title: An Autonomous Wireless Sensor Node With Asynchronous ECG Monitoring in 0.18 μ m CMOS.
abstract: The design of a 13.56 MHz/402 MHz autonomous wireless sensor node with asynchronous ECG monitoring for near field communication is presented. The sensor node consists of an RF energy harvester (RFEH), a power management unit, an ECG readout, a data encoder and an RF backscattering transmitter. The energy harvester supplies the system with 1.25 V and offers a power conversion efficiency of 19% from a -13 dBm RF source at 13.56 MHz. The power management unit regulates the output voltage of the RFEH to supply the ECG readout with VECG = 0.95 V and the data encoder with VDE = 0.65 V . The ECG readout comprises an analog front-end (low noise amplifier and programmable voltage to current converter) and an asynchronous level crossing ADC with 8 bits resolution. The ADC output is encoded by a pulse generator that drives a backscattering transmitter at 402 MHz. The total power consumption of the sensor node circuitry is 9.7 μ W for a data rate of 90 kb/s and a heart rate of 70 bpm. The chip has been designed in a 0.18 μm CMOS process and shows superior RF input power sensitivity and lower power consumption when compared to previous works.
authors.forename: Andre L
authors.initials: AL
authors.lastname: Mansano
authors.forename: Yongjia
authors.initials: Y
authors.lastname: Li
authors.forename: Sumit
authors.initials: S
authors.lastname: Bagga
authors.forename: Wouter A
authors.initials: WA
authors.lastname: Serdijn
mesh_terms: D000669:Amplifiers, Electronic; D015374:Biosensing Techniques / Q000295:instrumentation; D004562:Electrocardiography / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D059015:Wireless Technology / Q000295:instrumentation*