Tri-axial Accelerometry
Captures linear acceleration on x, y, and z axes to quantify sway path, directional instability, and movement intensity.
How Does it Work?
Our system technically measures balance by utilizing a mobile device’s internal tri-axial Micro Electro-Mechanical Systems (MEMS) accelerometer to quantify postural sway and body tilt.
Fundamental Scientific Mechanisms
Postural Stability
Measures center-of-mass control and postural corrections under static stance conditions to identify fall-risk signatures.
Algorithmic Methodology
Sampling and Calculation
Signal streams are normalized and segmented per stance to derive time-domain and dispersion features.
Balance Scoring
A weighted model maps extracted features to a unified stability score and classifies performance bands.
Standardized Stances
Five validated stance conditions reduce variability and support repeatable comparison across sessions.
Scientific Validation
Bench Testing
Sensor output and derived metrics were verified against known movement patterns and controlled stimuli.
Test-Retest Reliability
Repeat assessments demonstrate stable outputs under equivalent stance conditions and protocols.
Sensitivity to Impairment
The model differentiates subtle stability changes associated with neurological and musculoskeletal decline.
What is the Measurement Process?
Data Collection and Sampling
Sensor Usage
The protocol uses smartphone accelerometer data and orientation context during each timed stance.
Sampling Rate
Motion is sampled continuously at high frequency to preserve micro-movement details.
Test Duration
Each stance window is fixed so data quality and score comparability remain clinically consistent.
Device Placement
Standardized in-pocket placement reduces positional noise and supports repeatable acquisition.
Algorithmic Calculation
Raw movement streams are processed through filtering and signal quality checks, then transformed into interpretable stability indicators.
Raw Measurements
Axis-level acceleration and derived sway vectors feed feature extraction for each stance trial.
Test Conditions
Condition-specific coefficients account for stance difficulty while preserving cross-test consistency.
Thresholding
Decision thresholds convert continuous metrics into graded risk bands and pass/fail signals.
Scoring Output
Pass Score
Minimum performance criteria indicate whether baseline stability is within accepted bounds.
Final Result
A consolidated clinical output summarizes balance status and flags potential fall-risk concerns.
Average Score
Rolling score history helps clinicians monitor trend direction, recovery, and intervention response.