Wearable Textile with Integrated Electrotherapy and Sensing for Joint Pain Management

Osteoarthritis (OA) is the most common musculoskeletal condition, with knee OA being the most prevalent. People with knee OA in the UK are predicted to increase from 4.7 to 8.3 million by 2035. Knee joint pain typically reduces physical activity, independence, and quality of life. Currently knee OA pain is managed by medication (NSAIDs/opioids) which costs £195.3 million per annum. However, medication may cause serious side effects. Uncontrolled pain ultimately may necessitate joint arthroplasty. 106,572 primary knee replacements were performed in 2019, 98% of which resulted from knee OA, costing ~£800 million per annum in the UK.

This project aims to develop an electrotherapy product, based on a wearable garment, to relieve knee OA pain through transcutaneous electrical nerve stimulation (TENS), and exercise muscles through electrical muscle stimulation (EMS). Sensing yarns integrated into the garment will accurately monitor joint movements providing users with real-time feedback. The TENS/EMS electrodes and sensing yarn will be integrated into a discreet and aesthetic garment for everyday use. The product will be controlled by a wireless controller unit. An app will allow the user to access their treatment data and monitor progress, record feedback, and communicate with healthcare professionals remotely. The product will allow users to manage their pain and exercise muscles wherever and whenever required. This will lead to better patient outcomes while reducing healthcare costs.

This project builds on our previous successful feasibility studies of a textile with integrated electrodes for pain relief and muscle stimulation, and a sensing textile for movement monitoring together with the associated electronics. Early-stage TENS prototypes have been co-designed and tested with people with knee OA and healthcare professionals. User test results have demonstrated pain reduction, ease of use and user comfort. The feedback collected through public and patient engagement and user testing has informed the design of the product targeted in this proposal.

The product will be co-developed with end users who will iteratively feedback their user requirements and test prototypes. Subcontractors will support user-centred design and the development of scalable manufacturing process to achieve market fit and volume production. A home usability test will be conducted to ensure the product is suitable for independent use in the home environment.

A pilot Randomized Controlled Trial (RCT) will be conducted to establish efficacy in pain management and inform a future definitive RCT. An ISO13485 Quality Management System and technical documentation will be developed to demonstrate compliance with UK and EU Medical Device Regulations. We will disseminate the research outcomes and engage stakeholders to promote technology uptake in order to capture the economic and societal benefits of the product.

Osteoarthritis affects 8.75 million people in the UK with the knee being most commonly affected. Knee osteoarthritis causes pain, decreases quality of life, reduces productivity and increases healthcare costs.
Transcutaneous Electrical Nerve Stimulation (TENS) is a non-pharmacological therapy providing pain relief by stimulating sensory nerves to block pain signals and produce the body's natural painkiller endorphins. TENS is recommended by NICE as an adjunct to three core osteoarthritis treatments (access to information, exercise, weight loss). TENS devices often include Electrical Muscle Stimulation (EMS) allowing the user to strengthen muscles. There are, however, a number of issues with existing devices:

1) Both TENS and EMS are delivered using either sticky gel electrodes or basic dry electrodes which are uncomfortable. Gel electrodes require regular replacement, adding cost.
2) No existing TENS machines have sensors allowing users/clinicians to monitor progress, customise treatment, or assess knee function.
3) Current products provide many stimulation programmes but insufficient guidance on which to use, making it difficult for the user to select the best settings/programmes for their needs.

We will address these issues by developing a wearable electrotherapy product with three main technical advances:

1) Long-life and comfortable electrodes, covering both the knee joint for TENS pain relief and the thigh to strengthen muscles via EMS, embedded in a discreet and aesthetic garment for everyday use.
2) Sensing yarn hidden in the garment to monitor activities and assess knee function.
3) Assessment tool built into the product to assist patients to choose customised settings.

The product will be co-developed with end users, design companies, and manufacturers to ensure widespread adoption, market fit and scalability to volume production. A clinical pilot study will establish efficacy in pain management. A Quality Management System and technical documentation will be developed to demonstrate regulatory compliance.