Diabetic neuropathy, a common complication of diabetes, manifests itself in the loss of sensation in the feet leading to chronic pain and ulcers, in severe cases even to amputations. While previous interventions have aimed to alleviate the symptoms, the non-invasive neuroprosthesis developed by an international research team led by Stanisa Raspopovic from MedUni Vienna addresses the cause. The system, which can be worn like a normal sock, uses targeted electrical impulses to restore the disrupted information to the nerves and thus gives back the lost sensory perception. A recent study published in the journal "Nature Communications" shows promising results in patients.
The international research team led by Stanisa Raspopovic from MedUni Vienna’s Center for Medical Physics and Biomedical Engineering and first authors Noemi Gozzi and Lauren Chee from ETH Zurich, together with Zurich and Balgrist University Hospitals, developed and tested the wearable, non-invasive neuroprosthesis "NeuroStep" on 14 patients with diabetic neuropathy. This nerve damage, which occurs in up to 50 percent of people with diabetes as a result of permanently high blood glucose levels, can currently only be treated symptomatically. It leads to serious consequences such as chronic pain, foot ulcers and even amputation, severely affecting the quality of life of people with neuropathy.
To get to the root of the problem, the researchers are focussing on electrical nerve stimulation: "In previous research into the potential use of this method for neuropathies, the electrical impulses were applied at different positions and with various configurations, finally resulting in the optimal location at the ankle level, with a personalised technological solution", says Stanisa Raspopovic, describing the technological steps to develop the "smart sock" with integrated electrodes. This technology is used to stimulate the still partially functional nerve tracts through the skin and to restore the impaired sensation. This is done using a personalised calibration procedure that adapts the stimulation to the patient’s individual degree of nerve damage. The wearable system works in closed loop while walking, providing real-time sensory feedback. For example, when patients step on their heel, they experience a corresponding induced sensation from the sock at that exact location, enhancing their balance and confidence.
Improvements after just one day’s use
The preliminary results recently published on patients prove the research team right: after just one day of using the neuroprosthesis, the majority reported significant improvements in sensation and movement coordination, as well as reduced pain. Measurements taken by the researchers showed that the electrical stimulation not only subjectively restored feeling in the feet, but also objectively improved the patients’ sensory abilities and gait stability. Using magnetic resonance imaging, the study also shows that the brain processes these restored sensations in a similar way to natural sensory stimuli, allowing intuitive use of the neuroprosthesis.
"Our study results give us reason to hope that ’NeuroStep’ will not only improve patients’ quality of life, but also break a vicious circle," says Raspopovic. Reduced mobility as a result of diabetic neuropathy means that patients move less, which in turn accelerates the progression of diabetes and increases the risk of complications. More research is needed before "NeuroStep" can be used in clinical practice. Future studies, which the team is already conducting, will focus on the long-term use of the neuroprosthesis and its effect on the progression of diabetic neuropathy.
Publication: Nature Communications
Wearable non-invasive neuroprosthesis for targeted sensory restoration in neuropathy.
Noemi Gozzi, Lauren Chee, Ingrid Odermatt, Sanne Kikkert , Greta Preatoni, Giacomo Valle, Nikolai Pfender, Felix Beuschlein, Nicole Wenderoth, Carl Zipser, Stanisa Raspopovic*.
https://doi.org/10.1038/s41467-024-55152-7
