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Clinical evidence

The research behind the technology

About the randomized controlled trial

A recent study demonstrated an 86% reduction in diabetic foot ulcer recurrence when the Orpyx SI technology* was worn 4.5+ hours per day1

This research reports when patients with diabetes and a previous history of a healed foot ulcer receive high pressure audiovisual alerts through a sensory insole system; there is a significant reduction in diabetic foot ulcer incidence.

The randomized, controlled, multi-site trial, conducted at Manchester Metropolitan University and Lancashire Teaching Hospital in the UK, used Orpyx SI technology which provided patients with real-time feedback, enabling them to take immediate action when sustained high pressure was detected. High pressure can cause skin damage on the soles of the feet, which if left untreated could lead to foot ulcers, infections and, in the worst case scenario, amputations.

The Orpyx SI technology continuously measured levels of pressure on the bottom of the feet. The patient received an audiovisual alert through a dedicated smartwatch when there was a dangerous amount of sustained high pressure. This instant feedback included the location of the high pressure point and prompts allowing the wearer to take immediate action to relieve the pressure on the affected area of the foot.

*Study was conducted with first generation SurroSense Rx® which has the same pressure algorithm as Orpyx SI Sensory Insoles

The only digital diabetic foot RPM solution backed by an RCT

58 people with diabetes, who had a high-risk of developing foot ulcers, participated in this 18 month study while going about their daily lives. Around half of the people received pressure alerts from the device (n=18), while the other half did not (n=22). The results of the study published in The Lancet Digital Health journal showed that the group receiving the pressure alerts were 71% less likely to develop recurrent foot ulcers compared to the group who didn’t receive the instant feedback. A subgroup of patients that wore the sensory insoles greater than 4.5 hours a day were 86% less likely to re-ulcerate.

“These results are meaningful as they reflect what is actually occurring on the plantar surface of the foot as the patients go about their daily activities,” stated Neil Reeves, PhD, study lead and Professor of Musculoskeletal Biomechanics at Manchester Metropolitan University in Manchester, UK. “Even more importantly, we know education alone is not sufficient to change the behaviour of patients with diabetic peripheral neuropathy (DPN). With this system, the patient can react to the alerts and immediately change their behaviour to relieve high pressures when they occur.”

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Cost-effectiveness study

A peer-reviewed study showed a drastic decrease in the occurrence of foot ulcers and a substantial cost savings when using SOC + Orpyx technology2

A peer-reviewed, prospective cohort study used inputs from 15 patients with a recent history of DFUs, and decision tree models to estimate clinical outcome probabilities and associated costs. It compared the results of the prevailing standard of care (SOC) against the SOC applied in conjunction with the Orpyx SI technology. Comparative cost of care was calculated over short-term (3 months) and long-term (18 months) periods. The 2018 study was conducted from the third-party payer perspective with costs in 2017 USD.

Sensory insoles could provide substantial savings to the U.S. healthcare system

These results reflect an 83.72% decrease in event occurrence over 3 months, a 77.42% decrease in event occurrence over 18 months, and a 70% overall reduction in cost of care.

Given the debilitating nature of DFUs and their complications, members are often required to take time off of work or modify ambulatory work duties; this results in loss of income. For privately insured members, these work-related costs were found to be $3,259.168. Due to the recurrent nature of DFUs, there is potential for this cost to multiply within one year, thus increasing the cost burden for members with a DFU. More specifically, 49% of members with a DFU experience recurrence in the first year. From this, it can be inferred that reducing DFU recurrence will also reduce indirect costs incurred by members. Extrapolating this theory suggests that reducing DFU recurrence by 86% would generate indirect savings of approximately $2,800 per DFU.

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Patient case series

Innovative plantar sensory insoles to prevent foot ulcer recurrence and guide treatment plans in patients with diabetic peripheral neuropathy3

This 17-patient case series examines the use of Orpyx SI® Custom sensory insoles in patients at risk of DFU formation. Patients were remotely monitored by a nurse for plantar pressure, temperature, step-count, and hours of use, and were provided with real-time cues for pressure offloading as they went about their daily lives. The data collected from the sensory insole system was used to track activity, ulceration, and response to feedback from real-time alerts. Patients were contacted when areas of concern were seen based on collected data. The patients were provided with coaching and education related to reducing risk factors and overall support to improve foot health.

Participant-level alerts and RPM interactions resulted in participants coming back for a visit before a wound developed for proactive intervention

Of the 17 patients provided with the sensory insole system, 1 withdrew (no data collected) and 1 presented with a DFU. On average, patients used the sensory insole system for 4.7 hours per day, and increased usage over time. The patient who presented with a DFU had below average adherence (2.2 hours per day) prior to DFU development. Patients indicated that wearing the insoles with the real-time alerts increased their awareness of activities that due to their peripheral neuropathy, put them at risk for development of a wound. They also experienced more open communication with their providers. This system offers early intervention for at-risk patients, preventing more serious complications from occurring. Providers received information that they have never had before, allowing them to proactively bring patients into the clinic or office before a wound develops. 

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Clinical evidence

Orpyx clinical research
  • Innovative intelligent insole system reduces diabetic foot ulcer recurrence at plantar sites: a prospective, randomised, proof-of-concept study, Abbott et al (2019)​
  • Cost effectiveness of smart insoles in preventing ulcer recurrence for people in diabetic foot remission, Najafi et al (2018)
  • Smarter Sole Survival, Najafi et al (2017)
  • A Foreign Body Through the Shoe of a Person with Diabetic Peripheral Neuropathy Alters Contralateral Biomechanics, Chatwin et al (2018)​
  • Use of the SurroSense Rx System for Sensory Substitution of the Insensate Plantar Aspect Resurfaced with Latissimus Dorsi Muscle Free Flap and Skin Graft: A Retrospective Case Study, Everett et al (2017)
  • Novel Pressure-Sensing Smart Insole System Used for the Prevention of Pressure Ulceration in the Insensate Foot: A Case Report, Alfonso & Chiu (2017)
  • Validation of Plantar Pressure Measurements for a Novel In-Shoe Plantar Sensory Replacement Unit, Ferber et al (2013)
Plantar pressure
  • Bus S. The Role of Pressure Offloading on Diabetic Foot Ulcer Healing and Prevention of Recurrence. Plastic and Reconstructive Surgery. 2016;138: 179S-187S
  • Jones P. et al. In-shoe pressure thresholds for people with diabetes and neuropathy at risk of ulceration: a systematic review. Journal of Diabetes and its Complications. 2021; 35(3): 107815
  • Chatwin KE. et al. The role of foot pressure measurement in the prediction and prevention of diabetic foot ulceration – a comprehensive review. Diabetes Metabolism Research and Reviews. 2019; 36(4):e3258
  • Home Monitoring of foot skin temperatures to prevent ulceration, Lavery et al (2004)​
  • Preventing diabetic foot ulcer recurrence in high-risk patients, Lavery et al (2007)​
  • Skin temperature monitoring reduces the risk for DFU in high-risk patients, Armstrong et al (2007)
Step count and activity
  • Colberg SR, Sigal RJ, Yardley JE, Riddell MC, Dunstan DW, Dempsey PC, et al. Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association. Diabetes Care 2016 Nov;39(11):2065-2079.
  • Armstrong DG, Lavery LA, Holtz-Neiderer K, Mohler MJ, Wendel CS, Nixon BP, Boulton AJM. Variability in activity may precede diabetic foot ulceration. Diabetes Care 2004 Aug;27(8):1980-1984.
  • Maluf KS, Mueller MJ. Novel Award 2002: comparison of physical activity and cumulative plantar tissue stress among subjects with and without diabetes mellitus and a history of recurrent plantar ulcers. Clin Biomech 2003 Aug;18(7):567–575.
  • Lott DJ, Maluf KS, Sinacore DR, Mueller MJ. Relationship between changes in activity and plantar ulcer recurrence in a patient with diabetes mellitus. Phys Ther. 2005 Jun;85(6):579-588.
  • Gray K, Game F, Pinnington L. Encouraging reduction of activity amongst patients with diabetic foot ulcers. Wounds UK 2018 Jul;14(3):34-39.
  • LeMaster JW, Mueller MJ, Reiber GE, Mehr DR, Madsen RW, Conn VS. Effect of weight-bearing activity on foot ulcer incidence in people with diabetic peripheral neuropathy: feet first randomized controlled trial. Phys Ther. 2008 Nov;88(11):1385-1398.
  • Mueller MJ, Tuttle LJ, Lemaster JW, Strube MJ, McGill JB, Hastings MK, et al. Weight-bearing versus nonweightbearing exercise for persons with diabetes and peripheral neuropathy: a randomized controlled trial. Arch Phys Med Rehabil 2013 May;94(5):829-838.
  • LeMaster JW, Reiber GE, Smith DG, et al. Daily weight-bearing activity does not increase the risk of diabetic foot ulcers. Med Sci Sports Exerc. 2003 Jul;35:1093–1099.
Diabetic foot ulcers
  • Dr. Sicco A. Bus. (2018, May 28). IWDGF Guidelines. Retrieved October 01, 2020, from;
  • Bus et al. Guidelines on the prevention of foot ulcers in persons with diabetes (IWGDF 2019 update). Diab Metab Res Rev. 2020. e3269
  • Waaijman R, de Haart M, Arts MLJ, Wever D, Verlouw AJWE, Nollet F, Bus SA. Risk factors for plantar foot ulcer recurrence in neuropathic diabetic patients. Diabetes Care 2014 Jun; 37(6): 1697-1705.
  • Lazzarini PA, Crews RT, Van Netten JJ, Bus SA, Fernando ME, Chadwick PJ, et al. Measuring Plantar Tissue Stress in People With Diabetic Peripheral Neuropathy: A Critical Concept in Diabetic Foot Management. J Diab Sci Technol 2019 Sep;13(5):869-880.
  • Mueller MJ, Maluf KS. Tissue adaptation to physical stress: a proposed “Physical Stress Theory” to guide physical therapist practice, education, and research. Phys Ther. 2002 Apr;82:383– 403.

1. Abbot CA, et al. Innovative intelligent insole system reduces diabetic foot ulcer recurrence at plantar sites: a prospective, randomised, proof-of-concept study. Lancet Digital Health Oct. 2019; 1: e308–18. *Study was conducted with first generation SurroSense Rx® which has the same pressure algorithm as Orpyx SI Sensory Insoles 2. Najafi B et al, Cost effectiveness of smart insoles in preventing ulcer recurrence for people in diabetic foot remission. Wound Care Management (2018) Volume 1(1): 5-7. 3. Liden et al. Innovative Plantar Sensory Insoles to Prevent Foot Ulcer Recurrence and Guide Treatment Plans in Patients with Diabetic Peripheral Neuropathy. Poster presented at SAWC Fall; Oct 14-16, 2022; Las Vegas, NV