Apparatus and method to control atmospheric water vapor composition and concentration during dynamic cooling of biological tissues in conjunction with laser irradiations
US5997530A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 1998 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Apr 13, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2090/049
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Cryogen spray cooling of skin surface with millisecond cryogen spurts is an effective method for establishing a controlled temperature distribution in tissue and protecting the epidermis from nonspecific thermal injury during laser mediated dermatological procedures. Control of humidity level, spraying distance and cryogen boiling point is material to the resulting surface temperature. Decreasing the ambient humidity level results in less ice formation on the skin surface without altering the surface temperature during the cryogen spurt. For a particular delivery nozzle, increasing the spraying distance to 85 millimeters lowers the surface temperature. The methodology comprises establishing a controlled humidity level in the theater of operation of the irradiation site of the biological tissues before and/or during the cryogenic spray cooling of the biological tissue. At cold temperatures calibration was achieved by mounting a thermistor on a thermoelectric cooler. The thermal electric cooler was cooled from from 20.degree. C. to about -20.degree. C. while measuring its infrared emission.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.