Abstract: A computer-implemented method for direct photoplethysmography or direct PPG comprises obtaining during a time interval plural PPG signals for respective sensors in a wearable device; and combining the plural PPG signals to thereby obtain a multi-sensor PPG signal.

Abstract: A computer-implemented method for synchronizing a PPG signal with an ECG signal includes: recording the ECG and PPG signals semi-synchronously; cutting the PPG signal into PPG signal pieces; for a PPG signal piece: determining distances d between a vector of PPG peak times and respective vectors of ECG peak times for respective ECG signal pieces obtained by applying different offsets o; determining a best matching ECG signal piece with minimal distance do; and registering start time x of the PPG signal piece, start time yo of the best matching ECG signal piece, and the minimal distance do; determining an offset and drift between the PPG signal and ECG signal as the offset and slope of a regression model modelling the relation between the start time x and start time yo, inverse weighted by the minimal distance do; applying the offset and drift to the PPG signal.

Abstract: A computer-implemented method for generating an annotated photoplethysmography signal, includes: recording an electrocardiogram or ECG signal; recording a photoplethysmography or PPG signal, semi-synchronously with the recording of the ECG signal; annotating segments in the ECG signal either algorithm-based or expert-based; time-aligning the PPG signal and the ECG signal; detecting ECG beats in the ECG signal; detecting PPG beats in the PPG signal; pairing the ECG beats onto the PPG beats; deriving annotations for PPG signal segments based on the nature of the ECG segment annotations and on how the ECG beats can be paired with the PPG beats; and annotating the PPG signal segments using the annotations, thereby generating the annotated PPG signal.

Abstract: A computer-implemented method for contact photoplethysmography, abbreviated contact PPG, comprises obtaining during a time interval plural PPG signals for sub-regions of a lens or video frame; and combining the plural PPG signals to thereby obtain a multi-region PPG signal.

Abstract: A computer-implemented method for contact photoplethysmography, abbreviated contact PPG, comprises obtaining during a time interval plural PPG signals for sub-regions of a lens or video frame; and combining the plural PPG signals to thereby obtain a multi-region PPG signal.

Abstract: A computer-implemented method for direct photoplethysmography or direct PPG comprises obtaining during a time interval plural PPG signals for respective sensors in a wearable device; and combining the plural PPG signals to thereby obtain a multi-sensor PPG signal.

Abstract: The present invention relates to a method (1) for creating a diamond structure (38) on a substrate (31). This method comprises the steps of providing (2) a substrate (31), providing (3) a mold (25) on the substrate (31), providing (4) a diamond seed solution (34) in the mold (25), and removing (6) the mold (25) such that a diamond structure (38) remains on the substrate (31).