In April 2018, Mindfield Biosystems conducted systematic comparison measurements between the eSense Skin Response and two established reference systems. The results show that the eSense matches the precision of significantly more expensive clinical systems.
Methodology
All measurements were performed on the same subject, with both devices attached simultaneously to the same hand. Electrode positions were swapped between measurements to control for position-related differences.
| Property | eSense Skin Response | NeXus-4 | Shimmer3 GSR |
|---|---|---|---|
| Manufacturer | Mindfield Biosystems | Mind Media | Consensys/Shimmer |
| Type | Wired sensor (smartphone microphone input) | 4-channel clinical system | Research wearable |
| Certification | CE | CE IIa, FDA registered | CE |
| Sampling rate | 10 Hz | 32 Hz | 10 Hz |
| Software | eSense App v2.1.0 | BioTrace V2017A | Consensys |
| Price range | €169 (Bundle) | approx. €3,000–5,000 (discontinued) | from €650 |
Electrodes: Medical single-use gel electrodes (identical gel quality), changed after each measurement. Display: Samsung Galaxy Tab S2 (SM-T819, Android 7.0).
Measurement Setup
Reference Devices
NeXus-4 (Mind Media)
Shimmer3 GSR
Results: eSense vs. NeXus-4
Two 10-minute measurements with simultaneous recording. Electrode positions were swapped between measurements (index/middle finger vs. ring/little finger).
Measurement 3: NeXus-4 on index/middle finger, eSense on ring/little finger
Both curves show good agreement in waveform shape. Absolute amplitudes differ due to the different finger positions.
Measurement 4: Positions swapped
Observation: The device on the index/middle finger consistently shows smaller amplitudes than the one on the ring/little finger — regardless of which device is in which position. The cause: increased keratinization of more frequently used fingers from typing and writing.
Results: eSense vs. Shimmer3 GSR
Two additional 10-minute measurements with the Shimmer3 GSR as reference.
Measurement 5: Simultaneous recording
Both systems track the same physiological events in the same temporal sequence. Absolute values differ due to different electrode positions, but the pattern of skin conductance changes is exactly comparable.
Conclusion
Comparison Results
The comparison measurements show that absolute amplitude depends on many factors — device, measurement method, electrode position, and skin characteristics. However, it is clearly evident that changes in skin conductance are recorded exactly and comparably by all systems. The eSense Skin Response matches the precision of significantly more expensive systems.
The eSense Skin Response thus fulfills its purpose of enabling optimal biofeedback training and is suitable for scientific studies — as confirmed by the independent validation by Emory University (r = 0.94) and additional peer-reviewed studies.
Downloads
Download the complete report and raw data:
- Comparison Measurements eSense Skin Response (PDF, English)
- Vergleichsmessungen eSense Skin Response (PDF, Deutsch)
- Raw data of all measurements (CSV, ZIP) — eSense, NeXus-4 and Shimmer3 measurement data
Note
These comparison measurements were conducted by Mindfield Biosystems in their own laboratory. For independent scientific validation, see Hinrichs et al. 2017 (Emory University), who found a correlation of r = 0.94 with the clinical lab standard Biopac.