Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

Wearable blood pressure sensors for cardiovascular monitoring and machine learning algorithms for blood pressure estimation

A Publisher Correction to this article was published on 04 July 2025

This article has been updated

Abstract

With advances in materials science and medical technology, wearable sensors have become crucial tools for the early diagnosis and continuous monitoring of numerous cardiovascular diseases, including arrhythmias, hypertension and coronary artery disease. These devices employ various sensing mechanisms, such as mechanoelectric, optoelectronic, ultrasonic and electrophysiological methods, to measure vital biosignals, including pulse rate, blood pressure and changes in heart rhythm. In this Review, we provide a comprehensive overview of the current state of wearable cardiovascular sensors, focusing particularly on those that measure blood pressure. We explore biosignal sensing principles, discuss blood pressure estimation methods (including machine learning algorithms) and summarize the latest advances in cuffless wearable blood pressure sensors. Finally, we highlight the challenges of and offer insights into potential pathways for the practical application of cuffless wearable blood pressure sensors in the medical field from both technical and clinical perspectives.

Key points

  • Wearable blood pressure (BP) sensors utilize diverse sensing methodologies, including mechanoelectric, optoelectronic, ultrasonic and electrophysiologic technologies, that facilitate continuous cardiovascular monitoring.

  • Various approaches, including pulse wave analysis, pulse wave velocity and arterial wall dynamics, as well as advanced machine learning and deep learning algorithms that build on these methods, are being explored to improve the accuracy of BP estimation in wearable cuffless BP sensors.

  • Cuffless BP sensors still face obstacles in achieving clinical-grade reliability due to issues with sensor calibration, motion artefacts and placement accuracy.

  • Further improvements in sensor materials and system integration are crucial for improving the accuracy and clinical applicability of wearable BP sensors.

  • Comprehensive clinical trials are essential to validate the performance of wearable BP sensors and ensure compliance with established medical standards for broader adoption in health-care settings.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Wearable BP sensors for cardiovascular health care.
Fig. 2: Principles of biosignal data acquisition related to BP.
Fig. 3: Biosignal analysis theories for BP estimation.
Fig. 4: Deep learning algorithms for advanced BP estimation.
Fig. 5: Advances in wearable BP sensors.

Similar content being viewed by others

Change history

References

  1. Lewington, S., Clarke, R., Qizilbash, N., Peto, R. & Collins, R. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet 360, 1903–1913 (2002).

    Article  PubMed  Google Scholar 

  2. Jones, D. W., Appel, L. J., Sheps, S. G., Roccella, E. J. & Lenfant, C. Measuring blood pressure accurately: new and persistent challenges. JAMA 289, 1027–1030 (2003).

    Article  PubMed  Google Scholar 

  3. Malik, R. et al. Relationship between blood pressure and incident cardiovascular disease: linear and nonlinear Mendelian randomization analyses. Hypertension 77, 2004–2013 (2021).

    Article  CAS  PubMed  Google Scholar 

  4. Fuchs, F. D. & Whelton, P. K. High blood pressure and cardiovascular disease. Hypertension 75, 285–292 (2020).

    Article  CAS  PubMed  Google Scholar 

  5. Wu, C. Y. et al. High blood pressure and all-cause and cardiovascular disease mortalities in community-dwelling older adults. Medicine 94, e2160 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  6. Perera, Y., Raitt, J., Poole, K., Metcalfe, D. & Lewinsohn, A. Non-invasive versus arterial pressure monitoring in the pre-hospital critical care environment: a paired comparison of concurrently recorded measurements. Scand. J. Trauma. Resusc. Emerg. Med. 32, 77 (2024).

    Article  PubMed  PubMed Central  Google Scholar 

  7. Bowdle, T. A. Complications of invasive monitoring. Anesthesiol. Clin. North. Am. 20, 333–350 (2002).

    Article  Google Scholar 

  8. Quan, X. et al. Advances in non‐invasive blood pressure monitoring. Sensors 21, 4373 (2021).

    Article  Google Scholar 

  9. Sladen, A. Complications of invasive hemodynamic monitoring in the intensive care unit. Curr. Probl. Surg. 25, 75–145 (1988).

    Article  Google Scholar 

  10. Ramasamy, S. & Balan, A. Wearable sensors for ECG measurement: a review. Sens. Rev. 38, 412–419 (2018).

    Article  Google Scholar 

  11. Yoo, J., Yan, L., Lee, S., Kim, H. & Yoo, H. J. A wearable ECG acquisition system with compact planar-fashionable circuit board-based shirt. IEEE Trans. Inf. Technol. Biomed. 13, 897–902 (2009).

    Article  PubMed  Google Scholar 

  12. Lyu, Q., Gong, S., Yin, J., Dyson, J. M. & Cheng, W. Soft wearable healthcare materials and devices. Adv. Healthc. Mater. 10, e2100577 (2021).

    Article  PubMed  Google Scholar 

  13. Shrivastava, S., Trung, T. Q. & Lee, N. E. Recent progress, challenges, and prospects of fully integrated mobile and wearable point-of-care testing systems for self-testing. Chem. Soc. Rev. 49, 1812–1866 (2020).

    Article  CAS  PubMed  Google Scholar 

  14. James, G. D. & Gerber, L. M. Measuring arterial blood pressure in humans: auscultatory and automatic measurement techniques for human biological field studies. Am. J. Hum. Biol. https://doi.org/10.1002/ajhb.23063 (2018).

  15. Kario, K. Sleep and nocturnal hypertension: genes, environment, and individual profiles. J. Clin. Hypertens. 24, 1263–1265 (2022).

    Article  Google Scholar 

  16. Tomitani, N., Hoshide, S. & Kario, K. Accurate nighttime blood pressure monitoring with less sleep disturbance. Hypertens. Res. 44, 1671–1673 (2021).

    Article  PubMed  Google Scholar 

  17. Kario, K. Nocturnal hypertension new technology and evidence. Hypertension 71, 997–1009 (2018).

    Article  CAS  PubMed  Google Scholar 

  18. Lou, M. et al. Highly wearable, breathable, and washable sensing textile for human motion and pulse monitoring. ACS Appl. Mater. Interfaces 12, 19965–19973 (2020).

    Article  CAS  PubMed  Google Scholar 

  19. Kang, X. et al. A wearable and real-time pulse wave monitoring system based on a flexible compound sensor. Biosensors 12, 133 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Huang, Y. et al. Arteriosclerosis assessment based on single-point fingertip pulse monitoring using a wearable iontronic sensor. Adv. Healthc. Mater. 12, e2301838 (2023).

    Article  PubMed  Google Scholar 

  21. Wang, J. et al. Wearable multichannel pulse condition monitoring system based on flexible pressure sensor arrays. Microsyst. Nanoeng. 8, 16 (2022).

    Article  PubMed  PubMed Central  Google Scholar 

  22. Su, Y. et al. Muscle fibers inspired high-performance piezoelectric textiles for wearable physiological monitoring. Adv. Funct. Mater. 31, 2010962 (2021).

    Article  CAS  Google Scholar 

  23. Kim, K. et al. Highly sensitive and wearable liquid metal-based pressure sensor for health monitoring applications: integration of a 3D-printed microbump array with the microchannel. Adv. Healthc. Mater. 9, e2000313 (2019).

    Article  Google Scholar 

  24. Castaneda, D., Esparza, A., Ghamari, M., Soltanpur, C. & Nazeran, H. A review on wearable photoplethysmography sensors and their potential future applications in health care. Int. J. Biosens. Bioelectron. 4, 195–202 (2018).

    PubMed  PubMed Central  Google Scholar 

  25. Shaltis, P. A., Reisner, A. & Asada, H. H. Wearable, cuff-less PPG-based blood pressure monitor with novel height sensor. Conf. Proc. IEEE Eng. Med. Biol. Soc. 2006, 908–911 (2006).

    Article  PubMed  Google Scholar 

  26. Davies, H. J., Williams, I., Peters, N. S. & Mandic, D. P. In-ear SpO2: a tool for wearable, unobtrusive monitoring of core blood oxygen saturation. Sensors 20, 4879 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Joo, M. G. et al. Reflection-boosted wearable ring-type pulse oximeters for SpO2 measurement with high sensitivity and low power consumption. Biosensors 13, 711 (2023).

    Article  PubMed  PubMed Central  Google Scholar 

  28. Rodriguez-Labra, J. I., Kosik, C., Maddipatla, D., Narakathu, B. B. & Atashbar, M. Z. Development of a PPG sensor array as a wearable device for monitoring cardiovascular metrics. IEEE Sens. J. 21, 26320–26327 (2021).

    Article  CAS  Google Scholar 

  29. Steinberg, S., Huang, A., Ono, Y. & Rajan, S. Continuous artery monitoring using a flexible and wearable single-element ultrasonic sensor. IEEE Instrum. Meas. Mag. 25, 6–11 (2022).

    Article  Google Scholar 

  30. Huang, A., Yoshida, M., Ono, Y. & Rajan, S. Continuous measurement of arterial diameter using wearable and flexible ultrasonic sensor. 2017 IEEE Int. Ultrason. Symp. (IUS) 1–4 (IEEE, 2017).

  31. Peng, C., Chen, M., Sim, H. K., Zhu, Y. & Jiang, X. Noninvasive and nonocclusive blood pressure monitoring via a flexible piezo-composite ultrasonic sensor. IEEE Sens. J. 21, 2642–2650 (2021).

    Article  CAS  Google Scholar 

  32. Almohimeed, I., Agarwal, M. & Ono, Y. Wearable ultrasonic sensor using double-layer PVDF films for monitoring tissue motion. Can. Conf. Electr. Comput. Eng. https://doi.org/10.1109/CCECE.2018.8447859 (2018).

  33. Yin, L. et al. Chest-scale self-compensated epidermal electronics for standard 6-precordial-lead ECG. NPJ Flex. Electron. 6, 29 (2022).

    Article  Google Scholar 

  34. Zhang, S. et al. On-skin ultrathin and stretchable multifunctional sensor for smart healthcare wearables. NPJ Flex. Electron. 6, 11 (2022).

    Article  CAS  Google Scholar 

  35. Han, N. et al. Recent progress of biomaterials-based epidermal electronics for healthcare monitoring and human–machine interaction. Biosensors 13, 393 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Park, C., Chou, P. H., Bai, Y., Matthews, R. & Hibbs, A. An ultra-wearable, wireless, low power ECG monitoring system. Proceedings of the 2006 IEEE Biomedical Circuits and Systems Conference pp 241–244 (IEEE, 2006).

  37. Zhou, Z. B. et al. Wearable continuous blood pressure monitoring devices based on pulse wave transit time and pulse arrival time: a review. Materials 16, 2133 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Konstantinidis, D. et al. Wearable blood pressure measurement devices and new approaches in hypertension management: the digital era. J. Hum. Hypertens. 36, 945–951 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Islam, S. M. S. et al. Wearable cuffless blood pressure monitoring devices: a systematic review and meta-analysis. Eur. Hear. J. Digit. Heal. 3, 323–337 (2022).

    Article  Google Scholar 

  40. Mukkamala, R. et al. Evaluation of the accuracy of cuffless blood pressure measurement devices: challenges and proposals. Hypertension 78, 1161–1167 (2021).

    Article  CAS  PubMed  Google Scholar 

  41. Xu, H. et al. A high-sensitivity near-infrared phototransistor based on an organic bulk heterojunction. Nanoscale 5, 11850–11855 (2013).

    Article  CAS  PubMed  Google Scholar 

  42. He, J. et al. A universal high accuracy wearable pulse monitoring system via high sensitivity and large linearity graphene pressure sensor. Nano Energy 59, 422–433 (2019).

    Article  CAS  Google Scholar 

  43. Kang, S. et al. Highly sensitive pressure sensor based on bioinspired porous structure for real-time tactile sensing. Adv. Electron. Mater. https://doi.org/10.1002/aelm.201670065 (2016).

  44. Li, X. et al. Ultracomfortable hierarchical nanonetwork for highly sensitive pressure sensor. ACS Nano 14, 9605–9612 (2020).

    Article  CAS  PubMed  Google Scholar 

  45. Jian, M. et al. Flexible and highly sensitive pressure sensors based on bionic hierarchical structures. Adv. Funct. Mater. https://doi.org/10.1002/adfm.201606066 (2017).

  46. Barton, C. et al. Evaluation of a machine learning algorithm for up to 48-hour advance prediction of sepsis using six vital signs. Comput. Biol. Med. 109, 79–84 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  47. Gultepe, E. et al. From vital signs to clinical outcomes for patients with sepsis: a machine learning basis for a clinical decision support system. J. Am. Med. Inform. Assoc. 21, 315–325 (2014).

    Article  PubMed  Google Scholar 

  48. Babu, A., Ranpariya, S., Sinha, D. K., Chatterjee, A. & Mandal, D. Deep learning enabled early predicting cardiovascular status using highly sensitive piezoelectric sensor of solution-processable nylon-11. Adv. Mater. Technol. 8, 2202021 (2023).

    Article  CAS  Google Scholar 

  49. Slapni, Č., Ar, G., Mlakar, N. & Luštrek, M. Blood pressure estimation from photoplethysmogram using a spectro-temporal deep neural network. Sensors (Switzerland) 19, 3420 (2019).

    Article  Google Scholar 

  50. Fang, Y. et al. Ambulatory cardiovascular monitoring via a machine-learning-assisted textile triboelectric sensor. Adv. Mater. 33, e2104178 (2021).

    Article  PubMed  PubMed Central  Google Scholar 

  51. El-Hajj, C. & Kyriacou, P. A. A review of machine learning techniques in photoplethysmography for the non-invasive cuff-less measurement of blood pressure. Biomed. Signal. Process. Control. 58, 101870 (2020).

    Article  Google Scholar 

  52. Homayounfar, S. Z. & Andrew, T. L. Wearable sensors for monitoring human motion: a review on mechanisms, materials, and challenges. SLAS Technol. 25, 9–24 (2020).

    Article  PubMed  Google Scholar 

  53. Park, D. Y. et al. Self‐powered real‐time arterial pulse monitoring using ultrathin epidermal piezoelectric sensors. Adv. Mater. https://doi.org/10.1002/adma.201702308 (2017).

  54. Tian, Y., Hu, C., Peng, D. & Zhu, Z. Self-powered intelligent pulse sensor based on triboelectric nanogenerators with AI assistance. Front. Bioeng. Biotechnol. 11, 1236292 (2023).

    Article  PubMed  PubMed Central  Google Scholar 

  55. Zhang, F. et al. A highly accurate flexible sensor system for human blood pressure and heart rate monitoring based on graphene/sponge. RSC Adv. 12, 2391–2398 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  56. Mishra, R. B., El-Atab, N., Hussain, A. M. & Hussain, M. M. Recent progress on flexible capacitive pressure sensors: from design and materials to applications. Adv. Mater. Technol. 6, 2001023 (2021).

    Article  Google Scholar 

  57. Sun, Q. et al. Active matrix electronic skin strain sensor based on piezopotential-powered graphene transistors. Adv. Mater. 27, 3411–3417 (2015).

    Article  CAS  PubMed  Google Scholar 

  58. Dagdeviren, C. et al. Conformable amplified lead zirconate titanate sensors with enhanced piezoelectric response for cutaneous pressure monitoring. Nat. Commun. 5, 4496 (2014).

    Article  CAS  PubMed  Google Scholar 

  59. Chu, Y. et al. Human pulse diagnosis for medical assessments using a wearable piezoelectret sensing system. Adv. Funct. Mater. 28, 1803413 (2018).

    Article  Google Scholar 

  60. Tamura, T., Maeda, Y., Sekine, M. & Yoshida, M. Wearable photoplethysmographic sensors – past and present. Electron 3, 282–302 (2014).

    Article  Google Scholar 

  61. Hu, H. et al. Stretchable ultrasonic transducer arrays for three-dimensional imaging on complex surfaces. Sci. Adv. 4, eaar3979 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  62. Meziane, N., Webster, J. G., Attari, M. & Nimunkar, A. J. Dry electrodes for electrocardiography. Physiol. Meas. 34, R47–R69 (2013).

    Article  CAS  PubMed  Google Scholar 

  63. Donelan, J. M. et al. Biomechanical energy harvesting: generating electricity during walking with minimal user effort. Science 319, 807–810 (2008).

    Article  CAS  PubMed  Google Scholar 

  64. Damjanovic, D. Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics. Rep. Prog. Phys. 61, 1267–1324 (1998).

    Article  CAS  Google Scholar 

  65. Fu, H. & Cohen, R. E. Polarization rotation mechanism for ultrahigh electromechanical response. Nature 403, 281–283 (2000).

    Article  CAS  PubMed  Google Scholar 

  66. Tressler, J. F., Alkoy, S. & Newnham, R. E. Piezoelectric sensors and sensor materials. J. Electroceram. 2, 257–272 (1998).

    Article  CAS  Google Scholar 

  67. Wan, C. & Bowen, C. R. Multiscale-structuring of polyvinylidene fluoride for energy harvesting: the impact of molecular-, micro- and macro-structure. J. Mater. Chem. A 5, 3091–3128 (2017).

    Article  CAS  Google Scholar 

  68. Park, K. II et al. Highly-efficient, flexible piezoelectric PZT thin film nanogenerator on plastic substrates. Adv. Mater. 26, 2514–2520 (2014).

    Article  CAS  PubMed  Google Scholar 

  69. Kabra, H., Deore, H. A. & Patil, P. Review on advanced piezoelectric materials (BaTiO3, PZT). JETIR 6, 950–957 (2019).

    Google Scholar 

  70. Kim, M., Doh, I., Oh, E. & Cho, Y. H. Flexible piezoelectric pressure sensors fabricated from nanocomposites with enhanced dispersion and vapor permeability for precision pulse wave monitoring. ACS Appl. Nano Mater. 6, 22025–22035 (2023).

    Article  CAS  Google Scholar 

  71. Chun, K. Y., Seo, S. & Han, C. S. A wearable all-gel multimodal cutaneous sensor enabling simultaneous single-site monitoring of cardiac-related biophysical signals. Adv. Mater. 34, e2110082 (2022).

    Article  PubMed  Google Scholar 

  72. Yang, T. et al. Hierarchically structured PVDF/ZnO core-shell nanofibers for self-powered physiological monitoring electronics. Nano Energy 72, 104706 (2020).

    Article  Google Scholar 

  73. Tian, G. et al. Hierarchical piezoelectric composites for noninvasive continuous cardiovascular monitoring. Adv. Mater. 36, 2313612 (2024).

    Article  CAS  Google Scholar 

  74. Xiao, X., Chen, G., Libanori, A. & Chen, J. Wearable triboelectric nanogenerators for therapeutics. Trends Chem. 3, 279–290 (2021).

    Article  CAS  Google Scholar 

  75. Wang, Z. L., Chen, J. & Lin, L. Progress in triboelectric nanogenerators as a new energy technology and self-powered sensors. Energy Environ. Sci. 8, 2250–2282 (2015).

    Article  CAS  Google Scholar 

  76. Wang, H. S. et al. Performance-enhanced triboelectric nanogenerator enabled by wafer-scale nanogrates of multistep pattern downscaling. Nano Energy 35, 415–423 (2017).

    Article  CAS  Google Scholar 

  77. Lee, B. Y., Kim, S. U., Kang, S. & Lee, S. D. Transparent and flexible high power triboelectric nanogenerator with metallic nanowire-embedded tribonegative conducting polymer. Nano Energy 53, 152–159 (2018).

    Article  CAS  Google Scholar 

  78. Jeong, C. K. et al. Topographically-designed triboelectric nanogenerator via block copolymer self-assembly. Nano Lett. 14, 7031–7038 (2014).

    Article  CAS  PubMed  Google Scholar 

  79. Kim, D. et al. Direct-laser-patterned friction layer for the output enhancement of a triboelectric nanogenerator. Nano Energy 35, 379–386 (2017).

    Article  CAS  Google Scholar 

  80. Meng, K. et al. Kirigami-inspired pressure sensors for wearable dynamic cardiovascular monitoring. Adv. Mater. 34, e2202478 (2022).

    Article  PubMed  Google Scholar 

  81. Park, H. W. et al. Electron blocking layer-based interfacial design for highly-enhanced triboelectric nanogenerators. Nano Energy 50, 9–15 (2018).

    Article  CAS  Google Scholar 

  82. Chai, B. et al. Conductive interlayer modulated ferroelectric nanocomposites for high performance triboelectric nanogenerator. Nano Energy 91, 106668 (2022).

    Article  CAS  Google Scholar 

  83. Kim, D. W., Lee, J. H., You, I., Kim, J. K. & Jeong, U. Adding a stretchable deep-trap interlayer for high-performance stretchable triboelectric nanogenerators. Nano Energy 50, 192–200 (2018).

    Article  CAS  Google Scholar 

  84. Yu, Y. & Wang, X. Chemical modification of polymer surfaces for advanced triboelectric nanogenerator development. Extrem. Mech. Lett. 9, 514–530 (2016).

    Article  Google Scholar 

  85. Chen, G., Au, C. & Chen, J. Textile triboelectric nanogenerators for wearable pulse wave monitoring. Trends Biotechnol. 39, 1078–1092 (2021).

    Article  CAS  PubMed  Google Scholar 

  86. Dong, K. et al. A stretchable yarn embedded triboelectric nanogenerator as electronic skin for biomechanical energy harvesting and multifunctional pressure sensing. Adv. Mater. 30, e1804944 (2018).

    Article  PubMed  Google Scholar 

  87. Lin, Z. et al. Triboelectric nanogenerator enabled body sensor network for self-powered human heart-rate monitoring. ACS Nano 11, 8830–8837 (2017).

    Article  CAS  PubMed  Google Scholar 

  88. Ouyang, H. et al. Self-powered pulse sensor for antidiastole of cardiovascular disease. Adv. Mater. 29, 1703456 (2017).

    Article  Google Scholar 

  89. Fan, W. et al. Machine-knitted washable sensor array textile for precise epidermal physiological signal monitoring. Sci. Adv. 6, eaay2840 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  90. Yue, Y. et al. 3D hybrid porous Mxene-sponge network and its application in piezoresistive sensor. Nano Energy 50, 79–87 (2018).

    Article  CAS  Google Scholar 

  91. Fiorillo, A. S., Critello, C. D. & Pullano, A. S. Theory, technology and applications of piezoresistive sensors: a review. Sens. Actuat. A Phys. 281, 156–175 (2018).

    Article  CAS  Google Scholar 

  92. Choong, C. L. et al. Highly stretchable resistive pressure sensors using a conductive elastomeric composite on a micropyramid array. Adv. Mater. 26, 3451–3458 (2014).

    Article  CAS  PubMed  Google Scholar 

  93. Fang, X. et al. High‐performance MXene‐based flexible and wearable pressure sensor based on a micro‐pyramid structured active layer. Adv. Mater. Technol. 8, 2200291 (2023).

    Article  CAS  Google Scholar 

  94. Pang, C. et al. A flexible and highly sensitive strain-gauge sensor using reversible interlocking of nanofibres. Nat. Mater. 11, 795–801 (2012).

    Article  CAS  PubMed  Google Scholar 

  95. Pan, L. et al. An ultra-sensitive resistive pressure sensor based on hollow-sphere microstructure induced elasticity in conducting polymer film. Nat. Commun. 5, 3002 (2014).

    Article  PubMed  Google Scholar 

  96. Bijender, N. et al. Noninvasive blood pressure monitoring via a flexible and wearable piezoresistive sensor. ACS Omega 9, 6355–6365 (2024).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  97. Yao, H. et al. A flexible and highly pressure‐sensitive graphene–polyurethane sponge based on fractured microstructure design. Adv. Mater. 25, 6692–6698 (2013).

    Article  CAS  PubMed  Google Scholar 

  98. Liu, C. et al. High-performance piezoresistive flexible pressure sensor based on wrinkled microstructures prepared from discarded vinyl records and ultra-thin, transparent polyaniline films for human health monitoring. J. Mater. Chem. C. 10, 13064–13073 (2022).

    Article  CAS  Google Scholar 

  99. Luo, R. et al. Fragmented graphene aerogel/polydimethylsiloxane sponges for wearable piezoresistive pressure sensors. ACS Appl. Nano Mater. 6, 7065–7076 (2023).

    Article  CAS  Google Scholar 

  100. Xu, H. et al. Flexible waterproof piezoresistive pressure sensors with wide linear working range based on conductive fabrics. Nanomicro Lett. 12, 159 (2020).

    PubMed  PubMed Central  Google Scholar 

  101. Zheng, Y. et al. Conductive MXene/cotton fabric based pressure sensor with both high sensitivity and wide sensing range for human motion detection and E-skin. Chem. Eng. J. 420, 127720 (2021).

    Article  CAS  Google Scholar 

  102. Ding, X. et al. Highly accurate wearable piezoresistive sensors without tension disturbance based on weaved conductive yarn. ACS Appl. Mater. Interfaces 12, 35638–35646 (2020).

    Article  CAS  PubMed  Google Scholar 

  103. Yang, X., Wang, Y. & Qing, X. A flexible capacitive pressure sensor based on ionic liquid. Sensors 18, 2395 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  104. Zhang, Z. et al. Highly sensitive capacitive pressure sensor based on a micropyramid array for health and motion monitoring. Adv. Electron. Mater. 7, 2100174 (2021).

    Article  CAS  Google Scholar 

  105. Yang, J. C. et al. Microstructured porous pyramid-based ultrahigh sensitive pressure sensor insensitive to strain and temperature. ACS Appl. Mater. Interfaces 11, 19472–19480 (2019).

    Article  CAS  PubMed  Google Scholar 

  106. Ruth, S. R. A. et al. Rational design of capacitive pressure sensors based on pyramidal microstructures for specialized monitoring of biosignals. Adv. Funct. Mater. 30, 1903100 (2020).

    Article  CAS  Google Scholar 

  107. Ruth, S. R. A., Feig, V. R., Tran, H. & Bao, Z. Microengineering pressure sensor active layers for improved performance. Adv. Funct. Mater. 30, 2003491 (2020).

    Article  CAS  Google Scholar 

  108. Kim, J. O. et al. Highly ordered 3D microstructure-based electronic skin capable of differentiating pressure, temperature, and proximity. ACS Appl. Mater. Interfaces 11, 1503–1511 (2019).

    Article  CAS  PubMed  Google Scholar 

  109. Wei, P., Guo, X., Qiu, X. & Yu, D. Flexible capacitive pressure sensor with sensitivity and linear measuring range enhanced based on porous composite of carbon conductive paste and polydimethylsiloxane. Nanotechnology 30, 455501 (2019).

    Article  CAS  PubMed  Google Scholar 

  110. Wang, S. et al. High sensitivity capacitive flexible pressure sensor based on PDMS double wrinkled microstructure. J. Mater. Sci. Mater. Electron. 35, 78 (2024).

    Article  CAS  Google Scholar 

  111. Joo, Y. et al. Silver nanowire-embedded PDMS with a multiscale structure for a highly sensitive and robust flexible pressure sensor. Nanoscale 7, 6208–6215 (2015).

    Article  CAS  PubMed  Google Scholar 

  112. Bisri, S. Z., Shimizu, S., Nakano, M. & Iwasa, Y. Endeavor of iontronics: from fundamentals to applications of ion‐controlled electronics. Adv. Mater. https://doi.org/10.1002/adma.201607054 (2017).

  113. Liu, Q. et al. Highly transparent and flexible iontronic pressure sensors based on an opaque to transparent transition. Adv. Sci. https://doi.org/10.1002/advs.202000348 (2020).

  114. Bai, N. et al. Graded intrafillable architecture-based iontronic pressure sensor with ultra-broad-range high sensitivity. Nat. Commun. 11, 209 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  115. Lee, G. H. et al. Multifunctional materials for implantable and wearable photonic healthcare devices. Nat. Rev. Mater. 5, 149–165 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  116. Kim, K. B. & Baek, H. J. Photoplethysmography in wearable devices: a comprehensive review of technological advances, current challenges, and future directions. Electronics 12, 2923 (2023).

    Article  CAS  Google Scholar 

  117. Tamura, T. Current progress of photoplethysmography and SPO2 for health monitoring. Biomed. Eng. Lett. 9, 21–36 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  118. Lee, I. et al. Systematic review on human skin-compatible wearable photoplethysmography sensors. Appl. Sci. 11, 2313 (2021).

    Article  CAS  Google Scholar 

  119. Lee, H. et al. Toward all-day wearable health monitoring: an ultralow-power, reflective organic pulse oximetry sensing patch. Sci. Adv. 4, eaas9530 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  120. Khan, Y. et al. A flexible organic reflectance oximeter array. Proc. Natl Acad. Sci. USA 115, E11015–E11024 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  121. Lochner, C. M., Khan, Y., Pierre, A. & Arias, A. C. All-organic optoelectronic sensor for pulse oximetry. Nat. Commun. 5, 5745 (2014).

    Article  CAS  PubMed  Google Scholar 

  122. Yokota, T. et al. Ultraflexible organic photonic skin. Sci. Adv. 2, e1501856 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  123. Han, D. et al. Flexible blade-coated multicolor polymer light-emitting diodes for optoelectronic sensors. Adv. Mater. 29, 1606206 (2017).

    Article  Google Scholar 

  124. Jinno, H. et al. Self-powered ultraflexible photonic skin for continuous bio-signal detection via air-operation-stable polymer light-emitting diodes. Nat. Commun. 12, 2234 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  125. Xu, H. et al. Flexible organic/inorganic hybrid near‐infrared photoplethysmogram sensor for cardiovascular monitoring. Adv. Mater. https://doi.org/10.1002/adma.201700975 (2017).

  126. Bent, B., Goldstein, B. A., Kibbe, W. A. & Dunn, J. P. Investigating sources of inaccuracy in wearable optical heart rate sensors. NPJ Digit. Med. 3, 18 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  127. Maeda, Y., Sekine, M. & Tamura, T. Relationship between measurement site and motion artifacts in wearable reflected photoplethysmography. J. Med. Syst. 35, 969–976 (2011).

    Article  PubMed  Google Scholar 

  128. D’Orazio, J., Jarrett, S., Amaro-Ortiz, A. & Scott, T. UV radiation and the skin. Int. J. Mol. Sci. 14, 12222–12248 (2013).

    Article  PubMed  PubMed Central  Google Scholar 

  129. Boonya-ananta, T. et al. Synthetic photoplethysmography (PPG) of the radial artery through parallelized Monte Carlo and its correlation to body mass index (BMI). Sci. Rep. 11, 2570 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  130. Kim, J., Lee, T., Kim, J. & Ko, H. Ambient light cancellation in photoplethysmogram application using alternating sampling and charge redistribution technique. Annu. Int. Conf. IEEE Eng. Med. Biol. Soc. 2015, 6441–6444 (2015).

    PubMed  Google Scholar 

  131. Allen, J., Frame, J. R. & Murray, A. Microvascular blood flow and skin temperature changes in the fingers following a deep inspiratory gasp. Physiol. Meas. 23, 365–373 (2002).

    Article  PubMed  Google Scholar 

  132. Chong, J. W. et al. Photoplethysmograph signal reconstruction based on a novel hybrid motion artifact detection–reduction approach. Part I: motion and noise artifact detection. Ann. Biomed. Eng. 42, 2238–2250 (2014).

    Article  PubMed  Google Scholar 

  133. Charlton, P. H. et al. An assessment of algorithms to estimate respiratory rate from the electrocardiogram and photoplethysmogram. Physiol. Meas. 37, 610–626 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  134. Franklin, D. et al. Synchronized wearables for the detection of haemodynamic states via electrocardiography and multispectral photoplethysmography. Nat. Biomed. Eng. 7, 1229–1241 (2023).

    Article  PubMed  PubMed Central  Google Scholar 

  135. Khan, E., Al Hossain, F., Uddin, S. Z., Alam, S. K. & Hasan, M. K. A robust heart rate monitoring scheme using photoplethysmographic signals corrupted by intense motion artifacts. IEEE Trans. Biomed. Eng. 63, 550–562 (2016).

    Article  PubMed  Google Scholar 

  136. Lee, H., Chung, H., Kim, J. W. & Lee, J. Motion artifact identification and removal from wearable reflectance photoplethysmography using piezoelectric transducer. IEEE Sens. J. 19, 3861–3870 (2019).

    Article  Google Scholar 

  137. Wang, C. et al. Continuous monitoring of deep-tissue haemodynamics with stretchable ultrasonic phased arrays. Nat. Biomed. Eng. 5, 749–758 (2021).

    Article  CAS  PubMed  Google Scholar 

  138. Pang, D. C. & Chang, C. M. Development of a novel transparent flexible capacitive micromachined ultrasonic transducer. Sensors 17, 1443 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  139. Kruizinga, P. et al. Compressive 3D ultrasound imaging using a single sensor. Sci. Adv. 3, e170143 (2017).

    Article  Google Scholar 

  140. Lin, M., Hu, H., Zhou, S. & Xu, S. Soft wearable devices for deep-tissue sensing. Nat. Rev. Mater. 7, 850–869 (2022).

    Article  Google Scholar 

  141. Wang, C. C. et al. Monitoring of the central blood pressure waveform via a conformal ultrasonic device. Nat. Biomed. Eng. 2, 687–695 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  142. Lin, M. et al. A fully integrated wearable ultrasound system to monitor deep tissues in moving subjects. Nat. Biotechnol. 42, 448–457 (2024).

    Article  CAS  PubMed  Google Scholar 

  143. Hu, H. et al. A wearable cardiac ultrasound imager. Nature 613, 667–675 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  144. Sempionatto, J. R. et al. An epidermal patch for the simultaneous monitoring of haemodynamic and metabolic biomarkers. Nat. Biomed. Eng. 5, 737–748 (2021).

    Article  CAS  PubMed  Google Scholar 

  145. Hu, H. et al. Stretchable ultrasonic arrays for the three-dimensional mapping of the modulus of deep tissue. Nat. Biomed. Eng. 7, 1321–1334 (2023).

    Article  PubMed  Google Scholar 

  146. Gao, X. et al. A photoacoustic patch for three-dimensional imaging of hemoglobin and core temperature. Nat. Commun. 13, 7757 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  147. Padala, S. K., Cabrera, J. A. & Ellenbogen, K. A. Anatomy of the cardiac conduction system. Pacing Clin. Electrophysiol. 44, 15–25 (2021).

    Article  PubMed  Google Scholar 

  148. Becker, D. E. Fundamentals of electrocardiography interpretation. Anesth. Prog. 53, 53–64 (2006).

    Article  PubMed  PubMed Central  Google Scholar 

  149. Veeraraghavan, R., Gourdie, R. G. & Poelzing, S. Mechanisms of cardiac conduction: a history of revisions. Am. J. Physiol. Heart Circ. Physiol. 306, H619–H627 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  150. Martis, R. J., Acharya, U. R. & Adeli, H. Current methods in electrocardiogram characterization. Comput. Biol. Med. 48, 133–149 (2014).

    Article  PubMed  Google Scholar 

  151. Homsy, J. & Podrid, P. J. in MGH Cardiology Board Review (eds Gaggin, H. & Januzzi, J., Jr.) 580–622 (Springer, 2014).

  152. AlGhatrif, M. & Lindsay, J. A brief review: history to understand fundamentals of electrocardiography. J. Community Hosp. Intern. Med. Perspect. 2, 14383 (2012).

    Article  Google Scholar 

  153. Lujan, M. R., Perez-Pozuelo, I. & Grandner, M. A. Past, present, and future of multisensory wearable technology to monitor sleep and circadian rhythms. Front. Digit. Heal. 3, 721919 (2021).

    Article  Google Scholar 

  154. Searle, A. & Kirkup, L. A direct comparison of wet, dry and insulating bioelectric recording electrodes. Physiol. Meas. 21, 271–283 (2000).

    Article  CAS  PubMed  Google Scholar 

  155. Lim, C. et al. Tissue-like skin-device interface for wearable bioelectronics by using ultrasoft, mass-permeable, and low-impedance hydrogels. Sci. Adv. 7, eabd6716 (2021).

    Article  Google Scholar 

  156. Ha, M., Lim, S. & Ko, H. Wearable and flexible sensors for user-interactive health-monitoring devices. J. Mater. Chem. B 6, 4043–4064 (2018).

    Article  CAS  PubMed  Google Scholar 

  157. Gao, W., Ota, H., Kiriya, D., Takei, K. & Javey, A. Flexible electronics toward wearable sensing. Acc. Chem. Res. 52, 523–533 (2019).

    Article  CAS  PubMed  Google Scholar 

  158. Ling, Y. et al. Disruptive, soft, wearable sensors. Adv. Mater. 32, e1904664 (2020).

    Article  PubMed  Google Scholar 

  159. Ma, Z. et al. Permeable superelastic liquid-metal fibre mat enables biocompatible and monolithic stretchable electronics. Nat. Mater. 20, 859–868 (2021).

    Article  CAS  PubMed  Google Scholar 

  160. Son, D. et al. An integrated self-healable electronic skin system fabricated via dynamic reconstruction of a nanostructured conducting network. Nat. Nanotechnol. 13, 1057–1065 (2018).

    Article  CAS  PubMed  Google Scholar 

  161. Zhang, L. et al. Fully organic compliant dry electrodes self-adhesive to skin for long-term motion-robust epidermal biopotential monitoring. Nat. Commun. 11, 4683 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  162. Chen, X. et al. Fabric-substrated capacitive biopotential sensors enhanced by dielectric nanoparticles. Nano Res. 14, 3248–3252 (2021).

    Article  CAS  Google Scholar 

  163. Jeong, J. W. et al. Capacitive epidermal electronics for electrically safe, long-term electrophysiological measurements. Adv. Healthc. Mater. 3, 642–648 (2014).

    Article  CAS  PubMed  Google Scholar 

  164. Liu, J., Hahn, J. O. & Mukkamala, R. Error mechanisms of the oscillometric fixed-ratio blood pressure measurement method. Ann. Biomed. Eng. 41, 587–597 (2013).

    Article  PubMed  Google Scholar 

  165. Colquhoun, D., Dunn, L. K., McMurry, T. & Thiele, R. H. The relationship between the area of peripherally-derived pressure volume loops and systemic vascular resistance. J. Clin. Monit. Comput. 27, 689–696 (2013).

    Article  PubMed  Google Scholar 

  166. Kwon, H. M. et al. Estimation of stroke volume variance from arterial blood pressure: using a 1-D convolutional neural network. Sensors 21, 5130 (2021).

    Article  PubMed  PubMed Central  Google Scholar 

  167. Solà, J. & Delgado-Gonzalo, R. The Handbook of Cuffless Blood Pressure Monitoring: A Guide for Clinicians, Researchers, and Engineers (Springer, 2019).

  168. Wołos, K. et al. Non-invasive assessment of stroke volume and cardiovascular parameters based on peripheral pressure waveform. PLoS Comput. Biol. 20, e1012013 (2024).

    Article  PubMed  PubMed Central  Google Scholar 

  169. Kim, J. et al. Soft wearable pressure sensors for beat-to-beat blood pressure monitoring. Adv. Healthc. Mater. 8, e1900109 (2019).

    Article  PubMed  Google Scholar 

  170. Li, S. et al. Monitoring blood pressure and cardiac function without positioning via a deep learning–assisted strain sensor array. Sci. Adv. 9, eadh0615 (2023).

    Article  PubMed  PubMed Central  Google Scholar 

  171. Yi, Z. et al. Piezoelectric dynamics of arterial pulse for wearable continuous blood pressure monitoring. Adv. Mater. 34, e2110291 (2022).

    Article  PubMed  Google Scholar 

  172. Yao, Y. et al. Estimation of central pulse wave velocity from radial pulse wave analysis. Comput. Methods Prog. Biomed. 219, 106781 (2022).

    Article  Google Scholar 

  173. Mishra, B. & Thakkar, N. Cuffless blood pressure monitoring using PTT and PWV methods. Proceedings of the 2017 International Conference on Recent Innovations in Signal Processing and Embedded Systems pp 395–401 (IEEE, 2017).

  174. Ma, Y. et al. Relation between blood pressure and pulse wave velocity for human arteries. Proc. Natl Acad. Sci. USA 115, 11144–11149 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  175. Chung, H. U. et al. Skin-interfaced biosensors for advanced wireless physiological monitoring in neonatal and pediatric intensive-care units. Nat. Med. 26, 418–429 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  176. Liu, C. et al. Wireless, skin‐interfaced devices for pediatric critical care: application to continuous, noninvasive blood pressure monitoring. Adv. Healthc. Mater. 10, e2100383 (2021).

    Article  PubMed  Google Scholar 

  177. Yoon, Y. Z. et al. Cuff-less blood pressure estimation using pulse waveform analysis and pulse arrival time. IEEE J. Biomed. Heal. Inform. 22, 1068–1074 (2018).

    Article  Google Scholar 

  178. Zhang, G., Gao, M., Xu, D., Olvier, N. B. & Mukkamala, R. Pulse arrival time is not an adequate surrogate for pulse transit time as a marker of blood pressure. J. Appl. Physiol. 111, 1681–1686 (2011).

    Article  PubMed  Google Scholar 

  179. Carek, A. M., Conant, J., Joshi, A., Kang, H. & Inan, O. T. SeismoWatch: wearable cuffless blood pressure monitoring using pulse transit time. Proc. ACM Interact. Mob. Wearable Ubiquitous Technol. 1, 40 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  180. Li, H. et al. Wearable skin-like optoelectronic systems with suppression of motion artifacts for cuff-less continuous blood pressure monitor. Natl. Sci. Rev. 7, 849–862 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  181. Meng, K. et al. Flexible weaving constructed self‐powered pressure sensor enabling continuous diagnosis of cardiovascular disease and measurement of cuffless blood pressure. Adv. Funct. Mater. 29, 1806388 (2019).

    Article  Google Scholar 

  182. Proença, J., Muehlsteff, J., Aubert, X. & Carvalho, P. Is pulse transit time a good indicator of blood pressure changes during short physical exercise in a young population? Annu. Int. Conf. IEEE Eng. Med. Biol. Soc. 2010, 598–601 (2010).

    PubMed  Google Scholar 

  183. Elgendi, M. et al. The use of photoplethysmography for assessing hypertension. NPJ Digit. Med. 2, 60 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  184. Baier, D., Teren, A., Wirkner, K., Loeffler, M. & Scholz, M. Parameters of pulse wave velocity: determinants and reference values assessed in the population-based study LIFE-Adult. Clin. Res. Cardiol. 107, 1050–1061 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  185. Pereira, T., Correia, C. & Cardoso, J. Novel methods for pulse wave velocity measurement. J. Med. Biol. Eng. 35, 555–565 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  186. Gao, S. C., Wittek, P., Zhao, L. & Jiang, W. J. Data-driven estimation of blood pressure using photoplethysmographic signals. Proceedings of the 2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society pp 766–769 (IEEE, 2016).

  187. He, R. et al. Beat-to-beat ambulatory blood pressure estimation based on random forest. Proceedings of the 2016 IEEE 13th International Conference on Wearable and Implantable Body Sensor Networks (BSN) pp 194–198 (IEEE, 2016).

  188. Suzuki, S. & Oguri, K. Cuffless blood pressure estimation by error-correcting output coding method based on an aggregation of AdaBoost with a photoplethysmograph sensor. Proceedings of the 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society pp 6765–6768 (IEEE, 2009).

  189. Sideris, C., Kalantarian, H., Nemati, E. & Sarrafzadeh, M. Building continuous arterial blood pressure prediction models using recurrent networks. Proceedings of the 2016 IEEE International Conference on Smart Computing (SMARTCOMP) pp 1–5 (IEEE, 2016).

  190. Baek, S., Jang, J. & Yoon, S. End-to-end blood pressure prediction via fully convolutional networks. IEEE Access. 7, 185458–185468 (2019).

    Article  Google Scholar 

  191. Jeong, D. U. & Lim, K. M. Combined deep CNN–LSTM network-based multitasking learning architecture for noninvasive continuous blood pressure estimation using difference in ECG-PPG features. Sci. Rep. 11, 13539 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  192. Ma, C. et al. KD-informer: a cuff-less continuous blood pressure waveform estimation approach based on single photoplethysmography. IEEE J. Biomed. Heal. Inform. 27, 2219–2230 (2023).

    Article  Google Scholar 

  193. Mieloszyk, R. et al. A comparison of wearable tonometry, photoplethysmography, and electrocardiography for cuffless measurement of blood pressure in an ambulatory setting. IEEE J. Biomed. Heal. Inform. 26, 2864–2875 (2022).

    Article  Google Scholar 

  194. Duan, K., Qian, Z., Atef, M. & Wang, G. A feature exploration methodology for learning based cuffless blood pressure measurement using photoplethysmography. Proceedings of the 2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society pp 6385–6388 (IEEE, 2016).

  195. Kachuee, M., Kiani, M. M., Mohammadzade, H. & Shabany, M. Cuffless blood pressure estimation algorithms for continuous health-care monitoring. IEEE Trans. Biomed. Eng. 64, 859–869 (2017).

    Article  PubMed  Google Scholar 

  196. Goli, S. & Jayanthi, T. Cuff less continuous non-invasive blood pressure measurement using pulse transit time measurement. Int. J. Recent. Dev. Eng. Technol. 2, 86–91 (2014).

    Google Scholar 

  197. Mousavi, S. S. et al. Cuff-less blood pressure estimation using only the ECG signal in frequency domain. Proceedings of the 2018 8th International Conference on Computer and Knowledge Engineering (ICCKE) pp 147–152 (IEEE, 2018).

  198. Cattivelli, F. S. & Garudadri, H. Noninvasive cuffless estimation of blood pressure from pulse arrival time and heart rate with adaptive calibration. Proceedings of the 2009 Sixth International Workshop on Wearable and Implantable Body Sensor Networks pp 114–119 (IEEE, 2009).

  199. Zhang, B., Ren, H., Huang, G., Cheng, Y. & Hu, C. Predicting blood pressure from physiological index data using the SVR algorithm 08 information and computing sciences 0801 artificial intelligence and image processing. BMC Bioinforma. 20, 109 (2019).

    Article  Google Scholar 

  200. Yi, C., Jian, C. & Wenqiang, J. Continuous blood pressure measurement based on photoplethysmography. Proceedings of the 2019 14th IEEE International Conference on Electronic Measurement and Instruments (ICEMI) pp 1656–1663 (2019).

  201. Khalid, S. G., Zhang, J., Chen, F. & Zheng, D. Blood pressure estimation using photoplethysmography only: comparison between different machine learning approaches. J. Healthc. Eng. 2018, 1548647 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  202. Krizhevsky, A., Sutskever, I. & Hinton, G. E. ImageNet classification with deep convolutional neural networks. Commun. ACM 60, 84–90 (2017).

    Article  Google Scholar 

  203. Hattiya, T., Dittakan, K. & Musikasuwan, S. Diabetic retinopathy detection using convolutional neural network: a comparative study on different architectures. Eng. Access. 7, 50–60 (2021).

    Google Scholar 

  204. Liu, Z. et al. A ConvNet for the 2020s. Proceedings of the 2022 IEEE/CVF Conference on Computer Vision and Pattern Pattern Recognition pp 11966–11976 (IEEE, 2022).

  205. Woo, S. et al. ConvNeXt V2: co-designing and scaling ConvNets with masked autoencoders. Proceedings of the 2023 IEEE/CVF Conference on Computer Vision and Pattern Recognition pp 16133–16142 (IEEE, 2023).

  206. Dosovitskiy, A. et al. An image Is worth 16×16 words: transformers for image recognition at scale. ICLR 2021 — 9th Int. Conf. Learn. Represent. (ICLR, 2021).

  207. Arnab, A. et al. ViViT: a video vision transformer. Proceedings of the IEEE/CVF International Conference on Compute Vision (ICCV) pp 6816–6826 (IEEE, 2021).

  208. Radford, A. Improving language understanding by generative pre-training. Homol. Homotopy Appl. 9, 399–438 (2018).

    Google Scholar 

  209. Raffel, C. et al. Exploring the limits of transfer learning with a unified text-to-text transformer. J. Mach. Learn. Res. 21, 1–67 (2020).

    Google Scholar 

  210. OpenAI. GPT-4 technical report. Preprint at arXiv http://arxiv.org/pdf/2303.08774 (2023).

  211. Devlin, J., Chang, M. W., Lee, K. & Toutanova, K. in Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies Vol. 1 (eds Burstein, J., Doran, C. & Solorio, T.) 4171–4186 (Association for Computational Linguistics, 2019).

  212. Abdel-hamid, O. et al. Convolutional neural networks for speech recognition. IEEE/ACM Trans. Audio Speech Lang. Process. 22, 1533–1545 (2014).

    Article  Google Scholar 

  213. Sainath, T. N. et al. Deep convolutional neural networks for large-scale speech tasks. Neural Netw. 64, 39–48 (2015).

    Article  PubMed  Google Scholar 

  214. Dong, L., Xu, S. & Xu, B. Speech-transformer: a no-recurrence sequence-to-sequence model for speech recognition. Proceedings of the IEEE International Conference on Acoustics Speech and Signal Processing (ICASSP) pp 5884–5888 (IEEE, 2018).

  215. Baldi, P. Autoencoders, unsupervised learning, and deep architectures. PMLR 27, 37–49 (2012).

    Google Scholar 

  216. Li, X., Wu, S. & Wang, L. Blood pressure prediction via recurrent models with contextual layer. WWW'17: Proceedings of the 26th International Conference on World Wide Web pp 685–693 (International World Wide Web Conferences, 2017).

  217. Li, Y. H., Harfiya, L. N., Purwandari, K. & Lin, Y. D. Real-time cuffless continuous blood pressure estimation using deep learning model. Sensors 20, 1–19 (2020).

    Google Scholar 

  218. Hochreiter, S. & Schmidhuber, J. Long short-term memory. Neural Comput. 9, 1735–1780 (1997).

    Article  CAS  PubMed  Google Scholar 

  219. Hüsken, M. & Stagge, P. Recurrent neural networks for time series classification. Neurocomputing 50, 223–235 (2003).

    Article  Google Scholar 

  220. Su, P. et al. Long-term blood pressure prediction with deep recurrent neural networks. Proceedings of the 2018 IEEE EMBS International Conference on Biomedical and Health Informatics pp 323–328 (IEEE, 2018).

  221. Mao, S. & Sejdic, E. A review of recurrent neural network-based methods in computational physiology. IEEE Trans. Neural Netw. Learn. Syst. 34, 6983–7003 (2023).

    Article  PubMed  PubMed Central  Google Scholar 

  222. Senturk, U., Yucedag, I. & Polat, K. Repetitive neural network (RNN) based blood pressure estimation using PPG and ECG signals. Proceedings of the 2018 2nd International Symposium on Multidisciplinary Studies and Innovative Technologies (ISMSIT) pp 1–4 (2018).

  223. Park, S. R. & Lee, J. W. in Proceedings of the 18th Annual Conference of the International Speech Communication Association: Interspeech 2017 (ed. Lacerda, F.) 1993–1997 (ISCA, 2017).

  224. Shimazaki, S., Kawanaka, H., Ishikawa, H., Inoue, K. & Oguri, K. Cuffless blood pressure estimation from only the waveform of photoplethysmography using CNN. Proceedings of the 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) pp 5042–5045 (IEEE, 2019).

  225. Eom, H. et al. End-to-end deep learning architecture for continuous blood pressure estimation using attention mechanism. Sensors 20, 2338 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  226. Esmaelpoor, J., Hassan, M. & Kadkhodamohammadi, A. A multistage deep neural network model for blood pressure estimation using photoplethysmogram signals. Comput. Biol. Med. 120, 103719 (2020).

    Article  PubMed  Google Scholar 

  227. Shi, Y., Yuan, W., Hu, S. & Lou, Y. Convolutional quasi-recurrent network for real-time speech enhancement. J. Xidian Univ. 49, 183–190 (2022).

    Google Scholar 

  228. Zihlmann, M., Perekrestenko, D. & Tschannen, M. Convolutional recurrent neural networks for electrocardiogram classification. Comput. Cardiol. 44, 1–4 (2017).

    Google Scholar 

  229. Keren, G. & Schuller, B. Convolutional RNN: an enhanced model for extracting features from sequential data. Proceedings of the International Joint Conference on Neural Networks (IJCNN) pp 3412–3419 (IEEE, 2016).

  230. Mohiuddin, K. et al. Retention is all you need. CIKM '23: Proceedings of the 32nd ACM International Conference on Information and Knowledge Management.pp 4752–4758 (Association for Computing Machinery, 2023).

  231. Celler, B. G., Le, P. N., Argha, A. & Ambikairajah, E. Blood pressure estimation using time domain features of auscultatory waveforms and GMM-HMM classification approach. Annu. Int. Conf. IEEE Eng. Med. Biol. Soc. 2019, 208–211 (2019).

    PubMed  Google Scholar 

  232. Sadrawi, M. et al. Genetic deep convolutional autoencoder applied for generative continuous arterial blood pressure via photoplethysmography. Sensors 20, 3829 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  233. Taniguchi, H. et al. in Medical Image Computing and Computer-Assisted Intervention – MICCAI 2015 (eds Navab, N., Hornegger, J, Wells, M. W. & Frangi, A. F) 209–217 (Springer, 2015).

  234. Athaya, T. & Choi, S. An estimation method of continuous non-invasive arterial blood pressure waveform using photoplethysmography: a U-net architecture-based approach. Sensors 21, 1867 (2021).

    Article  PubMed  PubMed Central  Google Scholar 

  235. Mahmud, S. et al. A shallow U-net architecture for reliably predicting blood pressure (BP) from photoplethysmogram (PPG) and electrocardiogram (ECG) signals. Sensors 22, 919 (2022).

    Article  PubMed  PubMed Central  Google Scholar 

  236. Mehrabadi, M. A., Aqajari, S. A. H., Zargari, A. H. A., Dutt, N. & Rahmani, A. M. Novel blood pressure waveform reconstruction from photoplethysmography using cycle generative adversarial networks. Annu. Int. Conf. IEEE Eng. Med. Biol. Soc. 2022, 1906–1909 (2022).

    PubMed  Google Scholar 

  237. Min, S. et al. Clinical validation of a wearable piezoelectric blood‐pressure sensor for continuous health monitoring. Adv. Mater. 35, e2301627 (2023).

    Article  PubMed  Google Scholar 

  238. Zhou, S. et al. Clinical validation of a wearable ultrasound sensor of blood pressure. Nat. Biomed. Eng. https://doi.org/10.1038/s41551-024-01279-3 (2024).

  239. Kouz, K., Scheeren, T. W. L., De Backer, D. & Saugel, B. Pulse wave analysis to estimate cardiac output. Anesthesiology 134, 119–126 (2021).

    Article  PubMed  Google Scholar 

  240. Qiu, S., Yan, B. P. Y. & Zhao, N. Stroke-volume-allocation model enabling wearable sensors for vascular age and cardiovascular disease assessment. NPJ Flex. Electron. 8, 24 (2024).

    Article  Google Scholar 

  241. Pollreisz, D. & TaheriNejad, N. Detection and removal of motion artifacts in PPG signals. Mob. Netw. Appl. 27, 728–738 (2022).

    Article  Google Scholar 

  242. Sayer, G. et al. Continuous monitoring of blood pressure using a wrist-worn cuffless device. Am. J. Hypertens. 35, 407–413 (2022).

    Article  PubMed  Google Scholar 

  243. Trudeau, L. Central blood pressure as an index of antihypertensive control: determinants and potential value. Can. J. Cardiol. 30, S23–S28 (2014).

    PubMed  Google Scholar 

  244. Kim, J. S., Kim, D. W., Jung, H. T. & Choi, J. W. Controlled lithium dendrite growth by a synergistic effect of multilayered graphene coating and an electrolyte additive. Chem. Mater. 27, 2780–2787 (2015).

    Article  CAS  Google Scholar 

  245. Deng, R. & He, T. Flexible solid-state lithium-ion batteries: materials and structures. Energies 16, 4549 (2023).

    Article  CAS  Google Scholar 

  246. Gljušćić, P., Zelenika, S., Blažević, D. & Kamenar, E. Kinetic energy harvesting for wearable medical sensors. Sensors 19, 4922 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  247. Mo, X. et al. Piezoelectrets for wearable energy harvesters and sensors. Nano Energy 65, 104033 (2019).

    Article  CAS  Google Scholar 

  248. Zou, Y., Raveendran, V. & Chen, J. Wearable triboelectric nanogenerators for biomechanical energy harvesting. Nano Energy 77, 105303 (2020).

    Article  CAS  Google Scholar 

  249. Nozariasbmarz, A. et al. Review of wearable thermoelectric energy harvesting: from body temperature to electronic systems. Appl. Energy 258, 114069 (2020).

    Article  Google Scholar 

  250. Wang, Y. et al. Self-powered wearable pressure sensing system for continuous healthcare monitoring enabled by flexible thin-film thermoelectric generator. Nano Energy 73, 104773 (2020).

    Article  CAS  Google Scholar 

  251. Oh, Y. S. et al. Battery-free, wireless soft sensors for continuous multi-site measurements of pressure and temperature from patients at risk for pressure injuries. Nat. Commun. 12, 5008 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  252. Lin, R. et al. Wireless battery-free body sensor networks using near-field-enabled clothing. Nat. Commun. 11, 444 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  253. Ouyang, W. et al. A wireless and battery-less implant for multimodal closed-loop neuromodulation in small animals. Nat. Biomed. Eng. 7, 1252–1269 (2023).

    Article  PubMed  Google Scholar 

  254. Li, J. et al. Thin, soft, wearable system for continuous wireless monitoring of artery blood pressure. Nat. Commun. 14, 5009 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  255. Ge, Y. et al. Contactless WiFi sensing and monitoring for future healthcare - emerging trends, challenges, and opportunities. IEEE Rev. Biomed. Eng. 16, 171–191 (2023).

    Article  PubMed  Google Scholar 

  256. Enriko, I. K. A. & Gustiyana, F. N. Wi-Fi HaLow: literature review about potential use of technology in agriculture and smart cities in Indonesia. Proceedings of the 2024 International Conference on Green Energy, Computing and Sustainable Technology (GECOST) pp 277–281 (IEEE, 2024).

  257. Yoo, J. Y. et al. Wireless broadband acousto-mechanical sensing system for continuous physiological monitoring. Nat. Med. 29, 3137–3148 (2023).

    Article  CAS  PubMed  Google Scholar 

  258. Bai, L., Ciravegna, F., Bond, R. & Mulvenna, M. A low cost indoor positioning system using bluetooth low energy. IEEE Access. 8, 136858–136871 (2020).

    Article  Google Scholar 

  259. Selvan, S., Zaman, M., Gobbi, R. & Wong, H. Y. Recent advances in the design and development of radio frequency-based energy harvester for powering wireless sensors: a review. J. Electromagn. Waves Appl. 32, 2110–2134 (2018).

    Article  Google Scholar 

  260. Kwon, K. et al. A battery-less wireless implant for the continuous monitoring of vascular pressure, flow rate and temperature. Nat. Biomed. Eng. 7, 1215–1228 (2023).

    Article  PubMed  Google Scholar 

  261. Boutry, C. M. et al. Biodegradable and flexible arterial-pulse sensor for the wireless monitoring of blood flow. Nat. Biomed. Eng. 3, 47–57 (2019).

    Article  CAS  PubMed  Google Scholar 

  262. Smuck, M., Odonkor, C. A., Wilt, J. K., Schmidt, N. & Swiernik, M. A. The emerging clinical role of wearables: factors for successful implementation in healthcare. NPJ Digit. Med. 4, 45 (2021).

    Article  PubMed  PubMed Central  Google Scholar 

  263. Stergiou, G. S. et al. A universal standard for the validation of blood pressure measuring devices: Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Collaboration Statement. Hypertension 71, 368–374 (2018).

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

The authors receive support from the National Research Foundation of Korea (NRF) by grants funded by the Korean government (MSIT; RS-2024-00406240 and RS-2023-00273231).

Author information

Authors and Affiliations

Authors

Contributions

S.M., J.A., J.H.L. and J.H.K. researched data for the article; S.M., J.A., J.H.L. and S.H.E. wrote the manuscript; S.M., J.A., J.H.L., H.-S.A. and J.-Y.H. contributed to the discussion of its content; and K.J.L., D.J.J., C.D.Y., S.X. and J.A.R. reviewed or edited the manuscript before submission.

Corresponding author

Correspondence to Keon Jae Lee.

Ethics declarations

Competing interests

The authors declare no competing interest.

Peer review

Peer review information

Nature Reviews Cardiology thanks Alberto Avolio and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Min, S., An, J., Lee, J.H. et al. Wearable blood pressure sensors for cardiovascular monitoring and machine learning algorithms for blood pressure estimation. Nat Rev Cardiol 22, 629–648 (2025). https://doi.org/10.1038/s41569-025-01127-0

Download citation

  • Accepted:

  • Published:

  • Issue date:

  • DOI: https://doi.org/10.1038/s41569-025-01127-0

This article is cited by

Search

Quick links

Nature Briefing: Translational Research

Sign up for the Nature Briefing: Translational Research newsletter — top stories in biotechnology, drug discovery and pharma.

Get what matters in translational research, free to your inbox weekly. Sign up for Nature Briefing: Translational Research