Israel21C is reporting about Arbel Medical and their efforts to develop a system that will successfully and precisely freeze tumors, specifically within the breasts. Seeking FDA approval, they plan to put their cryotherapy system through clinical trials early next year.
Liquid nitrogen is pumped to the end of a thin needle probe cooling the tip to the extreme cold required for cryotherapy. Utilizing ultrasound, surgeons can then guide the needle to the exact location of the lump and then freeze the unwanted tissue inside the body.
About the same size as a washing machine, the IceSense apparatus can be operated even in local clinics and medical centers. Providing treatment for breast lumps in local medical centers would be a big step towards the current trend in the US to conduct as much surgery as possible in local clinics by using non-invasive methods. This keeps expensive and over-worked operating rooms and teams free for more serious surgical procedures that require a hospital environment…
Arbel engineer Alexander Levin explains that building a system to work with surgically small and precise amounts of liquid nitrogen was a challenge. Just keeping the nitrogen as a liquid while it is transferred to the probe required a newly designed siphon, but the real problem was concentrating the nitrogen in the end of the probe without freezing the entire length of the shaft. If the temperature of the shaft became super-cold it would freeze healthy tissue along its length.
“We needed to overcome all of these problems,” Levin recalls.
Levin resolved the difficulties by pulsing the nitrogen instead of using a steady flow. The pulses of just 0.2 grams of nitrogen do not cool the shaft of the probe but when collected in the tip the liquid boils into gas drawing heat from the end of the probe and the surrounding body tissue. The gaseous nitrogen is then drawn off back down the probe. As the temperature at the end of the probe plummets, an ice-ball forms around the tip freezing the surrounding body tissue.
The pulse mechanism enables precise and subtle temperature control at the tip of the probe ensuring the resulting ice-ball freezes only the target tissue. The IceSense pulse system gives surgeons precise control over the size and application of the ice-ball to minimize any collateral damage and target only the intended tissue.