Advice

The technology

The technology

The ReStore Soft Exo‑Suit (ReWalk Robotics) is a device designed to help people having walking gait training after a stroke or brain injury that has affected the movement in one of their legs. It is intended to be used during physiotherapy sessions to help the user relearn the movements needed for walking. The system comprises:

  • a waistbelt that holds the powerpack and an actuator attached to a pulley cartridge

  • a fabric-based calf-wrap to secure the device to the person

  • a shoe insole for the foot needing assistance that attaches to the mechanical cables

  • sensors that clip to the shoes of both feet to monitor gait

  • mechanical cables connecting the different pieces of the system together to assist the person's ankle in motion (plantarflexion and dorsiflexion)

  • a handheld controller with the integrated therapist interface app to enable therapists to control the mode and amount of assistance from ReStore.

The system weighs around 5 kg in total. The actuator in the waistbelt produces movement, which is conveyed through the pulley cartridge to mechanical cables attached to the calf-wrap and the insole. The system can move the foot in 2 ways. When the cable near the heel (the posterior cable) is shortened, the heel is pulled up to create plantarflexion which gives forward propulsion. When the cable on the top of the foot (the anterior cable) is shortened, the top of the foot is pulled up to create dorsiflexion which allows ground clearance of the foot as it moves forward.

Force sensors in the calf-wrap and motion sensors clipped onto the user's shoes record movement of the feet and the forces delivered with each step. A proprietary algorithm is used to process the data in real time, to build a picture of the user's gait cycle. This information is used to match the timing and level of mechanical assistance to the affected foot, to synchronise movement to the user's natural gait. If the user's gait speed, step length or walking direction changes, the system detects this change and adjusts the level of mechanical assistance accordingly. Stance time ratio (the ratio of time spent in stance on each foot) and step count are also recorded.

The foot movement data can be viewed on the handheld controller, which is linked to the suit via Bluetooth. This information can be used by healthcare professionals to adjust the level of mechanical assistance applied, and to monitor each user's progress during therapy. The software on the controller includes pre-programmed walking tests such as 10‑metre, 2‑minute and 6‑minute walking tests.

The handheld controller can also be used to quickly change ReStore's mode:

  • In assist mode, data from the motion sensors calculates the level and timing of mechanical assistance to the affected foot.

  • In slack mode, data from the motion sensors can be viewed on the handheld controller but the cables are released so that no mechanical assistance is applied. This allows the user to practice walking without assistance, without having to interrupt the training session to remove the device.

  • In brace mode, the cables are locked into position to provide continuous ankle support. Data from the motion sensors can be viewed on the handheld controller.

The modes can be switched to help with gait training, and gait data can be collected in any mode, so that data from different sessions can be compared. ReStore can be used alongside aids such as hoists, walking sticks and frames, and can be used on a treadmill.

The company notes that ReStore should not be used with ankle foot orthosis because it would restrict ankle movement and prevent rehabilitation.

Innovations

The company says that the ReStore Soft Exo‑Suit is innovative for the following reasons:

  • The system creates 2 directions of flex in the ankle, which helps to avoid compensatory issues such as hip hiking and circumduction.

  • The technology can be used to train the plantarflexion movement, which is not well addressed by other treatment options.

  • The real-time data analytics allow the foot movement to be adaptive to the user's natural gait and level of need.

  • The mechanised foot movement reduces the need for physiotherapists to manually move the user's foot while they walk. The company says that up to 3 physiotherapists are needed per patient for gait training with manual foot movement but only 1 is needed with ReStore.

There are technologies that appear to fulfil a similar function to ReStore. NICE has published a medtech innovation briefing on Ekso exoskeleton. Ekso exoskeleton uses battery-powered motors to drive the legs and help people to relearn step patterns and weight shifts, to try to regain their natural gait. ReStore provides plantarflexion and dorsiflexion assistance to the affected leg, taking feedback from a sensor on the unaffected leg to improve speed and symmetry in the walking gait.

Current care pathway

Standard care for managing movement difficulties after stroke includes physiotherapy and fitness, strength and repetitive task training. Walking therapy is recommended for people who have had a stroke and who are able to walk, with or without assistance. Treadmill training, with or without body weight support, should be considered as one option for walking therapy. Electromechanical gait training should only be used as part of a research study, according to NICE's guideline on stroke rehabilitation in adults.

The medium- to longer-term care of people who have had a traumatic brain injury may include rehabilitation to improve mobility and independence. Rehabilitation plans should be goal-oriented and be tailored to each person's needs, taking account of their views, cultural background and lifestyle before the injury. When offering movement and motor control therapy to people with an acquired brain injury, partial bodyweight treadmill training, strength training, gait re-education to improve walking ability, and exercise to improve fitness should be considered (British Society of Rehabilitation Medicine, 2003).

The following publications have been identified as relevant to this care pathway:

Population, setting and intended user

The ReStore Soft Exo‑Suit is intended to be used in physiotherapy clinics, in a secondary care, outpatient or community care setting.

ReStore would be used by people who have hemiplegia or hemiparesis resulting from stroke, who are 142 cm to 192 cm tall and weigh less than 120 kg. It is contraindicated in pregnancy and in people who have serious comorbidities that may prevent ReStore from being used safely, including:

  • severe peripheral artery disease

  • unresolved deep vein thrombosis

  • restricted range of ankle movements that may prevent safe walking

  • cognitive disabilities or mental health conditions that may prevent the user following instructions

  • open wounds or broken skin where the exosuit touches the body

  • urethane allergy.

Additional monitoring and support may be needed for people who have:

  • severe aphasia that limits their ability to express their needs or discomfort

  • uncontrolled muscle spasticity

  • mild to moderate peripheral artery disease

  • a need for more than moderate assistance from a therapist to walk a short distance.

In clinics the use of ReStore would be supervised by physiotherapists or neurological physiotherapists. The company says that typically 1 to 3 physiotherapists are needed to supervise each patient at a gait training session. ReWalk Robotics trains physiotherapists to use ReStore. Training usually takes about 4 hours and is in person. It includes a presentation, hands-on training with ReStore, and an exam. A physiotherapist can become a 'lead therapist' through another training session including an extra hour of training, clinical use of the ReStore with at least 5 patients, and an exam. The company says that all training is included in the device purchase cost.

Costs

Technology costs

The ReStore Soft Exo‑Suit costs £22,995 per unit (excluding VAT). The company estimates that the annual cost of using ReStore Soft Exo‑Suit would be around £4,000, assuming 10 new users each month and assuming that both cartridges are replaced every year. It is expected to last 2 to 3 years. The cost includes a 2‑year warranty, servicing and maintenance.

Calf-wrap liners and cable cartridges are additional costs. A calf-wrap liner is similar to a prosthetics sleeve and is worn on the calf as a barrier to protect the user's skin. The liners come in 4 sizes and are not intended to be shared between users. Each user can wash and re-use their own liner multiple times. Each liner costs £24 and they are sold in packs of 10. Twenty calf-wrap liners (5 of each size) are included in the purchase price. Cable cartridges are the mechanical cables that provide the lifting forces to the user's foot. The cables can be re-used between users but need to be replaced every 600,000 total steps (300,000 paretic steps) in assist mode, which is approximately 1 year of moderate to heavy usage. The cable cartridge can be refurbished for £524 or replaced for £1,277. A starter kit of 2 cable cartridges (1 of each size) is included in the purchase price.

Costs of standard care

Gait rehabilitation therapy is provided by physiotherapists in the NHS. The cost of outpatient physiotherapy is from £55 to £66 per session (National Cost Collection data 2018/2019).

Resource consequences

The ReStore Soft Exo‑Suit is currently being used by 2 private physiotherapy practices. The company is in discussions about trialling it at 1 NHS site.

If ReStore is adopted in the NHS it would be an additional cost to standard care. If it is shown to have long-term benefits such as improved gait retraining in people recovering from stroke, then costs could be saved from the reduced costs of treating falls. There is currently no evidence to support this, however. Savings could also be made if using ReStore reduces staffing costs by reducing the number of physiotherapists needed in gait rehabilitation sessions. There was no published evidence on how ReStore affects staffing but the experts suggested that it could reduce the number of staff needed in therapy sessions. ReStore can be used alongside other gait training aids and would not require any additional changes in facilities or infrastructure.