More than ten million people worldwide are living with Parkinson’s disease (PD), the second most common neurodegenerative disease in the world. In many cases, the patient’s mobility is affected as the disease progresses. To help alleviate the issue, a team of cross-disciplinary PolyU academics have developed a novel Intelligent Wearable System, integrating devices which can detect abnormal gait in real-time and provide the wearer with a sensory cue to correct it. Through clinical trials, it has proven to be a convenient tool for enhancing the mobility of PD patients.

Falls follow freezing of gait

Most of the symptoms of PD are related to movement, with the prevalence of falls high among patients in the moderate stage of PD. These falls are largely caused by a sudden, transient inability to walk, known as freezing of gait (FoG), which leads to slow and reduced movement in patients, triggering difficulties with initiating a step or increasing the variability of continuous steps.

Combined detection and cueing in one system

Prof. Tao Xiaoming

 

To help PD patients initiate their first steps as soon as they encounter FoG, PolyU formed an interdisciplinary research team, led by Professor Tao Xiaoming, Director of the Research Institute for Intelligent Wearable Systems (RI-IWEAR) and Chair Professor of Textile Technology; and Professor Margaret Mak, Shun Hing Education and Charity Fund Professor in Rehabilitation Sciences and Associate Dean of the Faculty of Health and Social Sciences. Their clinical study was supported enthusiastically by the Hong Kong Parkinson’s Disease Association.

Prof. Margaret Mak

With Professor Mak providing PD-specific knowledge and arranging clinical trials, Professor Tao built a system tackling the real-life mobility problems PD patients are facing. The team then developed the first-ever integrated solution – the Intelligent Wearable System – which combines the functions of detecting abnormal gait and providing signals in a single system, and is also more convenient to use than other prevailing therapies.

 

The Intelligent Wearable System is powered by a novel type of pressure-sensing technology. It substantially reduces the amount of data that needs to be transferred and processed, enabling the gait of PD patients to be continuously monitored, and the onset of FoG to be detected automatically and accurately. When FoG is detected, the system provides timely visual and auditory cues to help restore normal movement.

The system enhanced the mobility of 88% PD patients

A two-phase clinical trial was conducted to evaluate the effectiveness of the system.

First phase of clinical trial

• Aim: to collect data, develop and train the algorithm for the detection of FoG

• Participants: 29 PD patients

• Method: 35 trials

• Result: The smart insoles can detect gait well with high accuracy of up to 95% and an algorithm developed from the data collected from smart insoles can achieve a high accuracy of over 97% for off-line detection of FoG.

Second phase of clinical trial

• Aim: to evaluate the performance of the whole system comprehensively

• Participants: 16 PD patients

• Method: survey

• Result: The system can automatically detect FoG occurrence with an accuracy of around 94% and provide sensory cueing with a short average delay of 0.37 seconds from the onset of FoG to the provision of cueing operation.

The trial found that among PD patients

• 88% confirmed that the wearable system could effectively enhance their walking

• 81% regarded the system as comfortable to use

• 70% overcame FoG

User feedback from the clinical trial suggests that the Intelligent Wearable System is an effective and convenient tool for enhancing the mobility of people with PD.

How the Intelligent Wearable System works

Step 1: Patient wears devices

The System comprises four devices worn by the PD patient to detect abnormal gait:

 

1.  a pair of smart insoles
2.  a smartphone with a specially designed application
3.  a pair of earphones
4.  a laser light

Step 2: Smart insoles receive data when the patient walks

The insoles include Pressure-Sensing Units, a microcontroller unit and Bluetooth technology. When the PD patient walks, the sensing units pick up the pressure signals to monitor any walking abnormality.

Step 3: Smart insoles send data to smartphone application

The smart insole collects the data and processes it, before sending it to the smartphone application using Bluetooth technology.

Step 4: Smartphone application triggers cueing devices

The smartphone application monitors the patient’s gait. When FoG is detected, it sends a wireless signal to the cueing devices.

Step 5: Earphones and laser light provide cues to help walking

Auditory and visual cues, controlled by the smartphone application, are provided to the PD patient to select either one option at a time. For the auditory cue, the patient chooses a rhythmic tone from the app, with the tone played into the earphones. For the visual cue, a laser light generator projects a line, with an adjustable angle and distance, on the ground in front of the patient.