Tom (Geonho) Park

All Publications

• Fetal monitoring for high-risk pregnancies using a wearable ultrasound patch. Nature biotechnology Park, G., Bian, Y., Huang, H., Zhou, S., Qin, S., Lin, M., Yang, X., Lee, A., Ramkumar, A., Tome, M., Lander, J., Chen, X., Wang, S., Bheemreddy, P., Stanton, L., Sheng, R., Guo, G., Shehada, M., Wang, R., Roa, A., Lu, C., Yue, W., Wu, R. S., Gao, X., Hu, H., Yaghi, A., Liu, M., Impey, L., Collins, S. L., Papageorghiou, A. T., Laurent, L. C., Wear, K. A., Georgieva, A., Xu, S. 2026

  Abstract

  Ultrasonography is widely used for fetal monitoring but it requires sonographers and is limited to snapshot evaluations at discrete intervals. Here we report a wearable ultrasound patch (UPatch) for continuous and autonomous fetal monitoring. The UPatch can acquire anatomical structures and blood flow velocities, demonstrating good agreement with a handheld clinical ultrasound device on 62 pregnancies. Real-time image segmentation allows autonomous tracking of target vessels to acquire continuous blood flow spectra during fetal and maternal movements without a sonographer. Continuous monitoring data from 52 pregnant women aligned with stratified perinatal conditions, including healthy, small for gestational age, large for gestational age, gestational diabetes, preeclampsia and gestational hypertension. With further technology development, integration with a miniaturized circuit could enable fully wireless operation and greater user mobility. The UPatch could provide continuous assessment of fetal compromise in high-risk pregnancies, expanding prenatal-care capabilities.

  View details for DOI 10.1038/s41587-026-03140-1

  View details for PubMedID 42191988

• Wearable ultrasound technology NATURE REVIEWS BIOENGINEERING Zhou, S., Park, G., Lin, M., Yang, X., Xu, S. 2025; 3 (10): 835-854

  View details for DOI 10.1038/s44222-025-00329-y

  View details for Web of Science ID 001529116200001

• Integration of chemical and physical inputs for monitoring metabolites and cardiac signals in diabetes. Nature biomedical engineering Chang, A. Y., Lin, M., Yin, L., Reynoso, M., Ding, S., Liu, R., Dugas, Y., Casanova, A., Park, G., Li, Z., Luan, H., Askarinam, N., Zhang, F., Xu, S., Wang, J. 2025

  Abstract

  The development of closed-loop systems towards effective management of diabetes requires the inclusion of additional chemical and physical inputs that affect disease pathophysiology and reflect cardiovascular risks in patients. Comprehensive glycaemic control information should account for more than a single glucose signal. Here, we describe a hybrid flexible wristband sensing platform that integrates a microneedle array for multiplexed biomarker sensing and an ultrasonic array for blood pressure, arterial stiffness and heart-rate monitoring. The integrated system provides a continuous evaluation of the metabolic and cardiovascular status towards improving glycaemic control and alerting patients to cardiovascular risks. The multimodal platform offers continuous glucose, lactate and alcohol monitoring, along with simultaneous ultrasonic measurements of blood pressure, arterial stiffness and heart rate, to support understanding of the interplay between interstitial fluid biomarkers and physiological parameters during common activities. By expanding the continuous monitoring of patients with diabetes to additional biomarkers and key cardiac signals, our integrated multiplexed chemical-physical health-monitoring platform holds promise for addressing the limitations of existing single-modality glucose-monitoring systems towards enhanced management of diabetes and related cardiovascular risks.

  View details for DOI 10.1038/s41551-025-01439-z

  View details for PubMedID 40603746

  View details for PubMedCentralID 8126822

• Clinical validation of a wearable ultrasound sensor of blood pressure. Nature biomedical engineering Zhou, S., Park, G., Longardner, K., Lin, M., Qi, B., Yang, X., Gao, X., Huang, H., Chen, X., Bian, Y., Hu, H., Wu, R. S., Yue, W., Li, M., Lu, C., Wang, R., Qin, S., Tasali, E., Karrison, T., Thomas, I., Smarr, B., Kistler, E. B., Khiami, B. A., Litvan, I., Xu, S. 2025; 9 (6): 865-881

  Abstract

  Options for the continuous and non-invasive monitoring of blood pressure are limited. Cuff-based sphygmomanometers are widely available, yet provide only discrete measurements. The clinical gold-standard approach for the continuous monitoring of blood pressure requires an arterial line, which is too invasive for routine use. Wearable ultrasound for the continuous and non-invasive monitoring of blood pressure promises to elevate the quality of patient care, yet the isolated sonographic windows in the most advanced prototypes can lead to inaccurate or error-prone measurements, and the safety and performance of these devices have not been thoroughly evaluated. Here we describe validation studies, conducted during daily activities at home, in the outpatient clinic, in the cardiac catheterization laboratory and in the intensive care unit, of the safety and performance of a wearable ultrasound sensor for blood pressure monitoring. The sensor has closely connected sonographic windows and a backing layer that improves the sensor's accuracy and reliability to meet the highest requirements of clinical standards. The validation results support the clinical use of the sensor.

  View details for DOI 10.1038/s41551-024-01279-3

  View details for PubMedID 39567702

  View details for PubMedCentralID 137445

• A wearable echomyography system based on a single transducer. Nature electronics Gao, X., Chen, X., Lin, M., Yue, W., Hu, H., Qin, S., Zhang, F., Lou, Z., Yin, L., Huang, H., Zhou, S., Bian, Y., Yang, X., Zhu, Y., Mu, J., Wang, X., Park, G., Lu, C., Wang, R., Wu, R. S., Wang, J., Li, J., Xu, S. 2024; 7 (11): 1035-1046

  Abstract

  Wearable electromyography devices can detect muscular activity for health monitoring and body motion tracking, but this approach is limited by weak and stochastic signals with a low spatial resolution. Alternatively, echomyography can detect muscle movement using ultrasound waves, but typically relies on complex transducer arrays, which are bulky, have high power consumption and can limit user mobility. Here we report a fully integrated wearable echomyography system that consists of a customized single transducer, a wireless circuit for data processing and an on-board battery for power. The system can be attached to the skin and provides accurate long-term wireless monitoring of muscles. To illustrate its capabilities, we use this system to detect the activity of the diaphragm, which allows the recognition of different breathing modes. We also develop a deep learning algorithm to correlate the single-transducer radio-frequency data from forearm muscles with hand gestures to accurately and continuously track 13 hand joints with a mean error of only 7.9°.

  View details for DOI 10.1038/s41928-024-01271-4

  View details for PubMedID 40677283

  View details for PubMedCentralID PMC12269893

• A Pressure-Sensitive, Repositionable Bioadhesive for Instant, Atraumatic Surgical Application on Internal Organs. Advanced materials (Deerfield Beach, Fla.) Nam, K. S., Kim, Y., Park, G., Hwang, K., Kim, M., Chong, J., Jeon, J., Yang, C., Lu, Y. H., Paniccia, C., Choi, J., Kim, D. G., Lee, H., Oh, S. W., Kim, S., Rhyu, J. W., Kang, J., Hyun, J. K., Karp, J. M., Lee, Y., Yuk, H., Park, S. 2024: e2407116

  Abstract

  Pressure-sensitive adhesives are widely utilized due to their instant and reversible adhesion to various dry substrates. Though offering intuitive and robust attachment of medical devices on skin, currently available clinical pressure-sensitive adhesives do not attach to internal organs, mainly due to the presence of interfacial water on the tissue surface that acts as a barrier to adhesion. In this work, a pressure-sensitive, repositionable bioadhesive (PSB) that adheres to internal organs by synergistically combining the characteristic viscoelastic properties of pressure-sensitive adhesives and the interfacial behavior of hydrogel bioadhesives, is introduced. Composed of a viscoelastic copolymer, the PSB absorbs interfacial water to enable instant adhesion on wet internal organs, such as the heart and lungs, and removal after use without causing any tissue damage. The PSB's capabilities in diverse on-demand surgical and analytical scenarios including tissue stabilization of soft organs and the integration of bioelectronic devices in rat and porcine models, are demonstrated.

  View details for DOI 10.1002/adma.202407116

  View details for PubMedID 39148184

• Transcranial volumetric imaging using a conformal ultrasound patch. Nature Zhou, S., Gao, X., Park, G., Yang, X., Qi, B., Lin, M., Huang, H., Bian, Y., Hu, H., Chen, X., Wu, R. S., Liu, B., Yue, W., Lu, C., Wang, R., Bheemreddy, P., Qin, S., Lam, A., Wear, K. A., Andre, M., Kistler, E. B., Newell, D. W., Xu, S. 2024; 629 (8013): 810-818

  Abstract

  Accurate and continuous monitoring of cerebral blood flow is valuable for clinical neurocritical care and fundamental neurovascular research. Transcranial Doppler (TCD) ultrasonography is a widely used non-invasive method for evaluating cerebral blood flow1, but the conventional rigid design severely limits the measurement accuracy of the complex three-dimensional (3D) vascular networks and the practicality for prolonged recording2. Here we report a conformal ultrasound patch for hands-free volumetric imaging and continuous monitoring of cerebral blood flow. The 2 MHz ultrasound waves reduce the attenuation and phase aberration caused by the skull, and the copper mesh shielding layer provides conformal contact to the skin while improving the signal-to-noise ratio by 5 dB. Ultrafast ultrasound imaging based on diverging waves can accurately render the circle of Willis in 3D and minimize human errors during examinations. Focused ultrasound waves allow the recording of blood flow spectra at selected locations continuously. The high accuracy of the conformal ultrasound patch was confirmed in comparison with a conventional TCD probe on 36 participants, showing a mean difference and standard deviation of difference as -1.51 ± 4.34 cm s-1, -0.84 ± 3.06 cm s-1 and -0.50 ± 2.55 cm s-1 for peak systolic velocity, mean flow velocity, and end diastolic velocity, respectively. The measurement success rate was 70.6%, compared with 75.3% for a conventional TCD probe. Furthermore, we demonstrate continuous blood flow spectra during different interventions and identify cascades of intracranial B waves during drowsiness within 4 h of recording.

  View details for DOI 10.1038/s41586-024-07381-5

  View details for PubMedID 38778234

  View details for PubMedCentralID PMC11875229

• Thermally Drawn Multi-material Fibers Based on Polymer Nanocomposite for Continuous Temperature Sensing ADVANCED FIBER MATERIALS Ryu, W., Lee, Y., Son, Y., Park, G., Park, S. 2023; 5 (5): 1712-1724

  View details for DOI 10.1007/s42765-023-00306-3

  View details for Web of Science ID 001007472500001

• A fully integrated wearable ultrasound system to monitor deep tissues in moving subjects. Nature biotechnology Lin, M., Zhang, Z., Gao, X., Bian, Y., Wu, R. S., Park, G., Lou, Z., Zhang, Z., Xu, X., Chen, X., Kang, A., Yang, X., Yue, W., Yin, L., Wang, C., Qi, B., Zhou, S., Hu, H., Huang, H., Li, M., Gu, Y., Mu, J., Yang, A., Yaghi, A., Chen, Y., Lei, Y., Lu, C., Wang, R., Wang, J., Xiang, S., Kistler, E. B., Vasconcelos, N., Xu, S. 2023

  Abstract

  Recent advances in wearable ultrasound technologies have demonstrated the potential for hands-free data acquisition, but technical barriers remain as these probes require wire connections, can lose track of moving targets and create data-interpretation challenges. Here we report a fully integrated autonomous wearable ultrasonic-system-on-patch (USoP). A miniaturized flexible control circuit is designed to interface with an ultrasound transducer array for signal pre-conditioning and wireless data communication. Machine learning is used to track moving tissue targets and assist the data interpretation. We demonstrate that the USoP allows continuous tracking of physiological signals from tissues as deep as 164mm. On mobile subjects, the USoP can continuously monitor physiological signals, including central blood pressure, heart rate and cardiac output, for as long as 12h. This result enables continuous autonomous surveillance of deep tissue signals toward the internet-of-medical-things.

  View details for DOI 10.1038/s41587-023-01800-0

  View details for PubMedID 37217752

• A wearable cardiac ultrasound imager. Nature Hu, H., Huang, H., Li, M., Gao, X., Yin, L., Qi, R., Wu, R. S., Chen, X., Ma, Y., Shi, K., Li, C., Maus, T. M., Huang, B., Lu, C., Lin, M., Zhou, S., Lou, Z., Gu, Y., Chen, Y., Lei, Y., Wang, X., Wang, R., Yue, W., Yang, X., Bian, Y., Mu, J., Park, G., Xiang, S., Cai, S., Corey, P. W., Wang, J., Xu, S. 2023; 613 (7945): 667-675

  Abstract

  Continuous imaging of cardiac functions is highly desirable for the assessment of long-term cardiovascular health, detection of acute cardiac dysfunction and clinical management of critically ill or surgical patients1-4. However, conventional non-invasive approaches to image the cardiac function cannot provide continuous measurements owing to device bulkiness5-11, and existing wearable cardiac devices can only capture signals on the skin12-16. Here we report a wearable ultrasonic device for continuous, real-time and direct cardiac function assessment. We introduce innovations in device design and material fabrication that improve the mechanical coupling between the device and human skin, allowing the left ventricle to be examined from different views during motion. We also develop a deep learning model that automatically extracts the left ventricular volume from the continuous image recording, yielding waveforms of key cardiac performance indices such as stroke volume, cardiac output and ejection fraction. This technology enables dynamic wearable monitoring of cardiac performance with substantially improved accuracy in various environments.

  View details for DOI 10.1038/s41586-022-05498-z

  View details for PubMedID 36697864