An ASIC for Gripper Finger Haptic Force Feedback in Minimally Invasive Surgery

In this article, we present an application specific integrated circuit (ASIC) for gripper finger haptic force feedback in minimally invasive surgery (MIS). It consists of a driving current source, a sensing channel, a digital to analog converter (DAC), a power management unit (PMU), a clock generator and a digital control unit (DCU). The driving current source features a 6-bit DAC to provide a temperature-insensitive current from 0.27 mA to 1.15 mA for the sensor array. The sensing channel contains a programmable instrumentation amplifier (PIA), a low-pass filter (LPF), an incremental analog-to-digital converter (ADC) with its input buffer (BUF). The gain of the sensing channel ranges from 2.76 to 140. The DAC generates a tunable reference voltage to compensate possible sensor array offset. The input referred noise of the sensing channel is around 3.6 μVrms at a sampling rate of 850S/s. A custom 2-wire communication protocol is implemented to support two chips on gripper fingers operating in parallel with low latency, ensuring real-time surgical condition estimation for surgeons. Manufactured in the TSMC 180nm CMOS technology, this chip occupies only 1.37 mm² core area, and the entire system requires only 4 wires (including power / ground) to operate. Combined with its high accuracy, low latency, and high integration level, this work allows real-time, high-performance haptic force feedback with compact system size, particularly suitable for MIS applications.