A new device for ultrasonic monitoring of cryosurgery

Author

Laplace, E. ; Laugier, P. ; Saied, A. ; Berger, G.

Volume

3

fYear

1994

fDate

Oct. 31 1994-Nov. 3 1994

Firstpage

1581

Abstract

One of the main difficulty encountered in cryosurgery is to know the extent and depth of the frozen tissue boundary during the freezing process. It has been previously demonstrated that the echo of the advancing freezing front could be detected by means of ultrasound on in vitro pig skin. The ultrasonic measurement consists in noting the total transit time for an ultrasonic pulse travelling through the frozen skin and reflected by the ice boundary. In this paper we describe the experimental results obtained with a prototype that combines the cryoprobe and the ultrasonic transducer. A small transducer of 5 mm diameter with a center frequency of 20 MHz was inserted into a hole that was drilled in the center of the cryoprobe. This study permits to design the optimal characteristics of the transducer operating in this range of low temperatures (impedance matching, backing, center frequency, broadband). Our prototype enables in vivo cryosurgery real time monitoring

Keywords

biomedical ultrasonics; biothermics; low-temperature techniques; patient monitoring; skin; surgery; ultrasonic transducers; 20 MHz; 5 mm; backing; broadband; center frequency; cryoprobe; cryosurgery; design; freezing process; frozen skin; frozen tissue boundary; hole; ice boundary; impedance matching; in vitro pig skin; low temperatures; optimal characteristics; real time monitoring; total transit time; ultrasonic measurement; ultrasonic monitoring; ultrasonic pulse; ultrasonic transducer; Biological thermal factors; Biomedical acoustic imaging; Biomedical monitoring; Biomedical transducers; Skin; Surgery;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1994. Proceedings., 1994 IEEE

Conference_Location

Cannes, France

Print_ISBN

0-7803-2012-3

Type

conf

DOI

10.1109/ULTSYM.1994.401894

Filename

401894