Embodiments herein provide a method and system for continuously validating a user during an established authenticated session using Photoplethysmogram (PPG) and accelerometer data. State of the art approaches are mostly based on feature extraction and ML modelling for PPG based continuous session validation, while a template based approach in the art follows a complicated approach. The method disclosed herein utilizes less computation intensive template based approach to continuously validate the user across the session. The method comprises preprocessing a PPG data or PPG signal acquired from a wearable device worn by the user to identify segments of negligible motion. A first segment, after authentication using conventional authentication mechanism, serves as the initial reference. The chosen segments are then tested one by one with respect to the reference. If the templates in a segment match those of the reference, it is updated as the new reference, else a re-authentication is triggered.

A method is provided that includes determining a quality of a data portion of an input sensor data stream based, at least in part, on data of a first data type and determining between, at least, generation of two or more streams of a second, different data type including at least one synthesised data stream of the second data type. Determining between generation of two or more streams of a second, different data type is based, at least in part, on the determined quality. The synthesis is based, at least in part, on the data of the first data type. The method further includes causing generation of at least one stream of the second, different data type based, at least in part, on the determination between generation of two or more streams of the second, different data type.

Movement detection of at least one part of a subject located inside a magnetic resonance imaging (MRI) device is provided. A method includes performing an MR scan by executing a programmable MR sequence protocol. The sequence protocol includes MR excitation pulses to be transmitted via a parallel transmit system and receive time windows for receiving magnetic resonance signals via a receive system. The MR sequence protocol includes, in between the MR excitation pulses, the generation of multi-channel pilot tone signals that are transmitted via the parallel transmit system and an RF transmit coil array. During transmission of the multi-channel pilot tone signals, the pilot tone signals are received with an RF receive coil array. The received pilot tone signals are forwarded via the receive system to an analyzing unit, and movement of at least one part of the subject is determined by analyzing the received pilot tone signal.

Methods and apparatuses for heart rate detection are described. In one example, a headphones apparatus and method includes emitting a first light in a first light direction directed at a left ear location from a left ear light emitter, and detecting a detected first light at a left ear light detector following interaction of the first light with a left ear tissue. The method includes emitting a second light in a second light direction directed at a right ear location from a right ear light emitter, the right ear location different from the left ear location. The method further includes detecting a detected second light at a right ear light detector following interaction of the second light with a right ear tissue, and estimating a heart rate from the detected first light and the detected second light.

A method for detecting cardiac arrhythmia based on a photoplethysmographic (PPG) signal is provided. The method includes: receiving a PPG signal and a motion signal corresponding to a motion made by a user; extracting PPG signal segments and motion signal segments corresponding to a time period from the PPG signal and the motion signal, respectively, at every time period; filtering out motion artifact noise in the PPG signal segments according to the PPG signal segments and the motion signal segments, and converting the PPG signal segments and the motion signal segments into PPG spectrum diagrams and motion spectrum diagrams, respectively; obtaining an estimated heart rate according to the PPG spectrum diagrams and the motion spectrum diagrams; and determining whether cardiac arrhythmia is present based on the filtered PPG signal segments and the estimated heart rate.

An adaptive noise quantification system and associated methods are disclosed for use in the dynamic biosignal analysis of a user. In at least one embodiment, the system includes a biosignal sensor positioned and configured for obtaining and transmitting data related to a select at least one vital of the user as a biosignal, and a motion sensor positioned and configured for obtaining and transmitting data related to a motion level of the user as a motion signal. A computing device is configured for receiving and processing the biosignal and motion signal.

A tomographic imaging system comprises a support carrying an image data acquisition system and defining a reference coordinate frame. A scan plan control sets the image-data acquisition system to acquire image-data from a selected imaging zone in the reference coordinate system. A motion detection system to detect movement and includes (i) a dynamic camera system to receive dynamic image information registered in the image coordinate frame of the dynamic camera system, (ii) an arithmetic unit configured to transform the selected imaging zone from the reference coordinate frame to the image coordinate-frame and a (iii) motion analyser to derive motion information from the registered dynamic image information in the transformed selected imaging zone. In the event of motion detected by the motion analyser in or near the imaging zone, the detected motion may be employed for motion correction.

Provided are a wearable device, as well as a heart rate tracking method and a heart rate tracking apparatus thereof. The method includes obtaining a photo pethysmo graphic (PPG) signal of the wearable device within a preset time, obtaining a frequency spectrum corresponding to the PPG signal by a short-time Fourier transformation of the PPG signal, generating a curve cluster according to the frequency spectrum, and in response to determining a curve that meets a preset condition in the curve cluster, acquiring a jumped heart rate according to the curve that meets the preset condition to track the heart rate.

An illumination source may be configured to illuminate the skin of the user. An illumination detector may detect electromagnetic radiation reflected of the skin of the user. A compensation module may be configured to determine the position of the skin of the user relative to the illumination detector. A processor may be configured to determine a heart rate of the user by analyzing information corresponding to an amount of the electromagnetic radiation detected by the illumination detector. The processor may also determine the heart rate of the user by compensating for the position of the skin of the user as determined by the compensation module.

While performing heart rate estimation of a user, if the user is in motion, a signal is measured and is likely to have noise data, which in turn affects accuracy of estimated heart rate value. Method and system for heart rate estimation when the user is in motion is disclosed. The system estimates value of a noise signal present in a measured PPG signal by performing a Principal Component Analysis (PCA) of an accelerometer signal collected along with the PPG signal. The system further estimates value of a true cardiac signal for a time window, based on value of the true cardiac signal in a pre-defined number of previous time windows. The system then estimates frequency spectrum of a clean PPG signal based on the estimated noise signal and the true cardiac signal. The system further performs heart rate estimation based on the clean PPG signal.