BioPatRec pattern recognition eases 48-year phantom limb pain

A 72-year-old with 48 years of intractable phantom limb pain reached pain-free periods after ML-driven phantom motor execution.

21ⓘ

AI system

System

Phantom motor execution: BioPatRec myoelectric pattern recognition (LDA and MLP classifiers) driving augmented/virtual reality and a racing game

Model

Linear discriminant analysis and multilayer perceptrons within BioPatRec.

Release

Exact release not established.

Application developer

Chalmers University of Technology, Biomedical Engineering Division (academic lab; study part-funded by Integrum AB)

Role

The classifiers converted muscle signals into movements of a virtual limb.

Configuration

BioPatRec used one-versus-one linear discriminant analysis and a multilayer perceptron for each degree of freedom.

Inputs and outputs

Not assessed

Autonomy

Not assessed

Workflow

Decodable residual muscle activity in the stump. Classifier-driven virtual limb that responds to the patient's own effort. Repeated sessions with gamified motor execution.

Human oversight

Not assessed

Relation to AI

The pattern-recognition classifiers turn stump EMG into predicted phantom movements that the virtual limb executes. The authors argue that this engagement of motor circuitry, rather than a mirror of the contralateral limb, is the therapeutic mechanism. So the AI component is central, though the single-case design cannot isolate it.

AI contribution

The pattern-recognition classifiers turn stump EMG into predicted phantom movements that the virtual limb executes. The authors argue that this engagement of motor circuitry, rather than a mirror of the contralateral limb, is the therapeutic mechanism. So the AI component is central, though the single-case design cannot isolate it.

Benefits

Outcome identifiers

Not assessed

Benefit

after ten weeks near-absent pain developing into completely pain-free periods

Category

Improved Physical Health

Status

Not assessed

Beneficiary groups

People. Society.

Beneficiaries

Not assessed

Reach

Not assessed

Distribution and access

Not assessed

Duration

Not assessed

Expected?

Yes

Costs and harms

Not assessed

Measurement

Studies

Not assessed

Study design

Not assessed

Measurement

Not assessed

Setting and sample

Not assessed

Measures

after ten weeks near-absent pain developing into completely pain-free periods

Comparison

the patient's pain after 48 years of conventional treatments (mirror therapy, drugs, acupuncture, hypnosis)

Results

Reference: constant burning pain of an intensity of 3 on a scale from 0 to 10 (SF-MGPQ). Result: gradually reduced to complete pain-free periods.

Additional value from AI

Not assessed

Limitations

Not assessed

Denominators

Not assessed

Materials for replication

Not assessed

Money

Kind of value

Not assessed

Amount

Not assessed

Currency and prices

Not assessed

Period and unit

Not assessed

Realization

Not assessed

Recipients and payers

Not assessed

Gross or net

Not assessed

Included costs

Not assessed

Comparison

Not assessed

Method

Not assessed

Return and payback

Not assessed

People and places

Participants

Developer: Chalmers University of Technology, Biomedical Engineering Division (academic lab; study part-funded by Integrum AB). Operator: Chalmers University of Technology and Sahlgrenska University Hospital, Gothenburg (inferred from author affiliations; the paper does not name the treatment site).

Jurisdictions

Benefit: Gothenburg, Sweden (inferred from author affiliations). Developer: Sweden. Operator: Sweden.

Ownership and control

Not assessed

Dependencies

Not assessed

Cross-border connections

Not assessed

Geopolitical implications

Not assessed

Follow-up

Conditions for replication

Patient can produce distinguishable EMG patterns for phantom movements. Weekly or twice-weekly sessions sustained over months. Augmented-reality display of the restored limb.

Replication attempts

1 follow-up entries. Benefit recurred: 1.

Later findings

2 December 2016. A single-group trial of 14 patients at four clinics in Sweden and Slovenia reported significant reductions in phantom limb pain that held at six-month follow-up.

Availability

Not assessed

Institutional decision

Not assessed

Grounds

Not assessed

Action and result

Not assessed

Success criterion

Not assessed

Evidence

Source numbers

AIBD-0054-source-0001–0003

Citations

Numbered references below.

Language

Not assessed

Source relationships

Developer

Original evidence

Not assessed

Access and versions

Not assessed

Supported findings

Not assessed

Evidence strength

Not assessed

Missing evidence

Not assessed

Grades

Assessed benefits

People. Society.

Depth

People: 2. Society: 1.

Reasons

People: An identifiable patient with 48 years of treatment-resistant pain reached pain-free periods and regained phantom movement. The case gives no long-term follow-up, so a durable life-changing effect is not established. Society: Single case. The same group later ran a 14-patient trial. No population effect is documented.

Observed or intended

Not assessed

Rubric

Not assessed

Assessor and date

Not assessed

Alternative assessments

Not assessed

Fill

The makers' claim

Entry details

Kind

Not assessed

Field

Rehabilitation medicine / chronic pain. Upper-limb amputees with phantom limb pain.

Purpose

Treat phantom limb pain by letting the patient execute phantom movements decoded from stump muscle activity

Dates

Date basis unassessed: 2013 (precision unassessed). Updated: 21 October 2026.

Stage

Not assessed

Version

SHA-256: 137884106506…

References

Other identifiers

Not assessed

Category mappings

Not assessed

Brief

Not assessed

Revisions

6 revisions. Latest: 21 October 2026.

Sources

  1. Peer-reviewed study Developer

    Ortiz-Catalan M, Guðmundsdóttir RA, Kristoffersen MB, et al. (2016). Phantom motor execution facilitated by machine learning and augmented reality as treatment for phantom limb pain: a single group, clinical trial in patients with chronic intractable phantom limb pain. Lancet 388(10062):2885-2894.

  2. Case report Developer

    Ortiz-Catalan M, Sander N, Kristoffersen MB, Håkansson B, Brånemark R (2014). Treatment of phantom limb pain (PLP) based on augmented reality and gaming controlled by myoelectric pattern recognition: a case study of a chronic PLP patient. Frontiers in Neuroscience 8:24.