Ring-type biomedical vortex flu detector for continuous blood pressure measurement
Ring-type Biomedical Eddy Current Sensor for Continuous Blood Pressure Monitoring
S.-H. Ni, Y.-L. Sung, D.-Y. Hsu, C.-Y. Huang, D.-N. Lai, T.-W. Wang*, "Ring-type Biomedical Eddy Current Sensor for Continuous Blood Pressure Monitoring," IEEE Transactions on Instrumentation and Measurement, vol. 73, Art no. 4010214, pp. 1-14, 2024.
Vascular condition measurement device (Invention Patent, Certificate No.: I838112)
Abstract— Continuous cuffless blood pressure (BP) sensors are evolving for long-term cardiovascular monitoring, especially in diagnostic and prognostic stages. The existing techniques rely on photoplethysmography (PPG) and bio-impedance that have limitations, such as sensitivity to skin tone and high skin-electrode contact impedance that would degrade physiological signals measurement. To this end, this study presents a novel wearable coil-based ring-type sensor utilizing the novel biomedical eddy current technique for continuous BP measurement. The LC-based ring sensor generates the AC magnetic fields along with the finger in parallel with the digital arteries, detecting the resonant frequency variations in response to real-time vessel pulsations. The proposed ring-type sensor is characterized by its compact form with a diameter of 2.42 cm and supporting wireless data transmission. To optimize personalized sensing, the various resonant frequencies on vessel pulse measurements were investigated by human trials. The novel ring sensor is employed for the estimation of BP, demonstrating high Pearson's correlations (systolic correlations) BP (SBP): 0.88, diastolic BP (DBP): 0.80) and low mean absolute error (MAE) within 10 subjects (SBP: 3.64 ± 2.71 mmHg, DBP: 3.20 ± 2.66 mmHg), revealing the significant potential use of biomedical eddy current-based ring sensor for continuous, accurate, and comprehensive cardiovascular monitoring.
Index Terms— Biomedical eddy current sensor, continuous blood pressure measurement, electromagnetic induction, resonant circuit, wearable sensor.
Abstract: A vascular condition measurement device includes a signal transceiver and a control module. The signal transceiver has a tunnel structure for setting up a test site. The signal transceiver outputs a first electromagnetic signal to the test site through the tunnel structure to generate an eddy current at the test site, and receives a second electromagnetic signal generated corresponding to the eddy current. The control module is coupled to the signal transceiver and includes a signal generation unit and a processing unit. The signal generation unit generates an AC signal and provides it to the signal transceiver to generate the first electromagnetic signal. The processing unit calculates a feature signal based on the first and second electromagnetic signals. The feature signal corresponds to at least one state of at least one blood vessel at the test site.