ASHRAE Research to Improve Tools for Fighting Cancer.

Business Editors & Health/Medical Writers

ATLANTA--(BUSINESS WIRE)--Jan. 13, 2003

Research that will help improve tools used to freeze cancerous tissue, thereby eliminating the need for invasive surgeries, is being conducted by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).

Cryosurgery, a medical procedure that freezes tissues, is being successfully used to treat various types of cancer with an effectiveness that is comparable to surgery.

Clinical tests have shown that cryosurgery can be very effective provided that doctors have access to the correct instrumentation and tools.

The ASHRAE research will contribute to this rapidly growing area of cancer treatment by providing medical personnel and instrument manufacturers with data and tools that will improve cryosurgical probe designs.

Principal investigator of the project, Design Data for Optimization of Cryosurgical Probes, is Gregory Nellis, Ph.D., and co-investigator is Sanford Klein, Ph.D., both at the University of Wisconsin-Madison. The project will include the creation of a computer program that will allow cryosurgical probe design information to be accessed more conveniently.

The project represents the first ASHRAE research project on the subject of cryogenics.

Cryosurgery is a medical technique for treating cancer in which the tumors are frozen in-situ. Frozen tumors can then either be left alone to be reabsorbed by the body or surgically removed without worry of spreading the cancer by accidentally puncturing the tumor.

Cryosurgery involves the use of small diameter catheters or probes with tips that are cooled to a very low temperature in order to freeze cancerous tissue. Cryosurgical probes have, until recently, been relatively large and therefore invasive devices that use liquid nitrogen to provide the cooling, according to investigators.

Recent advancements in the area of cryogenic refrigeration have allowed smaller probes with the same cooling power, according to the investigators.

"Clinical studies have shown that the effectiveness of cryosurgical treatments is dependent upon the thermal characteristics of the freezing process," Nellis said. "It is currently difficult for medical personnel to select the best system for a given procedure or for medical device companies to optimize the design of catheters because there is little information regarding how refrigerant composition, flow rate, operating pressures, and probe geometry translate into refrigeration power and tip temperature, which in turn results in a certain size of ice-ball and freezing rate."

The project will benefit manufacturers in helping them design improved catheters that are optimized for the specific requirements of the cryosurgical application, according to Nellis.

"We hope that this project will result in improvements in refrigeration power and a reduction in the size of cryogenic probes," he said. "This could increase the number of applications for cryosurgery and improve its effectiveness."

ASHRAE, founded in 1894, is an international organization of 55,000 persons. Its sole objective is to advance through research, standards writing, publishing and continuing education the arts and sciences of heating, ventilation, air conditioning and refrigeration to serve the evolving needs of the public.