Biosignal measuring module for wearable sensor device

Abstract

According to first aspect of the invention, there is provided a biosignal measuring module for a wearable sensor device comprising a circuit board, a light barrier, at least two lenses, a non-transparent and at least partly conductive main cover, attaching means, and a coupling interface According to a second aspect of invention, there is provided a wearable sensor device comprising the biosignal measuring module.

Description

[0001]BIOSIGNAL^MEASURING^MODULE^FOR^WEARABLE^SENSOR^DEVICE TECHNICAL FIELD The invention relates to a field of wearable sensor devices capable of measuring biosignals. TECHNICAL BACKGROUND Different kind of wearable sensor devices are widely used to carry out biosignal measurements from a user of the device. The wearable sensor device refers to a system which is worn by the user and comprises a plurality of sensors for providing biosignal based data from the user. The sensor solutions used in the biosignal measuring are very sensitive that causes many challenges when implementing in the wearable sensor devices. The know sensor implementations have many drawbacks. The aim of the invention is to alleviate drawbacks relating to the sensor implementations in the wearable sensor devices. BRIEF DESCRIPTION The present invention is defined by the subject matter of the independent claims. Embodiments are defined in the dependent claims. The embodiments and features, if any, described in this specification that do not fall under the scope of the independent claim are to be interpreted as examples useful for understanding various embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS In the following the invention will be described in greater detail by means of preferred embodiments with reference to the attached drawings, in which Figures 1A and 1B illustrate a biosignal measuring module according to an embodiment of the invention; Figure 2 illustrates an example of a wearable sensor device with the biosignal measuring module according to an embodiment of the invention; Figures 3, 4, 5, 6A, 6B and 7 illustrate the biosignal measuring module according to some embodiments of the invention. DETAILED DESCRIPTION OF THE INVENTION The following embodiments are exemplifying. Although the specification may refer to “an”, “one”, or “some” embodiment(s) in several locations of the text, this does not necessarily mean that each reference is made to the same embodiment(s), or that a particular feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments. Embodiments of the invention relate to a biosignal measuring module used in wearable sensor devices. The wearable sensor device shall be understood widely in the content of this application. The wearable sensor device may refer to a system used in training, health, and / or medical applications, for example. The system may be a device having a user interface, a wireless data transfer capability, a casing, a battery and attaching means for achieving wearability, for example. The user interface may be very simple like a button for controlling the system, for example. The casing may, at least partly, cover the device and the biosignal measuring module may be assembled in the casing. One example of such wearable sensor devices is a wearable training computer like a wrist device which is configured to carry out measurements during a physical exercise performed by a user. The wearable sensor device may also be comprised or configured to be coupled with a garment or garments (or apparel). Examples of such garments may include bra(s), swimming apparel, such as swimming suit or cap, and glove(s). The garment or apparel may be worn by the user. In some embodiments, the wearable sensor device is integrated as a part of the garment or apparel. Due to simplicity reasons, the wearable sensor device is described as the wearable training computer like the wrist device in this application. However, it is important to realize that embodiments described in relation to wrist device may be utilized by other types of wearable sensor devices, i.e. the embodiments are not necessarily limited to the wrist device or devices. The wearable training computer may be a portable system attachable to the user’s body. The wearable training computer is configured to measure physiological training data from the user’s performance during the physical exercise and to output the training data to the user via a user interface of the training computer and / or via a user interface of another apparatus. The biosignal measuring module in the wearable training computer may comprise all or at least part of sensors used for measuring the biosignal from the user`s body. In an embodiment, the wearable sensor device, like the wearable training computer, may further comprise an apparatus configured to be attached to an object, in other words, to achieve wearability. Such an apparatus may comprise an attachment structure designed and arranged to receive the training computer in a fixed, integrated, or detachable manner and to attach the training computer to the object. The attachment may be realized by a band that may be designed to encircle the object such that the band is attached around the object. The band may comprise locking parts at ends of the band where the locking parts form mutually counterparts such as a buckle and a catch. The locking parts may fix the band around the object as is commonly known in the field of wristwatches, wrist computers etc. The object may be the user and the band may be designed to be attached around the user’s wrist, making the wearable training computer the wrist device. Other forms of attachment of wearable devices are equally possible, e.g. the device may be integrated or attached to a garment such as a shirt, pants, harness, strap, or headwear. The sensors of the wearable sensor device may employ one or more measurement technologies for measuring different parameters form the user. The sensors may measure one or more of the following features from the user: motion, electrocardiogram (ECG), photoplethysmogram (PPG), bioimpedance, galvanic skin response and / or body temperature. For measuring the motion, the sensor device may comprise an inertial sensor such as an accelerometer and / or gyroscope, or a magnetometer, or any a sensor fusion that is any combination of these motion sensors, and the sensor device may output motion measurement data. The wearable sensor device measuring ECG or PPG may output heart activity measurement data. The wearable sensor device may comprise one or more electrodes attachable to the user's skin to measure an electric property from the skin which, through appropriate signal processing techniques, may be processed into an ECG signal, biocimpedance signal, or galvanic skin response signal. In some techniques, the heart activity measurement data may represent appearance of R waves of electric heart impulses. In PPG measurements a light emitted by a light emitter diode or a similar light source and reflected back from the user’s skin is be sensed by using a photo diode or a similar light sensing component. The sensed light is then converted into an electric measurement signal in the light sensing component and signal pro- cessing is used to detect desired signal components from the electric measurement signal. In the PPG measurements, P waves may be detected which enables computation of a PP interval and a heart rate, for example. The biosignal measuring module is configured to enable the wearable sensor device to measure all or at least part of the features mentioned above. The structure of the different wearable sensor devices varies between different models and manufactures. The purpose of use of the wearable sensor device affects the structures, for example. The sensor technology and its implementation in the structures are essential to get measured high quality data from the user`s body. As described above, the wearable sensor device may comprise several different sensors for different purposes and all the sensors may have different requirements for the structures. This causes many challenges, and the invention is aimed to alleviate these challenges. Referring to Figure 1, according to a first aspect of the invention, there is provided a biosignal measuring module 100 for a wearable sensor device comprising a circuit board 104 having one or more emitters 106A and detectors 106B for optical measuring, and a data bus interface 108 configured to transfer measured data from the module 100 to the wearable sensor device, a light barrier 110 having at least a first light channel 112A for a light emitted by the emitter 106A and a second light channel 112B for the light detected by the detector 106B wherein the first and the second light channels 112A – B are isolated from each other, at least two lenses 114A - B configured to enable access of the light of the emitter 106A and / or the detector 106B, a non-transparent and at least partly conductive main cover 116, configured to be arranged against a skin of a user of the wearable sensor device, having at least two openings 118A - B for receiving the at least two lenses 114A - B such that the lenses are aligned with the light channels 112A – B, attaching means 120 configured to attach the light barrier 110 with the main cover 116 and / or the circuit board 104, and a coupling interface configured to enable coupling of the biosignal measuring module 100 with the wearable sensor device. The biosignal measuring module (also module later in this application) is a separate module that is configured to provide a modular structure for assembling the sensor(s) and all the needed structures of the sensor(s) into the wearable sensor device (also device later in this application). The separate module is connectable with the wearable sensor device and is configured to fit in the different kind of the wearable sensor devices. The module may be an own sales item which can be purchased and assembled into the wearable sensor devices of the different manufacturers, for example. Hence, the manufacturer of the wearable sensor devices may obtain the module and assemble it into the own product. The module as well as the device may be separately assembled, and the assembled module is then coupled with the assembled device. As illustrated in Figure 1, the module 100 comprises the circuit board 104 having at least the sensor(s) for the optical measurement of the biosignals. A photoplethysmogram (PPG) is one example in which optical sensors are applied. For example, in PPG measurement a light emitted by a light emitter diode (emitter) or a similar light source and reflected back from the user’s skin is sensed by using a photo diode or a similar light sensing component (detector). The sensed light is then converted into an electric measurement signal in the light sensing component and signal processing is used to detect desired signal components from the electric measurement signal. In the PPG measurements, P waves may be detected which enables computation of a PP interval and the heart rate, for example. The above- mentioned components are placed on the circuit board of the module. The module may comprise a plurality of emitter and detectors depending on the implementation. A surface-mounted technology (SMT) and / or a chip on board technology (COB) may be applied in the circuit board. In an embodiment, the circuit board may comprise two boards. A first board may be based on the COB comprising the optical components like bonded dies and a second board may be based on the SMT comprising other components. The circuit board 104 further comprises an interface 108 for transferring data from the module to the wearable sensor device. The interface may be implemented by the data bus, for example. The circuit board may comprise a first connector configured to be connected to its counter connector placed on the wearable sensor device, for example. The connectors may be a boar to board type of connectors, for example. The data measured by the biosignal measuring module may be transferred to the wearable sensor device via the data bus, for example. Furthermore, the data bus may be used for transmitting data from wearable sensor device to the module. The circuit board may further comprise an interface for coupling the module with a power source. The power source may be a battery of the wearable sensor device, for example. In an embodiment, the module comprises the own power source like the battery. Sill referring to Figure 1, the module 100 further comprises the light barrier 110. The light barrier is configured to guide the lights desired ways in the optical measuring. The light barrier may be a plate kind of structure having channels 112A – B (through holes) for guiding the light. The channels may be isolated from each other by a wall, for example. The light barrier may be made of non-transparent material for ensuring that the light cannot escape from the channel to undesired direction. The light barrier guides the light from the emitter to the issue of the user and / or back from the tissue to the detector, for example. If transparent material is used in the main cover, the (inner) wall of the channel may be covered by a non-transparent layer, for example. This enables use of a transparent material in the light barrier. The light barrier 110 may comprise the first channel 112A for the light provided by the emitter 106A to the tissue of the user, and the second channel 112B for receiving the light back from the tissue to the detector 106B. The first and the second channels are isolated from each other by a partition wall to enable the proper measurement. There may be a plurality of emitter and detector pairs in the circuit board, and then the light barrier may comprise own channel for each emitter and detector. The module 100 further comprises the non-transparent and at least partly conductive main cover 116. One side of the main cover is configured to be arranged against a skin of the user of the wearable sensor device in which the module is assembled. For example, the sensor device may be the wearable training computer like the wrist device and then the main cover sets against the skin of the wrist when the device is tightened around the wrist. The main cover is the outermost component in the module when the module is integrated into the wearable sensor device. The main cover comprises at least two openings 118A - B for receiving the at least two lenses 114A – B. The light of optical measurement is configured to go through the openings and lenses. Hence, the lenses 114A – B and openings 118A – B are aligned with the light channels 112A – B to enable access of the light from the components assembled on the circuit board. The lenses may be (synthetic) sapphire lenses, for example. The lens may be cylindrical and may comprise two opposite planes and a side wall between them. In an embodiment, the lenses are attached by an adhesive. Referring to Detail A in Figure 4, the adhesive may be set between a side wall 126 of the lens 114A - B and a side wall 128 of the opening 118A - B. In another embodiment, the lenses are attached by a double-sided tape. Still referring to Figure 4 and Detail A, in another embodiment, the openings 118A – B comprise a step 130 in the inner wall 128 forming a plane 132 on which the lens 114A - B is set when coupled into the opening 118A - B. As described, the lens 114A – B may be cylindrical and may comprise two opposite planes and a side wall between them. One plane of the lens may be set against the plane 132 of the opening 118A – B as illustrated in Figure 4. At least one of the planes of the lens may be partly covered by a non-transparent layer in the vicinity of the side wall as illustrated in Figure 5 (black area). The plane in which the non- transparent layer is, is configured to be set against the plane of the opening. For example, the adhesive may be dispensed on this non-transparent area. The main cover and openings on it may also guide the light. The openings may also be non-transparent and are capable of isolate the emitted light and detected light from each other in the optical measurement. The non- transparency may be achieved by using the non-transparent material in the main cover or arranging the non-transparent layer on (inner) walls of the opening. The module further comprises attaching means 120 configured to attach the light barrier 110 with the main cover 116 and / or the circuit board 104. In other words, the attaching means bind the parts of the module together. As illustrated for example in Figure 1, the circuit board, the light barrier, and the main cover are a plate kind of parts forming layers which are attached together by the attaching means. In the assembled state of the module, the circuit board is assembled against the light barrier and the light barrier against the main cover. Then only the main cover is visible from the wearable sensor device, other part stays inside the device. Hence, the light barrier may be between the circuit board and the main cover in the structure of the module, and the attaching means may be set between the circuit board and the light barrier as well as between the light barriers and the main cover. In an embodiment, the attaching means comprises adhesive for gluing the parts (layers) together. In another embodiment, the attaching means comprises a double-sided tape comprising the adhesive on both side of the tape. The module further comprises the coupling interface configured to enable coupling of the biosignal measuring module 100 with the wearable sensor device 102 as illustrated in Figure 2. The coupling interface is configured to enable mechanical coupling of the module with the wearable sensor device. The coupling interface in the module may comprise a first coupling feature which is configured to be coupled with a second coupling feature arranged in the wearable sensor device. For example, the first coupling feature is configured to receive and lock with the second coupling feature or the other way round. In an embodiment, the first feature comprises a plane (surface) arranged in the module. The wearable sensor device may also comprise a plane (surface) which is configured to be coupled with the plane of the module. Chemical attaching means, like for example adhesive, may be applied between the planes to attach the module and the wearable sensor device together. As described above, the wearable sensor device may comprise the casing, and the plane in the wearable sensor device side may be arranged on the casing, for example. In another embodiment, the coupling interface comprises mechanical attaching means. There may be an integrated locking member in the module and / or a separate locking member may be used. The separate locking member may be a screw, for example. The wearable sensor device may comprise a counterpart for the mechanical attaching means. For example, if the attaching means comprises the screw, the counterpart may be a threaded hole. In an embodiment, the interface between the module and the sensor device further comprises a gasket for sealing the interface. The gasket may form an ingress protection (IP) against progress of dust and / or water into the device through the interface. In an embodiment, the coupling interface 122 is arranged within the main cover 116. As illustrated in Figures 1A and 1B, the main cover and the light barrier may be substantially round and a plate kind of structures. A radius of the main cover may be larger than a radius of the light barrier. When a centreline (point) of the main cover is aligned with a centreline of the light barrier, there is some space in the vicinity of the side edge of the main cover that is not covered by the light barrier due to the smaller radius of the light barrier. This part of the main cover may form the coupling interface which is configured to be coupled with the casing of the wearable sensor device. Referring now to Figure 7 which illustrates a simplified cross section view of the module and the casing of the wearable sensor device. The casing 134 of the wearable sensor device 102 may comprise a hole 136 for receiving the module 100. The hole 136 may comprise a first surface 138 of the device 102 which is configured to receive a first surface 140 of the module 100 which is arranged on the main cover 116. It can also be seen in Figure 7 that radius of the main cover is larger than the radius of the light barrier as described above. The first surface 140 in the module 100 is the space that is not covered by the light barrier 110 when they are coupled together and can be used for attaching the module with the device. These opposite surfaces 138, 140 may be attached together by the adhesive, for example. In other words, the adhesive may be put between the opposite surfaces which is configured to bind the surfaces together. The adhesive may also seal the surface. It may form an ingress protection (IP) surface preventing progress of dust and water into the device through the interface, for example. Referring now to Figure 3, in an embodiment, the circuit board 104 further comprise a processing circuitry 122 configured to process the measured data before transmitting to the wearable sensor device 102. Hence, the module may have the own processor for processing the data. The processor may also be capable of processing data received from a main processing unit of the wearable sensor device. The processing circuitry 122 in the module 100 is configured to interact with the main processing unit that provides many benefits. For example, loading of the main processing unit is lower, data processing is faster and power consumption is lower, for example. The processing circuitry 122 may be configured to preprocess the measured data before transmitting to the main processing unit making loading of the main processing unit lower. Hence, the module, when assembled in the wearable sensor device, adds the processing capacity of the system making capacity requirements of the main processing unit lower. This adds compatibility of module to the different kind of wearable sensor devices. In other words, the requirement for the processing capacity of the main processing unit is lower. The processing circuitry is configured to process for example activity, sleep, exercise and health related data. At least one of following features may flow from the processing circuitry to the main processing unit: heart rate, pulse to pulse interval, skin contact, finger contact, ECG, energy expenditure, activity classification, activity percentage and target, steps, sleep stage, nightly recovery, sleep charge, breathing disturbance detection, brain health analysis, cadence, walking / running speed and distance, swimming styles and distance, sources of energy expenditure, fuelling reminder, fitness results, orthostatic test results, serene mindful breathing exercise result, jump test result, blood pressure, systolic and diastolic pulse transit times, systolic and diastolic pulse arrival times, blood oxygen saturation, nightly skin temperature and / or weight management plans and tracking. In an embodiment, the biosignal measuring module further comprises one or more sensors for measuring at least electrocardiogram (ECG), temperature and / or bioimpedance from the user of the wearable sensor device 102. The electrocardiogram (ECG) sensor is configured to measure electric activity of the user's heart non-invasively. The ECG sensor may comprise electrodes configured to be coupled with the user's skin. The module itself may comprise one or more electrodes and / or the module is configured to be in contact with one or more electrodes which may locate outside of the module. The electrode may refer to a conductive point which is configured to act as an electrode when measuring the ECG. The temperature sensor is configured to measure a body temperature of the user. The temperature measurement may be performed from the skin of the user, for example. The temperature measurement data may be used to determine is the temperature inside a predetermined range, for example. The bioimpedance sensor may comprise one or more electrodes. In an embodiment, the bioimpedance measurement may be carried out by arranging signal feed electrode(s) and measurement the electrode(s) in the module. In another embodiment, the module is coupled with one or more electrodes for the bioimpedance measurement. The electrodes for the bioimpedance measurement may also be a combination of one or more electrodes placed in the module and one or more electrodes that are outside of the module but coupled with it. Referring to Figure 2, in an embodiment, the main cover 116 is at least partly conductive forming a first conductive member CM1 and the module 100 is coupled with a second conductive member CM2 for measuring the electrocardiogram, and wherein a galvanic connection is provided between the conductive members CM1 – 2. The conductive members act as an electrode for the ECG, for example. The main cover may be at least partly conductive forming a first electrode, and further the module may be coupled with other conductive point forming a second electrode wherein the first and the second electrodes are in skin contact with the user. The conductive part of the main cover, which forms the first electrode, may be connected to the circuit board. The circuit board may comprise a spring element that presses against the conductive main cover forming a connection from the circuit board to the conductive part of the main cover. The first electrode may be a conductive spot in the main cover and the second electrode may be a conductive spot in the wearable sensor device to which the module is assembled. For example, a first hand is in contact with the first conductive spot and a second hand is in contact with the second conductive spot in the ECG measuring. The next example describes how the first and the second electrodes may be implemented in the wrist device. The wrist device may be in a left hand of the user such that the first conductive spot in the main cover is against a skin of a left wrist. The second conductive spot (button) may by arranged on a casing of the wrist device which is touched by a right hand when measuring the ECG. Hence, the second electrode (conductive spot) is not arranged on the module, instead the module is configured to be in connection with the second electrode enabling the ECG measurement. The first and the second electrodes may be electrically separated, in other words, there may be arranged only a galvanic connection between the electrodes via the skin of the user of the wearable sensor device. The conductive member(s) or spot(s) may be connected with the circuit board of the module. There may be a conductor between the member / spot and the circuit board. For example, there may be the conductor arranged from the conductive member of the main cover to the circuit board. In an embodiment, the main cover is made of metal. A material of the main cover may comprise a stainless steel, for example. SUS316L grade steel may be used, for example. In an embodiment, the main cover is made of plastic. The plastic main cover may be manufactured by moulding, for example. The plastic used in the main cover may be non-transparent and / or the plastic main cover may be covered, at least partly, by non-transparent layer. Referring to Figures 6A and 6B, in an embodiment in which the main cover is made of plastic, the main cover 116 further comprises a metal insert 142. The metal insert may be a rim which covers an (outer) edge of the main frame and creates the conductive area to the main cover. The metal insert may be open from the middle, in other words, there may a hole in the middle of the metal insert as illustrated in Figure 6A and 6B. Hence, the metal insert may be O-shaped, for example. For example, the openings in the main cover (and lenses) may be arranged to be in the hole when the insert and the frame are assembled together. This allows access of the light from the optical components to the tissue of the user and the other way round. The metal insert may be attached to the main frame by mechanical and / or chemical attaching means, for example. The first conductive member CM1 in the main cover may be arranged on the metal insert. In an embodiment, the main cover 116 is made of glass. In an embodiment, the main cover 116 made of glass is covered, at least partly, by non- transparent layer to achieve the non-transparency in the cover. In an embodiment, the main cover 116 made of glass is covered at least partly by a conductive layer. The main cover made by class may be coated by using Physical Vapor Deposition (PVD) to produce a thin layer that covers at least partly the main cover. For example, CrSiCN composition may be used in the coating. The PVD provides the thin layer on a surface of the main cover which is non-transparent and conductive. In an embodiment, the main cover 116 further comprises one or more transparent spots on the non-transparent layer. Then the main cover may comprise one or more lenses and also one or more transparent spots. The transparent spot may be made by preventing forming the non-transparent layer in desired areas of the main cover in the coating process. This may be made by masking, for example. It is also possible to remove the non-transparent layer from the desired areas after coating. The transparent spots in the main cover let the light go through them. The spots may be used for emitting the light to the tissue of the user, and the lenses may be used for detecting the emitted light, for example. Hence, the transparent spots in the main cover may also be aligned with the light barrier and / or the optical components on the circuit board. In an embodiment, the circuit board 104 comprises a flexible portion 144, wherein the flexible portion 144 is coupled with one or more connectors to couple the module 100 with the wearable sensor device 102. As illustrated in Figures 1A and 1B, the circuit board may comprise a part which is substantially round, like the main cover and the light barrier, and in which most of the components are placed. The flexible part of the circuit board may extend from the round shaped part. In other words, a first end of the flexible part may be connected to the round shaped part. The flexible part may be substantially rectangular, for example. A second end of the flexible part may comprise the connector. There may be an extension at the second end in which the connector is assembled as illustrated in Figures 1A and 1B, for example. The connector is configured to couple the circuit board with the wearable sensor device. The connector may form the data bus interface for transmitting data between the processor of the module and the processor of the wearable sensor device. The flexible part of the circuit board enables moving of the connector in relation to the round shaped part of the circuit board. Hence, the round shaped part of the circuit board is stationary in the assembled state, and the extension in which the connector is placed is movable due to the flexible part. The movable connector enables that a counter connector for it can be in different locations in the wearable sensor device. In other words, it helps to integrate the module into the different kind of structures of the wearable sensor devices. In an embodiment, the main cover 116 comprises the light barrier 110. Hence, the light barrier may be integrated with the main cover to one entity. In other words, the main cover and the light barrier may be made of one piece. This reduces parts in the module and furthermore reduces needs for the attaching means. The main cover may be thicker, and the light channels may be formed in it, for example. In an embodiment, the coupling interface 122 is configured to detachably couple the module 100 with the wearable sensor device 102. In other words, the coupling interface enables removal of the module from the wearable sensor device. The removal may be needed if the module is damaged, for example. The coupling interface may comprise mechanical attaching means that are openable. The coupling member may also comprise chemical attaching means that can be opened by heat, for example. Referring now to Figure 2, according to another aspect of the invention there is provided a wearable sensor device 102 comprising a biosignal measuring module 100 comprising any of features described above. Figure 2 illustrates the wearable training computer 102 which is one example of the wearable sensor device. The wearable sensor device to which the module may be assembled may comprise the processing unit, the user interface, the wireless data transfer capability, the casing, the battery and attaching means for achieving wearability, for example. The wearable sensor device may comprise a coupling interface configured to receive the coupling interface of the module which couples the module to the device. The wearable sensor device may comprise the casing in which the coupling interface is arranged, for example. The coupling interface is described in more detail above. The biosignal measuring module according to the invention provides many benefits. It is configured to be integrated into the different kind of wearable devices in which sensor technology is used to measure biosignals. The coupling interface enables mechanical coupling of the module to the different kind of devices, and the data interface enables data transfer between the sensor module and the device. For example, producers of smart watches or any other sensor devices may obtain the module and integrate it into their products. The sensor technology used in the biosignal measurement is challenging and a lot of competence is required when developing biosignal measuring products. Furthermore, a lot of testing is required to ensure proper function of the biosignal measuring. The biosignal measuring module provides the solution that solves these issues since the module comprises all the features that are needed for the reliable biosignal measuring, and it is also easy to integrate. As used in this application, the term ‘circuitry’ refers to all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and / or digital circuitry, and (b) combinations of circuits and software (and / or firmware), such as (as applicable): (i) a combination of processor(s) or (ii) portions of processor(s) / software including digital signal processor(s), software, and memory(ies) that work together to cause an apparatus to perform various functions, and (c) circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present. This definition of ‘circuitry’ applies to all uses of this term in this application. As a further example, as used in this application, the term ‘circuitry’ would also cover an implementation of merely a processor (or multiple processors) or a portion of a processor and its (or their) accompanying software and / or firmware. The techniques and methods described herein may be implemented by various means. For example, these techniques may be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or combinations thereof. For a hardware implementation, the apparatus(es) of embodiments may be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), graphics processing units (GPUs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. For firmware or software, the implementation can be carried out through modules of at least one chipset (e.g. procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in a memory unit and executed by processors. The memory unit may be implemented within the processor or externally to the processor. In the latter case, it can be communicatively coupled to the processor via various means, as is known in the art. Additionally, the components of the systems described herein may be rearranged and / or complemented by additional components in order to facilitate the achievements of the various aspects, etc., described with regard thereto, and they are not limited to the precise configurations set forth in the given figures, as will be appreciated by one skilled in the art. It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

CLAIMS 1. A separate biosignal measuring module (100) connectable with a wearable sensor device comprising (102): a circuit board (104) having one or more emitters (106A) and detectors (106B) for optical measuring, and a data bus interface (108) configured to transfer measured data from the module (100) to the wearable sensor device (102); a light barrier (110) having at least a first light channel (112A) for a light emitted by the emitter (106A) and a second light channel (112B) for the light detected by the detector (106B) wherein the first and the second light channels (112A – B) are isolated from each other; at least two lenses (114A - B) configured to enable access of the light emitted by the emitter (106A) and / or detected by the detector (106B); a non-transparent and at least partly conductive main cover (116), configured to be arranged against a skin of a user of the wearable sensor device (100), having at least two openings (118A - B) for receiving the at least two lenses (114A - B) such that the lenses are aligned with the light channels (112A – B); attaching means (120) configured to attach the light barrier (110) with the main cover (116) and / or the circuit board (104); and a coupling interface (122) arranged within the main cover (116) configured to enable mechanical coupling of the biosignal measuring module (100) with the wearable sensor device (102).

2. The biosignal measuring module (100) of claim 1, wherein circuit board (104) further comprise a processing circuitry (124) configured to process at least the measured data before transmitting to the wearable sensor device (102).

3. The biosignal measuring module (100) of any preceding claim, wherein the module (100) further comprises one or more sensors for measuring at least electrocardiogram, temperature and / or bioimpedance from the user of the wearable sensor device (102).

4. The biosignal measuring module (100) of claim 3, wherein the main cover (116) comprises a first conductive member (CM1) and the module (100) is coupled with a second conductive member (CM2) for measuring the electrocardiogram, and wherein a galvanic connection is provided between theconductive members (CM1 – 2).

5. The biosignal measuring module (100) of any preceding claim, wherein the main cover (116) is made of metal.

6. The biosignal measuring module (100) of claims 1 - 4, wherein the main cover (116) is made of plastic.

7. The biosignal measuring module (100) of claim 6, wherein the main cover (112) comprises a metal insert (142).

8. The biosignal measuring module (100) of claims 1 - 4, wherein the main cover (116) is made of glass.

9. The biosignal measuring module (100) of claim 8, wherein the main cover (116) is covered at least partly by a conductive and a non-transparent layer.

10. The biosignal measuring module (100) of claim 9, wherein the main cover (116) further comprises one or more transparent spots in the non- transparent layer.

11. The biosignal measuring module (100) of any preceding claim, wherein the main cover (116) comprises the coupling interface (122).

12. The biosignal measuring module (100) of any preceding claim, wherein the circuit board (104) comprises a flexible portion (144), wherein the flexible portion (144) is coupled with one or more connectors to couple the module (100) with the wearable sensor device (102).

13. The biosignal measuring module (100) of any preceding claim, wherein the main cover (116) comprises the light barrier (110).

14. The biosignal measuring module (100) of any preceding claim, wherein the module (100) is detachably coupled with the wearable sensor device (102).

15. A wearbale sensor device (102) comprising a biosignal measuring module (100) according to any of claims 1 – 14.

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