A Flexible Near-Field Biosensor for Multisite Arterial Blood Flow Detection
Modern wearable devices show promising results in terms of detecting vital bodily signs from the wrist. However, there remains a considerable need for a device that can conform to the human body’s variable geometry to accurately detect those vital signs and to understand health better. Flexible radi...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-11-01
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| Series: | Sensors |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1424-8220/22/21/8389 |
| _version_ | 1827645518399930368 |
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| author | Noor Mohammed Kim Cluff Mark Sutton Bernardo Villafana-Ibarra Benjamin E. Loflin Jacob L. Griffith Ryan Becker Subash Bhandari Fayez Alruwaili Jaydip Desai |
| author_facet | Noor Mohammed Kim Cluff Mark Sutton Bernardo Villafana-Ibarra Benjamin E. Loflin Jacob L. Griffith Ryan Becker Subash Bhandari Fayez Alruwaili Jaydip Desai |
| author_sort | Noor Mohammed |
| collection | DOAJ |
| description | Modern wearable devices show promising results in terms of detecting vital bodily signs from the wrist. However, there remains a considerable need for a device that can conform to the human body’s variable geometry to accurately detect those vital signs and to understand health better. Flexible radio frequency (RF) resonators are well poised to address this need by providing conformable bio-interfaces suitable for different anatomical locations. In this work, we develop a compact wearable RF biosensor that detects multisite hemodynamic events due to pulsatile blood flow through noninvasive tissue–electromagnetic (EM) field interaction. The sensor consists of a skin patch spiral resonator and a wearable transceiver. During resonance, the resonator establishes a strong capacitive coupling with layered dielectric tissues due to impedance matching. Therefore, any variation in the dielectric properties within the near-field of the coupled system will result in field perturbation. This perturbation also results in RF carrier modulation, transduced via a demodulator in the transceiver unit. The main elements of the transceiver consist of a direct digital synthesizer for RF carrier generation and a demodulator unit comprised of a resistive bridge coupled with an envelope detector, a filter, and an amplifier. In this work, we build and study the sensor at the radial artery, thorax, carotid artery, and supraorbital locations of a healthy human subject, which hold clinical significance in evaluating cardiovascular health. The carrier frequency is tuned at the resonance of the spiral resonator, which is 34.5 ± 1.5 MHz. The resulting transient waveforms from the demodulator indicate the presence of hemodynamic events, i.e., systolic upstroke, systolic peak, dicrotic notch, and diastolic downstroke. The preliminary results also confirm the sensor’s ability to detect multisite blood flow events noninvasively on a single wearable platform. |
| first_indexed | 2024-03-09T18:40:22Z |
| format | Article |
| id | doaj.art-b44ab76b55114b20878fa4742c3bf76c |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-09T18:40:22Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-b44ab76b55114b20878fa4742c3bf76c2023-11-24T06:47:23ZengMDPI AGSensors1424-82202022-11-012221838910.3390/s22218389A Flexible Near-Field Biosensor for Multisite Arterial Blood Flow DetectionNoor Mohammed0Kim Cluff1Mark Sutton2Bernardo Villafana-Ibarra3Benjamin E. Loflin4Jacob L. Griffith5Ryan Becker6Subash Bhandari7Fayez Alruwaili8Jaydip Desai9Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USADepartment of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USADepartment of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USADepartment of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USADepartment of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USADepartment of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USADepartment of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USADepartment of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USADepartment of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USADepartment of Biomedical Engineering, Wichita State University, Wichita, KS 67260, USAModern wearable devices show promising results in terms of detecting vital bodily signs from the wrist. However, there remains a considerable need for a device that can conform to the human body’s variable geometry to accurately detect those vital signs and to understand health better. Flexible radio frequency (RF) resonators are well poised to address this need by providing conformable bio-interfaces suitable for different anatomical locations. In this work, we develop a compact wearable RF biosensor that detects multisite hemodynamic events due to pulsatile blood flow through noninvasive tissue–electromagnetic (EM) field interaction. The sensor consists of a skin patch spiral resonator and a wearable transceiver. During resonance, the resonator establishes a strong capacitive coupling with layered dielectric tissues due to impedance matching. Therefore, any variation in the dielectric properties within the near-field of the coupled system will result in field perturbation. This perturbation also results in RF carrier modulation, transduced via a demodulator in the transceiver unit. The main elements of the transceiver consist of a direct digital synthesizer for RF carrier generation and a demodulator unit comprised of a resistive bridge coupled with an envelope detector, a filter, and an amplifier. In this work, we build and study the sensor at the radial artery, thorax, carotid artery, and supraorbital locations of a healthy human subject, which hold clinical significance in evaluating cardiovascular health. The carrier frequency is tuned at the resonance of the spiral resonator, which is 34.5 ± 1.5 MHz. The resulting transient waveforms from the demodulator indicate the presence of hemodynamic events, i.e., systolic upstroke, systolic peak, dicrotic notch, and diastolic downstroke. The preliminary results also confirm the sensor’s ability to detect multisite blood flow events noninvasively on a single wearable platform.https://www.mdpi.com/1424-8220/22/21/8389RF resonatorbiosensormicrowave sensingblood flow sensorhemodynamicswearable sensor |
| spellingShingle | Noor Mohammed Kim Cluff Mark Sutton Bernardo Villafana-Ibarra Benjamin E. Loflin Jacob L. Griffith Ryan Becker Subash Bhandari Fayez Alruwaili Jaydip Desai A Flexible Near-Field Biosensor for Multisite Arterial Blood Flow Detection Sensors RF resonator biosensor microwave sensing blood flow sensor hemodynamics wearable sensor |
| title | A Flexible Near-Field Biosensor for Multisite Arterial Blood Flow Detection |
| title_full | A Flexible Near-Field Biosensor for Multisite Arterial Blood Flow Detection |
| title_fullStr | A Flexible Near-Field Biosensor for Multisite Arterial Blood Flow Detection |
| title_full_unstemmed | A Flexible Near-Field Biosensor for Multisite Arterial Blood Flow Detection |
| title_short | A Flexible Near-Field Biosensor for Multisite Arterial Blood Flow Detection |
| title_sort | flexible near field biosensor for multisite arterial blood flow detection |
| topic | RF resonator biosensor microwave sensing blood flow sensor hemodynamics wearable sensor |
| url | https://www.mdpi.com/1424-8220/22/21/8389 |
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