Design of a driver IC for an ultrasound catheter ablation system

High Intensity Focused Ultrasound (HIFU) is generally administered externally, or through body orifices such as the esophagus, the urethra, the uterus, or the rectum. The devices used in conventional treatment are not suitable to be used in endoscopic interventions or in intravascular catheterization due to their dimensions. This paper presents the design of a drive integrated circuit for driving a CMUT therapy array of 2 mm diameter such that whole device fit through key holes in endoscopic treatment or through vessels. The proposed ASIC is composed of (1) an 8 channel drive signal generator, (2) 8 high voltage drivers, and (3) a PLL for the local generation of a high frequency tunable master clock signal based on a low frequency reference. All designs are in austriamicrosystems h35 High-Voltage CMOS technology with 1.3×3 mm² die area including ESD protection pads.