Optimal Ultrasonic Pulse Transmission for Miniaturized Biomedical Implants

Zeinab Kashani, Mehdi Kiani

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This paper presents optimal ultrasonic pulse transmission that could be used for data transmission to/from millimeter-sized biomedical implants in general or the selfimage-guided ultrasonic (SIG-US) wireless power transfer (WPT), which we have recently proposed. To reduce the power consumption of the implant, data bits can be applied as sharp pulses across the implant's ultrasonic transducer, resulting in a signal in the form of a short ringing across the external unit transducer (or array). In SIG-US WPT, also short pulses are transmitted by the implant periodically. The relative delays in received signal by each external transducer in an array are then used to guide the beamformer for optimal steering of the power beam towards the implant. Through simulations and measurements, the effect of transmitted number of pulses (Np) on the amplitude of the received signal (VDRx) has been studied, which is vital for low-power robust transmission. In measurements with two identical disc-shaped transducers (spaced by d = 50 mm inside water) with the diameter of 1.2 mm and thickness of 0.9 mm (series resonance frequency of ~1.3 MHz), VDRx increased almost linearly with Np (50% duty cycle with the period of 1/1.3 MHz ~ 770 ns) up to Np = 5 beyond which VDRX increase was negligible and started to saturate at Np = 10. In the SIG-US context, it was also shown in measurements that for up to 25 mm misalignment of the implant at d = 50 mm, the relative delay in receiving 4 pulses increased from 40 ns to 4.75 μs, which are quite measurable.

Original languageEnglish (US)
Title of host publicationBioCAS 2019 - Biomedical Circuits and Systems Conference, Proceedings
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9781509006175
DOIs
StatePublished - Oct 2019
Event2019 IEEE Biomedical Circuits and Systems Conference, BioCAS 2019 - Nara, Japan
Duration: Oct 17 2019Oct 19 2019

Publication series

NameBioCAS 2019 - Biomedical Circuits and Systems Conference, Proceedings

Conference

Conference2019 IEEE Biomedical Circuits and Systems Conference, BioCAS 2019
CountryJapan
CityNara
Period10/17/1910/19/19

All Science Journal Classification (ASJC) codes

  • Artificial Intelligence
  • Biomedical Engineering
  • Electrical and Electronic Engineering
  • Instrumentation

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