An integrated circuit with transmit beamforming flip-chip bonded to a 2-D CMUT array for 3-D ultrasound imaging.
State-of-the-art 3-D medical ultrasound imaging requires transmitting and receiving ultrasound using a 2-D array of ultrasound transducers with hundreds or thousands of elements. A tight combination of the transducer array with integrated circuitry eliminates bulky cables connecting the elements of the transducer array to a separate system of electronics. Furthermore, preamplifiers located close to the array can lead to improved receive sensitivity. A combined IC and transducer array can lead to a portable, high-performance, and inexpensive 3-D ultrasound imaging system. This paper presents an IC flip-chip bonded to a 16 x 16-element capacitive micromachined ultrasonic transducer (CMUT) array for 3-D ultrasound imaging. The IC includes a transmit beamformer that generates 25-V unipolar pulses with programmable focusing delays to 224 of the 256 transducer elements. One-shot circuits allow adjustment of the pulse widths for different ultrasound transducer center frequencies. For receiving reflected ultrasound signals, the IC uses the 32-elements along the array diagonals. The IC provides each receiving element with a low-noise 25-MHz-bandwidth transimpedance amplifier. Using a field-programmable gate array (FPGA) clocked at 100 MHz to operate the IC, the IC generated properly timed transmit pulses with 5-ns accuracy. With the IC flip-chip bonded to a CMUT array, we show that the IC can produce steered and focused ultrasound beams. We present 2-D and 3-D images of a wire phantom and 2-D orthogonal cross-sectional images (Bscans) of a latex heart phantom.
Wygant
Ira O
IO
Edward L. Ginzton Lab., Stanford Univ., Stanford, CA, USA. iwygant@stanford.edu
Jamal
Nafis S
NS
Lee
Hyunjoo J
HJ
Nikoozadeh
Amin
A
Oralkan
Omer
O
Karaman
Mustafa
M
Khuri-Yakub
Butrus T
BT
D004452:Echocardiography; D004582:Electronics, Medical / Q000295:instrumentation*; D004867:Equipment Design; D021621:Imaging, Three-Dimensional / Q000295:instrumentation* / Q000379:methods; D019047:Phantoms, Imaging; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods