Forward-looking intracardiac ultrasound imaging using a 1-D CMUT array integrated with custom front-end electronics

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Ultrasound Technology

Background:

• Minimally invasive catheter-based electrophysiological (EP) interventions are standard for cardiac arrhythmias.
• Nonfluoroscopic intracardiac echocardiography (ICE) catheters improve EP guidance and reduce fluoroscopy.
• Current ICE catheters offer only side-looking imaging, limiting visualization.

Purpose of the Study:

• To develop a forward-looking ICE catheter for enhanced visualization during EP procedures.
• To integrate a 1-D CMUT array with custom transmit/receive circuitry for intracardiac imaging.
• To demonstrate the imaging capabilities of the developed forward-looking ICE catheter.

Main Methods:

• Fabrication of a 24-element, fine-pitch 1-D CMUT array (1.73 mm x 1.27 mm).
• Design of a custom integrated circuit (IC) with 24 transmit/receive channels (2.1 mm x 2.1 mm).
• Flip-chip bonding of the CMUT array to the IC, followed by PDMS coating and testing.

Main Results:

• Successful fabrication and integration of the CMUT array and custom IC.
• Achieved a pulse-echo center frequency of 9.2 MHz with 96% fractional bandwidth in water.
• Demonstrated imaging capability on phantoms and an ex vivo rabbit heart model.

Conclusions:

• The developed forward-looking ICE catheter shows promise for improved visualization in cardiac EP procedures.
• Integration of CMUTs and custom ICs enables high-performance intracardiac ultrasound imaging.
• This technology has the potential to reduce reliance on fluoroscopy and enhance procedural safety.