Orpyx: Putting Feet First with "Sole-Full" Technology

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By Laura Fonda Hochnadel

Get your feet wet. Get your foot in the door. Put your feet to the fire. Get off on the right foot. Jump in with both feet.

The number of clichés about feet are numerous, and for good reason. Feet are the foundation of the body; they provide the base support for standing posture and bipedalism. Despite their importance to our musculoskeletal system and overall well-being, feet are often overlooked when it comes to taking care of one's body. This oversight could be particularly detrimental to individuals who suffer from peripheral neuropathy of the foot, potentially resulting in ulceration, a loss in quality of life, amputation, or even death.

According to various sources, diabetes-related foot lesions are responsible for more hospitalizations than any other diabetes-related complication. Pedorthists, podiatrists, primary care physicians, and surgeons are among the many healthcare experts who agree that prevention is essential to help avoid the occurrence or recurrence of peripheral neuropathy-related foot ulcers, the most common cause of which is diabetes. Proactive foot care includes regularly checking one's feet for injuries such as blisters, cuts, and scratches; keeping one's feet clean and dry; maintaining proper nail care; wearing proper socks and protective therapeutic footwear; and offloading dangerous pressure areas prior to ulceration. But is that enough?

"We are able to offer patients insoles, proper fitting footwear, and education about their problem," says Breanne Everett, MD. "Then we tell them to take pressure off their feet." This advice only goes so far because these patients oftentimes can't feel when they are damaging their feet, so ulcers may occur or become aggravated. Because patients with peripheral neuropathy often lack sensation in their feet, Everett says she envisioned a simple system that would enable the patient and provider to know when pressure thresholds had been met. From this vision, Orpyx Medical Technologies, Calgary, Alberta, Canada, was born. The company's first patented product is the SurroSense Rx-pressure-sensitive shoe insoles that send real-time, wireless feedback to a wristband monitor or mobile application.

Everett, the cofounder, CEO, and president of Orpyx, first became interested in trying to find solutions to address the occurrence of foot ulcers due to neuropathic complications while she was a resident in plastic and reconstructive surgery at the University of Calgary. She watched the toll that diabetic foot ulcers and corresponding complications wreaked on patients. She says she teamed up with a couple of local surgeons and serial entrepreneur Kip Fyfe. "The two surgeons and Fyfe came on with more of an advisory role," she says. "Then we brought Marcel [Groenland] on board, and he has been the technical developer behind everything." Groenland, BSc, is the company's chief technology officer. Fyfe had worked with Groenland in a different capacity previously and recommended him for the position, as he knew Groenland had received a bachelor's degree in engineering and was considering a career in medicine. "Orpyx was a good fit," Everett says.

How SurroSense Rx Works

"Right now it is really based on what we know causes ulcers within patients with diabetes," Everett says. "We are looking at when [capillary] pressures are being exceeded, which means that blood supply is not getting to the tissue properly." If enough pressure is applied, the capillaries are squeezed closed, preventing blood flow to the area, resulting in tissue death and ulceration.

The SurroSense Rx uses eight force sensors that are embedded into an insole made of three layers of materials: an impressionable memory foam top layer that conforms to the shape of the foot, a polyurethane foam middle layer, and a structural bottom layer with a polypropylene stabilizing cup to maintain shape and biomechanical support, Everett explains. The pressure sensors are designed to measure when and for how long capillary pressure has been exceeded at distinct points on the foot. The data is analyzed, and Orpyx's proprietary algorithm converts the data into a risk profile that is transmitted to a corresponding wristband or mobile application using the ANT+ wireless profile. (Author's note: ANT+ technology was developed by Dynastream Innovations, Cochrane, Alberta, Canada, a company Fyfe cofounded and for which he previously served as president.) The output device provides a visual display of pressure indications on the feet and an auditory alert when a dangerous pressure threshold has been met, Everett says. The auditory alert signals the user to offload that pressure. And because the pressure thresholds are the same regardless of a person's body weight, the insoles do not require individual calibrations.

"The reason we choose to use ANT+ wireless communication in the design of the SurroSense is because of its extremely low power requirements," Groenland says. "One of the main design requirements of the SurroSense device was the ability to operate using a coin cell battery for at least six months; ANT+ allows us to meet that requirement."

The coin-cell batteries to which Groenland is referring power the entire system and are located in each of the insole nodes (on top of the shoelaces) and in the wristband, Everett says. The batteries for the insoles have about a six-month life span, while the rechargeable batteries in the wristband monitor need to be charged about once a month.

Beyond diabetes-related foot ulcers and diabetes-related neuropathy, the SurroSense Rx has the potential to help anyone with peripheral neuropathy attributed to any cause, Everett emphasizes. "Because lack of awareness of pressure is shared [among this population], a device...that alerts the user when damage is being done [to his or her feet] would be equally applicable to this subsegment of neuropathies."

Testing

Orpyx has been conducting in-house testing during product development, Everett says, which includes sensor validity and efficacy, and usability of the auditory and visual feedback system that is built into the device. Staff at the University of Calgary Running Injury Clinic, led by the clinic's director, Reed Ferber, PhD, CAT(C), ATC, assistant professor, faculties of kinesiology and nursing, are completing calibrations and proof-of-principle studies, in which the device will be tested on ten healthy participants.

According to the Orpyx website, David Armstrong, DPM, MD, PhD, director of the Southern Arizona Limb Salvage Alliance (SALSA) will be testing the clinical efficacy of SurroSense Rx. Armstrong is the acting principal investigator of a pilot study that will follow 30 patients with diabetic neuropathy who will use the device for three months. Outcomes of interest include incidence of ulceration, amputation, infection, surgical intervention, hospitalization, and mortality, as well as balance and gait outcomes.

Publishable research data for Ferber's studies will be available by the end of this year or early 2013, according to Everett, and Armstrong will commence his study in early 2013, with publishable research data available later in the year.

"The calibrations stuff is really tweaking what we already have," Everett says, and will be done before the product goes to market. "In terms of clinical efficacy and the utility of the device in a clinical setting, [that] is something that will come over time."

Future Developments

"We are currently working on a mobile application for smart phones, and that application will have the ability to send reports to [the users] or care providers," Everett says. "It will give data from the past several months with regard to how compliant the patient has been with the device, and what are the trouble areas and how effective the [patient] has been in offloading different areas."

Everett admits a limitation of the pressure-sensing device is that other causes of ulceration-temperature, shear, and friction-are not addressed. However, she says the company's intent is to incorporate other sensing abilities in the future to improve the device's diagnostic capabilities. According to Everett, a pressure-sensing device geared toward individuals with lower-limb amputations is already in the pipeline. "If you take that same technology and incorporate it into a circular pattern sort of an insole, you can connect that to the bottom of a residual limb to measure skin breakdown," she says.

In the meantime, the SurroSense Rx is designed as an additional therapy for proper foot care. "There still are the key tenets to diabetic foot care...," Everett says. "Included in that would be appropriate blood glucose monitoring and control...[ and the] many aspects to foot care the patient should still be following. The way we see our product fitting in is as an adjunct to those existing measures and really kind of dovetailing into the existing standard of care."

Laura Fonda Hochnadel can be reached at . Shantel Wolfe contributed to the research for this article.