Wristbot: A Novel Device for the Assessment of Proprioceptive Deficits After Stroke

The WristBot constitutes a comprehensive, integrated robotic system for the early diagnosis and rehabilitation of sensory and fine motor dysfunction to neurological or orthopedic disease. It has been validated in three clinical trials, including orthopaedic patients, Parkinsons disease and 9 chronic stroke patients. Its unique feature uses adaptive, progressive robot-aided therapy to achieve intensive, task specific wrist movements.

In the context of the proposed project we will target the stroke population. Integration refers here to the system's ability to perform the assessment of proprioceptive status and proprioceptive training in a single device. The scope of the current project is investigating the efficacy of the proprioceptive assessment of the WristBot and correlating the result throughout the rehabilitation protocol. The proposed technology comprises a hardware device with four motors that can apply torques to the human wrist about its three degrees of freedom (i.e. axes of rotation: wrist flexion/extension,abduction/adduction and forearm pronation/supination). This allows for guided and controlled movements of the wrist by delivering assistive, resistive, perturbation or no forces (patient actively moves the wrist). It contains a set of specialized software modules that a) allow for the objective, psychophysical assessment of sensory dysfunction in patients, and b) provide specialized training modules designed to improve sensory and motor functions of the wrist.

Inclusion criteria

• First clinical stroke (ischaemic or haemorrhagic) diagnosed by brain imaging CT or MRI
• Age 21 years to 85 years, both males and females.
• < 90 days of stroke on admission to rehabilitation
• Presence of either motor and /or sensory deficit detected by clinical examination.
• Ability to understand simple instructions.
• Ability to give own consent.
• Ability to sit supported in a chair for 60 minutes with appropriate rest breaks.

Exclusion criteria

• Non stroke -related causes of motor/sensory deficits
• Tetraplegia or tetraparesis
• Known diagnosis of cervical myelopathy, lower motor neuron weakness (Post polio, brachial plexopathy, peripheral neuropathy (Diabetic, carpel tunnel syndrome, B12 deficiency)
• Concomitant orthopaedic condition limiting wrist range of motion: active arm/wrist fractures, fixed contractures of the wrist joint, wrist joint arthritis, wrist fusion.
• Arm or wrist joint pain (Visual Analogue scale VAS >5/10) or instability
• Severe hemispatial neglect.
• Significant wrist spasticity with modified Ashworth Scale score 2 and above.
• Life expectancy <6 months, end stage renal or liver disease, terminal cancer.
• Pregnancy and lactation in female patients.
• Postural hypotension on sitting up
• Active skin conditions over wrist joint area which could be worsened by robotic fit (e.g. severe eczema, burns)