Every metric, defined. Every boundary, stated.

Camera Vital Check separates camera-measured outputs from calculated reference values, and explicitly locks metrics it does not support. This page defines exactly what is measured, how, and why certain metrics are not included.

What the camera actually measures

Three outputs only. Measured by the camera. Returned only when quality passes.

Camera-Measured

Heart Rate

bpm

Method

rPPG from green channel

Valid range

40–150 bpm

Confidence

High

Primary output. Reported only on valid scans.

Camera-Measured

Respiratory Rate

/min

Method

ROI motion frequency

Valid range

8–30 /min

Confidence

Moderate

Derived from slow chest/face movement. More variable than HR.

Camera-Measured

Scan Quality Grade

Method

8-signal composite score

Valid range

good / moderate / poor / invalid

Confidence

High

Not a vital sign. A measurement quality indicator.

Reference values from profile inputs

These are derived from user-provided data — age, height, weight, sex — not from the camera. They are presented as reference values, not measurements.

Body Mass Index (BMI)
weight / height²Standard Quetelet formula
BMI Prime
BMI / 25Relative to upper bound of healthy BMI
Healthy Weight Range
BMI 18.5–24.9 × height²For stated height
Resting Energy Expenditure (REE)
Mifflin-St JeorAge, sex, height, weight
Daily Energy Need
REE × activity factorHarris-Benedict multipliers
Body Surface Area (BSA)
DuBois formulaApproximation for adults

Metrics Camera Vital Check does not support — and why

Blood Pressure

No clinically validated camera-based BP method exists. PPG-derived BP requires calibration cuffs and individual baseline data.

Oxygen Saturation (SpO₂)

Requires near-infrared and red-channel ratio. Standard RGB cameras cannot measure SpO₂ reliably.

Blood Glucose

No valid mechanism for camera-based glucose measurement. Claims in this space are unsupported.

Arrhythmia Detection

Requires multi-lead ECG-grade signal. rPPG cannot capture rhythm with sufficient resolution for arrhythmia classification.

HRV (Heart Rate Variability)

Standard camera frame rates (25–60 FPS) are insufficient for the sub-second resolution required for clinical HRV analysis.

Stress Scoring

Stress is not a measurable physiological output of rPPG. Composite 'stress' scores from HR data alone are not validated.

The science Camera Vital Check is built on

Systematic Review

Remote Photoplethysmography: Current Capabilities and Future Directions

Literature review of rPPG accuracy, limitations, and validation standards.

Fairness Research

Skin Tone and rPPG: Accuracy Variation Across the Fitzpatrick Scale

Studies examining whether camera-based HR measurement performs equitably across different skin tones.

Standards

IEEE Standards for rPPG Validation Protocols

Proposed standardisation of validation methodology for camera-based vital signs.

Conditions

Lighting Conditions and rPPG Signal Quality

Controlled experiments on the effect of ambient light colour, brightness, and direction on rPPG signal quality.