Diabetic foot syndrome: Help through orthosis with sensors

A sensor-equipped orthosis is being developed at Bielefeld University of Applied Sciences to improve patient self-management during the treatment of diabetic foot syndrome.

Prof. Martin Kohlhase and Prof. Rena Isabel Amelung talk to MEDICA-tradefair.com about the interaction between engineering science and health as well as the aims of the project.

Prof. Kohlhase, Prof. Amelung, how does the orthosis work and what are its benefits?

Prof. Martin Kohlhase: We want to use the orthosis to identify movement patterns in order to record mobility behavior. We also want to detect changes in the foot. People who are discharged from hospital after foot surgery often do not see their doctor again until relatively late.

During this time, we want to care for patients using sensors in the orthosis. To do this, we want to collect data from the orthosis as well as vital data with wearables such as a smartwatch so that patients can practice self-management with the support of a smartphone.

The data can also be used by professional service providers such as orthopedic technicians, chiropodists and doctors via telemedicine. We are aiming for a cost-effective solution with just a few sensors so that we can survive on the market. Inaccurate data must be processed using intelligent software so that it provides specific information.

Prof. Rena Isabel Amelung: There is still no standardized, guideline-based solution for this. There is great potential for development. Up to now, we have often only known the maximum values above which damage to the foot occurs. We want to give those affected feedback and encourage them to manage themselves.

This includes, for example, using foot assessments to encourage them to check the skin on their feet for changes. As the sensitivity in the foot is reduced, those affected do not notice if a pressure point appears or if they have injured themselves.

How does this testing work?

Kohlhase: Because there is no conscious sensation of pain in a diabetic foot due to neuropathy, we work with healthy participants. We clarify where and how many sensors are placed in the orthosis. They should provide feedback on what a healthy person feels.

To automatically recognize movement patterns in the data later on, we need information, so-called labels, about the activities. This is how we train initial models for later interaction. The second step is to measure the feet of actual patients to have a reference measurement.

Amelung: Each orthosis is developed individually. Later, each model should have a certain proportion of sensors.

What is the focus of the overall HIS4DiaPedes project? What is being developed in other sub-projects?

Kohlhase: The funding program is aimed at hybrid interaction systems, which in our case is interaction for self-management. We are the only one of eight projects in the field of diabetes with a focus on the diabetic foot. Interdisciplinarity and interprofessionalism are important.

Another key for us is voice assistance to collect additional data, as not all technologies are fully available. Prevention is also a fundamental idea. If we successfully evaluate the signals from the orthosis, we can integrate the sensor technology into the orthopedic shoe in the next step.

Amelung: The orthopedic shoe is part of the treatment process both before and after the orthosis: in the case of diabetes and foot problems, insoles are usually used first, followed by an orthopedic shoe. If this is not enough, the patient is often hospitalized and fitted with an orthosis that is only on the foot for a few weeks. If things go well, an orthopedic shoe is then fitted again.

What opportunities and efforts are there for commercialization?

Kohlhase: Next year we will decide which solution modules are promising. We will provide a functional sample of the orthosis that will be validated with a random test. Suitable sensors for the orthosis, which meet all the regulations for medical devices, will then have to be developed. Partial solutions will find their way onto the market via our consortium partners. We are still deciding whether there will be a follow-up project or whether each of the companies will continue to develop solutions.

Amelung: From a medical-therapeutic perspective, we have researched what is useful for patients to strengthen their self-management and what information is of interest to the care providers. Not everything can be implemented. We know how we envisage the solution and what we have gathered from patients and service providers. But not everything is already integrated.