Continuous monitoring of arterial blood pressure (BP) in non-clinical (ambulatory) settings is essential for understanding numerous health conditions, including cardiovascular diseases. Besides their importance in medical diagnosis, ambulatory BP monitoring platforms can advance disease correlation with individual behaviour, daily habits and lifestyle, potentially enabling analysis of root causes, prognosis and disease prevention. Although conventional ambulatory BP devices exist, they are uncomfortable, bulky and intrusive. Here we introduce a wearable continuous BP monitoring platform that is based on electrical bioimpedance and leverages atomically thin, self-adhesive, lightweight and unobtrusive graphene electronic tattoos as human bioelectronic interfaces. The graphene electronic tattoos are used to monitor arterial BP for >300 min, a period tenfold longer than reported in previous studies. The BP is recorded continuously and non-invasively, with an accuracy of 0.2 ± 4.5 mm Hg for diastolic pressures and 0.2 ± 5.8 mm Hg for systolic pressures, a performance equivalent to Grade A classification.
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Nano-Micro Letters Open Access 09 August 2022
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The complete dataset supporting the findings of this study is available via the PhysioNet data repository at https://doi.org/10.13026/qcc8-n557. The associated preprocessed raw data are available and can be shared with interested parties upon reasonable request. Source data are provided with this paper.
The machine learning algorithm is publicly available via GitHub at https://github.com/TAMU-ESP/Graphene_BP. The custom codes used for data visualization are available from the corresponding authors upon request.
Jennings, J. R., Muldoon, M. F., Allen, B., Ginty, A. T. & Gianaros, P. J. Cerebrovascular function in hypertension: does high blood pressure make you old? Psychophysiology 58, 1–17 (2021).
Shaffer, F., McCraty, R. & Zerr, C. L. A healthy heart is not a metronome: an integrative review of the heartas anatomy and heart rate variability. Front. Psychol. 5, 1040 (2014).
Kwon, Y. et al. Blood pressure monitoring in sleep: time to wake up. Blood Press. Monit. 25, 61–68 (2020).
Magder, S. The meaning of blood pressure. Crit. Care 22, 257 (2018).
Benjamin, E. J. et al. Heart disease and stroke statistics—2019 update: a report from the American Heart Association. Circulation 139, e556–e528 (2019).
Flint, A. C. et al. Effect of systolic and diastolic blood pressure on cardiovascular outcomes. N. Engl. J. Med. 381, 243–251 (2019).
Kario, K. Management of hypertension in the digital era. Hypertension 76, 640–650 (2020).
Carey, R. M., Muntner, P., Bosworth, H. B. & Whelton, P. K. Prevention and control of hypertension. J. Am. Coll. Cardiol. 72, 1278–1293 (2018).
Kario, K. et al. Morning home blood pressure is a strong predictor of coronary artery disease: the honest study. J. Am. Coll. Cardiol. 67, 1519–1527 (2016).
Al Ghorani, H., Kulenthiran, S., Lauder, L., Böhm, M. & Mahfoud, F. Hypertension trials update. J. Hum. Hypertens. 35, 398–409 (2021).
Marrone, O. & Bonsignore, M. R. Blood-pressure variability in patients with obstructive sleep apnea: current perspectives. Nat. Sci. Sleep. 10, 229–242 (2018).
Salazar, M. R. et al. Nocturnal hypertension in high-risk mid-pregnancies predict the development of preeclampsia/eclampsia. J. Hypertens. 37, 182–186 (2018).
Stergiou, G. S. et al. A universal standard for the validation of blood pressure measuring devices. Hypertension 71, 368–374 (2018).
Bartels, K., Esper, S. A. & Thiele, R. H. Blood pressure monitoring for the anesthesiologist. Anesth. Analg. 122, 1866–1879 (2016).
Vischer, A. S. & Burkard, T. Principles of blood pressure measurement – current techniques, office vs ambulatory blood pressure measurement. Adv. Exp. Med. Biol. 956, 85–96 (2016).
Siu, A. L. et al. Screening for high blood pressure in adults: U.S. preventive services task force recommendation statement. Ann. Intern. Med. 163, 778–786 (2015).
Jeong, I. C., Bychkov, D. & Searson, P. C. Wearable devices for precision medicine and health state monitoring. IEEE Trans. Biomed. Eng. 66, 1242–1258 (2019).
Li, R., Liang, N., Bu, F. & Hesketh, T. The effectiveness of self-management of hypertension in adults using mobile health: systematic review and meta-analysis. JMIR mHealth uHealth 8, e17776 (2020).
\Asayama, K., Ohkubo, T. & Imai, Y. In-office and out-of-office blood pressure measurement. J. Hum. Hypertens. https://doi.org/10.1038/s41371-021-00486-8 (2021).
Pandit, J. A., Lores, E. & Batlle, D. Cuffless blood pressure monitoring. Clin. J. Am. Soc. Nephrol. 15, 1531–1538 (2020).
Wang, C. et al. Monitoring of the central blood pressure waveform via a conformal ultrasonic device. Nat. Biomed. Eng. 2, 687–695 (2018).
Wang, C. et al. Continuous monitoring of deep-tissue haemodynamics with stretchable ultrasonic phased arrays. Nat. Biomed. Eng. 5, 749–758 (2021).
Luo, N. et al. Flexible piezoresistive sensor patch enabling ultralow power cuffless blood pressure measurement. Adv. Funct. Mater. 26, 1178–1187 (2016).
Kim, J. et al. Soft wearable pressure sensors for beat-to-beat blood pressure monitoring. Adv. Healthc. Mater. 8, 1–9 (2019).
Yang, S., Zhang, Y., Cho, S. Y., Correia, R. & Morgan, S. P. Non-invasive cuff-less blood pressure estimation using a hybrid deep learning model. Opt. Quantum Electron. 53, 1–20 (2021).
Elgendi, M. et al. The use of photoplethysmography for assessing hypertension. npj Digit. Med. 2, 1–11 (2019).
Chang, Y. H., Huang, K. C., Yang, C. C. & Tsai, H. Y. Evaluation of absorbed light dose in human skin tissue during Light Therapy by 630nm LED light. In 2015 IEEE 12th International Conference on Networking, Sensing and Control 394–398 (IEEE, 2015); https://doi.org/10.1109/ICNSC.2015.7116069
Safar, M. E. & Boudier, H. S. Vascular development, pulse pressure, and the mechanisms of hypertension. Hypertension 46, 205–209 (2005).
Sel, K. et al. Electrical characterization of graphene-based e-tattoos for bio-impedance-based physiological sensing. In 2019 IEEE Biomedical Circuits and Systems Conference 1–4 (IEEE, 2019); https://doi.org/10.1109/BIOCAS.2019.8919003
Sel, K., Osman, D. & Jafari, R. Non-invasive cardiac and respiratory activity assessment from various human body locations using bioimpedance. IEEE Open J. Eng. Med. Biol. 2, 210–217 (2021).
Wang, T. W., Chen, W. X., Chu, H. W. & Lin, S. F. Single-channel bioimpedance measurement for wearable continuous blood pressure monitoring. IEEE Trans. Instrum. Meas. 70, 1–9 (2021).
Kabiri Ameri, S. et al. Graphene electronic tattoo sensors. ACS Nano 11, 7634–7641 (2017).
Ameri, S. K. et al. Imperceptible electrooculography graphene sensor system for human–robot interface. npj 2D Mater. Appl. 2, 19 (2018).
Kireev, D. et al. Fabrication, characterization and applications of graphene electronic tattoos. Nat. Protoc. 16, 2395–2417 (2021).
Ibrahim, B. & Jafari, R. Cuffless blood pressure monitoring from an array of wrist bio-impedance sensors using subject-specific regression models: proof of concept. IEEE Trans. Biomed. Circ. Syst. 13, 1723–1735 (2019).
American National Standards Institute, Association for the Advancement of Medical Instrumentation. ANSI/AAMI ES60601-1:2005/A1:2012, Medical Electrical Equipment Part 1: General Requirements for Basic Safety and Essential Performance (ANSI/AAMI 2012); https://webstore.ansi.org/Standards/AAMI/ansiaamies606012005r2012
Sel, K., Ibrahim, B. & Jafari, R. ImpediBands: body coupled bio-impedance patches for physiological sensing proof of concept. IEEE Trans. Biomed. Circ. Syst. 14, 757–774 (2020).
Webster, J. Medical Instrumentation: Application and Design 4th edn (John Wiley & Sons, 2010).
Miccoli, I., Edler, F., Pfnür, H. & Tegenkamp, C. The 100th anniversary of the four-point probe technique: the role of probe geometries in isotropic and anisotropic systems. J. Phys. Condens. Matter 27, 223201 (2015).
Brath, P. C. & Eisenach, J. C. Atlas of cardiovascular monitoring. Anesthesiology 93, 312–312 (2000).
Vlachopoulos, C., O’Rourke, M. & Nichols, W. W. McDonald’s Blood Flow in Arteries (CRC, 2011); https://doi.org/10.1201/b13568
Jang, H., Dai, Z., Ha, K.-H., Ameri, S. K. & Lu, N. Stretchability of PMMA-supported CVD graphene and of its electrical contacts. 2D Mater. 7, 014003 (2019).
Goldstein, D. S. & Cheshire, W. P. Beat-to-beat blood pressure and heart rate responses to the Valsalva maneuver. Clin. Auton. Res. 27, 361–367 (2017).
Johnson, B. D., Sackett, J. R., Schlader, Z. J. & Leddy, J. J. Attenuated cardiovascular responses to the cold pressor test in concussed collegiate athletes. J. Athl. Train. 55, 124–131 (2020).
Byambasukh, O., Snieder, H. & Corpeleijn, E. Relation between leisure time, commuting, and occupational physical activity with blood pressure in 125 402 Adults: the Lifelines cohort. J. Am. Heart Assoc. 9, e014313 (2020).
IEEE Engineering in Medicine and Biology Society IEEE Standard for Wearable, Cuffless Blood Pressure Measuring Devices IEEE 1708-2014 (IEEE, 2014).
Koshimizu, H., Kojima, R. & Okuno, Y. Future possibilities for artificial intelligence in the practical management of hypertension. Hypertens. Res. 43, 1327–1337 (2020).
Herakova, N., Nwobodo, N. H. N., Wang, Y., Chen, F. & Zheng, D. Effect of respiratory pattern on automated clinical blood pressure measurement: an observational study with normotensive subjects. Clin. Hypertens. 23, 15 (2017).
McEniery, C. M., Cockcroft, J. R., Roman, M. J., Franklin, S. S. & Wilkinson, I. B. Central blood pressure: current evidence and clinical importance. Eur. Heart J. 35, 1719–1725 (2014).
Asayama, K. et al. Nocturnal blood pressuremeasured by home devices: Evidence and perspective for clinical application. J. Hypertens. 37, 905–916 (2019).
Gaffey, A. E., Schwartz, J. E., Harris, K. M., Hall, M. H. & Burg, M. M. Effects of ambulatory blood pressure monitoring on sleep in healthy, normotensive men and women. Blood Press. Monit. 26, 93–101 (2021).
Soleimani, E., Mokhtari-Dizaji, M., Fatouraee, N. & Saberi, H. Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method. Ultrasonography 36, 144–152 (2017).
Kemmotsu, O. et al. Blood pressure measurement by arterial tonometry in controlled Hypotension. Anesth. Analg. 73, 54–58 (1991).
Lee, J. Y., Choi, E. Y., Jeong, H. J., Kim, K. H. & Park, J. C. Blood pressure measurement using finger cuff. Conf. Proc. IEEE Eng. Med. Biol. Soc. 7 S, 3575–3577 (2005).
Mazoteras Pardo, V., Losa Iglesias, M. E., López Chicharro, J. & Becerro de Bengoa Vallejo, R. The QardioArm app in the assessment of blood pressure and heart rate: reliability and validity study. JMIR mHealth uHealth 5, e198 (2017).
The work was supported in part by the Office of Naval Research under grant number N00014-18-1-2706, the Temple Foundation Endowed Professorship, the National Science Foundation under grant number 1738293 and the National Institute of Health under grant number 1R01EB028106. R.J. acknowledges useful discussions with the former founding director of the National Institute of Biomedical Imaging and Bioengineering (NIBIB) at the NIH, R. I. Pettigrew. We acknowledge J. Wozniak at the Texas Advanced Computing Center (TACC) at The University of Texas at Austin (http://www.tacc.utexas.edu) for creating Fig. 1a. The authors have permission to use and publish the image.
R.J. and B.I. filed a patent (US 2020/0138303 titled ‘System and method for cuff-less blood pressure monitoring’) related to this research; this patent is licensed to SpectroBeat LLC.
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Supplementary Figs. 1–26, Tables 1–10 and Notes 1–9.
Mechanical stability of graphene electronic tattoos.
Batch transfer of GETs.
Live recording of BP with GETs number 1.
Live recording of BP with GETs number 2.
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Kireev, D., Sel, K., Ibrahim, B. et al. Continuous cuffless monitoring of arterial blood pressure via graphene bioimpedance tattoos. Nat. Nanotechnol. 17, 864–870 (2022). https://doi.org/10.1038/s41565-022-01145-w
Nano-Micro Letters (2022)