OR06 - Pulpal Diagnosis by Electrodermal Activity and ECG-derived Skin Nerve Activity

Accurate diagnosis is essential for effective endodontic treatment. We previously reported that time-varying sympathetic index (TVSymp) derived from electrodermal activity (EDA) can potentially assist pulpal diagnosis. This approach is important for patients who cannot provide conclusive response to cold and EPT testing. We recently showed that ECG-derived skin nerve activity (SKNA) can assess sympathetic nerve system (SNS) activity aroused by pain. To overcome the low specificity of TVSymp, we aim to examine whether combining TVSymp and SKNA can improve the accuracy of pulpal diagnosis. We simultaneously collected TVSymp/SKNA data from 50 participants during cold and EPT testing following an approved IRB protocol. Each subject had one affected and two nearby healthy control teeth. EDA and ECG data were recorded by a wearable Shimmer 3 and ECG amplifier device, respectively. We also recorded patient-reported visual analog scale (VAS) scores (0-10). Statistical analysis was performed using R 4.2.0. Major findings include: 1) SKNA can identify the duration of sympathetic innervation, which is important for TVSymp data interpretation; 2) Both TVSymp/SKNA and VAS scores showed significant differences between negative response, normal pulp and pulpitis groups (p < 0.05 by one-way ANOVA followed by Tukey’s post hoc test); 3) Accuracy and specificity were improved by combined TVSymp/SKNA signals compared to single parameter by AUROC analysis. Future studies will test the practicality of a smartphone-based app coupled with EDA and ECG devices in chairside tests. We will also study whether TVSymp/SKNA physiomarkers can measure dental pain and be a reliable indicator for successful local anesthesia.