Study Overview
| Authors | Hinrichs R., Michopoulos V., Winters S., Rothbaum A.O., Rothbaum B.O., Ressler K.J., Jovanovic T. |
| Institution | Emory University Atlanta, USA |
| Journal | Depression and Anxiety (Wiley) |
| Year | 2017 |
| DOI | 10.1002/da.22610 |
| PubMed | PMC5466496 |
| Product | eSense Skin Response |
| Participants | 63 trauma-exposed adults |
What was investigated?
Independent researchers at Emory University Atlanta investigated whether an affordable mobile skin conductance device can reliably capture psychophysiological reactivity in individuals with post-traumatic stress disorder (PTSD). The core question was whether elaborate laboratory protocols could be replaced by a mobile system that is also practical in everyday clinical settings. To this end, the researchers first conducted a direct technical comparison of the eSense sensor with the clinical laboratory standard before using the device in the actual clinical study.
Methods
The study included 63 trauma-exposed adults (15 with a PTSD diagnosis, 48 without), recruited at Grady Memorial Hospital in Atlanta — on average one year after the respective traumatic event. In a single session, a two-minute resting measurement was first recorded as baseline, followed by a standardized trauma interview with 21 questions. Beforehand, in a separate preliminary experiment, the measurement accuracy of the eSense sensor was verified through simultaneous measurement alongside the clinical laboratory device Biopac (1000 Hz sampling rate) on the same participants.
Mindfield Product in this Study
The researchers used the eSense Skin Response by Mindfield Biosystems in combination with an iPad. The electrodes were attached to the non-dominant hand, and data acquisition was performed at a 10 Hz sampling rate. For technical validation, a simultaneous measurement with the clinical laboratory system Biopac was conducted in a separate preliminary experiment — both devices attached to the same participants simultaneously to directly verify the agreement of measured values. This pre-validation formed the methodological basis for the clinical use in the main study.
Results
Technical validation: The researchers reported a correlation of r = 0.94 between the eSense Skin Response and the clinical reference device Biopac in the pre-validation. This value indicates very high agreement between both systems.
Clinical study: The results showed that individuals with a PTSD diagnosis exhibited significantly greater skin conductance increases during the trauma interview than trauma-exposed individuals without PTSD (F₁,₆₁ = 8.25; p = 0.006). Each increase of 1 microsiemens was associated with a 76% increased statistical probability of a PTSD diagnosis (Odds Ratio: 1.76). The area under the ROC curve (AUC) was 0.79 (p = 0.001), indicating good diagnostic discriminability. Furthermore, skin conductance showed significant associations with overall PTSD severity (r = 0.42) as well as with individual symptom clusters such as intrusions, avoidance, and hyperarousal.
Significance
This study is considered the most important independent validation work for the eSense Skin Response. Independent scientists at a renowned US research institution used the device in a clinical study and confirmed both its technical reliability (r = 0.94 compared to the lab standard) and its practical applicability in psychophysiological research. The study was conducted without involvement of Mindfield Biosystems and published in the journal Depression and Anxiety with a high impact factor after peer review.
The findings demonstrate that mobile skin conductance measurement with the eSense Skin Response is applicable in clinical settings and delivers scientifically valid data — also as a basis for further research work (see related studies).
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