Complete Guide to Vitals AI Health Metrics

Vitals AI uses advanced rPPG (Remote Photoplethysmography) and Multi-Tonal Sensing (MTS) technology to extract physiological signals from a facial video scan. By combining these signals with user profile data, we provide a comprehensive overview of your health.

Below is a breakdown of every metric we measure and calculate.

Core Vital Signs

These metrics are estimated directly from the facial video analysis.

Heart Rate (HR)

What it is: The number of heartbeats per minute (bpm), reflecting overall cardiovascular health.

How it works: We analyze changes in light reflection from the skin, which vary with blood volume fluctuations during each heartbeat.

Ranges:

• Normal Resting: 60–100 bpm.
• Clinical Note: A resting HR > 80 bpm is associated with increased cardiovascular risk.

Blood Pressure (BP)

What it is: The pressure of blood pushing against the walls of your arteries.

How it works: We use Pulse Wave Analysis (PWA) to examine the shape and timing of the pulse waveform from the face5. Our Multi-Tonal Sensing (MTS) technology ensures accuracy across different skin tones and lighting conditions.

Classifications (2024 ESC Guidelines):

Category	Systolic (mmHg)	Diastolic (mmHg)
Normal	90–120	60–70
Elevated	121–135	71–85
Hypertension	≥135	≥85

 

Breathing Rate (BR)

What it is: The number of breaths taken per minute.

How it works: Detected via chest movements or skin color variations associated with blood oxygenation.

Normal Ranges:

• Adults: 12–20 bpm
• Adults (65+): 12–28 bpm
• Adults (80+): 10–30 bpm

Heart Rate Variability (HRV)

What it is: The variation in time between consecutive heartbeats (SDNN).

Why it matters: Higher HRV generally indicates better health and adaptability, while lower HRV is linked to stress and fatigue.

Note: There is no universal "normal." HRV is highly individual and should be tracked as a trend relative to your own baseline.

Cardiac Workload

What it is: The product of Heart Rate and Systolic BP (also known as Rate-Pressure Product).

Significance: It indicates cardiac oxygen consumption.

Normal Range: 90–216 mmHg/s.

Stress Index (SI)

What it is: A score derived from HRV that reflects the balance between your sympathetic (fight or flight) and parasympathetic nervous systems.

Ranges:

• Normal: 0–4
• High Stress: 5–9
• Critical: ≥9

Parasympathetic Activity (PA)

What it is: Measures the dominance of the "rest and digest" system.

How it works: Calculated using spectral analysis of HRV, specifically the High Frequency (HF) power relative to total power. Higher values indicate greater parasympathetic influence, which generally decreases with age.

Health Risk Assessments

These models combine your physiological scan data with profile data (age, gender, history) to predict long-term health outcomes.

Atherosclerotic Cardiovascular Disease (ASCVD) Risk

What it is: A 10-year estimate of developing heart disease, based on the Framingham Heart Study.

Group Variations: Because these models are largely based on Caucasian/white populations, estimates vary for other groups:

• Higher Risk: Compared to white populations, risk is generally higher among African American and American Indian populations.
• Lower Risk: Compared to white populations, risk is generally lower among Hispanic/Latino and Asian populations.

Risk Categories:

• Low: <5%
• Borderline: 5–<7.5%
• Intermediate: 7.5–<20%
• High: ≥20%

Cardiovascular Event Risk

What it is: Estimates the 10-year risk of a first major event (coronary death, heart attack, or stroke) using Pooled Cohort Equations.

Group Variations: Similar to ASCVD, risk estimates rely on models validated in white populations. Risk is generally higher in American Indian populations and lower in Hispanic/Latino and Asian populations compared to white populations.

Hypertension Risk

What it is: Estimates the likelihood of developing hypertension over the next 1, 2, or 4 years.

High Risk Threshold: A greater than 10% chance of developing hypertension in the next 4 years.

Diabetes Risk

We utilize two models to assess type 2 diabetes risk:

1. Framingham Score: Estimates 8-year risk based on factors like BMI, BP, and family history. High risk is defined as >10%.
2. FINDRISC: Estimates 10-year risk based on waist circumference, diet, and activity. Scores range from Very Low (0-7 points) to Very High (21-30 points).

Non-Alcoholic Fatty Liver Disease (NAFLD) Risk

What it is: Assesses the risk of fat buildup in the liver using Body Roundness Index (BRI) and Waist-to-Height Ratio (WHtR).

Key Statistics:

• Men: BRI (Odds Ratio = 5.484) and WHtR (Odds Ratio = 5.309) have a strong correlation with NAFLD.
• Women: BRI (Odds Ratio = 3.482) and WHtR (Odds Ratio = 3.854) are also strong indicators.
• High Risk Cutoffs: Men with BRI ≥ 4.00; Women with BRI ≥ 5.00.

Vascular Age

What it is: The calculated "age" of your cardiovascular system compared to your biological age.

Basis: It assumes all risk factors (cholesterol, BP, glucose) are at normal levels.

Wellness Score

What it is: A comprehensive 0–100 score reflecting overall well-being, not just the absence of disease.

Interpretation:

• 81–100 (Excellent): Optimal wellness with strong protective factors.
• 0–20 (Critical): Significant health risks requiring immediate attention.

Body Composition & Indices

These metrics focus on body shape, weight, and energy expenditure.

Body Mass Index (BMI)

What it is: A simple weight-to-height ratio49.

Categories:

• Normal weight: 18.5–24.9
• Obesity: ≥ 30

Body Fat Percentage (BFP)

What it is: The proportion of fat to total body weight.

Acceptable Ranges:

• Men: 18–24%
• Women: 25–31%

Body Roundness Index (BRI)

What it is: A measure of body fat distribution focusing on abdominal fat, which is a better predictor of heart health than BMI55.

Sensitivity: BRI has a sensitivity of 76.5% for men and 76.4% for women in predicting health risks.

Values: Scores range from 1 to 16; higher values indicate rounder body shapes and higher risk.

Waist-to-Height Ratio (WHtR)

What it is: The ratio of waist circumference to height.

Interpretation: A ratio of 0.5 or higher indicates increased risk of obesity-related health issues.

A Body Shape Index (ABSI)

What it is: Evaluates health risks based on body shape, specifically abdominal fat.

Risk Threshold: A value > 0.083 indicates increased risk.

Conicity Index (CI)

What it is: Models the body shape from a cylinder (1.0) to a double cone (1.73) to assess abdominal obesity.

High Risk: CI ≥ 1.275 for men; CI ≥ 1.285 for women.

Metabolic Rates

• Basal Metabolic Rate (BMR): The calories your body burns at complete rest. We use the Mifflin-St Jeor equation, considered the most reliable method.
• Total Daily Energy Expenditure (TDEE): The total calories used in 24 hours, including physical activity and digestion.