Passive Wearable Skin Patch Sensor Measures Limb Hemodynamics Based on Electromagnetic Resonance

Kim Cluff, Ryan Becker, Balakumar Jayakumar, Kiyun Han, Ernie Condon, Kenneth Dudley, George Szatkowski, Iraklis I. Pipinos, Ryan Z. Amick, Jeremy Patterson

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Objective: The objectives of this study were to design and develop an open-circuit electromagnetic resonant skin patch sensor, characterize the fluid volume and resonant frequency relationship, and investigate the sensor's ability to measure limb hemodynamics and pulse volume waveform features. Methods: The skin patch was designed from an open-circuit electromagnetic resonant sensor comprised of a single baseline trace of copper configured into a square planar spiral which had a self-resonating response when excited by an external radio frequency sweep. Using a human arm phantom with a realistic vascular network, the sensor's performance to measure limb hemodynamics was evaluated. Results: The sensor was able to measure pulsatile blood flow which registered as shifts in the sensor's resonant frequencies. The time-varying waveform pattern of the resonant frequency displayed a systolic upstroke, a systolic peak, a dicrotic notch, and a diastolic down stroke. The resonant frequency waveform features and peak systolic time were validated against ultrasound pulse wave Doppler. A statistical correlation analysis revealed a strong correlation (R2,= ,0.99) between the resonant sensor peak systolic time and the pulse wave Doppler peak systolic time. Conclusion: The sensor was able to detect pulsatile flow, identify hemodynamic waveform features, and measure heart rate with 98% accuracy. Significance: The open-circuit resonant sensor design leverages the architecture of a thin planar spiral which is passive (does not require batteries), robust and lightweight (does not have electrical components or electrical connections), and may be able to wirelessly monitor cardiovascular health and limb hemodynamics.

Original languageEnglish (US)
Pages (from-to)847-856
Number of pages10
JournalIEEE Transactions on Biomedical Engineering
Issue number4
StatePublished - Apr 2018


  • Open circuit resonant sensor
  • RF resonators
  • peripheral artery disease screening
  • point-of-care
  • sansEC
  • self resonance

ASJC Scopus subject areas

  • Biomedical Engineering


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