CC BY-NC-ND 4.0 · J Reconstr Microsurg Open 2021; 06(01): e11-e19
DOI: 10.1055/s-0041-1723995
Original Article

Developing a Wearable Sensor for Continuous Tissue Oxygenation Monitoring: A Proof of Concept Study

Richard M. Kwasnicki
1   Hamlyn Centre, Institute of Global Health Innovation, Imperial College, London, United Kingdom
,
Ching-Mei Chen
1   Hamlyn Centre, Institute of Global Health Innovation, Imperial College, London, United Kingdom
,
Alex J. Noakes
1   Hamlyn Centre, Institute of Global Health Innovation, Imperial College, London, United Kingdom
,
Shehan Hettiaratchy
1   Hamlyn Centre, Institute of Global Health Innovation, Imperial College, London, United Kingdom
,
Guang-Zhong Yang
1   Hamlyn Centre, Institute of Global Health Innovation, Imperial College, London, United Kingdom
,
Ara Darzi
1   Hamlyn Centre, Institute of Global Health Innovation, Imperial College, London, United Kingdom
› Author Affiliations
Funding This work was supported by an EPSRC grant (EP/H009744/1 ESPRIT).

Abstract

Objective Technologies facilitating continuous free tissue flap monitoring such as near infrared spectroscopy (NIRS) have been shown to improve flap salvage rates. However, the size and associated costs of such technology create a barrier to wider implementation. The aim of this study was to develop and validate a wearable sensor for continuous tissue oxygenation monitoring.

Materials and Methods A forearm ischemia model was designed by using a brachial pressure cuff inflation protocol. Twenty healthy subjects were recruited. The forearm tissue oxygenation of each subject was monitored throughout the pressure cuff protocol by using a new optical sensor (Imperial College London), and a gold standard tissue spectrometry system (O2C, Medizintecknik, LEA, Germany). Data were processed to allow quantitative deoxygenation episode comparisons between inflations and sensor modalities.

Results The correlation between O2C and optical sensor oxygenation measurements was moderate (average R = 0.672, p < 0.001). Incremental increases in cuff inflation duration resulted in a linear increase in deoxygenation values with both O2C and optical sensors, with significant differences recorded on consecutive inflations (wall shear rate, p < 0.005). The presence or absence of pulsatile blood flow was correctly determined throughout by both sensor modalities.

Conclusion This study demonstrates the ability of a small optical sensor to detect and quantify tissue oxygenation changes and assess the presence of pulsatile blood flow. Low power, miniaturized electronics make the device capable of deployment in a wearable form which may break down the barriers for implementation in postoperative flap monitoring.

Authors' Contributions

R.M.K., S.H., G.Z.Y., and A.D. conceptualized the study. C.M.C. and G.Z.Y. cooperated in hardware and software design. R.M.K., A.J.N., S.H., and A.D. performed the interpretation of data and clinical impact. All authors approved the manuscript.




Publication History

Received: 26 August 2020

Accepted: 14 December 2020

Article published online:
16 February 2021

© 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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  • References

  • 1 Oni G, Malata CM. New surgical technique: Simultaneous use of contiguous intercostal spaces during total rib preservation exposure of the internal mammary vessels in microvascular breast reconstruction. J Plast Reconstr Aesthet Surg 2019; 72 (09) 1525-1529
  • 2 Alt V, Donell ST, Chhabra A, Bentley A, Eicher A, Schnettler R. A health economic analysis of the use of rhBMP-2 in Gustilo-Anderson grade III open tibial fractures for the UK, Germany, and France. Injury 2009; 40 (12) 1269-1275
  • 3 Poder TG, Fortier PH. Implantable Doppler in monitoring free flaps: a cost-effectiveness analysis based on a systematic review of the literature. Eur Ann Otorhinolaryngol Head Neck Dis 2013; 130 (02) 79-85
  • 4 Che MP, Rozen WM, Whitaker IS. et al. Current evidence for postoperative monitoring of microvascular free flaps: a systematic review. Ann Plast Surg 2015; 74 (05) 621-632
  • 5 Genden EM, Rinaldo A, Suárez C, Wei WI, Bradley PJ, Ferlito A. Complications of free flap transfers for head and neck reconstruction following cancer resection. Oral Oncol 2004; 40 (10) 979-984
  • 6 Jandali S, Nelson JA, Sonnad SS. et al. Breast reconstruction with free tissue transfer from the abdomen in the morbidly obese. Plast Reconstr Surg 2011; 127 (06) 2206-2213
  • 7 Khouri RK, Cooley BC, Kunselman AR. et al. A prospective study of microvascular free-flap surgery and outcome. Plast Reconstr Surg 1998; 102 (03) 711-721
  • 8 Mangano DT, Layug EL, Wallace A, Tateo I. Multicenter Study of Perioperative Ischemia Research Group. Effect of atenolol on mortality and cardiovascular morbidity after noncardiac surgery. N Engl J Med 1996; 335 (23) 1713-1720
  • 9 Moran SL, Illig KA, Green RM, Serletti JM. Free-tissue transfer in patients with peripheral vascular disease: a 10-year experience. Plast Reconstr Surg 2002; 109 (03) 999-1006
  • 10 Moran SL, Salgado CJ, Serletti JM. Free tissue transfer in patients with renal disease. Plast Reconstr Surg 2004; 113 (07) 2006-2011
  • 11 Shestak KC, Jones NF. Microsurgical free-tissue transfer in the elderly patient. Plast Reconstr Surg 1991; 88 (02) 259-263
  • 12 Siemionow M, Arslan E. Ischemia/reperfusion injury: a review in relation to free tissue transfers. Microsurgery 2004; 24 (06) 468-475
  • 13 Chen KT, Mardini S, Chuang DC. et al. Timing of presentation of the first signs of vascular compromise dictates the salvage outcome of free flap transfers. Plast Reconstr Surg 2007; 120 (01) 187-195
  • 14 Kääriäinen M, Halme E, Laranne J. Modern postoperative monitoring of free flaps. Curr Opin Otolaryngol Head Neck Surg 2018; 26 (04) 248-253
  • 15 Karinja SJ, Lee BT. Advances in flap monitoring and impact of enhanced recovery protocols. J Surg Oncol 2018; 118 (05) 758-767
  • 16 Schmulder A, Gur E, Zaretski A. Eight-year experience of the Cook-Swartz Doppler in free-flap operations: microsurgical and reexploration results with regard to a wide spectrum of surgeries. Microsurgery 2011; 31 (01) 1-6
  • 17 Xipoleas G, Levine E, Silver L, Koch RM, Taub PJ. A survey of microvascular protocols for lower extremity free tissue transfer II: postoperative care. Ann Plast Surg 2008; 61 (03) 280-284
  • 18 Han ZF, Guo LL, Liu LB. et al. A comparison of the Cook-Swartz Doppler with conventional clinical methods for free flap monitoring: a systematic review and a meta-analysis. Int J Surg 2016; 32: 109-115
  • 19 Kohlert S, Quimby AE, Saman M, Ducic Y. Postoperative free-flap monitoring techniques. Semin Plast Surg 2019; 33 (01) 13-16
  • 20 Oda H, Beker L, Kaizawa Y. et al. A novel technology for free flap monitoring: pilot study of a wireless, biodegradable sensor. J Reconstr Microsurg 2020; 36 (03) 182-190
  • 21 Birkenfeld F, Naujokat H, Helmers AK, Purcz N, Möller B, Wiltfang J. Microdialysis in postoperative monitoring of microvascular free flaps: Experiences with a decision algorithm. J Craniomaxillofac Surg 2019; 47 (08) 1306-1309
  • 22 Kagaya Y, Miyamoto S. A systematic review of near-infrared spectroscopy in flap monitoring: Current basic and clinical evidence and prospects. J Plast Reconstr Aesthet Surg 2018; 71 (02) 246-257
  • 23 Newton E, Butskiy O, Shadgan B, Prisman E, Anderson DW. Outcomes of free flap reconstructions with near-infrared spectroscopy (NIRS) monitoring: a systematic review. Microsurgery 2020; 40 (02) 268-275
  • 24 Koolen PGL, Vargas CR, Ho OA. et al. Does increased experience with tissue oximetry monitoring in microsurgical breast reconstruction lead to decreased flap loss? the learning effect. Plast Reconstr Surg 2016; 137 (04) 1093-1101
  • 25 Creech B, Miller S. Evaluation of circulation in skin flaps. In: Grabb WC, Myers MB. eds. Skin Flaps. Boston: Little, Brown; 21-38
  • 26 Chen C, Kwasnicki RM, Curto VF, Yang G, Lo BPL. Tissue oxygenation sensor and an active in vitro phantom for sensor validation. IEEE Sens J 2019; 19 (18) 8233-8240
  • 27 Chen CM, Kwasnicki R, Lo B, Yang GZ. Wearable tissue oxygenation monitoring sensor and a forearm vascular phantom design for data validation. 11th International Conference on Wearable and Implantable Body Sensor Networks; June. 2014 ; Zurich, Switzerland. Accessed June 2014 at: https://ieeexplore.ieee.org/document/6855618
  • 28 Wolff KD, Uekermann B, Matthes G, Wartenberg E. Intracapillary hemoglobin oxygenation and interstitial pO2 in venous flaps: an experimental study in rats. Microsurgery 1998; 18 (05) 324-330
  • 29 Rothenberger J, Amr A, Schaller HE, Rahmanian-Schwarz A. Evaluation of a non-invasive monitoring method for free flap breast reconstruction using laser doppler flowmetrie and tissue spectrophotometry. Microsurgery 2013; 33 (05) 350-357
  • 30 Plasswilm L, Tannapfel A, Cordes N. et al. Hypoxia-induced tumour cell migration in an in vivo chicken model. Pathobiology 2000; 68 (03) 99-105
  • 31 Brell B, Temmesfeld-Wollbrück B, Altzschner I. et al. Adrenomedullin reduces Staphylococcus aureus alpha-toxin-induced rat ileum microcirculatory damage. Crit Care Med 2005; 33 (04) 819-826
  • 32 Knobloch K, Kraemer R, Lichtenberg A. et al. Achilles tendon and paratendon microcirculation in midportion and insertional tendinopathy in athletes. Am J Sports Med 2006; 34 (01) 92-97
  • 33 Beckert S, Witte MB, Königsrainer A, Coerper S. The impact of the micro-lightguide O2C for the quantification of tissue ischemia in diabetic foot ulcers. Diabetes Care 2004; 27 (12) 2863-2867
  • 34 Steele MH. Three-year experience using near infrared spectroscopy tissue oximetry monitoring of free tissue transfers. Ann Plast Surg 2011; 66 (05) 540-545
  • 35 Lohman RF, Ozturk CN, Djohan R, Tang HR, Chen H, Bechtel KL. Predicting skin flap viability using a new intraoperative tissue oximetry sensor: a feasibility study in pigs. J Reconstr Microsurg 2014; 30 (06) 405-412
  • 36 Smit JM, Zeebregts CJ, Acosta R, Werker PM. Advancements in free flap monitoring in the last decade: a critical review. Plast Reconstr Surg 2010; 125 (01) 177-185