A high-precision implantable pressure sensor with ultrasonic power-up and data uplink is presented. The fully packaged implant measures 1.7 × 2.3 × 7.8 mm3and includes a custom IC designed in a 180-nm HV BCD process, a pressure transducer, an energy storage capacitor, and a single piezoelectric transducer (piezo). In order to reduce overall dimensions, unique circuit and system design techniques are presented to enable a single time-multiplexed piezo for both power recovery and data uplink transmission. Implant performance is characterized at significant depths, 12 cm in a tissue phantom, offering a > 13× improvement over state of the art in the depth/volume figure of merit, while demonstrating a robust ultrasonic data uplink with better than 10-5bit error rate. A transient charging analysis is presented to derive the optimal piezo impedance and charging specifications to maximize overall harvesting efficiency. The IC features a front end with a 10-bit SAR ADC achieving a pressure full-scale range of 800 mmHg with a pressure resolution of 0.78 mmHg, exceeding the requirements for a wide range of in vivo pressure sensing applications. The pressure sampling rate is fully externally controlled, up to 1 ksps, in order to significantly decrease implant energy consumption and to allow for adaptable programming for specific applications.
No takes yet. Share an insight, caveat, or question.
Weber et al. (2018) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: