flows through the supply conduit to the tip, it tends to follow a flow path taking it more or less directly to the exhaust conduit. This creates a dead gas space inside the tip proximally of the end of the exhaust conduit, thereby minimizing direct cooling of portions of the probe adjacent to and proximally of the dead gas space and confining the freeze zone distal to that space. By adjusting the height of the exhaust conduit end proximally of the supply conduit end, the size of the freeze zone at the tip can be controlled. Further, if the probe has a defrost mode, defrost is enhanced because only the working end of the tip need be warmed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.