Table 5.
Detailed HRV acquisition methods.
| Signal source | Device/hardware | Software/processing | Technical notes |
|---|---|---|---|
| PPG | Optical PPG device not specified | MATLAB; Slope Sum Function (SSF) | HRV; PPG recorded at 1 kHz sampling rate; 4-min recordings (Mohd et al., 2020). |
| PPG | MAX30102 heart-rate sensor; ESP32-S3 microcontroller | Processing not reported | Prototype system using HRV, GSR, and accelerometer data; data processed by ESP32-S3 (Joshy et al., 2025). |
| ECG | Biopac MP150 | Artiifact software | HRV and skin conductance; 1 kHz sampling rate; 6-min recordings (Chiu et al., 2024). |
| Holter ECG | Portable ECG Holter | MindWare Bio Lab Acquisition Software; HRV Analyzing Software | HRV; IBI recorded at 500 Hz sampling rate; 50 Hz noise filter; 5-min recording (Thapa et al., 2021). |
| ECG | Device not specified | Software not specified | HRV and blood pressure; filtering using Smoothness Priors Detrending; 15-min recordings; artifact-free 5-min R–R segment analyzed (Tonhajzerova et al., 2021). |
| ECG | PowerLab system; disposable electrodes | Heart Rate Variability Module V7; MATLAB | HRV; R–R intervals recorded at 1 kHz sampling rate; 500 Hz anti-aliasing filter; 1 Hz high-pass filter (Matsushima et al., 2022). |
| ECG | DiANS PF8 device | Manual correction | EDA and HRV; R–R intervals recorded at 1 kHz sampling rate; FFT applied; 5-min recordings (Bujnakova et al., 2016). |
| Wearable | Polar RS800 | Kubios HRV v2.0; Polar Precision Performance software | HRV; R–R intervals; moderate filtering and visual correction; 15-min recordings (Gonzaga et al., 2021). |
| ECG | Biopac MP150 | Kubios HRV Premium | HRV and EDA; 1000 Hz sampling rate; noise detection using Kubios; 25-min recordings (Kehm et al., 2025). |
| ECG | PowerLab 16-channel system | HRV Analysis Software v1.1 | HRV; 1 kHz sampling rate; 15-min recordings; ectopic-free 5-min segment analyzed (Rukmani et al., 2016). |
| ECG | Compumedics system | In-house Brain Resource software | HRV; 500 Hz sampling rate; low-pass filter at 100 Hz; 50–60 min recordings (Griffiths et al., 2017). |
| Wearable; ECG | Polar RS800 thoracic belt; ECG ECT WS 2000 | Polar software; Kubios HRV | HRV; R–R intervals; ECG recorded at 1000 Hz sampling rate; nocturnal monitoring using R–R intervals; daytime ECG monitoring; 30-min recordings (Pace et al., 2016). |
| Holter ECG | Holter ECG monitor | Software not specified | HRV; ambulatory 24-h recordings (Yuksel and Ozcan, 2018). |
| Wearable | Polar H7 | Kubios HRV | HRV; R–R intervals; very low filter used; 10-min recordings (Robe et al., 2021). |
| ECG; PPG | Medicom 83 system | BioSigBrowser in MATLAB | HRV, EDA, respiration, and skin temperature; ECG and PPG recorded at 1000 Hz sampling rate; 13-min recordings (Ribeiro et al., 2024). |
| Wearable | Polar H10 | Kubios HRV v3.5 | HRV; R–R intervals; 5-min recordings (Tarlacı and Topal, 2026). |
| ECG | PowerLab; disposable electrodes | MATLAB | HRV; 1 kHz sampling rate; 1 Hz high-pass filter; 18-min recordings (Matsushima et al., 2016). |
| Wearable | Polar RS800CX | HRV analysis software | HRV; 5-min recordings; time-domain, frequency-domain, and nonlinear indices (Kalfiřt et al., 2023). |
| ECG | Biolab MindWare 3.0.4 | HRV 3.0.12; MATLAB R2014a; Kubios 2.2 | HRV; 500 Hz sampling rate; resting-state recordings (Bazelmans et al., 2019). |
| ECG | Biopac MP150 | HRV analysis software | HRV; short resting-state recordings; 5-min segments; RMSSD and HF (Lory et al., 2020). |
| ECG | Medical ECG cardio-monitor | HRV analysis software | HRV; head-up tilt test; 1000 Hz sampling rate; time-domain and frequency-domain indices (Bricout et al., 2018). |
| ECG | PowerLab 26T ECG | Manual Fast Fourier Transform | HRV; resting recordings; frequency-domain indices; 20–25 min recordings (Bharath et al., 2019). |
| ECG | BrainAmp ECG | QRS Tool; Kubios HRV 4.1.0 | HRV; task-based protocol; 1000 Hz sampling rate; time-domain, frequency-domain, and nonlinear indices (Riquelme et al., 2025). |
| Wearable | Shimmer device | Custom HRV processing | HRV; 20-min recordings; 200 Hz sampling rate; serious games (Palma et al., 2017). |
IBI, interbeat interval; EDA, electrodermal activity; GSR, galvanic skin response; FFT, fast Fourier transform; SSF, slope sum function; PPG, photoplethysmography; ECG, electrocardiography.