Myoelectrically Controlled Augmented Reality and Gaming for the Treatment of Phantom Limb Pain

The goal of the clinical investigation is to reduce phantom limb pain (PLP), a painful condition affecting 70% of amputees, so as to improve these patients' quality of life. Traditionally, mirror box therapy and other tools based on the same concept, have been used to alleviate pain, but their efficacy varies greatly. This project targets amputees for whom other PLP treatments have failed. Various virtual environments, including virtual/augmented reality, are controlled by the patient's phantom limb using muscle (myoelectric) signals from the stump. The patient learns to reactivates areas in the brain related to motor control of the missing limb.

The medical device is non-invasive and based on surface electromyography, a standard and widely used clinical and research tool. The surface electrodes are a standard disposable electrodes widely used in clinics and hospitals for EMG and/or ECG.

• Myoelectric amplifiers (battery operated and isolated from the power grid)
• Data acquisition electronics
• Personal computer
• Standard webcam
• Myoelectric pattern recognition (MPR) software
• Virtual Reality (VR)
• Augmented Reality (AR)
• Computer game

The clinical investigation period consists of 12 sessions per patient including 3 short follow-up assessments. Length of the session: 1.5 hours (the first sessions can take longer time due to learning/familiarization). The centers participating in this study can choose between the following treatment administrations:

• 2 times per week (advised)
• 1 time per week
• Daily (5 times per week)

Inclusion criteria

• Amputee patients older than 18 years.
• The patient has signed a written informed consent.
• Patients must have been treated with at least one of the following therapies:

• Conventional mirror training
• Transcutaneous electrical stimulation (TENS)
• Acupuncture
• Self-hypnosis
• Drug-based
• The last session of previous therapies (1 and 2) must be at least 1 month before beginning the treatment here proposed.
• In the case of drug-based treatments (5), the patient must report no PLP reduction for at least 1 month under the drug-based treatment and no variations on the medicaments dose. Any pain reduction potentially attributed to the drug-based treatment must be at least 3 months old.
• At least a portion of biceps and triceps muscles must be present.

Exclusion criteria

• Patient must not have a significant cognitive impairment that prevents them from following instructions.
• Upper limb amputees excluding shoulder disarticulation.
• Obese patient will not be automatically excluded, however, an evaluation in the system is required to analyse if sufficient electromyography signals can be recorded.
• Stump pain over 2 VAS of pain.
• Participating in any other clinical study that could interfere with the result in the ongoing study.
• Condition associated with risk of poor protocol compliance.
• Any other condition or symptoms preventing the patient from entering the study, according to the investigator´s judgement.