Hrev_master Veins and Lymphatics 2017; volume 6:6631 [page 20] [Veins and Lymphatics 2017; 6:6631] Innovation in compression: smart bandage technology to improve bandage application and monitoring Jerry Hutchinson Hutchinson WoundTech Limited, UK Introduction Although high compression delivered by elastic bandages or hosiery is widely accepted as the standard first line care for patients with venous disease but without significant arterial impairment1-6 the appli- cation of bandages in particular is subject to significant variation. In most cases the interface pressure, effectively the compres- sion dose, is not accurately known and is likely to be different from the ideal graduat- ed compression intended on application.7,8 Furthermore, as the dimensions of the affected limb change under the influence of external compression, the interface pressure changes (REF).1 Variability in the applica- tion and sustainability of interface pressure is likely to lead to variable clinical efficacy, for example, healing rates. Indeed, the heal- ing rates reported for VLU vary consider- ably.9-19 Technical solutions to variability in application of bandages include printed ovals or rectangles that change to circles or squares at the correct bandage extension; markings on orthostatic devices that are matched to a scale; bandage application at full stretch. Direct measurement of interface pressure may be used on application and for monitoring20 but pressure is usually meas- ured at only one anatomic location. Despite these solutions bandage application remains variable, and the application of reduced compression by reduced stretch in the pres- ence of arterial impairment is largely semi- quantitative at best. A new technology to report inter- face pressure Laplace’s Law governs the calculation of interface pressure applied by a material on a surface with a circular cross section. The accuracy of Laplace’s algorithm is known.21 The extension of an elastic materi- al can be measured accurately using strain gauge technology and the tension through- out its range of extension can be measured. The tension value is used with the radius of the surface to derive the interface pressure. This principle has been used to develop a functional prototype smart bandage (SB). The components of SB are an elastic bandage with the desired stretch properties into which three silver strain gauge trans- ducers are knitted (Figure 1); a connection point at a bandage extremity; digital elec- tronics to detect the transducer output and wirelessly connect to a user interface; a Bluetooth user interface, for example a Smartphone or tablet, with an app that reports the consistency and values of applied pressure in real time. Pressure is calculated using Laplace’s Law. The tension in the bandage material is derived from its known properties which are pre-pro- grammed into the electronics. Upon appli- cation the bandage extension, from which tension is computed, is reported by the transducer. Limb dimensions are derived by direct measurement of the patient’s leg and manually entered via the user interface. As the bandage is applied the system uses its integrated algorithm to show a real-time visual display of the accuracy of applica- tion, reporting the interface pressure as an absolute value. A colour-based scale shows yellow when pressure is too low, green when it is as intended, and red when over the target value. The bandager can thereby adjust the extension to achieve target pres- sure in real time. At the time of writing, a functional pro- totype is developed and is subject to a development agreement with a commercial partner. The anticipated benefits of SB include higher quality of bandage applica- tion; real-time monitoring of compression in-use; improved healing through greater accuracy in bandage application and main- tenance of dose; ability to account accurate- ly for lower compression in patients with significant arterial impairment; washability in re-usable products. References 1. Moneta GL, Partsch H. Compression for venous ulceration. In: Gloviczki P, ed. Handbook of venous disorders. 3rd ed. London: Hodder Arnold; 2009. pp 348-358. 2. Mosti G, Mattaliano V, Polignano R, Masina M. Compression therapy in the treatment of leg ulcers. Acta Vulnol 2009;7:1-20. 3. Comerota AJ. Intermittent pneumatic compression: physiologic and clinical basis to improve management of venous leg ulcers. J Vasc Surg 2011;53:1121-9. 4. Kahle B, Hermanns HJ, Gallenkemper G. Evidence-based treatment of chronic leg ulcers. Dtsch Arztebl Int 2011;108:231-7. 5. O’Meara S, Cullum N, Nelson EA, Dumville JC. Compression for venous leg ulcers. Cochrane Database Syst Rev 2012;11:CD000265. 6. Neumann HA, Cornu-Thénard A, Jünger M, et al. Evidence-based (S3) guidelines for diagnostics and treatment of venous leg ulcers. J Eur Acad Dermatol Venereol 2016 [Epub ahead of print]. 7. Lee AJ, Dale JJ, Ruckley CV, et al. Compression therapy: effects of posture and application techniques on initial pressures delivered by bandages of dif- ferent physical properties. Eur J Vasc Endovasc Surg 2006;31:542-52. 8. Dale JJ, Ruckley CV, Gibson B, et al. Multi-layer compression: comparison of four different four-layer bandage sys- tems applied to the leg. Eur J Vasc Endovasc Surg 2004;27:94-9. 9. Ukat A, Konig M, Vanscheidt W, Münter KC. Short-stretch versus multi- layer compression for venous leg ulcers: a comparison of healing rates. J Wound Care 2003;12:139-43. Correspondence: Jerry Hutchinson, Hutchinson WoundTech Limited, UK. E-mail: jhutchinson31@gmail.com This work is licensed under a Creative Commons Attribution 4.0 License (by-nc 4.0). ©Copyright J. Hutchinson, 2017 Licensee PAGEPress, Italy Veins and Lymphatics 2017; 6:6631 doi:10.4081/vl.2017.6631 Figure 1. Functional prototype Smart Bandage showing three transducers knitted into a compression bandage. No n c om me rci al us e o nly Conference presentation [Veins and Lymphatics 2017; 6:6631] [page 21] 10. Watson JM, Kang’ombe AR, Soares MO, et al. 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