Presage Arterial Pressure Waveform and Pulse Rate Model Card

THE FOLLOWING INFORMATION, AND PRESAGE'S SDK AND APP, ARE OFFERED FOR GENERAL WELLNESS AND INFORMATIONAL PURPOSES ONLY. NEITHER HAVE BEEN CLEARED BY THE FDA AND NEITHER MAY BE USED FOR MEDICAL DIAGNOSIS OR TREATMENT.

1. Model Details

Basic info: Presage vitals by video analysis generates a relative arterial pressure waveform and pulse rate from a video of a subject. This card covers 10.6-second pulse rate (vs EKG) and 60-second waveform analysis (vs BP).

Organization: Presage Technologies

Model date: 2026-08-06

Model version: dc437d54

Model type: A proprietary computer vision and signal processing pipeline extracts a relative arterial pressure waveform and pulse rate from video of a subject. Pulse rate is compared against EKG at 10.6s windows. The waveform is z-score normalized and compared against the Biopac BP reference at 60s windows.

License: The algorithm is currently proprietary, and licenses are granted with predefined agreement.

Contact: Questions can be sent to: support@presagetech.com

2. Intended Use

Model Uses

This model was intended for use in the analysis and non-diagnostic utility of arterial pressure waveform morphology and pulse rate. Requires a stationary device and video of a subject acquired at 25+ fps. Pulse rate range: 40-180 BPM.

Out-of-Scope Uses

As noted above. Not intended for diagnostic blood pressure measurement. Does not provide absolute systolic, diastolic, or MAP values in mmHg. Not an arrhythmia detection or monitoring device.

3. Validation

Reference Standard: Biopac MP160 3-lead ECG (for pulse rate comparison at 10.6s windows) and Biopac continuous blood pressure monitor (for waveform correlation at 60s windows). Waveforms z-score normalized before comparison.

Comparison Methodology: Arterial Pressure Waveform measurements from the camera-based system were compared against time-aligned reference measurements. Ground truth signals were checked for quality using labeled signal annotations; segments with poor signal quality were excluded from analysis.

4. Data Demographics

Category Distribution
Total 118 subjects, 418 videos
Camera (videos) e-con See3CAM CU27: 114, Logitech C920: 113, Samsung S24 Rear 24mm (tripod): 101, Samsung S24 Front 27mm (handheld): 90
Sex (subjects) Female: 63, Male: 55
Age Group (subjects) 18-25: 34, 26-35: 39, 36-45: 17, 46-55: 15, 56-65: 10, 65+: 2
Fitzpatrick (subjects) Type 1: 21, Type 2: 12, Type 3: 13, Type 4: 24, Type 5: 33, Type 6: 15
BMI (subjects) Mean: 27.9, Range: 16.5–54.3, N=118
Lighting (videos) Ring Light: 133, Lamp: 132, Window: 99

Reference standard: Biopac EKG and continuous blood pressure monitor.

5. Data Provenance

Reference Instrumentation: Biopac research-grade physiological sensors: 3-lead ECG (for pulse rate ground truth), continuous blood pressure monitor (for waveform correlation ground truth).

Camera Devices Tested: Samsung S24 Rear 24mm (tripod), Samsung S24 Front 27mm (handheld), e-con See3CAM CU27 (USB), Logitech C920 (tripod).

Average Camera Distance: Samsung S24/e-con/Logitech: 26", Samsung S24 handheld: 10"

Data Handling: All subject data is de-identified. Derived metrics and anonymized identifiers are retained. Data is securely stored with access restricted to trained researchers.

6. Factors

The arterial pressure model requires face detection and high-quality photoplethysmographic signal extraction.


These factors can affect model performance:


Lighting Conditions Tested:


Other factors:

7. Metrics

(at 80% Return Rate, Confidence >= 97)

  1. MAE: 0.36 BPM
  2. RMSE: 0.64 BPM

8. Quantitative Analysis

Computed vs Ground Truth at Confidence Thresholds

Bland-Altman Plot

Confidence Lookup Table

Confidence >= MAE (BPM) RMSE (BPM) Pearson r Return Rate (%) N (samples)
0 0.93 2.96 0.974 100.0 25126
10 0.90 2.81 0.976 99.7 25053
20 0.88 2.74 0.978 99.5 24995
30 0.84 2.58 0.980 99.0 24878
40 0.78 2.36 0.983 98.3 24707
50 0.73 2.20 0.985 97.5 24497
60 0.65 1.82 0.990 96.1 24140
65 0.60 1.67 0.992 95.2 23925
70 0.57 1.48 0.993 94.4 23715
75 0.52 1.28 0.995 93.4 23462
80 0.48 1.04 0.997 92.3 23182
85 0.45 0.91 0.997 91.0 22857
90 0.42 0.78 0.998 89.3 22427
95 0.39 0.68 0.999 85.0 21366
96 0.38 0.66 0.999 82.9 20822
97 0.36 0.64 0.999 80.0 20045
98 0.35 0.62 0.999 74.5 18707
99 0.32 0.59 0.999 63.7 16008

Performance

(at 80% Return Rate, Confidence >= 97)

By Camera Type

Camera Type N (samples) Return Rate (%) MAE (BPM) RMSE (BPM) Pearson r
Samsung S24 Rear 24mm (tripod) 6012 85.0 0.43 0.92 0.997
Samsung S24 Front 27mm (handheld) 1258 63.3 0.36 0.52 0.999
e-con See3CAM CU27 6252 78.2 0.35 0.49 0.999
Logitech C920 6523 80.9 0.32 0.46 0.999

By Fitzpatrick Skin Type

Fitzpatrick N (samples) Return Rate (%) MAE (BPM) RMSE (BPM) Pearson r
Type I 4033 93.2 0.33 0.53 0.999
Type II 2397 89.6 0.27 0.39 1.000
Type III 2638 92.7 0.49 1.14 0.997
Type IV 4434 87.4 0.33 0.49 0.999
Type V 5131 72.7 0.36 0.52 0.999
Type VI 1412 44.9 0.49 0.81 0.998
Fitzpatrick Type VI: Breakdown by Lighting Condition
Ring Light 539 54.6 0.37 0.49 0.997
Window 312 32.6 0.52 0.75 0.999
Lamp 424 40.0 0.64 1.17 0.983

Note: Types I-V are composites across all lighting conditions (Ring Light, Window, Lamp).

By Sex

Sex N (samples) Return Rate (%) MAE (BPM) RMSE (BPM) Pearson r
Male 10096 82.6 0.35 0.70 0.999
Female 9949 77.1 0.37 0.59 0.999

By Age Group

Age Group N (samples) Return Rate (%) MAE (BPM) RMSE (BPM) Pearson r
18-25 5813 82.6 0.46 0.88 0.997
26-35 6325 77.8 0.33 0.47 0.999
36-45 2777 77.9 0.38 0.63 0.999
46-55 2990 86.0 0.27 0.46 1.000
56-65 1902 83.1 0.27 0.37 0.999
65+ 61 15.4 0.49 0.72 0.999

By Lighting Type

Lighting N (samples) Return Rate (%) MAE (BPM) RMSE (BPM) Pearson r
Lamp 6115 77.3 0.42 0.87 0.997
Ring Light 6845 83.3 0.34 0.49 0.999
Window 4089 71.7 0.36 0.57 0.999

Confidence vs Waveform Correlation

Confidence >= Waveform Pearson r Return Rate (%) N (videos)
0 0.682 100.0 375
10 0.682 100.0 375
20 0.682 100.0 375
30 0.682 100.0 375
40 0.685 99.2 372
50 0.690 97.9 367
60 0.696 96.3 361
65 0.700 94.1 353
70 0.702 93.3 350
75 0.707 91.5 343
80 0.710 89.9 337
85 0.717 88.3 331
90 0.721 84.3 316
95 0.729 78.4 294
96 0.735 76.0 285
97 0.735 72.5 272
98 0.735 67.2 252
99 0.729 56.0 210

Waveform Example

9. Fairness & Equity

Bias Assessment Methodology: Performance is stratified by Fitzpatrick skin type (I-VI), sex, camera type, and age group. Per-group metrics and Confidence averages are reported in the Quantitative Analysis tables above.

10. Ethical Considerations

As a remote sensing device, the risks posed to the subjects in the trial are minimal, including the association of each subject with corresponding biometric data. Mitigation of these risks include de-identifying all subject data, including videos, prior to saving it. Additionally, all data is securely stored with access to a select number of trained researchers.

The model is not intended for human life-critical decisions, diagnostics or prognostication.

11. Limitations and Tradeoffs