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Monitoring of the central blood pressure waveform via a conformal ultrasonic device

Nature Biomedical Engineering volume 2, pages 687–695 (2018)Cite this article

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Abstract

Continuous monitoring of the central blood pressure waveform from deeply embedded vessels such as the carotid artery and jugular vein has clinical value for the prediction of all-cause cardiovascular mortality. However, existing non-invasive approaches, including photoplethysmography and tonometry, only enable access to the superficial peripheral vasculature. Although current ultrasonic technologies allow non-invasive deep tissue observation, unstable coupling with the tissue surface resulting from the bulkiness and rigidity of conventional ultrasound probes introduces usability constraints. Here, we describe the design and operation of an ultrasonic device that is conformal to the skin and capable of capturing blood pressure waveforms at deeply embedded arterial and venous sites. The wearable device is ultrathin (240 μm) and stretchable (with strains up to 60%), and enables the non-invasive, continuous and accurate monitoring of cardiovascular events from multiple body locations, which should facilitate its use in a variety of clinical environments.

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Fig. 1: Design and working principle of the stretchable ultrasonic device.
Fig. 2: Electrical, mechanical, acoustic and biocompatibility characterizations of the conformal ultrasonic device.
Fig. 3: Comparison between the conformal ultrasound sensor and a commercial tonometer, exercise haemodynamics monitoring and central arterial and venous pulse measurements.
Fig. 4: BP measurements from the central to peripheral arteries and validation using a commercial tonometer.
Fig. 5: ECG correlation-based PWV calculation to evaluate arterial stiffness.

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Data availability

The main data supporting the findings of this study are available within the Article and its Supplementary Information. The raw data generated in this study are available from the corresponding author upon reasonable request.

References

  1. McGhee, B. H. & Bridges, E. J. Monitoring arterial blood pressure: what you may not know. Crit. Care Nurse 22, 60–79 (2002).

    PubMed  Google Scholar 

  2. Avolio, A. P., Butlin, M. & Walsh, A. Arterial blood pressure measurement and pulse wave analysis—their role in enhancing cardiovascular assessment. Physiol. Meas. 31, 275–290 (2009).

    Google Scholar 

  3. Kumar, A. et al. Pulmonary artery occlusion pressure and central venous pressure fail to predict ventricular filling volume, cardiac performance, or the response to volume infusion in normal subjects. Crit. Care Med. 32, 691–699 (2004).

    Article  PubMed  Google Scholar 

  4. Dagdeviren, C. et al. Conformable amplified lead zirconate titanate sensors with enhanced piezoelectric response for cutaneous pressure monitoring. Nat. Commun. 5, 4496–4506 (2014).

    Article  PubMed  CAS  Google Scholar 

  5. Safar, M. E. et al. Central pulse pressure and mortality in end-stage renal disease. Hypertension 39, 735–738 (2002).

    Article  PubMed  CAS  Google Scholar 

  6. Trudeau, L. Central blood pressure as an index of antihypertensive control: determinants and potential value. Can. J. Cardiol. 30, 23–28 (2014).

    Article  Google Scholar 

  7. 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).

    Article  PubMed  PubMed Central  Google Scholar 

  8. Ding, F.-H. et al. Validation of the noninvasive assessment of central blood pressure by the SphygmoCor and Omron devices against the invasive catheter measurement. Am. J. Hypertens. 24, 1306–1311 (2011).

    Article  PubMed  Google Scholar 

  9. Agabiti-Rosei, E. et al. Central blood pressure measurements and antihypertensive therapy. Hypertension 50, 154–160 (2007).

    Article  PubMed  CAS  Google Scholar 

  10. Bruyndonckx, L. et al. Methodological considerations and practical recommendations for the application of peripheral arterial tonometry in children and adolescents. Int. J. Cardiol. 168, 3183–3190 (2013).

    Article  PubMed  Google Scholar 

  11. Avolio, A. P. et al. Role of pulse pressure amplification in arterial hypertension. Hypertension 54, 375–383 (2009).

    Article  PubMed  CAS  Google Scholar 

  12. Williams, B. et al. Differential impact of blood pressure-lowering drugs on central aortic pressure and clinical outcomes. Circulation 113, 1213–1225 (2006).

    Article  PubMed  CAS  Google Scholar 

  13. Moffitt, E. A. et al. Rate–pressure product correlates poorly with myocardial oxygen consumption during anaesthesia in coronary patients. Can. J. Anaesth. 31, 5–12 (1984).

    Article  CAS  Google Scholar 

  14. Roman, M. J. et al. Relations of central and brachial blood pressure to left ventricular hypertrophy and geometry: the Strong Heart Study. J. Hypertens. 28, 384–388 (2010).

    Article  PubMed  CAS  Google Scholar 

  15. Chen, C.-H. et al. Different effects of fosinopril and atenolol on wave reflections in hypertensive patients. Hypertension 25, 1034–1041 (1995).

    Article  PubMed  CAS  Google Scholar 

  16. Pini, R. et al. Central but not brachial blood pressure predicts cardiovascular events in an unselected geriatric population: the ICARe Dicomano Study. J. Am. Coll. Cardiol. 51, 2432–2439 (2008).

    Article  PubMed  Google Scholar 

  17. Langewouters, G., Settels, J., Roelandt, R. & Wesseling, K. Why use Finapres or Portapres rather than intraarterial or intermittent non-invasive techniques of blood pressure measurement? J. Med. Eng. Technol. 22, 37–43 (1998).

    Article  PubMed  CAS  Google Scholar 

  18. Kim, J. et al. Battery-free, stretchable optoelectronic systems for wireless optical characterization of the skin. Sci. Adv. 2, e1600418 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  19. Schwartz, G. et al. Flexible polymer transistors with high pressure sensitivity for application in electronic skin and health monitoring. Nat. Commun. 4, 1859–1870 (2013).

    Article  PubMed  CAS  Google Scholar 

  20. Sandberg, M., Zhang, Q., Styf, J., Gerdle, B. & Lindberg, L. G. Non‐invasive monitoring of muscle blood perfusion by photoplethysmography: evaluation of a new application. Acta Physiol. 183, 335–343 (2005).

    Article  CAS  Google Scholar 

  21. Hertzman, A. B. The blood supply of various skin areas as estimated by the photoelectric plethysmograph. Am. J. Physiol. Cell. Physiol. 124, 328–340 (1938).

    Google Scholar 

  22. 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 

  23. Xing, X. & Sun, M. Optical blood pressure estimation with photoplethysmography and FFT-based neural networks. Biomed. Opt. Express 7, 3007–3020 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  24. Drzewiecki, G. M., Melbin, J. & Noordergraaf, A. Arterial tonometry: review and analysis. J. Biomech. 16, 141–152 (1983).

    Article  PubMed  CAS  Google Scholar 

  25. Howard, G. et al. Carotid artery intimal-medial thickness distribution in general populations as evaluated by B-mode ultrasound. Stroke 24, 1297–1304 (1993).

    Article  PubMed  CAS  Google Scholar 

  26. Rotenberg, M. Y. & Tian, B. Bioelectronic devices: long-lived recordings. Nat. Biomed. Eng. 1, 48–50 (2017).

    Article  Google Scholar 

  27. Kim, D.-H. et al. Epidermal electronics. Science 333, 838–843 (2011).

    Article  PubMed  CAS  Google Scholar 

  28. Yokota, T. et al. Ultraflexible, large-area, physiological temperature sensors for multipoint measurements. Proc. Natl Acad. Sci. USA 112, 14533–14538 (2015).

    Article  PubMed  CAS  Google Scholar 

  29. Gao, W. et al. Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis. Nature 529, 509–514 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  30. Martín, A. et al. Epidermal microfluidic electrochemical detection system: enhanced sweat sampling and metabolite detection. ACS Sens. 2, 1860–1868 (2017).

    Article  PubMed  CAS  Google Scholar 

  31. Huang, X. et al. Materials and designs for wireless epidermal sensors of hydration and strain. Adv. Funct. Mater. 24, 3846–3854 (2014).

    Article  CAS  Google Scholar 

  32. Arndt, J. O., Klauske, J. & Mersch, F. The diameter of the intact carotid artery in man and its change with pulse pressure. Pflugers Arch. 301, 230–240 (1968).

    Article  CAS  Google Scholar 

  33. Zhou, Q., Lam, K. H., Zheng, H., Qiu, W. & Shung, K. K. Piezoelectric single crystal ultrasonic transducers for biomedical applications. Prog. Mater. Sci. 66, 87–111 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  34. Sun, P. et al. High frequency PMN-PT 1–3 composite transducer for ultrasonic imaging application. Ferroelectrics 408, 120–128 (2010).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  35. Arumugam, V., Naresh, M. & Sanjeevi, R. Effect of strain rate on the fracture behaviour of skin. J. Biosci. 19, 307–313 (1994).

    Article  Google Scholar 

  36. Kitamura, K., Jorgensen, C. R., Gobel, F. L., Taylor, H. L. & Wang, Y. Hemodynamic correlates of myocardial oxygen consumption during upright exercise. J. Appl. Physiol. 32, 516–522 (1972).

    Article  PubMed  CAS  Google Scholar 

  37. Ishibashi, Y., Duncker, D. J., Zhang, J. & Bache, R. J. ATP-sensitive K+ channels, adenosine, and nitric oxide-mediated mechanisms account for coronary vasodilation during exercise. Circ. Res. 82, 346–359 (1998).

    Article  PubMed  CAS  Google Scholar 

  38. Wain, R. A. et al. Accuracy of duplex ultrasound in evaluating carotid artery anatomy before endarterectomy. J. Vasc. Surg. 27, 235–244 (1998).

    Article  PubMed  CAS  Google Scholar 

  39. Donahue, S. P., Wood, J. P., Patel, B. M. & Quinn, J. V. Correlation of sonographic measurements of the internal jugular vein with central venous pressure. Am. J. Emerg. Med. 27, 851–855 (2009).

    Article  PubMed  Google Scholar 

  40. Butman, S. M., Ewy, G. A., Standen, J. R., Kern, K. B. & Hahn, E. Bedside cardiovascular examination in patients with severe chronic heart failure: importance of rest or inducible jugular venous distension. J. Am. Coll. Cardiol. 22, 968–974 (1993).

    Article  PubMed  CAS  Google Scholar 

  41. Mukkamala, R. & Xu, D. Continuous and less invasive central hemodynamic monitoring by blood pressure waveform analysis. Am. J. Physiol. Heart Circ. Physiol. 299, 584–599 (2010).

    Article  CAS  Google Scholar 

  42. Camacho, F., Avolio, A. & Lovell, N. Estimation of pressure pulse amplification between aorta and brachial artery using stepwise multiple regression models. Physiol. Meas. 25, 879–889 (2004).

    Article  PubMed  CAS  Google Scholar 

  43. Williams, B. et al. Differential impact of blood pressure-lowering drugs on central aortic pressure and clinical outcomes: principal results of the Conduit Artery Function Evaluation (CAFE) study. Circulation 113, 1213–1225 (2006).

    Article  PubMed  CAS  Google Scholar 

  44. Shirwany, N. A. & Zou, M.-h Arterial stiffness: a brief review. Acta Pharmacol. Sin. 31, 1267–1276 (2010).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  45. DeLoach, S. S. & Townsend, R. R. Vascular stiffness: its measurement and significance for epidemiologic and outcome studies. Clin. J. Am. Soc. Nephrol. 3, 184–192 (2008).

    Article  PubMed  Google Scholar 

  46. Mukkamala, R. et al. Toward ubiquitous blood pressure monitoring via pulse transit time: theory and practice. IEEE. Trans. Biomed. Eng. 62, 1879–1901 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  47. Ren, K., Liu, Y., Geng, X., Hofmann, H. F. & Zhang, Q. M. Single crystal PMN-PT/epoxy 1–3 composite for energy-harvesting application. IEEE Trans. Ultrason. Ferroelectr. Freq. Control 53, 631–638 (2006).

    Article  PubMed  Google Scholar 

  48. 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 

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Acknowledgements

The project was supported by the National Institutes of Health (NIH, grant R21EB025521) and the Center for Wearable Sensors at the University of California, San Diego. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. All bio-experiments were conducted in accordance with the ethical guidelines of the NIH and with the approval of the Institutional Review Board of the University of California, San Diego (IRB no. 170812). The authors thank K. Anagnostopoulos and H. Kim for discussions and advice regarding Picoscope DAQ, A. Kahn for discussions on PWV measurements, E. Topol, S. Steinhubl and E. Muse for stimulating discussions on ambulatory BP measurement, Q. Yang and R. Lal for mechanical vibration characterization of the 1–3 composite material, and S. Xiang for constructive feedback on manuscript preparation.

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  1. These authors contributed equally: Chonghe Wang, Xiaoshi Li, Hongjie Hu.

Authors and Affiliations

  1. Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA

    Chonghe Wang, Lin Zhang, Zhenlong Huang, Muyang Lin, Zhuorui Zhang, Hua Gong, Yuxuan Guo, Yusheng Lei, Yimu Chen, Chunfeng Wang, Yang Li, Tianjiao Zhang, Liangfang Zhang & Sheng Xu

  2. Materials Science and Engineering Program, University of California San Diego, La Jolla, CA, USA

    Xiaoshi Li, Hongjie Hu, Yue Gu & Sheng Xu

  3. School of Precision Instrument and Optoelectronic Engineering, Tianjin University, Tianjin, China

    Muyang Lin

  4. Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA, USA

    Zhenan Yin, Shubha Bhaskaran & Sheng Xu

  5. Department of Radiology, School of Medicine, University of California San Diego, La Jolla, CA, USA

    Brady Huang

  6. Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA

    Mitsutoshi Makihata & Albert P. Pisano

  7. The Key Laboratory of Materials Processing and Mold of Ministry of Education, School of Materials Science and Engineering, School of Physics & Engineering, Zhengzhou University, Zhengzhou, Henan, China

    Chunfeng Wang

  8. Department of Ophthalmology and Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA

    Zeyu Chen & Qifa Zhou

  9. Department of Bioengineering, University of California San Diego, La Jolla, CA, USA

    Sheng Xu

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Contributions

Chonghe Wang and S.X. designed the research. Chonghe Wang, X.L., M.L., Z.Z. and H.H. performed the experiment. Chonghe Wang performed the simulation. Chonghe Wang, M.L., Z.Z. and X.L. analysed the data. Chonghe Wang, Z.Z. and S.X. wrote the paper. All authors provided active and valuable feedback on the manuscript.

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Correspondence to Sheng Xu.

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Wang, C., Li, X., Hu, H. et al. Monitoring of the central blood pressure waveform via a conformal ultrasonic device. Nat Biomed Eng 2, 687–695 (2018). https://doi.org/10.1038/s41551-018-0287-x

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