Analysis of parameters derived from peripheral arterial tonometry and digital thermal monitoring signals for assessing endothelial dysfunction

Endothelial dysfunction is a well-known indication of the early stages of cardio vascular diseases. Non-invasive methods have grown with popularity in determining the endothelial health as it can be safely applied on people to obtain repeated measurements of vascular function overtime. This study presents a combined non-invasive endothelial function assessment method which acquires a Peripheral Arterial Tonometry (PAT) signal and a Digital Thermal Monitoring (DTM) signal from the fingertip. The endothelium was stimulated to induce reactive hyperemia by occluding the upper arm using a blood pressure cuff. The test was carried out on 11 diabetes and 21 non-diabetes participants and the acquired signals were pre-processed and subjected to parameter calculation. A one-way ANOVA carried out on the collected multivariate data set shows that the Reflection Index, TEMP-AUC, TMP-fall and Rise/fall parameters are significant in differentiating the non-diabetes from diabetes participants. A MANOVA carried out with the 4 significant parameters identified in ANOVA indicates that, when the parameters are considered together, it has a significant effect in differentiating diabetes participants from the non-diabetes participants. It suggests that with an extensive data collection, the system can be trained to a level which could assess the level of endothelial health thus could be used as a screening system for determining the likelihood of having vascular diseases.