Smart Wearable Assistive Device for Multiple Sclerosis Patients with Impaired Deep Sensation

Background Multiple sclerosis (MS) is a chronic disease of central nervous system causing numerous symptoms. These symptoms include decreased or absent proprioceptive sensation, due to involvement of deep sensory system and spinocerebellar tract, that affects normal gait, and postural stability resulting in repetitive falls. The theory was that, the perception of pressure sensation by the plantar surface, in patients with impaired deep sensation, can be conveyed to another area with intact deep sensation perception via a specialized designed device; a method of posterior column/spinocerebellar tract injury compensation via bypassing the functionally impaired segment. This study presents the design, implementation and validation of a prototype for a smart assistive device which substitutes the lack of plantar pressure sensation by stimulating the patient's back muscles proprioceptors. Material(s) and Method(s) In this pilot study five patients with MS (pwMS) having deep sensory impairment of lower limbs, motor power >=4, intact trunk and upper limbs, cerebellar functional system score of <=2 and EDSS 3-5 were included together with two normal control subjects. The proposed device is composed of two compact shoe insoles. Each has six embedded force sensing resistors (FSR) to measure plantar pressure, and a wireless transmitter. When the patient walks, the dynamic plantar pressure is transmitted wirelessly to the belt around the trunk. The belt houses two arrays of six small micro-vibrating motors corresponding to the location of the six sensors located in each insole. The receiver module in the belt initiates the micro-vibrators in a pattern that mirrors exactly the plantar pressure recorded from the insoles. Thus, the back of the patient receives real time feedback. Two types of experimental evaluation were conducted: quantitative balance assessment and quantitative gait assessment. Result(s) The results showed that there was an improvement of PwMS balance while using the smart assistive device during different postures of quiet stance. In addition, the results of the case study participating in gait assessment showed an improvement of gait kinematic parameters after rehabilitation with the device for one week. Conclusion(s) We developed an assistive device that can help to solve the balance problems suffered by some pwMS having deep sensory affection. Still, the device has to be further upgraded to be more user friendly. Multiple sclerosis (MS) is a chronic disease of central nervous system causing numerous symptoms. These symptoms include decreased or absent proprioceptive sensation, due to involvement of deep sensory system and spinocerebellar tract, that affects normal gait, and postural stability resulting in repetitive falls. The theory was that, the perception of pressure sensation by the plantar surface, in patients with impaired deep sensation, can be conveyed to another area with intact deep sensation perception via a specialized designed device; a method of posterior column/spinocerebellar tract injury compensation via bypassing the functionally impaired segment. This study presents the design, implementation and validation of a prototype for a smart assistive device which substitutes the lack of plantar pressure sensation by stimulating the patient's back muscles proprioceptors. In this pilot study five patients with MS (pwMS) having deep sensory impairment of lower limbs, motor power >=4, intact trunk and upper limbs, cerebellar functional system score of <=2 and EDSS 3-5 were included together with two normal control subjects. The proposed device is composed of two compact shoe insoles. Each has six embedded force sensing resistors (FSR) to measure plantar pressure, and a wireless transmitter. When the patient walks, the dynamic plantar pressure is transmitted wirelessly to the belt around the trunk. The belt houses two arrays of six small micro-vibrating motors corresponding to the location of the six sensors located in each insole. The receiver module in the belt initiates the micro-vibrators in a pattern that mirrors exactly the plantar pressure recorded from the insoles. Thus, the back of the patient receives real time feedback. Two types of experimental evaluation were conducted: quantitative balance assessment and quantitative gait assessment. The results showed that there was an improvement of PwMS balance while using the smart assistive device during different postures of quiet stance. In addition, the results of the case study participating in gait assessment showed an improvement of gait kinematic parameters after rehabilitation with the device for one week. We developed an assistive device that can help to solve the balance problems suffered by some pwMS having deep sensory affection. Still, the device has to be further upgraded to be more user friendly.