Technology

A camera, some math, and a lot of training data.

SmartScanPro runs two engines on one API surface: a remote photoplethysmography (rPPG) signal-processing stack for the human face, and a purpose-built OCR + layout model for medical device displays and clinical documents.

The rPPG pipeline

From raw pixels to heart rate, in ten stages.

Every stage is auditable and benchmarked independently. Nothing is a black box.

1. Face detection

Lightweight CNN locates the face at 30+ fps on a mid-range phone. ROI tracked across frames.

2. Region segmentation

Forehead & cheek regions segmented — these maximise the green-channel pulsatile signal.

3. Colour-space lift

POS / CHROM / ICA combined with a learned skin-melanin-aware weighting for cross-Fitzpatrick fairness.

4. Signal extraction

Per-frame RGB means → detrended, bandpass-filtered (0.7–4 Hz), windowed into 10 s overlapping frames.

5. Quality gating

SNR, motion, lighting-variance checks. Reject low-quality windows and tell the user why.

6. Frequency analysis

FFT + autocorrelation ensemble. Peak picking with prior from previous windows.

7. Waveform reconstruction

Kalman-smoothed PPG estimate — feeds HRV, SpO₂, respiratory rate, and pulse-wave features.

8. Derived metrics

HRV (RMSSD, SDNN, pNN50), respiratory sinus arrhythmia, stress index, autonomic balance.

9. Calibration

Age / gender / BMI conditioning heads trained against large-cohort reference data for wellness BP.

Signal processing

The pulsatile signal is tiny — we amplify it carefully.

A skin region's green channel varies by ~1 % with each heartbeat. Here's what that looks like after our bandpass filter.

Reconstructed PPG waveform (10 s window)

Device OCR

The other engine: reading medical devices.

Document AI

Purpose-trained OCR + layout model on 400k+ medical-device photos. Reads 7-seg LCD, e-ink, backlit LCD, thermal receipts.

Field grounding

Each extracted value is bound to a pixel bounding box — auditors can click a JSON field and see where it came from.

Per-field confidence

Every value carries a calibrated probability. Use it to triage manual review or set auto-approval thresholds.

See it running on your own face.

The live demo uses the same engine we ship in production.