# Differences in photoplethysmography morphological features and feature time series between two opposite emotions: Happiness and sadness

> Research article (Artery Research, 2017) · cited 41× · AI/ML

**Wikidata**: [openalex:W2589779729](https://www.wikidata.org/wiki/openalex:W2589779729)  
**Source**: https://4ort.xyz/entity/differences-in-photoplethysmography-morphological-features-and-feature-time-series-between-two-opposite-emotions-happine