Abstract: There is provided a wearable device for measuring cardiac activity of a user, the wearable device comprising: an optical cardiac activity sensor unit configured to be placed in contact with a measurement area and to enable cardiac activity measurement of the user to obtain a cardiac activity signal; a plurality of electrodes configured to enable bioimpedance measurement on the measurement area to obtain a bioimpedance signal; a detector unit for detecting changes in the bioimpedance signal; and a reducer unit for reducing a motion artefact effect on the cardiac activity signal based on the detected changes in the bioimpedance signal.

Abstract: A solution for proximity detection of an object is disclosed. According to an aspect, there is provided a portable training computer, including a communication circuitry configured to operate according to Bluetooth technology; a radio frequency radiator circuitry coupled to the communication circuitry and configured to receive transmission signals from the communication circuitry and radiate the transmission signals as transmission bursts; a measurement circuitry coupled to the radio frequency radiator circuitry and configured to measure an electric property of the radio frequency radiator circuitry and to determine proximity of an object with respect to the radio frequency radiator circuitry on the basis of the measured electric property; and a controller configured to synchronise measurement timings of the measurement circuitry with the transmission bursts.

Abstract: A solution for optical biometric measurements is disclosed. According to an aspect, a sensor device includes a sensor head configured to face a skin of a human body. The sensor head includes: at least one optical emitter configured to emit light towards a direction of the skin; at least one photodetector configured to sense the emitted light from the direction of the skin; and an array of parallel light guide elements arranged to form a plurality of parallel light paths directing light from the at least optical emitter to the at least one photodetector. Each light guide element includes, between a first end and a second end of the light guide element, an optically transparent core and an optical barrier surrounding the core. The core together with the optical barrier focuses light along the core between the ends.

Abstract: The present document discloses a solution for estimating blood pulse wave characteristics by using multiple measurement locations of a human body. According to an aspect, a method includes detecting, in a first measurement signal measured by a first heart activity sensor associated with a first location of a human body, a first occurrence of a blood pulse wave; detecting, in a second measurement signal measured by a second heart activity sensor from a second location of the human body different from the first location, a second occurrence of the blood pulse wave; estimating, on the basis of said detections synchronized to a common clock, time characteristics of the blood pulse wave; and computing, on the basis of said time characteristics, a metric representing a physiological condition of the human body.

Abstract: A wearable training computer comprising a processing circuitry configured to determine a location of the wearable training computer based on received location information. Based on the location of the wearable training computer, the processing circuitry is further configured to select a satellite positioning system configuration used for determining the location of the wearable training computer during a physical exercise.

Abstract: A computer-implemented method for providing training guidance in connection with a physical exercise includes: measuring, by using a heart activity sensor, heart activity of a user during a physical exercise; measuring, by using a bioimpedance measurement sensor, bioimpedance of the user during the physical exercise; computing, by a processing circuitry, a stroke volume from the bioimpedance synchronized to a cardiac cycle of the user by using the measured heart activity; computing, by the processing circuitry, training intensity by using at least the computed the stroke volume; comparing, by the processing circuitry, the training intensity with at least one threshold; and outputting at least one training guidance instruction on the basis of the comparison.

Abstract: A computer-implemented method estimates sleep quality of a user. A related computer system, a computer program product, and a data structure are also described.

Abstract: There is provided a method in a collector device of a physiological performance measurement system, which includes: broadcasting a timing signal on a predetermined radio channel; receiving a data packet from each of a plurality of peripheral devices configured to perform measurements with respect to one or more users and to transmit physiological measurement data on the one or more users to the collector device, wherein the data packet indicates a clock value of the respective peripheral device as a response to the broadcasting the timing signal; and synchronizing data streams from the plurality of peripheral devices with each other based on the indicated clock values. A respective method is described for the peripheral device.

Abstract: A computer-implemented method estimates sleep quality of a user. A related computer system, a computer program product, and a data structure are also described.

Abstract: A wearable training computer includes a global navigation satellite system (GNSS) antenna arrangement configured to provide a group of antenna configurations for receiving a GNSS signal, wherein each antenna configuration provides different radio frequency properties. The wearable training computer further includes a measurement circuitry configured to measure performance of the GNSS antenna and a processing circuitry configured to select, based on at least an activity type of a user of the wearable training computer, a subset of the antenna configurations from the group of the antenna configurations, and further configured to select, from the subset of the antenna configurations based on the measured GNSS antenna performance, an antenna configuration for receiving the GNSS signal.

Abstract: A method includes: supporting a normal operation mode, during which functionalities of a portable apparatus are available through an operating system of the apparatus, wherein the operating system includes a plurality of layers including a kernel and library functions layer; supporting a limited operation mode during which the apparatus is configured to execute a physical activity algorithm based on physical activity data corresponding to a physical activity session performed by a user of the apparatus, wherein the physical activity algorithm applies a direct low-level hardware access bypassing at least the layers above the kernel and the library functions-layer; and switching between the normal operation mode and the limited operation mode

Abstract: A method of estimating a stress level of a human by an apparatus using heart activity measurement data includes: executing a breathing exercise application by the apparatus, starting a breathing exercise of the breathing exercise application and outputting, during the breathing exercise, breathing instructions to a user of the apparatus; acquiring a set of heart activity measurement data samples measured by a heart activity sensor from the user during the breathing exercise; computing a set of inter-heartbeat interval samples of the set of heart activity measurement data samples; computing a cardiac coherence of the user during the exercise from the set of inter-heartbeat interval samples; measuring a respiratory rate of the user during the breathing exercise; computing a score of the breathing exercise on the basis of the respiratory rate and the cardiac coherence, the score indicating a stress level of the user; and outputting the score through an interface of the apparatus.

Abstract: An apparatus includes a band configured to attach a physical activity measurement device to a human body, and electroactive material comprised in the band. The electroactive material is configured to change at least one of size and shape of the band in response to an electric input from the physical activity measurement device to the electroactive material.

Abstract: A measurement system includes one or more sensor devices that measure physiological measurement data; an apparatus including a portable electronic device and/or server computer that performs operations including receiving the physiological measurement data from the sensor device; associating the physiological measurement data with a user account of the user; determining whether the received physiological measurement data includes physiological measurement data required by an algorithm; as a response to determining that the received physiological measurement data includes physiological measurement data required by the algorithm, performing the algorithm; and as a response to determining that the received physiological measurement data includes the physiological measurement data required by the algorithm included in a coaching category that is in an inactive state, changing the coaching category to an active state.

Abstract: A method includes: supporting a normal operation mode, during which functionalities of a portable apparatus are available through an operating system of the apparatus, wherein the operating system includes a plurality of layers including a kernel and library functions layer; supporting a limited operation mode during which the apparatus is configured to execute a physical activity algorithm based on physical activity data corresponding to a physical activity session performed by a user of the apparatus, wherein the physical activity algorithm applies a direct low-level hardware access bypassing at least the layers above the kernel and the library functions-layer; and switching between the normal operation mode and the limited operation mode.

Abstract: A system for monitoring muscle load, is configured to perform operations including: obtaining, from at least one sensor, measurement data on an exerciser; determining, based on the measurement data, a number of repetitions of a macroscopic movement performed during a physical exercise; determining, based on a conversion entry corresponding to a type of the physical exercise, muscle load coefficient of one or more muscles loaded in the physical exercise; utilizing the muscle load coefficient of the one or more muscles and the number of repetitions in determining muscle load data indicating muscle specific muscle load caused by the physical exercise performed by the exerciser; and outputting the muscle load data.

Abstract: A solution for measuring a cardiogram of a user is disclosed. According to an aspect, a portable training computer includes a communication circuitry including a radio frequency antenna and configured to transmit a radio frequency signal through the antenna, a measurement circuitry coupled to the antenna and configured to measure an electric property of the antenna, and at least one processor configured to, in a first measurement mode, detect presence of an object in proximity with the antenna on the basis of the measured electric property, and in a second measurement mode, detect motion of a body of a user of the portable training computer with respect to the antenna on the basis of the measured electric property and compute a cardiogram of the user in the basis of the detected motion.

Abstract: A system for monitoring performance of a user includes at least one processor, and at least one memory including a computer program code. The at least one memory and the computer program code are configured, with the at least one processor, to cause the system to perform operations including obtaining force data measured by at least one force sensor coupled with one or more poles and velocity data measured by at least one sensor for measuring velocity of the user, determining poling power based on the force data and the velocity data, and outputting a poling power indicator based on the determined poling power.

Abstract: A method, apparatus, and computer program for estimating user's physiological state from gait measurements carried out during a physical exercise are disclosed. The physiological state is computed from at least one of step interval variability and stride interval variability acquired from the gait measurements.