SyneuraX

The SyneuraX AI science programme

Every rehabilitation signal is a new scientific question.

SyneuraX captures responses, movement and care trajectories in virtual reality. This map pairs each data layer with each algorithm family: its purpose, the performance reported in the literature, and how strong that evidence is.

14data layers
16algorithm families
89data × algorithm pairs
62applications

Combination map

Each cell pairs a data layer with an algorithm family, and its number counts the applications. Select a cell to see them.

Bayesian adaptivePsychometricsCognitive modellingHierarchical and longitudinalSignal processingMachine learningDeep learningBandits and RLLanguage modelsRAG and knowledgeSpeech AIGenerative contentAnomaly detectionCausal and trial designPrivacy-preservingSimulation and twins
Per-trial responses
Level parameters
Session history
Cognitive profile
Hand and arm motion
Head and posture
Gaze
Physiology
Speech and language
Clinician decisions
Clinical records and scales
Content and stimuli
Technical telemetry
Multi-centre data

AI applications in rehabilitation: purpose and performance

Figures come from published studies of comparable systems and populations. They are not SyneuraX results.

62 applications

Strong evidenceExercises and difficulty

Threshold estimation with QUEST+ and Psi

Purpose

Picks the most informative next stimulus in a short assessment block, reaching each person's threshold in few trials.

Performance in the literature

In the method paper, under 30 trials sufficed for threshold and about 300 for slope.

Data

Per-trial responsesLevel parameters

Algorithm

Bayesian adaptive
Moderate evidenceExercises and difficulty

Adaptive Design Optimization (ADO)

Purpose

Optimises the test design using group and individual priors, shortening assessment.

Performance in the literature

Moderate evidence, mostly from vision science.

Data

Per-trial responsesLevel parametersSession history

Algorithm

Bayesian adaptiveHierarchical and longitudinal
Moderate evidenceExercises and difficulty

Between-session progression suggestions

Purpose

Uses the person's trend to suggest the next session's level to the clinician, supporting adherence.

Performance in the literature

In a 224-patient multicentre trial, adaptive training improved compliance (p=0.009) while the primary outcome was equal (OR 1.02).

Data

Session historyLevel parametersCognitive profile

Algorithm

Hierarchical and longitudinalMachine learning
ExploratoryExercises and difficulty

Bayesian Knowledge Tracing

Purpose

Estimates the probability of skill mastery from success and error sequences.

Performance in the literature

Established in education; little tested in rehabilitation.

Data

Per-trial responsesSession history

Algorithm

Bayesian adaptive
ExploratoryExercises and difficulty

Deep Knowledge Tracing

Purpose

Learns learning patterns from long sequences to predict next performance.

Performance in the literature

Its advantage has been seen only on very large datasets.

Data

Per-trial responsesSession historyMulti-centre data

Algorithm

Deep learning
ExploratoryExercises and difficulty

Contextual bandits for exercise ordering

Purpose

Learns the best option per person for low-risk choices such as exercise order.

Performance in the literature

Clinical evidence is limited: one study of 27 people with diabetes. Personalisation must be tested as real rather than spurious.

Data

Session historyLevel parametersCognitive profile

Algorithm

Bandits and RL
ExploratoryExercises and difficulty

Reinforcement learning for difficulty control

Purpose

Learns a long-horizon difficulty policy from care trajectories, tested first in simulation.

Performance in the literature

Estimates from observational data are prone to bias and need very careful evaluation design.

Data

Per-trial responsesSession historyLevel parameters

Algorithm

Bandits and RLSimulation and twins
ExploratoryExercises and difficulty

Closed-loop adaptation to arousal

Purpose

Aligns exercise intensity with the person's physiological signals.

Performance in the literature

Our review found no randomised trial of this approach.

Data

PhysiologyPer-trial responses

Algorithm

Bandits and RLMachine learning

Source

No direct source found
Moderate evidenceExercises and difficulty

Randomised comparison of algorithm and simple rule

Purpose

Shows whether an algorithm truly beats a transparent rule at equal dose.

Performance in the literature

Reference effect: in stroke, VR versus alternative therapy has a small effect (SMD 0.20, low certainty). SMART and micro-randomised designs suit an effect of this size.

Data

Session historyLevel parametersClinical records and scales

Algorithm

Causal and trial design
Strong evidenceMeasurement and reporting

Hierarchical Bayesian patient estimates

Purpose

Models measurement error and returns a value with an uncertainty interval for each index.

Performance in the literature

Analysis choice alone moved reliability from about 0 to above 0.9.

Data

Per-trial responsesCognitive profile

Algorithm

Hierarchical and longitudinal
Strong evidenceMeasurement and reporting

Index reliability audit

Purpose

Measures each index's stability across repeat sessions so only dependable ones reach the report.

Performance in the literature

Accepted ICC bands: below 0.5 poor, 0.5–0.75 moderate, 0.75–0.9 good, above 0.9 excellent. Cognitive-task reliability has been reported from 0 to 0.82.

Data

Cognitive profileSession history

Algorithm

Hierarchical and longitudinal
Strong evidenceMeasurement and reporting

Base-rate tables for indices

Purpose

Shows how many low scores are normal in a healthy person, preventing false alarms.

Performance in the literature

In one battery, 45.9% of people had at least one score at or below the 16th percentile.

Data

Cognitive profile

Algorithm

PsychometricsHierarchical and longitudinal
Strong evidenceMeasurement and reporting

Reliable Change Index

Purpose

Separates real patient change from measurement noise and practice effects.

Performance in the literature

A standard clinical method; higher reliability makes smaller changes detectable.

Data

Session historyCognitive profile

Algorithm

Hierarchical and longitudinal
Strong evidenceMeasurement and reporting

Mixed-effects growth models

Purpose

Estimates each person's trajectory despite irregular sessions and missing data.

Performance in the literature

An established method for analysing clinical change.

Data

Session historyCognitive profile

Algorithm

Hierarchical and longitudinal
Moderate evidenceMeasurement and reporting

Drift Diffusion Model

Purpose

Separates processing speed, caution and motor time in two-choice tasks.

Performance in the literature

Test-retest above r=0.70; about 68% accuracy for MCI detection.

Data

Per-trial responses

Algorithm

Cognitive modelling
Moderate evidenceMeasurement and reporting

Stop-Signal Reaction Time

Purpose

Estimates how quickly an initiated response can be stopped.

Performance in the literature

Consensus calls for at least 50 stop trials; the best estimator reached r=0.57 in simulation.

Data

Per-trial responses

Algorithm

Cognitive modelling
Moderate evidenceMeasurement and reporting

Item Response Theory and adaptive testing

Purpose

Achieves the precision of a full item bank with far fewer items.

Performance in the literature

11 items reached r=0.94 against the full bank, in simulation.

Data

Per-trial responsesCognitive profile

Algorithm

Psychometrics
Moderate evidenceMeasurement and reporting

Factor analysis of cognitive domains

Purpose

Tests the domain structure against data and builds valid composite scores.

Performance in the literature

Established; the unity of some constructs such as attention and inhibition is debated.

Data

Cognitive profile

Algorithm

Psychometrics
Moderate evidenceMeasurement and reporting

Normative modelling and regression norms

Purpose

Places each person against peers of similar age, sex and education.

Performance in the literature

Strong in brain imaging; applying it to VR behaviour is a new research direction.

Data

Cognitive profileMulti-centre dataClinical records and scales

Algorithm

Hierarchical and longitudinalMachine learning
Strong evidenceMeasurement and reporting

Regularised regression baseline

Purpose

A simple, interpretable model every more complex model must beat.

Performance in the literature

Across 282 comparisons, machine learning showed no advantage over logistic regression in low-bias studies. External validation needs at least 100 events.

Data

Cognitive profileClinical records and scales

Algorithm

Machine learning
ExploratoryMeasurement and reporting

Cognitive screening from VR behaviour

Purpose

Flags signs of mild cognitive impairment from exercise performance for further assessment.

Performance in the literature

Pooled AUC of about 0.95 is reported, mostly from small case-control samples with little external validation. Machine learning did not raise pooled accuracy.

Data

Cognitive profilePer-trial responsesClinical records and scales

Algorithm

Machine learning
ExploratoryMeasurement and reporting

Multimodal deep clinical prediction

Purpose

Combines behaviour and movement to predict disease course or treatment response.

Performance in the literature

In one review, 20 of 21 abstracts recommending clinical use lacked external validation.

Data

Per-trial responsesHand and arm motionClinical records and scales

Algorithm

Deep learning
ExploratoryMeasurement and reporting

Cognitive digital twin

Purpose

Simulates the response to different exercise scenarios from each person's model parameters.

Performance in the literature

Our review found no direct clinical evidence; a long-term research direction.

Data

Per-trial responsesSession historyCognitive profile

Algorithm

Simulation and twinsCognitive modelling

Source

No direct source found
Strong evidenceMeasurement and reporting

Patient-level validation

Purpose

Keeps each patient's data on one side of the train/test split so true accuracy is measured.

Performance in the literature

Data leakage can overstate accuracy by 29–55%.

Data

Per-trial responsesSession history

Algorithm

Machine learning
Moderate evidenceMovement and body

Reach kinematics

Purpose

Extracts movement time, peak speed and hand path to track motor performance.

Performance in the literature

In 39 healthy adults, Quest 3 against OptiTrack: 0.68–3% movement-time error and about 4.8–8.8% speed error.

Data

Hand and arm motion

Algorithm

Signal processing
Moderate evidenceMovement and body

Range-of-motion trends

Purpose

Follows session-to-session range of motion with no added equipment.

Performance in the literature

Controller error up to 13.52 mm, mostly in static conditions.

Data

Hand and arm motion

Algorithm

Signal processing
Moderate evidenceMovement and body

Movement smoothness (SPARC, LDLJ)

Purpose

Measures motor control quality beyond speed and range.

Performance in the literature

On Vicon in 31 stroke patients, ICC was 0.912 and 0.911; validation on Quest is the next research step.

Data

Hand and arm motion

Algorithm

Signal processing
ExploratoryMovement and body

Estimating Fugl-Meyer scores

Purpose

Estimates the clinical motor score from movement data, enabling assessment between visits.

Performance in the literature

With wearable IMUs: 7% normalised error in 11 people. A Quest-only estimator has not been published.

Data

Hand and arm motionClinical records and scales

Algorithm

Machine learningDeep learning
Moderate evidenceMovement and body

VR Box and Block equivalent

Purpose

Measures manual dexterity with a task mirroring the clinical test in VR.

Performance in the literature

Correlation with the physical test is reported as moderate to high; agreement between the two still needs establishing.

Data

Hand and arm motionClinical records and scales

Algorithm

Signal processingMachine learning
ExploratoryMovement and body

Trunk compensation detection

Purpose

Detects when a patient substitutes trunk movement for arm movement.

Performance in the literature

In a preprint, macro-F1 fell from 0.80 in healthy people to 0.43 in patients; a trunk sensor may help.

Data

Hand and arm motionHead and posture

Algorithm

Machine learningDeep learning
ExploratoryMovement and body

Postural sway from headset motion

Purpose

Estimates static balance from head motion.

Performance in the literature

A force-plate study reported correlations that vary by metric.

Data

Head and posture

Algorithm

Signal processing
ExploratoryMovement and body

Tremor analysis

Purpose

Extracts hand tremor features to follow movement disorders.

Performance in the literature

No Quest validity study was found; a wrist sensor is a better candidate.

Data

Hand and arm motion

Algorithm

Signal processingDeep learning

Source

No direct source found
ExploratoryMovement and body

Self-supervised motion learning

Purpose

Learns movement representations from unlabelled data so models need fewer clinical labels.

Performance in the literature

No direct comparison with simple models on VR data was found; must be judged on patient-level splits.

Data

Hand and arm motionHead and postureMulti-centre data

Algorithm

Deep learning
ExploratoryMovement and body

Gaze markers in cognitive exercises

Purpose

Adds fixation, dwell time and antisaccade error alongside behavioural responses.

Performance in the literature

In a preprint on Quest Pro, about 1.04° accuracy at 89 Hz. Quest 3 and 3S have no eye tracking.

Data

GazePer-trial responses

Algorithm

Signal processingCognitive modelling
Moderate evidenceMovement and body

Heart rate and pulse-rate variability

Purpose

Follows session physiological load with a wrist or chest sensor.

Performance in the literature

In 931 people, optical sensing estimated HRV with non-uniform bias; ECG is needed for clinical outcomes.

Data

Physiology

Algorithm

Signal processing
ExploratoryMovement and body

Affective state estimation

Purpose

Estimates emotional state from several signals.

Performance in the literature

Reported accuracy is limited, and this use is a distinct high-risk category under the EU AI Act.

Data

PhysiologyGazeSpeech and language

Algorithm

Machine learningDeep learning
Moderate evidenceClinician assistance

Automated reports with locked numbers

Purpose

Software computes the numbers, the model writes the prose and the clinician signs off.

Performance in the literature

In the NOHARM benchmark (preprint) over 80% of severe errors were omissions, so a mandatory-findings checklist is central to the design.

Data

Cognitive profileSession history

Algorithm

Language models
ExploratoryClinician assistance

Natural-language level design

Purpose

Turns a clinician's request into valid parameters, passing a validator before use.

Performance in the literature

No clinician study was found yet; the validator and human approval block invalid output.

Data

Level parametersClinician decisions

Algorithm

Language models

Source

No direct source found
Moderate evidenceClinician assistance

Grounded answers from clinical guidelines

Purpose

Answers clinicians with direct quotes from approved sources and declines when none applies.

Performance in the literature

Hallucination rose from 5 per 100 in one turn to 40 per 100 after 10 turns; single-turn design is safer.

Data

Clinical records and scalesContent and stimuli

Algorithm

RAG and knowledgeLanguage models
ExploratoryClinician assistance

Suggested care-plan options

Purpose

Shows the clinician several reasoned options; the decision always stays with the clinician.

Performance in the literature

No randomised trial in rehabilitation was found, and automation bias must be designed against.

Data

Session historyCognitive profileClinical records and scales

Algorithm

Language modelsMachine learning

Source

No direct source found
ExploratoryClinician assistance

Decline and plateau alerts

Purpose

Shows clinicians unexpected changes in a patient's course earlier.

Performance in the literature

Should first be evaluated silently on multi-patient longitudinal data.

Data

Session historyCognitive profile

Algorithm

Hierarchical and longitudinalAnomaly detection

Source

No direct source found
Moderate evidenceClinician assistance

Persian drafting with a local model

Purpose

Generates report text on the clinic computer, so data stays on site.

Performance in the literature

On PersianMedQA, Persian-branded models scored 34.87% and 24.22% against 83.09% for GPT-4.1, so model choice needs Persian testing.

Data

Cognitive profileClinician decisions

Algorithm

Language models
Moderate evidenceSpeech and language

Verbal fluency with clinician review

Purpose

Converts speech to text and timing so the language domain can be measured.

Performance in the literature

Preliminary Persian norms exist. Whisper can invent text during pauses, so human review is required.

Data

Speech and languageCognitive profile

Algorithm

Speech AI
ExploratorySpeech and language

Speech biomarkers of cognitive impairment

Purpose

Studies speech features as early-sign research markers.

Performance in the literature

Samples are small: ADReSS-M had only 46 test speakers.

Data

Speech and languageClinical records and scales

Algorithm

Speech AIMachine learning
ExploratorySpeech and language

Persian clinical speech corpus

Purpose

Builds a consented Persian speech collection, which is scarce in this field.

Performance in the literature

Published Persian studies have around 50 participants, and Persian and English patterns differ.

Data

Speech and languageMulti-centre data

Algorithm

Speech AIMachine learning
ExploratorySpeech and language

Language indices from Word Factory

Purpose

Turns performance in the Persian word exercise into language measurement indices.

Performance in the literature

Needs a validity study against standard language tests.

Data

Per-trial responsesCognitive profile

Algorithm

PsychometricsHierarchical and longitudinal

Source

No direct source found
Moderate evidenceSpeech and language

Multilingual voice guidance

Purpose

Delivers exercise instructions in the patient's language with natural voice, important for low literacy.

Performance in the literature

Pre-produced, human-reviewed text removes the risk of live errors.

Data

Content and stimuli

Algorithm

Speech AIGenerative content

Source

No direct source found
ExploratorySpeech and language

Rule-first VR coach

Purpose

Guides and encourages patients with clinically approved lines.

Performance in the literature

One study covered 21 healthy people outside VR; no study with older adults or patients in VR was found.

Data

Session historySpeech and languageContent and stimuli

Algorithm

Language modelsSpeech AI
ExploratorySpeech and language

Open conversation with a language model

Purpose

Free conversation with patients for engagement and support.

Performance in the literature

A meta-analysis found no low-bias trial, and data on older adults was very scarce.

Data

Session historySpeech and language

Algorithm

Language modelsSpeech AI
Moderate evidenceContent generation

Template-generated stimuli with controlled difficulty

Purpose

Creates equivalent versions of each exercise so repetition does not become memorisation.

Performance in the literature

There is real evidence for semi-parallel forms; equivalence must be calibrated on people.

Data

Content and stimuliLevel parametersPer-trial responses

Algorithm

Generative contentPsychometrics
ExploratoryContent generation

LLM-drafted stimuli

Purpose

Drafts new stimulus ideas for designer review.

Performance in the literature

No evidence was found for psychometric equivalence of LLM-generated cognitive items.

Data

Content and stimuli

Algorithm

Language modelsGenerative contentPsychometrics

Source

No direct source found
ExploratoryContent generation

AI-generated environments

Purpose

Produces varied, locally relevant environments faster.

Performance in the literature

The effect of environment changes on measurement must be tested so scores stay comparable.

Data

Content and stimuliLevel parameters

Algorithm

Generative content

Source

No direct source found
ExploratoryContent generation

Stimulus localisation for new languages

Purpose

Speeds translation and cultural adaptation, then tests psychometric equivalence.

Performance in the literature

Machine translation alone does not carry over test validity; local norms are needed.

Data

Content and stimuliMulti-centre data

Algorithm

Language modelsPsychometrics

Source

No direct source found
Moderate evidenceSafety and data quality

Data-quality gate

Purpose

Removes invalid sessions and trials before indices are computed.

Performance in the literature

A limit of about 3.2 m/s for implausible hand speed is a useful starting point.

Data

Hand and arm motionHead and postureTechnical telemetry

Algorithm

Anomaly detection
ExploratorySafety and data quality

Cybersickness prediction

Purpose

Suggests a break before symptoms worsen.

Performance in the literature

A systematic review found no model predicting a first event.

Data

Head and postureGazePhysiology

Algorithm

Machine learningDeep learning
ExploratorySafety and data quality

Fatigue and dropout prediction

Purpose

Identifies patients at risk of stopping care for earlier follow-up.

Performance in the literature

A real need: in FINGER only 12% completed all sessions.

Data

Session historyHand and arm motion

Algorithm

Machine learningHierarchical and longitudinal
ExploratorySafety and data quality

Identifying clinician-assisted sessions

Purpose

Separates sessions with outside help from measurement.

Performance in the literature

No validated method was found; manual recording is the better starting point.

Data

Technical telemetryHead and postureClinician decisions

Algorithm

Anomaly detection

Source

No direct source found
Moderate evidenceSafety and data quality

Subgroup fairness testing

Purpose

Evaluates model performance separately by age, sex, education and accent.

Performance in the literature

Model performance drops in low-resource languages (preprint).

Data

Cognitive profileSpeech and languageMulti-centre data

Algorithm

Machine learningCausal and trial design
ExploratorySafety and data quality

Device and network monitoring

Purpose

Detects tracking, performance and network problems before they affect a session.

Performance in the literature

An engineering practice, judged by fewer lost sessions.

Data

Technical telemetry

Algorithm

Anomaly detection

Source

No direct source found
ExploratoryMulti-centre science

Federated analysis for multi-centre norms

Purpose

Combines aggregate clinic results without moving raw data.

Performance in the literature

Benefit is limited with few sites, and differential privacy can reduce utility (preprint).

Data

Multi-centre dataCognitive profile

Algorithm

Privacy-preservingHierarchical and longitudinal
Moderate evidenceMulti-centre science

Synthetic data for software testing

Purpose

Tests software and parameter recovery without patient data.

Performance in the literature

Defensible for testing; not a substitute for clinical samples, and no privacy guarantee on its own.

Data

Per-trial responsesMulti-centre data

Algorithm

Generative contentSimulation and twins
ExploratoryMulti-centre science

Individual effects with N-of-1 designs

Purpose

Shows which type of exercise worked better for this particular patient.

Performance in the literature

Our review found no study in VR rehabilitation.

Data

Session historyCognitive profile

Algorithm

Causal and trial designHierarchical and longitudinal

Source

No direct source found

Scientific approach

Code for numbers, models for prose

Deterministic code computes every clinical number. Language models write prose only.

Clinicians decide

Algorithms suggest. Clinicians approve or change the care plan.

Beat the simple method

Complex models must outperform a transparent method in a registered comparison with patient-level data splits.

Valid measurement first

Reliability and validity come before prediction, because no model beats the measurements it learns from.