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Case Study S002
2018 Release

Sørensen 2018: Definition of Fiducial Points

Kasper Sørensen et al.
Access Paper

Quick Conclusion: Serves as a reference for identifying SCG fiducial points based on synchronized ultrasound data in healthy subjects.

📊 Key Accuracy Metrics

MetricResult
Aortic valve closure (AC) correlationr=0.94, bias -5ms
Mitral valve opening (MO) correlationr=0.87, bias -7ms
Aortic valve opening (AO) correlationr=0.60, bias -3ms
Mitral valve closure (MC) correlationr=0.71, bias 4ms

🔍 Study Analysis

Objective & Population

Observational / Methodology Study. Cohort: Healthy subjects (20-80 years) (N=42).

What it Supports

Documents the mapping of 8 physiologic mechanical events to SCG waveform features, with high correlation observed for valve closures (r=0.94).

What it Does Not Support

The study does not provide evidence for automated real-time detection in moving subjects or clinical diagnosis of pathologies, as it focused on defining fiducial points in healthy, resting individuals.

🛠 Technical Context

Featured Illustration

Figure 4.  Overall mean electrocardiogram and seismocardiogram signal from 34 subjects. The circles indicate the mean location of the following physiologic events found in ultrasound images, from left: Atrial systole (AS), peak atrial inflow (PAI), mitral valve closure (MC), aortic valve opening (AO), peak systolic outflow (PSO), aortic valve closing (AC), mitral valve opening (MO), early ventricular filling (EVF). The grey areas indicate the 95% confidence intervals of the means for the physiologic events found in the ultrasound images.

Figure 4.  Overall mean electrocardiogram and seismocardiogram signal from 34 subjects. The circles indicate the mean location of the following physiologic events found in ultrasound images, from left: Atrial systole (AS), peak atrial inflow (PAI), mitral valve closure (MC), aortic valve opening (AO), peak systolic outflow (PSO), aortic valve closing (AC), mitral valve opening (MO), early ventricular filling (EVF). The grey areas indicate the 95% confidence intervals of the means for the physiologic events found in the ultrasound images.

Study Snapshot

Metadata Summary

Target Population

Healthy subjects (20-80 years)

N

Sample Size

42 Subjects

Validated Metric

r=0.94, bias -5ms

Critical Appraisal
supporting

“Defined and mapped 8 physiologic cardiac events to SCG fiducial points with high correlation for valve closures.”