WO2023144529A1

WO2023144529A1 - Method, computer-readable medium and system for guiding a breathing exercise performed by a user

Info

Publication number: WO2023144529A1
Application number: PCT/GB2023/050162
Authority: WO
Inventors: Clare Simpson; Martin ASHBY
Original assignee: Prevayl Innovations Limited
Priority date: 2022-01-28
Filing date: 2023-01-25
Publication date: 2023-08-03
Also published as: GB202201101D0

Abstract

The user is prompted to exhale and inhale in a controlled manner over a time span (2402). A sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span are obtained (2404). A measure of the heartrate variability of the user is calculated from samples (2406). A health metric for the user is generated according to a comparison between the measure of the heartrate variability of the user and historic heartrate variability values of the user when performing guided breathing exercises (2408). The health metric may be output to the user along with the measure of the heartrate variability. The heartrate for the user may also be determined. The heartrate may be used to set a resting heartrate for the user. A method of triggering a guided breathing exercise based on whether a stress condition is detected from heartbeat data samples is also provided.

Description

METHOD, COMPUTER-READABLE MEDIUM AND SYSTEM FOR GUIDING A BREATHING EXERCISE PERFORMED BY A USER

[0001] The present invention is directed towards a method of guiding a breathing exercise performed by a user, a computer readable medium and a system for performing the same.

BACKGROUND

[0002] Guided breathing exercises are designed to regulate the breathing rate of a user by prompting the user to adopt a controlled breathing pattern. Guided breathing exercises are typically performed when the user is in an at rest position such as when they are seated or lying down.

[0003] Guided breathing exercises can provide a number of health benefits particularly in terms of reducing stress. Guided breathing exercises are also known as mindfulness exercises or stress reduction/management exercises.

[0004] United States Patent Application Publication No. 2016166197 A1 discloses a method and apparatus for providing biofeedback during a meditation exercise. The wearable device includes one or more biometric sensors and a user interface. The method involves prompting the user, via the user interface, to perform a meditation exercise, the meditation exercise being associated with a target physiological metric related to the physiology of the user. The method involves measuring, based on output of at least one of the one or more biometric sensors, a physiological metric of the user during the meditation exercise. The method involves determining a performance score indicating the user's performance during the meditation exercise based on comparing the measured physiological metric with the target physiological metric. The method involves providing, via the user interface, based on the performance score, feedback information indicative of the user's performance during the meditation exercise. A baseline heart rate variability is determined based on measurements taken at times other than the mediation exercise. When the user’s baseline heart rate variability is relatively high, the processor calibrates the determination of the performance score to be more sensitive to changes in the user’s heartrate variability.

[0005] United States Patent Application Publication No. 2010/0324427 A1 discloses a system and a kit for stress and relaxation management. A cardiac activity sensor is used for measuring the heart rate variability signal of the user and a respiration sensor for measuring the respiratory signal of the user. The system contains a user interaction device having an input unit for receiving user specific data and an output unit for providing information output to the user. A processor is used to assess the stress level of the user by determining a user related stress index. The processor is also used to monitor the user during a relaxation exercise by means of determining a relaxation index based on the measured HRV and respiratory signals. The relaxation index is continuously adapted to the incoming measured signals and based thereon the processor instructs the output unit to provide the user with biofeedback and support messages. [0006] While guided breathing exercises are known to provide health benefits, it can be challenging for users to comply with guided breathing exercises and repeatedly perform them. Generally, health benefits occur gradually though repeated performance of guided breathing exercises such as once a day. There is a need to encourage users to perform guided breathing exercises.

SUMMARY

[0007] According to the present invention, there is provided a method, computer-readable medium and system as set out in the accompanying claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

[0008] According to a first aspect of the disclosure, there is provided a computer-implemented method of generating a health metric for a user. The method comprises prompting a user to exhale and inhale in a controlled manner over a time span as part of a guided breathing exercise. The method comprises obtaining a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span. The method comprises calculating a measure of the heartrate variability of the user from the heartbeat data samples. The method further comprises generating a health metric for the user according to a comparison between the measure of the heartrate variability of the user and historic heartrate variability values of the user when performing guided breathing exercises.

[0009] Advantageously, heartbeat data samples are recorded during the guided breathing exercise performed by the user. The heartbeat samples are used to calculate the heartrate variability of the user during the guided breathing exercise which is in turn used to generate a health metric for the user. The health metric is based on a comparison of the heartrate variability for the current guided breathing exercise to historic heartrate variability values obtained during previous guided breathing exercises performed by the user. The health metric is able to indicate whether the heartrate variability of the user is improving (increasing), decreasing, or maintaining at the same level. This provides the user with an indication of their heart health and enables the user to see the benefits of performing the guided breathing exercises. Regular use of guided breathing exercises is expected to increase heartrate variability and therefore improve heart health. Providing the health metric enables the user to see the health benefits associated with guided breathing and helps ensure user compliance with guided breathing exercises. Moreover, providing the health metric provides the user with an overall indication of their heart health which can be used by the user to determine what sort of exercises they should do. If the heart rate variability is lower than the user's historic heartrate variability values, then the user can consider resting or performing reduced intensity workouts. A low heartrate variability is a sign of overtraining which can lead to injury of the user if high intensity exercise continues to be performed.

[0010] The method may further comprise prompting the user to hold their breath between exhales and inhales. [0011] The heartbeat data samples may comprise inter-beat interval, IBI, values representing the time between successive heartbeats. IBI values represent the time between corresponding peaks in successive heartbeats. The peaks are usually R peaks in an ECG signal, but the present disclosure is not limited to this example. Other peaks in the ECG signal could be used to calculate the IBI values for example. The present disclosure is also not limited to ECG signals and other signals indicate of the heart activity of the user may be used.

[0012] Generating the health metric may comprise comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user when performing guided breathing exercises. A moving average of a previous number of guided breathing exercises may be used.

[0013] The method may further comprise outputting the measure of the heartrate variability to the user. Outputting may comprise displaying the measure to the user, generating an audio output, generating a haptic output or a combination thereof.

[0014] The method may further comprise outputting the health metric to the user. Outputting may comprise displaying the health metric to the user, generating an audio output, generating a haptic output or a combination thereof.

[0015] The method may further comprise calculating a measure of the heartrate of the user from the heartbeat data samples.

[0016] The method may further comprise outputting the measure of the heartrate of the user.

[0017] Generating the health metric may further comprise comparing the measure of the heartrate of the user to historic average heartrate values of the user when performing guided breathing exercises.

[0018] Generating the health metric may further comprise comparing the measure of the heartrate of the user to a measure of the average historic heartrate of the user when performing guided breathing exercises.

[0019] Generating the health metric may further comprise comparing the measure of the heartrate of the user to one or measures representative of the heartrate of the general population and/or physiological norms. Advantageously, this helps identify whether the user has an abnormal heartrate.

[0020] The method may further comprise establishing a communication session with a wearable electronics module; and receiving the heartbeat data samples from the electronics module during the time span.

[0021] According to a second aspect of the disclosure, there is provided a computer-readable medium having instructions recorded thereon which, when executed by a processor, cause the processor to perform the method of the first aspect of the disclosure.

[0022] According to a third aspect of the disclosure, there is provided a system comprising a processor and a memory, the memory storing instructions which when executed by the processor cause the processor to perform operations. The operations comprising prompting a user to exhale and inhale in a controlled manner over a time span as part of a guided breathing exercise. The operations comprising obtaining a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span. The operations comprising calculating a measure of the heartrate variability of the user from the heartbeat data samples. The operations comprising generating a health metric for the user according to a comparison between the measure of the heartrate variability of the user and historic heartrate variability values of the user when performing guided breathing exercises.

[0023] The prompting may further comprise prompting the user to hold their breath between exhales and inhales.

[0024] The heartbeat data samples may comprise inter-beat interval, IBI, values representing the time between successive heartbeats.

[0025] Generating the health metric may comprise comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user when performing guided breathing exercises.

[0026] The operations performed by the processor may further comprise outputting the measure of the heartrate variability to the user.

[0027] The operations performed by the processor may further comprise calculating a measure of the heartrate of the user from the heartbeat data samples.

[0028] Generating the health metric may further comprise comparing the measure of the heartrate of the user to historic average heartrate values of the user when performing guided breathing exercises.

[0029] The operations performed by the processor may further comprise establishing a communication session with a wearable electronics module; and receiving the heartbeat data samples from the electronics module during the time span.

[0030] The system may comprise a user electronic device, and wherein the user electronic device comprises the processor and the memory.

[0031] The system may comprise the wearable electronics module.

[0032] According to a fourth aspect of the disclosure, there is provided a computer-implemented method comprising prompting a user to exhale and inhale in a controlled manner over a time span as part of a guided breathing exercise, obtaining a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span, calculating a measure of the heartrate variability of the user from the heartbeat data samples, and outputting the measure of the heartrate variability to the user.

[0033] Advantageously, heartbeat data samples are recorded during the guided breathing exercise performed by the user. The heartbeat samples are used to calculate the heartrate variability of the user during the guided breathing exercise which is in turn output to the user. From this, the user is able to determine whether their heartrate variability is improving (increasing), decreasing, or maintaining at the same level. This provides the user with an indication of their heart health and enables the userto see the benefits of performing the guided breathing exercises. Regular use of guided breathing exercises is expected to increase heartrate variability and therefore improve heart health. Providing the heartrate variability enables the user to see the health benefits associated with guided breathing and helps ensure user compliance with guided breathing exercises. Moreover, providing the heartrate variability provides the user with an overall indication of their heart health which can be used by the user to determine what sort of exercises they should do. If the heart rate variability is lower than the user's historic heartrate variability values, then the user can consider resting or performing reduced intensity workouts. A low heartrate variability is a sign of overtraining which can lead to injury of the user if high intensity exercise continues to be performed.

[0034] The prompting may further comprise prompting the user to hold their breath between exhales and inhales.

[0035] The heartbeat data samples may comprise inter-beat interval, IBI, values representing the time between successive heartbeats.

[0036] The method may further comprise calculating a measure of the heartrate of the user from the heartbeat data samples.

[0037] The method may further comprise outputting the measure of the heartrate to the user.

[0038] The method may further comprise: generating a health metric for the user according to a comparison between the measure of the heartrate variability of the user and historic heartrate variability values of the user when performing guided breathing exercises.

[0039] Generating the health metric may comprise comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user when performing guided breathing exercises.

[0040] The method may further comprise outputting the health metric to the user.

[0041] The method may further comprise establishing a communication session with a wearable electronics module; and receiving the heartbeat data samples from the electronics module during the time span.

[0042] According to a fifth aspect of the disclosure, there is provided a computer-readable medium having instructions recorded thereon which, when executed by a processor, cause the processor to perform the method of the fourth aspect of the disclosure.

[0043] According to a sixth aspect of the disclosure, there is provided a system comprising a processor and a memory, the memory storing instructions which, when executed by the processor, cause the processor to perform operations comprising prompting a user to exhale and inhale in a controlled manner over a time span as part of a guided breathing exercise, obtaining a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span, calculating a measure of the heartrate variability of the user from the heartbeat data samples, and outputting the measure of the heartrate variability to the user. [0044] The prompting may further comprise prompting the user to hold their breath between exhales and inhales.

[0045] The heartbeat data samples may comprise inter-beat interval, IBI, values representing the time between successive heartbeats.

[0046] The operations performed by the processor may further comprise calculating a measure of the heartrate of the user from the heartbeat data samples.

[0047] The operations performed by the processor may further comprise outputting the measure of the heartrate to the user.

[0048] The operations performed by the processor may further comprise generating a health metric for the user according to a comparison between the measure of the heartrate variability of the user and historic heartrate variability values of the user when performing guided breathing exercises.

[0049] Generating the health metric may comprise comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user when performing guided breathing exercises.

[0050] The operations performed by the processor may further comprise outputting the health metric to the user.

[0051] The operations performed by the processor may further comprise establishing a communication session with a wearable electronics module; and receiving the heartbeat data samples from the electronics module during the time span.

[0052] The system may comprise a user electronic device, and wherein the user electronic device comprises the processor and the memory.

[0053] The system may comprise the wearable electronics module.

[0054] According to a seventh aspect of the disclosure, there is provided a computer- implemented method comprising: prompting a user to exhale and inhale in a controlled manner over a time span as part of a guided breathing exercise; obtaining a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span; calculating a measure of the heartrate of the user from the heartbeat data samples; and setting a resting heartrate for the user using the measure of the heartrate.

[0055] Advantageously, heartbeat data is obtained during the guided breathing exercise and used to set a resting heartrate for the user. This provides a convenient mechanism for obtaining a resting heartrate that is accurate and specific to the user. This approach avoids the need to estimate the resting heartrate based on factors such as the age of the user. This approach also avoids the need for complicated laboratory setups to determine the resting heartrate.

[0056] The heartbeat data samples may comprise inter-beat interval, IBI, values representing the time between successive heartbeats.

[0057] The method may further comprise using the resting heartrate to set a heartrate reserve for the user. The heartrate reserve may be used in setting training zones for the user. [0058] The method may further comprise outputting the measure of the heartrate of the user.

[0059] The method may further comprise calculating a measure of the heartrate variability of the user from the heartbeat data samples.

[0060] The method may further comprise generating a health metric for the user according to a comparison between the measure of the heartrate variability of the user and historic heartrate variability values of the user when performing guided breathing exercises.

[0061] Generating the health metric may comprise comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user when performing guided breathing exercises.

[0062] Generating the health metric may further comprises comparing the measure of the heartrate of the user to historic average heartrate values of the user when performing guided breathing exercises.

[0063] Generating the health metric may further comprise comparing the measure of the heartrate of the user to a measure of the average historic heartrate of the user when performing guided breathing exercises.

[0064] The method may further comprise outputting the health metric to the user.

[0065] The method may further comprise establishing a communication session with a wearable electronics module; and receiving the heartbeat data samples from the electronics module during the time span.

[0066] According to an eighth aspect of the disclosure, there is provided a computer-readable medium having instructions recorded thereon which, when executed by a processor, cause the processor to perform the method of the seventh aspect of the disclosure.

[0067] According to a ninth aspect of the disclosure, there is provided a system comprising a processor and a memory, the memory storing instructions which when executed by the processor cause the processor to perform operations comprising: prompting a user to exhale and inhale in a controlled manner over a time span as part of a guided breathing exercise; obtaining a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span; calculating a measure of the heartrate of the user from the heartbeat data samples; and setting a resting heartrate for the user using the measure of the heartrate.

[0068] The prompting may further comprise prompting the user to hold their breath between exhales and inhales.

[0069] The heartbeat data samples may comprise inter-beat interval, IBI, values representing the time between successive heartbeats.

[0070] The operations performed by the processor may further comprise using the resting heartrate to set a heartrate reserve for the user.

[0071] The operations performed by the processor may further comprise outputting the measure of the heartrate of the user. [0072] The operations performed by the processor may further comprise calculating a measure of the heartrate variability of the user from the heartbeat data samples.

[0073] The operations performed by the processor may further comprise generating a health metric for the user according to a comparison between the measure of the heartrate variability of the user and historic heartrate variability values of the user when performing guided breathing exercises.

[0074] Generating the health metric may comprise comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user when performing guided breathing exercises.

[0075] Generating the health metric may further comprise comparing the measure of the heartrate of the user to historic average heartrate values of the user when performing guided breathing exercises.

[0076] Generating the health metric may further comprise comparing the measure of the heartrate of the user to a measure of the average historic heartrate of the user when performing guided breathing exercises.

[0077] The system may further comprise outputting the health metric to the user.

[0078] The operations performed by the processor may further comprise establishing a communication session with a wearable electronics module; and receiving the heartbeat data samples from the electronics module during the time span.

[0079] The system may comprise a user electronic device, and wherein the user electronic device comprises the processor and the memory.

[0080] The system may comprise the wearable electronics module.

[0081] According to a tenth aspect of the disclosure, there is provided a computer-implemented method of triggering a guided breathing exercise, the method comprising: obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user over the time span; determining from heartbeat data samples whether a stress condition is present; and in response to determining that a stress condition is present, prompting the user to perform a guided breathing exercise.

[0082] Advantageously, the method determines whether to recommend that a user performs a guided breathing exercise based on heartbeat data samples received from the user. The heartbeat data samples are processed to determine whether a stress condition is present. Guided breathing exercises are known to reduce stress. Therefore, prompting a user to conduct a guided breathing exercise when they are determined to be stressed is beneficial in achieving favourable health outcomes for the user.

[0083] The heartbeat data samples may comprise inter-beat interval, IBI, values representing the time between successive heartbeats

[0084] Determining from the heartbeat data samples whether a stress condition is present may comprise: determining a measure of the heartrate variability of the user from the heartbeat data samples; and determining, from the measure of the heartrate variability, whether the stress condition is present.

[0085] Determining, from the measure of the heartrate variability whether the stress condition is present may comprise comparing the measure of the heartrate variability to one or more historic measures of heartrate variability for the user.

[0086] Determining, from the measure of the heartrate variability whether the stress condition is present may comprise comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user.

[0087] Obtaining the sequence of heartbeat data samples may comprise: obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user when in a first position.

[0088] Determining from the heartbeat data samples whether a stress condition is present may comprise: determining from the heartbeat data samples a measure of the heartrate variability of the user when in the first position; and determining, from the measure of the heartrate variability, whether the stress condition is present.

[0089] Obtaining the sequence of heartbeat data samples may comprise: obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user when in a second position.

[0090] Determining from the heartbeat data samples whether a stress condition is present may comprise: determining from the heartbeat data samples a measure of the heartrate variability of the user when in the first position; determining from the heartbeat data samples a measure of the heartrate variability of the user when in the second position; and determining, from the measure of the heartrate variability when in the first position and from the measure of the heartrate variability when in the second position, whether the stress condition is present.

[0091] The method may further comprise guiding a breathing exercise performed by the user.

[0092] According to an eleventh aspect of the disclosure, there is provided a computer-readable medium having instructions recorded thereon which, when executed by a processor, cause the processor to perform the method of the tenth aspect of the disclosure.

[0093] According to a twelfth aspect of the disclosure, there is provided a system for triggering a guided breathing exercise, the system comprising a processor and a memory, the memory storing instructions which when executed by the processor cause the processor to perform operations comprising: obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user over the time span; determining from heartbeat data samples whether a stress condition is present; and in response to determining that a stress condition is present, prompting the user to perform a guided breathing exercise.

[0094] The heartbeat data samples may comprise inter-beat interval, IBI, values representing the time between successive heartbeats [0095] Determining from the heartbeat data samples whether a stress condition is present may comprise: determining a measure of the heartrate variability of the user from the heartbeat data samples; and determining, from the measure of the heartrate variability, whether the stress condition is present.

[0096] Determining, from the measure of the heartrate variability, whether the stress condition is present may comprise comparing the measure of the heartrate variability to one or more historic measures of heartrate variability for the user.

[0097] Determining, from the measure of the heartrate variability, whether the stress condition is present may comprise comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user.

[0098] Obtaining the sequence of heartbeat data samples may comprise: obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user when in a first position.

[0099] Determining from the heartbeat data samples whether a stress condition is present may comprise: determining from the heartbeat data samples a measure of the heartrate variability of the user when in the first position; and determining, from the measure of the heartrate variability, whether the stress condition is present.

[0100] Obtaining the sequence of heartbeat data samples may comprise: obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user when in a second position.

[0101] Determining from the heartbeat data samples whether a stress condition is present may comprise: determining from the heartbeat data samples a measure of the heartrate variability of the user when in the first position; determining from the heartbeat data samples a measure of the heartrate variability of the user when in the second position; and determining, from the measure of the heartrate variability when in the first position and from the measure of the heartrate variability when in the second position, whether the stress condition is present.

[0102] The operations performed by the processor may further comprise establishing a communication session with a wearable electronics module; and receiving the heartbeat data samples from the electronics module during the time span.

[0103] The system may comprise a user electronic device, and wherein the user electronic device comprises the processor and the memory.

[0104] The system may comprise the wearable electronics module.

[0105] According to a thirteenth aspect of the disclosure, there is provided computer- implemented method of triggering a guided breathing exercise, the method comprising: obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user when in a first position, the heartbeat data samples comprising inter-beat interval, IBI, values representing the time between successive heartbeats; obtaining, from the IBI values, a measure of the heartrate variability of the user when in the first position; obtaining a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user when in a second position, the heartbeat data samples comprising inter-beat interval, IBI, values representing the time between successive heartbeats; obtaining, from the IBI values, a measure of the heartrate variability of the user when in the second position; determining from the measure of the heartrate variability of the user when in the first position and the measure of the heartrate variability of the user when in the second position whether a stress condition is present; and in response to determining that a stress condition is present, prompting the user to perform a guided breathing exercise.

[0106] In the above examples of the present disclosure, the heartbeat data may be derived from an ECG signal, but this is not required in all examples and other signals indicative of the heartrate are within the scope of the present disclosure. Other signals indicative of the heartrate include photoplethysmography (PPG) signals, ballistocardiogram (BCG) signals, and electromagnetic cardiogram (EMCG) signals.

BRIEF DESCRIPTION OF THE DRAWINGS

[0107] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0108] FIG. 1 illustrates a signal trace for an ECG signal.

[0109] FIG. 2 illustrates an ECG waveform that includes electrical signals for two successive heartbeats.

[0110] FIG. 3 illustrates an example system in accordance with aspects of the present disclosure.

[0111] FIG. 4 illustrates a schematic for an example electronics module in accordance with aspects of the present disclosure.

[0112] FIG. 5 illustrates an example wearable article in accordance with aspects of the present disclosure.

[0113] FIG. 6 illustrates an example wearable assembly comprising an electronics module and wearable article in accordance with aspects of the present disclosure.

[0114] FIG. 7A illustrates an external view of an example electronics module in accordance with aspects of the present disclosure.

[0115] FIG. 7B illustrates an external view of an example electronics module in accordance with aspects of the present disclosure.

[0116] FIG. 8 illustrates a schematic for an example electronics module in accordance with aspects of the present disclosure.

[0117] FIG. 9 illustrates a more detailed schematic for an example electronics module in accordance with aspects of the present disclosure.

[0118] FIG. 10 illustrates an example analogue-to-digital frontend of an electronics module according to aspects of the present disclosure. [0119] FIG. 11 illustrates an example method according to aspects of the present disclosure. [0120] FIG. 12 illustrates an example method according to aspects of the present disclosure.

[0121] FIG. 13 illustrates an example user electronic device according to aspects of the present disclosure.

[0122] FIG. 14 illustrates a page of an application running on a user electronic device according to aspects of the present disclosure.

[0123] FIG. 15 illustrates a page of an application running on a user electronic device according to aspects of the present disclosure.

[0124] FIG. 16 illustrates a page of an application running on a user electronic device according to aspects of the present disclosure.

[0125] FIG. 17 illustrates a page of an application running on a user electronic device according to aspects of the present disclosure.

[0126] FIG. 18 illustrates a page of an application running on a user electronic device according to aspects of the present disclosure.

[0127] FIG. 19 illustrates a page of an application running on a user electronic device according to aspects of the present disclosure.

[0128] FIG. 20 illustrates a page of an application running on a user electronic device according to aspects of the present disclosure.

[0129] FIG. 21 illustrates a page of an application running on a user electronic device according to aspects of the present disclosure.

[0130] FIG. 22 illustrates a page of an application running on a user electronic device according to aspects of the present disclosure.

[0131] FIG. 23 illustrates a method for guiding a breathing exercise performed by a user according to aspects of the present disclosure.

[0132] FIG. 24 illustrates a method for guiding a breathing exercise performed by a user according to aspects of the present disclosure.

[0133] FIG. 25 illustrates a method fortriggering the performance of a guided breathing exercise according to aspects of the present disclosure.

DETAILED DESCRIPTION

[0134] "Wearable article" refers to any form of article which may be worn by a user such as a smartwatch, necklace, garment, bracelet, or glasses. The wearable article may be a textile article. The wearable article may be a garment. The garment may refer to an item of clothing or apparel. The garment may be a top. The top may be a shirt, t-shirt, blouse, sweater, jacket/coat, or vest. The garment may be a dress, garment brassiere, shorts, pants, arm or leg sleeve, vest, jacket/coat, glove, armband, underwear, headband, hat/cap, collar, wristband, armband, chestband, waistband, stocking, sock, or shoe, athletic clothing, personal protective equipment, including hard hats, swimwear, wetsuit, or dry suit. [0135] The type of wearable garment may dictate the type of biosignals to be detected. For example, a hat or cap may be used to detect electroencephalogram or magnetoencephalogram signals.

[0136] The wearable article (e.g., a garment) may be constructed from a woven or a non-woven material. The wearable article may be constructed from natural fibres, synthetic fibres, or a natural fibre blended with one or more other materials which can be natural or synthetic. The yarn may be cotton. The cotton may be blended with polyester and/or viscose and/or polyamide according to the application. Silk may also be used as the natural fibre. Cellulose, wool, hemp, and jute are also natural fibres that may be used in the wearable article. Polyester, polycotton, nylon and viscose are synthetic fibres that may be used in the wearable article.

[0137] The garment may be a tight-fitting garment or a loose-fitting (e.g., freeform garment). A tight-fitting garment helps ensure that the sensor devices of the garment are held in contact with or in the proximity of a skin surface of the wearer. The tight-fitting garment may be a compression garment. The tight-fitting garment may be an athletic garment such as an elastomeric athletic garment. A loose-fitting garment is generally more comfortable to wear over extended time periods and during sleep.

[0138] The garment has sensing units provided on an inside surface which are typically held in close proximity to a skin surface of a wearer wearing the garment. This enables the sensing units to measure biosignals for the wearer wearing the garment.

[0139] "Wearer" refers to the person or other form of animal who is wearing, or otherwise holding, the wearable article and/or electronics module. The wearer may also be referred to as a user. Although the user and wearer may be different entities in certain situations.

[0140] "Biosignal", “biological signal” refers to signals from living beings that can be continually measured or monitored. Biosignals may be electrical or non-electrical signals. Signal variations can be time variant or spatially variant.

[0141] "Sensing units" refers to one or more elements more measuring signals from a wearer of the wearable article. A sensing unit may comprise the combination of a sensor, such as an electrode, a connection region, and a communication pathway coupling the electrode to the connection region. An electronics module communicatively coupled to the connection region is able to obtain measurement signals from the sensor via the communication pathway and connection region. The sensing units may be made of a (electrically) conductive material such as a conductive yarn, conductive ink, conductive transfer, or conductive paste. When formed form conductive yarn, the sensing units may be knitted, woven, embroidered, stitched, or otherwise incorporated into the wearable article. The sensing units may be integrally formed with the wearable article such as by being integrally knitted with the wearable article.

[0142] The sensing units may be arranged to measure one or more biosignals of a wearer wearing the wearable article.

[0143] Sensing units may be used for measuring one or a combination of bioelectrical, bioimpedance, biochemical, biomechanical, bioacoustics, biooptical or biothermal signals of the wearer. The sensing units may be incorporated into the wearable article, an electronics module coupled to or forming part of the wearable article or may be shared between the electronics module and the wearable article. For example, the wearable article may comprise sensors (e.g., sensing electrodes) while the electronics module may comprise the processing logic for the sensing electrodes. The processing logic will review the signals from the sensors and perform operations such as filtering and analogue-to-digital conversion on the signals. The bioelectrical measurements include electrocardiograms (ECG), electrogastrograms (EGG), electroencephalograms (EEG), and electromyography (EMG). The bioimpedance measurements include plethysmography (e.g., for respiration), body composition (e.g., hydration, fat, etc.), and electroimpedance tomography (EIT). The biomagnetic measurements include magnetoneurograms (MNG), magnetoencephalography (MEG), magnetogastrogram (MGG), magnetocardiogram (MCG). The biochemical measurements include glucose/lactose measurements which may be performed using chemical analysis of the wearer’s sweat. The biomechanical measurements include blood pressure. The bioacoustics measurements include phonocardiograms (PCG). The biooptical measurements include photoplethysmography (PPG) and orthopantomograms (OPG). The biothermal measurements include skin temperature and core body temperature measurements.

[0144] ECG sensing is used to provide a plethora of information about a person’s heart. It is one of the simplest and oldest techniques used to perform cardiac investigations. In its most basic form, it provides an insight into the electrical activity generated within heart muscles that changes over time. By detecting and amplifying these differential biopotential signals, a lot of information can be gathered quickly, including the heart rate.

[0145] A typical ECG waveform or trace is illustrated in Figure 1 showing the QRS complex. Figure 2 shows an ECG waveform of two successive heartbeats. The time difference between the two R peaks in the ECG waveform is the inter-beat interval (IBI) also known as the R-R interval. This time is usually expressed in milliseconds. IBI values represent the time between successive heartbeats.

[0146] "Electronics module" may refer to an electronic device that is able to communicatively couple with sensing units in a wearable article so as to obtain measurement signals from the sensing units and/or apply signals to the sensing units. The electronics module may also be a stand-alone component that performs measurements using internal sensors without communicatively coupling to a wearable article.

[0147] Electronics modules typically comprise a sensing interface for communicatively coupling with the wearable article, a controller, and a wireless communicator for communicating with an external device such as a user electronic device over a wireless communication protocol.

[0148] The electronics module is typically removably coupled to the wearable article such that it is retained by the wearable article when worn. The electronics module can be removed from the wearable article so that the wearable article can be washed without damaging the internal electronics of the electronics module. The electronics module can also be removed from the wearable article for charging. In other examples, the electronics module is integrally formed with the wearable article such as when the wearable article/electronics module form a smartwatch.

[0149] Generally, the electronics module comprises all of the components required for data transmission and processing such that the wearable article only comprises the sensing units. In this way, the manufacture of the wearable article may be simplified. In addition, it may be easier to clean a wearable article which has fewer electronic components attached thereto or incorporated therein. Furthermore, the removable electronics module may be easier to maintain or troubleshoot than embedded electronics. The electronics module may comprise flexible electronics such as a flexible printed circuit (FPC).

[0150] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. [0151] The terms and words used in the following description and claims are not limited to the bibliographical meanings but are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

[0152] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[0153] FIG. 3 shows a system according to aspects of the present disclosure. The system comprises a wearable assembly 302 and a user electronic device 304. The wearable assembly 302 is worn by a user who in this embodiment is the wearer 306 of the wearable assembly 302.

[0154] The wearable assembly 302 comprises a wearable article 308 which, in this is example, is in the form of a garment.

[0155] The wearable assembly 302 comprises an electronics module 310. The electronics module 310 is releasably coupled to the wearable article 308. The wearable article 308 comprises an electronics module holder (not shown) arranged to removably retain the electronics module 310. The electronics module holder enables the electronics module to be attached and removed from the wearable article 308.

[0156] In some examples, the electronics module holder comprises a pocket such as a garment pocket. The pocket has an opening through which the electronics module 310 may be inserted and removed from the pocket. The pocket may be formed from fabric layers of the wearable article 308.

[0157] The present disclosure is not limited to electronics module holders in the form pockets. [0158] The electronics module 310 may be configured to be releasably mechanically coupled to the wearable article 308. The mechanical coupling of the electronics module 310 to the wearable article 308 may be provided by a mechanical interface such as a clip, a plug and socket arrangement, etc. The mechanical coupling or mechanical interface may be configured to maintain the electronics module 310 in a particular orientation with respect to the wearable article 308 when the electronics module 310 is coupled to the wearable article 308. This may be beneficial in ensuring that the electronics module 310 is securely held in place with respect to the wearable article 308 and/or that any electronic coupling of the electronics module 310 and the wearable article 308 can be optimized. The mechanical coupling may be maintained using friction or using a positively engaging mechanism, for example.

[0159] The electronics module 310 is arranged to wirelessly communicate data to the user electronic device 304. Various protocols enable communication between the electronics module 310 and the user electronic device 304. Example communication protocols include Bluetooth ®, Bluetooth ® Low Energy, and near-field communication (NFC).

[0160] The system also comprises a remote server 312 which may be in communication with the user electronic device 304 and/or the electronics module 310.

[0161] FIG. 4 shows a simplified diagram of an example electronics module 310 according to aspects of the present disclosure. The electronics module 310 comprises a controller 402 and a sensing interface 404 communicatively coupled to the controller 402.

[0162] The sensing interface 404 in this example comprises a first electrical contact 406 and a second electrical contact 408. The sensing interface 404 receives measurement signals from the electrical contacts 406, 408. The measurement signals, or a processed version thereof, are provided to the controller 402. The measurement signals may be any form of biosignal as described above. The sensing interface 404 is therefore able to receive physiological signals from a wearer of the electronics module 310.

[0163] The controller 402 is able to process the signals received from the sensing interface. The controller 402 may control a wireless communicator (not shown) of the electronics module 310 to transmit data to an external device such as user electronic device 304 of FIG. 3.

[0164] FIG. 5 shows a simplified diagram of an example wearable article 308. The wearable article 308 comprises a fabric layer 502.

[0165] A first communication interface 504 is provided on the fabric layer 502. The first communication interface 504 is accessible from the electronics module holder of the wearable article 308.

[0166] The first communication interface 504 is communicatively coupled to a first sensor 506 via a first communication pathway 508. The first communication interface 504, first sensor 506 and first communication pathway 508 form a first sensing unit of the wearable article 308. The first sensor 506 is in the form of an electrode. The first sensor 506 may be provided on the wearable article 308 such that it faces the skin surface of the wearer when the wearable article 308 is worn. This enables the first sensor 506 to contact the skin surface and measure biosignals from the skin surface and/or apply signals to the skin surface. Signals may be applied to the skin surface in therapeutic applications for example.

[0167] A second communication interface 510 is provided on the fabric layer 502. The second communication interface 510 is accessible from the electronics module holder of the wearable article 308.

[0168] The second communication interface 510 is communicatively coupled to a second sensor 512 via a second communication pathway 514. The second communication interface 510, second sensor 512, and second communication pathway 514 form a second sensing unit of the wearable article 308. The second sensor 512 is in the form of an electrode. The second sensor 512 may be provided on the wearable article 308 such that it faces the skin surface of the wearer when the wearable article 308 is worn. This enables the second sensor 512 to contact the skin surface and measure biosignals from the skin surface and/or apply signals to the skin surface. Signals may be applied to the skin surface in therapeutic applications for example.

[0169] In this example, the first sensor 506 and second sensor 512 are electrodes. This is not required in all examples. Other forms of sensors such as temperature sensors, optical sensors, chemical sensors, and moisture sensors may be included. The wearable article 308 may include any combination of different types of sensors.

[0170] FIG. 6 shows a simplified diagram of an electronics module 310 coupled to a wearable article 308 to form an example wearable assembly 302. The electronics module 310 is positioned inside an electronics module holder 602 of the wearable article 308 which in this example is in the form of a pocket.

[0171] The first communication interface 504 and the second communication interface 510 are provided on a first surface of fabric layer 604 such that they are located within the pocket space. The first sensor 506 and the second sensor 512 are provided on a second surface of fabric layer 606 that opposes the first surface of fabric layer 604. The first sensor 506 and second sensor 512 are arranged such that they face towards the skin surface of the wearer of the wearable article 308. The first and second communication pathways are not shown in FIG. 6 but as discussed above in relation to FIG. 5, couple the sensors to their respective communication interfaces 504, 510.

[0172] The electronics module 310 is positioned within the pocket space. The first electrical contact 406 of the electronics module 310 contacts and is electrically coupled to the first communication interface 504. The second electrical contact 408 of the electronics module 310 contacts and is electrically coupled to the second communication interface 510. The electronics module 310 is therefore coupled to the first sensor 506 and the second sensor 512 via the communication pathways, communication interfaces 504, 510, and electrical contacts 406, 408.

[0173] FIG. 7A and FIG. 7B show external views of an electronics module 310 according to aspects of the present disclosure. The electronics module 310 has a housing 702. Components of the electronics module 310 such as the controller 402 are disposed within the housing 702. The first electrical contact 406 and the second electrical contact 408 are located on an external surface of the housing 702.

[0174] The electronics module 310 may have a length of between 20 mm and 60 mm, a width of between 15 mm and 35 mm, and a depth of between 5 mm and 15 mm. In some examples, the electronics module 310 has a length of between 30 mm and 40 mm or between 35 mm and 38 mm. In some examples, the electronics module 310 has a width of between 20 mm and 30 mm or between 24 and 26 mm. In preferred examples, the electronics module 310 has a width of 25 mm. In some examples, the electronics module 310 has a depth of between 8 mm and 12 mm or between 9 mm and 11 mm. In preferred examples, the electronics module 310 has a depth of between 9.7 mm and 10 mm. In one particular example, the electronics module 310 has a length of 38 mm, a width of 25 mm and a depth of 9.6 mm.

[0175] FIG. 8 shows a simplified schematic diagram for an example electronics module 310 as shown in FIG. 6. It will be appreciated that not all of the components shown in FIG. 8 are required and additional components may also be provided.

[0176] The electronics module 310 comprises a controller 402 and a sensing interface 404 as described in FIG. 6. The sensing interface 404 comprises a first electrical contact 406 and a second electrical contact 408. The controller 402 is communicatively coupled to the sensing interface 404 and is operable to receive signals from the sensing interface 404 for further processing.

[0177] The sensing interface 404 comprises electrical contacts 406, 408 in this example. This means that the communicative coupling in this example is a conductive coupling formed by direct contact between the electrical contacts 406, 408 and the connection regions of the wearable article, but this is not required in all examples. The communicative coupling may be a wireless (e.g., inductive) coupling.

[0178] The electronics module 310 further comprises a power source 802 and a power receiving interface 804.

[0179] The power source 802 may comprise one or a plurality of power sources. The power source 802 may be a battery. The battery may be a rechargeable battery. The battery may be a rechargeable battery adapted to be charged wirelessly such as by inductive charging. The power source 802 may comprise an energy harvesting device. The energy harvesting device may be configured to generate electric power signals in response to kinetic events such as kinetic events performed by the wearer of the wearable article. The kinetic event could include walking, running, exercising or respiration of the wearer. The energy harvesting material may comprise a piezoelectric material which generates electricity in response to mechanical deformation of the converter. The energy harvesting device may harvest energy from body heat of the wearer. The energy harvesting device may be a thermoelectric energy harvesting device. The power source may be a super capacitor, or an energy cell.

[0180] The power receiving interface 804 is operable to receive power from an external power store for charging the power source. The power receiving interface 804 may be a wired or wireless interface. A wireless interface may comprise one or more wireless power receiving coils for receiving power from the external power store. In some examples, one or both of the first and second electrical contacts 406, 408 may also function as the power receiving interface 804 to enable power to be received from the external power store.

[0181] The power receiving interface 804 may also be coupled to the controller 402 to enable direct communication between the controller 402 and an external device if required.

[0182] The electronics module 310 further comprises a wireless communicator 806. The wireless communicator 806 may utilise any communication protocol such as used for communication over: a wireless wide area network (WWAN), a wireless metro area network (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN), Bluetooth ® Low Energy, Bluetooth ® Mesh, Thread, Zigbee, IEEE 1002.15.4, Ant, a Global Navigation Satellite System (GNSS), a cellular communication network, or any other electromagnetic RF communication protocol. The cellular communication network may be a fourth generation (4G) LTE, LTE Advanced (LTE-A), LTE Cat-M1 , LTE Cat-M2, NB-loT, fifth generation (5G), sixth generation (6G), and/or any other present or future developed cellular wireless network.

[0183] The electronics module 310 further comprises a sensor 808. The sensor 808 may comprise one or a combination of an optical sensor, temperature sensor, motion sensor, magnet sensor, and location sensor. Other sensors may also be included in the electronics module 310.

[0184] FIG. 9 shows a more detailed schematic diagram for the example electronics module 310 shown in FIG. 6 and FIG. 8.

[0185] The electronics module 310 comprises a controller 402, sensing interface 404, first electrical contact 406, second electrical contact 408, sensor 808, power source 802, and power receiving interface 804 as described above.

[0186] The controller 402 comprises an internal memory 902. The controller 402 is also communicatively connected to an external memory 904 which in this example is a NAND Flash memory. The external memory 904 is used to for the storage of data when no wireless connection is available between the electronics module 310 and an external device such as a user electronic device (e.g., user electronic device 304 of FIG. 3). The external memory 904 may have a storage capacity of at least 1 GB and preferably at least 2 GB.

[0187] The electronics module 310 also includes additional peripheral devices that are used to perform specific functions as will be described in further detail herein.

[0188] The power source 802 in this example is a lithium ion battery. The battery is rechargeable and charged via power receiving interface 804. The power receiving interface 804 is arranged to receive wireless power inductively. Of course, the present disclosure is not limited to recharging via inductive charging and instead other forms of charging such as a wired connection or far field wireless charging are within the scope of the present disclosure. Additional battery management functionality is provided in terms of a charge controller 906, battery monitor 908 and regulator 910. These components may be provided through use of a dedicated power management integrated circuit (PMIC).

[0189] The controller 402 is communicatively connected to a battery monitor 908 so that that the controller 402 may obtain information about the state of charge of the battery.

[0190] The electronics module 310 comprises a first wireless communicator 912 and a second wireless communicator 914.

[0191] The first wireless communicator 912 s arranged to communicatively couple with an external device over a first wireless communication protocol. The first wireless communication protocol may be a Bluetooth ® protocol, Bluetooth ® 5 or a Bluetooth ® Low Energy protocol but is not limited to any particular communication protocol. In the present embodiment, the first wireless communicator 912 is integrated into controller 402. The first wireless communicator 912 enables communication between the external device and the controller 402 for configuration and set up of the controller 402 and the peripheral devices as may be required. Configuration of the controller 402 and peripheral devices utilises the Bluetooth ® protocol in this example.

[0192] Other wireless communication protocols can also be used, such as used for communication over: a wireless wide area network (WWAN), a wireless metro area network (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN), Bluetooth ® Low Energy, Bluetooth ® Mesh, Thread, Zigbee, IEEE 1002.15.4, Ant, a Global Navigation Satellite System (GNSS), a cellular communication network, or any other electromagnetic RF communication protocol. The cellular communication network may be a fourth generation (4G) LTE, LTE Advanced (LTE-A), LTE Cat-M1 , LTE Cat-M2, NB-loT, fifth generation (5G), sixth generation (6G), and/or any other present or future developed cellular wireless network.

[0193] The second wireless communicator 914 is arranged to communicatively couple with an external device using a second communication protocol. The external device is powered to induce a magnetic field in an antenna of the second wireless communicator 914. When the external device is placed in the magnetic field of the antenna of the second wireless communicator 914, the external device induces current in the second wireless communicator 914. This induced current is used to retrieve the information from a memory and transmit the same back to the external device. The controller 402 is arranged to energize the second wireless communicator 914 to transmit information.

[0194] In an example operation, the external device is a user electronic device (e.g., user electronic device 304 of FIG. 3). The user electronic device is brought into proximity with the electronics module 310. In response to this, the electronics module 310 is configured to energize the second wireless communicator 914 to transmit information to the user electronic device over the second wireless communication protocol. Beneficially, this means that the act of the user electronic device approaching the electronics module 310 energizes the second wireless communicator 914 to transmit the information to the user electronic device. [0195] The information may comprise a unique identifier for the electronics module 310. The unique identifier for the electronics module 310 may be an address for the electronics module 310 such as a MAC address or Bluetooth ® address.

[0196] The information may comprise authentication information used to facilitate the pairing between the electronics modules 310 and the user electronic device over the first wireless communication protocol. This means that the transmitted information is used as part of an out of band (OOB) pairing process.

[0197] The information may comprise application information which may be used by the user electronic device to start an application on the user electronic device or configure an application running on the user electronic device. The application may be started on the user electronic device automatically (e.g., without user input). Alternatively, the application information may cause the user electronic device to prompt the user to start the application on the user electronic device. The information may comprise a uniform resource identifier such as a uniform resource location to be accessed by the user electronic device, or text to be displayed on the user electronic device for example. It will be appreciated that the same electronics module 310 can transmit any of the above example information either alone or in combination. The electronics module 310 may transmit different types of information depending on the current operational state of the electronics module 310 and based on information it receives from other devices such as the user electronic device.

[0198] The electronics module 310 has sensors 808 including a motion sensor 918, a temperature sensor 920, a magnetic field sensor 922, and a location sensor 924. It will be appreciated that not all of these sensors 808 are required in all examples and additional sensors, such as optical sensors, chemical sensors, humidity sensors, and pressure sensors may also be provided.

[0199] The location sensor 924 may be a GNSS (Global Navigation Satellite System) device which is arranged to provide location and position data for applications as required. In particular, the location sensor 924 provides geographical location data at least to a nation state level. Any device suitable for providing location, navigation or for tracking the position could be utilised. The GNSS device may include Global Positioning System (GPS), BeiDou Navigation Satellite System (BDS) and the Galileo system devices.

[0200] The motion sensor 918 in this example is in the form of an inertial measurement unit (IMU) which may comprise an accelerometer and optionally one or both of a gyroscope and a magnetometer. A gyroscope/magnetometer is not required in all examples, and instead only an accelerometer may be provided, or a gyroscope/magnetometer may be present but put into a low power state.

[0201] The IMU can therefore be used to detect can detect orientation and gestures with eventdetection interrupts enabling motion tracking and contextual awareness. It has recognition of freefall events, tap and double-tap sensing, activity or inactivity, stationary/motion detection, and wakeup events in addition to 6D orientation. A single tap, for example, can be used enable toggling through various modes or waking the electronics module 310 from a low power mode.

[0202] Known examples of IMUs that can be used for this application include the ST LSM6DSOX manufactured by STMicroelectronics. This IMU a system-in-package IMU featuring a 3D digital accelerometer and a 3D digital gyroscope.

[0203] Another example of a known IMU suitable for this application is the LSM6DSO also be STMicroelectronics.

[0204] The IMU can include machine learning functionality, for example as provided in the ST LSM6DSOX. The machine learning functionality is implemented in a machine learning core (MLC). The machine earning processing capability uses decision-tree logic. The MLC is an embedded feature of the IMU 211 and comprises a set of configurable parameters and decision trees. As is understood in the art, decision tree is a mathematical tool composed of a series of configurable nodes. Each node is characterized by an “if-then-else” condition, where an input signal (represented by statistical parameters calculated from the sensor data) is evaluated against a threshold.

[0205] Decision trees are stored and generate results in the dedicated output registers. The results of the decision tree can be read from the application processor at any time. Furthermore, there is the possibility to generate an interrupt for every change in the result in the decision tree, which is beneficial in maintaining low-power consumption.

[0206] Decision trees can be generated using a known machine learning tool such as Waikato Environment for Knowledge Analysis software (Weka) developed by the University of Waikato or using MATLAB® or Python™.

[0207] The electronics module 310 further comprises a light source 926, such as a light emitting diode, for conveying status information about the electronics module 310 and/or the wearer of the electronics module 310. More generally, any form of output unit may be provided in addition to or instead of the light source 926. The output unit may comprise one or a combination of an audio output unit, a visual output unit (e.g., light source 926 or a display) and a haptic feedback unit.

[0208] The electronics module 310 also comprises conventional electronics components which are not shown in FIG. 9 including a power-on-reset generator, a development connector, a real time clock and a PROG header.

[0209] The electronics module 310 in this example comprises first wireless communicator 912 and second wireless communicator 914 but this is not required in all examples. More generally, the electronics module 310 may have one or a plurality of wireless communicators to enable the electronics module 310 to communicate wirelessly over an external device such as a user electronic device or a remote server.

[0210] The electronics module 310 may additionally comprise a Universal Integrated Circuit Card (UICC) that enables the garment to access services provided by a mobile network operator (MNO) or virtual mobile network operator (VMNO). The UICC may include at least a read-only memory (ROM) configured to store an MNO or VMNO profile that the garment can utilize to register and interact with an MNO or VMNO. The LIICC may be in the form of a Subscriber Identity Module (SIM) card. The electronics module 310 may have a receiving section arranged to receive the SIM card. In other examples, the LIICC is embedded directly into a controller of the electronics module 310. That is, the UICC may be an electronic/embedded UICC (elllCC). A elllCC is beneficial as it removes the need to store a number of MNO profiles, i.e., electronic Subscriber Identity Modules (eSIMs). Moreover, eSIMs can be remotely provisioned to garments. The electronics module 310 may comprise a secure element that represents an embedded Universal Integrated Circuit Card (eUlCC).

[0211] The sensing interface comprises an analogue-to-digital front end 916 that couples signals received from the electrical contacts 406, 408 to the controller 406 and optionally an electrostatic discharge (ESD) protection circuit. The analogue-to-digital frontend is shown in detail in FIG. 10.

[0212] FIG. 10 is a schematic illustration of the component circuitry for the analogue-to-digital front end 916 shown in FIG. 9.

[0213] In the example described herein, the analogue-to-digital front end 916 is an integrated circuit (IC) chip which converts the raw analogue biosignal received via the sensing interface into a digital signal for further processing by the controller (e.g., controller 402 of FIG. 9). ADC IC chips are known, and any suitable one can be utilised to provide this functionality. ADC IC chips for ECG and bioimpedance applications include, for example, the MAX30001 chip produced by Maxim Integrated Products Inc.

[0214] The analogue-to-digital front end 916 includes an input 1002 and an output 1004.

[0215] Raw biosignals from the sensing interface (e.g., sensing interface 404 of FIG. 9) are input to the analogue-to-digital front end 916, where received signals are processed in an ECG channel 1006 and a bioimpedance (BIOZ) channel 1008 and subject to appropriate filtering through high pass and low pass filters for static discharge and interference reduction as well as for reducing bandwidth prior to conversion to digital signals. The reduction in bandwidth is important to remove or reduce motion artefacts that give rise to noise in the signal due to movement of the sensors coupled to the sensing interface.

[0216] The output digital signals may be decimated to reduce the sampling rate prior to being passed to a serial programmable interface 1010 of the analogue-to-digital front end 916. Signals are output to the controller via the serial programmable interface 1010.

[0217] The digital signal values output to the controller 103 are stored in a FIFO data buffer. The controller 402 performs operations to generate biological metrics from the digital signal values. The operations are performed in real-time while the ADC front end 139 are outputting new digital signals to the controller 402.

[0218] ADC front end IC chips suitable for ECG applications may be configured to determine information from the input biosignals such as heart rate and the QRS complex and including the R-R interval. Alternatively, the determination of such inter-beat interval (IBI) values can be determined by the controller 402. [0219] The determining of the QRS complex can be implemented for example using the known Pan Tomkins algorithm as described in Pan, Jiapu; Tompkins, Willis J. (March 1985). "A Real- Time QRS Detection Algorithm". IEEE Transactions on Biomedical Engineering. BME-32 (3): 230- 236.

[0220] The controller 402 can also be configured to apply digital signal processing (DSP) to the digital signal from the analogue-to-digital front end 916.

[0221] The DSP may include noise filtering additional to that conducted in the analogue-to- digital front end 916 and may also include additional processing to determine further information about the signal from the analogue-to-digital front end 916.

[0222] The controller 402 is configured to send the biosignals to the user electronic device 304. The biosignals sent to the user electronic device 304 in this example comprise the inter beat interval (IBI) values representing the time differences between successive R peaks in the measured ECG signal.

[0223] FIG. 11 shows an aspect of a method for calculating R-R intervals from digital ECG signal values received in real-time via the analogue-to-digital front end 916 of the electronics module 310. The ECG signal values are received by the controller 402 from the analogue-to-digital front end 916 and stored in the FIFO buffer.

[0224] The controller repeatedly performs a signal processing operation.

[0225] In step 1102, the controller reads a number M of signal values from the FIFO buffer. Each of the signal values is a value that represents the amplitude of the ECG signal at a particular time point. In this example M is 16 such that 16 ECG signal values are read from the FIFO buffer.

[0226] In step 1104, the controller detrends the signal values so as to remove baseline wander and/or other low frequency components. In an example operation, the controller calculates the trend in the signal values and then subtracts the calculated trend from each of the signal values.

[0227] Calculating the trend comprises identifying the maximum and minimum signal values read from the FIFO buffer. The maximum signal value is added to a buffer that stores the maximum signal values obtained over time. The minimum signal value is added to a buffer that stores the minimum signal values obtained over time. The current trend is then calculated by calculating the average of the maximum value stored in the buffer of maximum signal values and the minimum value stored in the buffer of minimum signal values.

[0228] The detrended signal values are calculated by subtracting the calculated current trend from each of the signal values. The detrended signal values are added to a FIFO detrended signal buffer.

[0229] In step 1106, the detrended signal values are filtered. The filtering is performed to remove components from the signal that do not resemble R-peaks. A bandpass filter centred around the frequency associated with the shape and width of the R-peak can be used to perform this task. [0230] Some filtering approaches use a bandpass filter with a central frequency in the range of 17 to 19 Hz. HR or FIR filters may be used, however, they are generally not effective due to ripples and lobes that may be present around the R-peaks in the ECG signal. The interaction between these secondary peaks and other components of the ECG signal can lead to ambiguity in the identity of the actual main peak.

[0231] Preferred bandpass filtering approaches analyse a signal of the instantaneous amplitude associated with the R-peak frequency. These approaches exploit the fact that R-peaks are approximately symmetrical features which means that the location of the peak in the spectral amplitude is normally close to the location of the centre of the R-peak itself. The signal of instantaneous amplitude can be obtained using a complex filter and by calculating the absolute magnitude of the real and imaginary component for each filtered signal value.

[0232] In a preferred implementation, the complex filter used is a complex Morlet wavelet. The Morlet wavelet has optimal frequency resolution due to its Gaussian envelope. The Morlet wavelet is also useful because it is symmetrical across the y-axis which means that only half of the filter coefficients need to be stored in RAM.

[0233] The filtered signal values are added to a FIFO filtered signal buffer.

[0234] In step 1108 the controller detects peaks in the filtered signal values. At this stage, the controller is identifying any peaks, including small and spurious peaks, in the filtered signal values. The peak detection process identifies local maxima in the signal values. Peak detection can be performed by simply looking for negative gradients in the filtered signal values. Other peak detections will be known by the skilled person. The detected peaks are added to an array of peaks.

[0235] In step 1110, the controller determines whether at least N signal values have been read from the FIFO buffer. Here, N is a number that is greater than M. N may be selected by the skilled person as desired to ensure that there are likely to be a certain desired number of peaks within the array of peaks. For example, N may be selected such that signal values representative of at least 4 seconds of data have been obtained to ensure that there are at least 2 characteristic (or true) peaks in array. The number N will depend on the sampling rate of the signal values provided to the controller. For example, if the sampling rate is 512Hz and at least 4 seconds of data are required, then N = 2048. Other values of N are within the scope of the present disclosure.

[0236] If less than N signal values have been obtained then the method returns to step 1102 so that additional samples are gathered, filtered, and added to the filtered signal buffer. Steps 1102 to 1108 are repeated until the N signal values are obtained.

[0237] If N or more signal values have been obtained, the method proceeds to step 1112.

[0238] In step 1112, the controller removes anomalous detected peaks. In some examples, this means that the controller removes detected peaks that have an amplitude less than a threshold level. The thresholding process is intended to remove peaks that are not R-peaks in the ECG signal. The thresholding level is determined according to an adjustable threshold value multiplied by the average spectral power for the filtered signal values. Using the average spectral power enables the thresholding level to adapt based on the power of the signal. The adjustable threshold value may also be modified based on user parameters or other information.

[0239] In step 1114, the heart rate is calculated from the remaining peaks. R-R intervals by determining the time duration between successive ones of the remaining R-peals. Only one R-R interval may be determined if only one R-peak remains after step 1112. In this case, the R-R interval will be determined using the timestamp of the last R-peak found in the previous window of data. An average of the R-R intervals is taken, and the reciprocal of the average R-R interval gives the heartrate.

[0240] One or more additional steps may be performed prior to step 1114 such as to check the remaining peaks after step 1112 and remove or compensate for spurious remaining peaks. These spurious peaks may be due to noise spikes, ectopic beats, or other ECG components. An example process for detecting spurious peaks is disclosed in Mateo J, Laguna P. Analysis of heart rate variability in the presence of ectopic beats using the heart timing signal. IEEE Trans Biomed Eng. 2003 Mar;50(3):334-43. Another example process for detecting spurious peaks is disclosed in the inventor's pending UK Patent Application No. GB2018354.7 filed on 23 November 2020, the disclosures of which are hereby incorporated by reference.

[0241] Once the heartrate is determined, the controller enters a new signal processing operation such that the process outlined in FIG. 11 is repeated.

[0242] Advantageously, the process outlined in FIG. 11 is optimised for performance in realtime as ECG signal values are being determined by the analogue-to-digital front end 916 and output to the controller 402. Peaks are detected in the signal values as they are being obtained from the analogue-to-digital front end 916 and then the correction of the detected peaks (step 1112) and the calculation of R-R intervals (step 1114) are only performed once a sufficient number, N, of signal values have been read from the FIFO buffer. This approach is memory efficient as it does not require that the N signal values are stored in memory prior to the performance of steps 1112 and 1114. Instead, only a smaller number of values representative of the peaks are required to be stored. Being memory efficient is particularly important for wearable electronics modules as their small size limits the available space for memory units and battery capacity.

[0243] FIG. 12 shows an aspect of a method for calculating a breathing rate from bioimpedance values received in real-time via the analogue-to-digital front end 916 of the electronics module 310. The bioimpedance signal values are received by the controller 402 from the analogue-to- digital front end 916 and stored in the FIFO buffer.

[0244] The controller repeatedly performs a signal processing operation.

[0245] In step 1202 the controller reads a number M of signal values from the FIFO buffer. Each of the signal values is a value that represents the amplitude of the impedance signal at a particular time point. [0246] In step 1204, the controller filters the M signal values. Any kind of filter may be used as desired by the skilled person. In preferred examples, the filter is a bandpass filter with a passband of 0.1 - 0.5 Hz.

[0247] In step 1206, the controller detects extrema in the M filtered signal values and adds the filtered signal values to an array. The extrema are local maxima and minima in the M filtered signal values.

[0248] In step 1208, the controller determines whether at least N signal values have been read from the FIFO buffer. Here, N is a number that is greater than M. N may be selected by the skilled person as desired to ensure that there are likely to be a certain desired number of extrema within the array such that an accurate breathing rate can be determined. For example, N may be selected such that signal values representative of at least 120 seconds of data have been obtained. The number N will depend on the sampling rate of the signal values provided to the controller. For example, if the sampling rate is 64Hz and at least 120 seconds of data are required, then N = 7680. Other values of N are within the scope of the present disclosure.

[0249] If less than N signal values have been obtained then the method returns to step 1202 so that additional samples are gathered, filtered, and extrema detected. Steps 1202 to 1206 are repeated until the N signal values are obtained.

[0250] If N or more signal values have been obtained, the method proceeds to step 1210.

[0251] In step 1210, the controller calculates the vertical differences between subsequent local extrema and takes their absolute values. The third quartile (75 percentile) Q of the absolute values is then determined and used to set a threshold value. The threshold value is a multiple of Q?) . The multiple can be set as appropriate by the skilled person. It will be appreciated that the multiple is less than 1 , preferably less than 0.5 and preferably still in the range of 0. 2 to 0.4. In a preferred example, the multiple is 0.3 such that the threshold value is 0.3 x Q%.

[0252] In step 1214, the controller finds the pair of subsequent extrema separated by the smallest (absolute) difference.

[0253] In step 1216, the identified smallest difference is compared to the threshold value threshold value defined in step 1210.

[0254] If the smallest difference is less than threshold value, then pair is interpreted to be caused by a random fluctuation, is irrelevant to respiration, and is removed from the array of extrema values in step 1218. The method then returns to step 1214 to again find the pair of subsequent extrema in the array with the smallest (absolute) difference. In this way pairs of extrema are removed from the array until all of the remaining pairs of extrema have a smallest difference greater than the threshold value.

[0255] If the smallest difference is not less than the threshold value, the controller proceeds to step 1220 and calculates the breathing rate from the remaining extrema values in the array.

[0256] The breathing rate may be calculated by determining the duration of each of the breathing cycles contained within the array and dividing this duration by the total number of breathing cycles contained within the array. The reciprocal of this value is then taken to obtain the breathing rate. The duration of each of the breathing cycles can be determined by calculating the difference between index values for successive local maxima in the array

[0257] In some examples, the array is divided into segments and the breathing rate is determined for each of these windows. For example, if the array covers 120 seconds of data, the array is divided into 30 second segments, and the breathing rate is determined for each of these segments. These average values may then be smoothed using a moving average filter. The moving average filter can consider breathing rate values determined in a previous signal processing operation. The moving average filter may have a window of 120 seconds for example. [0258] Once the average breathing rate is determined, the controller enters a new signal processing operation such that the process outlined in FIG. 12 is repeated.

[0259] Advantageously, the process outlined in FIG. 12 is optimised for performance in realtime as impedance signal values are being determined by the analogue-to-digital front end 916 and output to the controller 402. Extrema are detected in the signal values as they are being obtained from the analogue-to-digital front end 916 and then the correction of the detected peaks (step 1214 - 1218) and the calculation of breathing rate (step 1220 are only performed once a sufficient number, N, of signal values have been read from the FIFO buffer. This approach is memory efficient as it does not require that the N signal values are stored in memory prior to the performance of steps 1210- 132. Instead, only a smaller number of values representative of the extrema (i.e., their amplitude values and index values) are required to be stored. Being memory efficient is particularly important for wearable electronics modules as their small size limits the available space for memory units and battery capacity.

[0260] After determining the biological metric, the controller 402 of the electronics module 310 may control a communicator of the electronics module 310 such as the second wireless communicator 914 to transmit the biological metric to an external device such as user electronic device 304. User electronic device 304 may display or otherwise output the biological metric to the wearer.

[0261] Referring to FIG. 13, there is shown a schematic diagram of a user electronic device 304 according to an example aspect of the present disclosure. The user electronic device 304 is in the form of a mobile phone or tablet and comprises a controller 1302, a memory 1304, a wireless communicator 1306, a display 1308, a user input unit 1310, a capturing device in the form of a camera 1312 and an inertial measurement unit 1314. The controller 1302 provides overall control to the user electronic device 304.

[0262] The user input unit 1310 receives inputs from the user such as a user credential.

[0263] The memory 1304 stores information for the user electronic device 304.

[0264] The display 1308 is arranged to display a user interface for applications operable on the user electronic device 304.

[0265] The inertial measurement unit 1314 provides motion and/or orientation detection and may comprise an accelerometer and optionally one or both of a gyroscope and a magnetometer. [0266] The user electronic device 304 may also include a biometric sensor. The biometric sensor may be used to identify a user or users of device based on unique physiological features. The biometric sensor may be: a fingerprint sensor used to capture an image of a user's fingerprint; an iris scanner or a retina scanner configured to capture an image of a user's iris or retina; an ECG module used to measure the user’s ECG; or the camera of the user electronic arranged to capture the face of the user. The biometric sensor may be an internal module of the user electronic device 304. The biometric module may be an external (stand-alone) device which may be coupled to the user electronic device 304 by a wired or wireless link.

[0267] The controller 1302 is configured to launch an application which is configured to display insights derived from the biosignal data processed by the analogue-to-digital frontend (e.g., analogue-to-digital front end 916 of FIG. 10) of the electronics module (e.g., electronics module 310 of FIG. 9) , input to electronics module controller (e.g., controller 402 of FIG. 9), and then transmitted from the electronics module. The transmitted data is received by the wireless communicator 1306 of the user electronic device 304 and input to the controller 1302.

[0268] Insights include, but are not limited to, heart rate, respiration rate, core temperature but can also include identification data for the wearer using the wearable assembly (e.g., wearable assembly 302 of FIG. 3).

[0269] The display 1308 is also configured to display an ECG signal trace. To display a signal trace may use raw ECG data from the electronics module.

[0270] The display 1308 may be a presence-sensitive display and therefore may comprise the user input unit 1310 The presence-sensitive display may include a display component and a presence-sensitive input component. The presence sensitive display may be a touch-screen display arranged as part of the user input unit 1310.

[0271] User electronic devices 304 in accordance with the present disclosure are not limited to mobile phones or tablets and may take the form of any electronic device which may be used by a user to perform the methods according to aspects of the present disclosure. The user electronic device 304 may be a smartphone, tablet personal computer (PC), mobile phone, smart phone, video telephone, laptop PC, netbook computer, personal digital assistant (PDA), mobile medical device, camera, or wearable device. The user electronic device 304 may include a head-mounted device such as an Augmented Reality, Virtual Reality or Mixed Reality head-mounted device. The user electronic device 304 may be desktop PC, workstations, television apparatus or a projector, e.g., arranged to project a display onto a surface.

[0272] In use, the electronics module 310 is configured to receive raw biosignal data from the sensors of the wearable article and which are coupled to the controller 402 via the sensing interface 404 and the analogue-to-digital front end 916 for further processing and transmission to the user electronic device 304 as described above. The data transmitted to the user electronic device 304 includes raw or processed biosignal data such as ECG data, heart rate, respiration data, breathing rate, core temperature, IMU data and other insights as determined, and as required. [0273] The controller 1302 of the user electronic device 304 is also operable to launch an application which is configured to receive, process and display data, such as raw or processed biosignal data, from the electronics module. A user, such as the wearer, is able to configure the application, using user inputs, to receive, process and display the received data in accordance with these user inputs.

[0274] The user electronic device 304 is arranged to receive the transmitted data from the electronics module via the communicator 1306 and which are coupled to the controller 1302, and then to process and display the data in accordance with the user configuration.

[0275] The controller 1302 of the user electronic device 304 is operable to display information to a user on the display 1308 as part of the user interface. Information displayed can include the biological metric determined by the electronics module 310 as described above. Other insights and data can be displayed on the display 1308 as part of the user interface and as required. Examples might be a heart rate in beats per minute, core temperature data and respiration rate.

[0276] FIG. 14 to FIG. 22 show a series of pages of the application run by the user electronic device 304 which may be displayed on the display 1308 of the user electronic device 304 according to aspects of the present disclosure.

[0277] FIG. 14 shows a menu page 1402 of the application. The menu page 1402 displays a plurality of interface elements in the form of a workout button 1404, a bodycheck button 1406, and a guided breathing button 1408 that allow the user to perform different activities and receive different insights based on the activity data received from the electronics module.

[0278] The workout button 1404 takes the user to a workout page so that they may record their performance during a workout, such as a run or cycle, using the electronics module. The workout page may display information to the user in real-time while performing their workout.

[0279] The bodycheck button 1406 takes the user to a bodycheck page so that they may perform a bodycheck operation. In a bodycheck operation a user is prompted to adopt one or more positions while heartrate data for the user is obtained. This heartrate data is used to generate a recovery score for the user which provides an indication of how well recovered the user is.

[0280] An example bodycheck operation may involve the user adopting a resting position for a first predetermined time period followed by a standing position for a second predetermined time period. The bodycheck operation may be a form of orthostatic heartrate (OHR) test. The orthostatic heart rate (OHR) test (and other similar tests) is an established and widely used test for monitoring the fitness level of a user. OHR test results can indicate whether the user is stressed, overtired, overtrained, or is ill. OHR tests are widely used in the managing of training of athletes and other individuals.

[0281] The guided breathing button 1408 takes the user to a guided breathing page so that the user may perform a guided breathing exercise. In a guided breathing exercise, the user is prompted to inhale and exhale according to a controlled breathing pattern which is typically designed to relax and calm the user. [0282] In response to interacting with the guided breathing button 1408, the controller 1302 of the user electronic device 304 determines whether the user electronic device 304 is in communication with an electronics module 310.

[0283] If a communication session has not been established, the user is taken to page 1502 as shown in FIG. 15. The page 1502 displays an interface element 1504 to enable the userto connect to their electronics module 310. In response to selecting the interface element 1504, the user is prompted to tap their user electronic device 304 against the electronics module 310 to trigger a pairing process between the user electronic device 304 and the electronics module 310.

[0284] The page 1502 additionally displays a prompt 1508 to the user to put on their electronics module 310 and a button 1506 to start guided breathing. The button 1506 is disabled as the connection with the electronics module 310 has not yet been established.

[0285] Once a communication session has been established with the electronics module 310, the user is taken to page 1602 as shown in FIG. 16. The page 1602 displays connection information 1604 for the electronics module 310 connected to the user electronic device 304. The connection information 1604 includes the identity 1606 of the electronics module and a battery status 1608 of the electronics module 310.

[0286] The page 1602 additionally displays a prompt 1610 for the user to sit down and adopt a relaxed position. The button 1506 is also displayed and is enabled for selection. Once the button 1506 is selected, the guided breathing exercise starts.

[0287] FIG. 17 to FIG. 21 show the page 1702 displayed by the user electronic device 304 at various times during the guided breathing exercise. The guided breathing exercise lasts a predetermined period of time. In this example, the predetermined period of time is 5 minutes. The predetermined period of time may be longer or shorter than 5 minutes. A timer 1704 displays amount of time that has elapsed during the guided breathing exercise.

[0288] In FIG. 17 a prompt 1706 is displayed to the user to take a long exhale through their nose to begin the guided breathing exercise.

[0289] In FIG. 18 to FIG. 21 an animated element 1804 is displayed to guide the user through the breathing exercise. The animated element 1804 display, both through graphics and text, instructions for the user. In addition to and/or separately from the visual instructions, audio and/or haptic feedback may be used to guide the user through the breathing exercise.

[0290] The animated element 1804 prompts the user to, in sequence: close their mouth and inhale through their nose for 4 seconds (FIG. 21); hold their breath for 4 seconds (FIG. 20); exhale through their mouth for 4 seconds (FIG. 18); and hold their breath for 4 seconds (FIG. 19). This breathing cycle is repeated for 5 minutes. Of course, these breathing steps are not required to be performed for 4 seconds and could be performed for different time periods depending on the type of breathing exercise being performed. Different guided breathing techniques may require to user to breath in through their nose or their mouth and breath our through their nose or their mouth and, in some instances, breath in or out through specific nostrils. [0291] At the same time as guiding the user through the breathing exercise, the user electronic device 304 is receiving physiological data from the electronics module 310. In this example, the physiological data includes heartrate data and, in particular, a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span. The heartbeat data samples comprising inter-beat interval, IBI, values representing the time between successive heartbeats. In this example, the IBI values are calculated by the controller 402 of the electronics module 310 from digital signal values received from the analogue-to-digital front end 916. An example method of calculating IBI values is described above in relation to FIG. 11 .

[0292] The heartrate data in this example also includes an electrocardiography signal representing the electrical activity of the heart. The electrocardiography signal comprises the digital signal values generated by the analogue-to-digital front end 916. The electrocardiography signal is displayed to the user during the guided breathing exercise as an ECG trace 1802.

[0293] FIG. 22 shows a summary screen page 2202 that is displayed to the user at the end of the guided breathing exercise. The summary screen page 2202 displays metrics based on the heartbeat data received from the electronics module during the guided breathing exercise.

[0294] The summary screen displays the average heartrate 2204 of the user during the guided breathing exercise. This is referred to as the resting heartrate in the FIG. 22 as it may be considered as an indication of the heartrate of the user at rest.

[0295] The measure of the average heartrate of the user over the duration of the guided breathing exercise is derived, by the user electronic device 304, using the heartbeat data received from the electronics module during the guided breathing exercise. This may involve determining an average IBI value from the IBI values received from the electronics module. The average IBI value is in milliseconds and is typically converted into a measure of the heartrate in beats per minute by dividing 60000 by the average IBI value.

[0296] The average IBI value is typically the mean IBI value. The mean IBI value is a measure of the sum of the IBI values divided by the total number of IBI values. In other words, the mean IBI value is determined according to the formula:

[0298] where IBI is the sequence of IBI values for the user over the first time period.

[0299] Advantageously, displaying the average heartrate of the user provides the user within an indication of the heartrate at rest. This can help the user to determine whether their current resting heartrate is increased, maintained, or reduced relative to their expected resting heartrate. This can provide the user with an indication of their heart health and their recovery state. An elevated average heartrate would indicate that the user is in an under recovered state and should consider reducing their exercise intensity. Meanwhile, a maintained or reduced average heartrate would indicate that the user is in a recovered state and can exercise as normal. In preferred examples, the user electronic device 304 will compare the average heartrate of the user to historic heartrate values of the user obtained from previously performed guided breathing exercises. The user electronic device 304 may output the result of this comparison to the user. In this way, the user is informed of how their current heartrate compares to their baseline resting heartrate.

[0300] The summary screen displays the average heartrate variability 2206 of the user during the guided breathing exercise.

[0301] The measure of the average heartrate variability of the user over the duration of the guided breathing exercise is derived, by the user electronic device 304, using the heartbeat data recorded received from the electronics module 310 during the guided breathing exercise. This may involve computing the root mean square of successive differences for the IBI values.

[0302] The measure of the root mean square of successive differences, RMSSD, between successive heartbeats is a time domain measure of heart rate variability. The RMSSD is obtained by calculating each successive time difference between heartbeats. Each of these values is then squared and the result is averaged before the square root of the total is obtained. RMSSD is determined according to the formula:

[0304] where IBI is the sequence of IBI values for the user over the first time period.

[0305] The present disclosure is not limited to the user of RMSSD as a heartrate variability measure. Other heartrate variability measures that may be used with the present disclosure include the standard deviation of IBI values (SDRR), the standard deviation of differences between adjacent IBI values (SDSR), the percentage of adjacent IBI values (NN) differing by more than 25 ms (pNN25), and the percentage of adjacent IBI values (NN) differing by more than 50 ms (pNN50).

[0306] Advantageously, displaying the average heartrate variability of the user provides an indication to the user of their heartrate variability during the guided breathing exercise. This can help the user to determine whether their current heartrate variability is increased, maintained, or reduced relative to their expected heartrate variability. This can provide the user with an indication of their heart health and their recovery state. A reduced heartrate variability would indicate that the user is in an under recovered state and should consider reducing their exercise intensity. Meanwhile, a maintained or increased heartrate variability would indicate that the user is in a recovered state and can exercise as normal. In preferred examples, the user electronic device 304 will compare the heartrate variability of the user to historic heartrate variability values of the user obtained from previously performed guided breathing exercises. The user electronic device 304 may output the result of this comparison to the user. In this way, the user is informed of how their current heartrate variability compares to their baseline resting heartrate.

[0307] All of the heartbeat values recorded over the guided breathing exercise may be used to compute the average heartrate and heartrate variability measures. This is not required in all examples, and only a subset of the heartbeat data recorded over the first time period may be used to compute these measures. [0308] The summary screen also displays a plot 2208 showing how the user's heartrate varied during the guided breathing exercise. The individual heartrate values are calculated from IBI values obtained over four second windows. Other time windows can be used to calculate the heartrate values.

[0309] The summary screen may display a plot showing how the user’s breathing rate varied during the guided breathing exercise. The breathing rate data may be determined from bioimpedance measurements performed using sensing electrodes of the wearable article. The sensing electrodes may be the same as those used for performing ECG sensing.

[0310] In other examples, the breathing rate is determined from a heart rate signal such as an ECG or PPG signal. Heart rate signals are known to exhibit respiratory modulations including baseline wander, amplitude modulation, and frequency modulation. The breathing rate can be estimated by analysing one or more of these modulations. Further information on how respiratory information can be extracted from ECG and PPG signals can be found in Charlton PH, Birrenkott DA, Bonnici T, Pimentel MAF, Johnson AEW, Alastruey J, Tarassenko L, Watkinson PJ, Beale R, Clifton DA. Breathing Rate Estimation From the Electrocardiogram and Photoplethysmogram: A Review. IEEE Rev Biomed Eng. 2018;11 :2-20. doi: 10.1109/RBME.2017.2763681 . Epub 2017 Oct 24. PMID: 29990026; PMCID: PMC7612521 .

[0311] In a preferred implementation, breathing rate is estimated from ECG signals. The ECG signal is processed to identify the R-peaks in the ECG signal. A time series of amplitude signal values is obtained where each signal value represents the amplitude of an R-peak in the ECG signal. Interpolation may then be used to increase the number of amplitude signal values. The peaks and troughs in the amplitude signal are identified. A peak represents an exhalation, and a trough represents an inhalation.

[0312] FIG. 23 shows a flow diagram for a method of guiding a breathing exercise performed by a user according to aspects of the present disclosure. The method is performed by the user electronic device 304.

[0313] In Step 2302, the method prompts the user to exhale and inhale in a controlled manner over a time span. As discussed above, the time span may be any desired time span such as a time span of 5 minutes. The prompt may be audible, visual, or haptic prompt or may be a combination of any of audible, visual, and haptic prompts. The method may also prompt the user to hold their breath between exhales and inhales.

[0314] In Step 2304, the method obtains a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span, the heartbeat data samples comprising inter-beat interval, IBI, values representing the time between successive heartbeats. As discussed above, the heartbeat data samples may be received from an electronics module 310 in wireless communication with the user electronic device 304.

[0315] In Step 2304, the method calculates a measure of the heartrate of the user from the IBI values. The measure of the heartrate of the user may be a measure of the average heartrate of the user over the time span. [0316] In Step 2308, the method calculates a measure of the heartrate variability of the user from the IBI values. The measure of the heartrate variability of the user may be a measure of the average heartrate variability of the user over the time span.

[0317] In Step 2310, the method outputs the measure of the heartrate and the measure of the heartrate variability to the user. For example, the measure of the heartrate and the measure of the heartrate variability may be displayed on display 1308 of the user electronic device 304.

[0318] In some examples, the measure of the heartrate of the user can be used to set a resting heartrate for the user. The resting heartrate is a variable that is used in a number of health insights such as in calculating calorie consumption and the heartrate training zone that the user is in. Beneficially, setting the resting heartrate from the measure of the heartrate obtained during the guided breathing exercise can provide an accurate estimate of the resting heartrate of the user which is specific to the user and has a high degree of confidence as representing the heartrate of the user when in a resting and relaxed state. This improves on methods which use a default resting heartrate for all users or estimate the resting heartrate based on factors such as the age of the user. In addition, this approach avoids the need to use a controlled, laboratory setting to determine the resting heartrate. Beneficially, this approach also enables the resting heartrate value used in calculations to adapt based on physical changes of the user.

[0319] By way of example, the resting heartrate (HRrest) can be used in determining the heartrate reserve (HRR) of a user. The HRR is determined by subtracting the user's maximum heartrate from their resting heartrate. The HRR is commonly used to determine different heartrate training zones which indicate different exercise intensity levels.

[0320] In an example implementation, different training zones are defined according to different percentage ranges:

[0321] Zone 0: < 50 % intensity;

[0322] Zone 1 : 50%-60% intensity;

[0323] Zone 2: 60%-70% intensity;

[0324] Zone 3: 70% - 80% intensity;

[0325] Zone 4: 80% - 90% intensity; and

[0326] Zone 5: 90% - 100 % intensity.

[0327] The specific training zones for a user are then computed by calculating HRR x intensity% + HRrest.

[0328] For example, if a user has a maximum heartrate of 200 and a resting heartrate of 60 then their HRR = 200-60 = 140. The training zones for that user are therefore:

[0329] Zone 0: < 130 bpm;

[0330] Zone 1 : 130 bpm-144 bpm;

[0331] Zone 2: 144 bpm - 158 bpm;

[0332] Zone 3: 158 bpm - 172 bpm; [0333] Zone 4: 172 bpm - 186 bpm; and

[0334] Zone 5: 186 bpm - 200 bpm intensity.

[0335] During a workout, the user electronic device 304 receives heartbeat data samples from the electronics module 310 and uses this to determine the heartrate of the user. The determined heartrate is compared to the different training zone bands to determine which training zone the user is in.

[0336] FIG. 24 shows a flow diagram for a method of guiding a breathing exercise performed by a user according to aspects of the present disclosure. The method is performed by the user electronic device 304.

[0337] Step 2402 comprises prompting a user to exhale and inhale in a controlled manner over a time span. As discussed above, the time span may be any desired time span such as a time span of 5 minutes. The prompt may be audible, visual, or haptic prompt or may be a combination of any of audible, visual, and haptic prompts.

[0338] Step 2404 comprises obtaining a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span, the heartbeat data samples comprising inter-beat interval, IBI, values representing the time between successive heartbeats. As discussed above, the heartbeat data samples may be received from an electronics module 310 in wireless communication with the user electronic device 304.

[0339] Step 2406 comprises calculating a measure of the heartrate variability of the user from the IBI values. The measure of the heartrate variability of the user may be a measure of the average heartrate variability of the user over the time span.

[0340] Step 2408 comprises generating a health metric for the user according to a comparison between the measure of the heartrate variability of the user and historic heartrate variability values of the user when performing guided breathing exercises. The historic heartrate variability values have been obtained by the user electronic device 304 from previous guided breathing exercises and are stored in the memory 1304 of the user electronic device 304.

[0341] In an example, the health metric provides an indication of whether the user is improving their heartrate variability, maintaining their heartrate variability, or reducing their heartrate variability. The health metric is output to the user. This provides an indication to the user of whether they are improving their heartrate variability as a result of conducting guided breathing exercises and the extent at which they are improving their heartrate variability. A higher heartrate variability is associated with better cardiac health.

[0342] In an example method of generating the health metric, the heartrate variability is compared to a moving average of the historic heartrate variability values of the user previously obtained when the user was performing guided breathing exercises. The moving average may be a 10 day moving average. The 10 day moving average is just one example and other time windows can be used to calculate the average historic heartrate variability for the user. From the comparison, the method is able to determine whether the measured heartrate variability has increased relative to the moving average, decreased, or stayed at around the same value. [0343] In some examples, the method additionally comprises calculating a measure of the heartrate of the user from the IBI values. The measure of the heartrate of the user may be a measure of the average heartrate of the user over the time span.

[0344] Generating the health metric may also comprise comparing the measure of the heartrate to historic heartrate values of the user when performing guided breathing exercises. The historic heartrate values have been obtained by the user electronic device 304 from previous guided breathing exercises and are stored in the memory 1304 of the user electronic device 304.

[0345] In this example, the health metric provides an indication of whether the user is increasing their heartrate, maintaining their heartrate, or reducing their heartrate. The health metric is output to the user. This provides an indication to the user of whether they are reducing their heartrate as a result of conducting guided breathing exercises and the extent at which they are improving their heartrate. A lower heartrate is associated with better cardiac health.

[0346] Two separate health metrics may be output to the user. The first health metric is obtained from the heartrate variability and the second health metric is obtained from the heartrate. Alternatively, a single health metric may be provided based on a combination of the heartrate variability and the heartrate.

[0347] In the above examples, the guided breathing exercise is triggered on demand by the user via the menu page 1402 (FIG. 14). In some examples, the user electronic device 304 will recommend when to perform the guided breathing exercise based on activity data received from the electronics module.

[0348] FIG. 25 shows a flow diagram for a method of triggering a guided breathing exercise according to aspects of the present disclosure. The method is performed by the user electronic device.

[0349] Step 2502 of the method comprises obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user over the time span, the heartbeat data samples comprising inter-beat interval, IBI, values representing the time between successive heartbeats.

[0350] Step 2504 of the method comprises determining from the IBI values whether a stress condition is present.

[0351] Step 2506 of the method comprises, in response to determining that a stress condition is present, prompting the user to perform a guided breathing exercise.

[0352] Advantageously, in this method the user electronic device 304 determines when a stress condition is present from the IBI values and uses this to recommend to the user to perform a guided breathing exercise. Guided breathing exercises are known to reduce stress. The user electronic device 304 may display a prompt to the user to perform a guided breathing exercise. If the user accepts, then the application may transition to page 1602 (FIG. 16) to begin a guided breathing exercise.

[0353] In some examples, determining from the IBI values whether a stress condition is present comprises: determining a measure of the heartrate variability of the user from the IBI values; and determining, from the measure of the heartrate variability, whether the stress condition is present. A stress condition is likely to be present if the heartrate variability is reduced.

[0354] In some examples, determining, from the measure of the heartrate variability, whether the stress condition is present comprises comparing the measure of the heartrate variability to one or more historic measures of heartrate variability for the user. A stress condition is likely to be present if the heartrate variability is reduced relatively to the user's historic (baseline) heartrate variability.

[0355] In some examples, determining, from the measure of the heartrate variability, whether the stress condition is present comprises comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user.

[0356] In an example implementation, the controller 1302 of the user electronic device 304 determines whether to recommend that a guided breathing exercise is performed based on the result of a bodycheck operation. The bodycheck operation is performed in response to the user selecting the bodycheck button 1406 (FIG. 14).

[0357] In a bodycheck operation, the user electronic device 304 prompts the user to adopt a first, resting, position. The first position may be a sitting position or lying down position for example. While the user is in the first position, the user electronic device 304 receives a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user when in the first position. The heartbeat data samples comprise inter-beat interval, IBI, values representing the time between successive heartbeats.

[0358] The user electronic device 304 receives heartbeat samples for a first time period of three minutes (other time ranges are possible). After the end of the first time period, the user electronic device 304 prompts the user to adopt a second position by standing up, relaxing, and breathing normally. This instructs the user to adopt the second, standing, position.

[0359] While the user is in the second position, the user electronic device 304 receives a sequence of heartbeat data samples from the user representative of the heartbeat activity of the user when in the second position. The heartbeat data samples comprise inter-beat interval, IBI, values representing the time between successive heartbeats. The user electronic device 304 receives heartbeat samples for a second time period of three minutes (other time ranges are possible).

[0360] The first time period may be a predefined time period. The first time period may be selected as appropriate by a healthcare professional. Usually, a time period sufficiently long is selected so as to compensate for any minor fluctuations in the user’s heartbeat. The first time period may be greaterthan or equal to 30 seconds, greater than or equal to 1 minute, greater than or equal to 2 minutes, or greater than or equal to 3 minutes. The first time period may be less than 10 minutes, less than 7 minutes, or less than 5 minutes. In some examples, the first time period is 3 minutes.

[0361] The second time period is usually desired to commence quickly afterthe first time period. Typically, the second time period commences between 1 and 10 seconds afterthe first time period. [0362] The second time period may be a predefined time period. The second time period may be selected as appropriate by a healthcare professional. Usually, a time period sufficiently long is selected so as to compensate for any minor fluctuations in the user’s heartbeat. The second time period may be greaterthan or equal to 30 seconds, greater than or equal to 1 minute, greater than or equal to 2 minutes, or greater than or equal to 3 minutes. The second time period may be less than 10 minutes, less than 7 minutes, or less than 5 minutes. In some examples, the second time period is 3 minutes.

[0363] The user electronic device 304 then determines whether a stress condition is present based on the IBI values obtained during the first time period and the second time period.

[0364] The user electronic device 304 determines a measure of the average heartrate, HRfirst, of the user over the first time period.

[0365] The user electronic device 304 determines a measure of the average heartrate variability, HRVfirst, of the user over the first time period.

[0366] The user electronic device 304 determines a measure of the average heartrate, HRsecond, of the user over the second time period.

[0367] The user electronic device 304 determines a measure of the average heartrate variability, HRVsecond, of the user over the second time period.

[0368] The obtained values of HRfirst, HRVfirst, HRsecond, and HRVsecond are used to determine whether a stress condition is present. This comprises comparing the values of HRfirst, HRVfirst, HRsecond, and HRVsecond to historic values for the user. Decision logic will these comparisons to determine whether an overall stress condition is present for the user.

[0369] HRVfirst and HRVsecond are compared to historic measures of the heartrate variability for the user when in the first and second positions. In examples, a two week moving average of historic heartrate variability data for the user is compared to the values of HRVfirst and HRVsecond. The two week moving average is just one example and other time windows can be used to calculate the historic heartrate variability for the user. If HRVfirst is lower than the historic heartrate variability for the user when in the first position, then this indicates that the user is stressed. If HRVsecond is lower than the historic heartrate variability for the user when in the first position, then this indicates that the user is stressed.

[0370] HRfirst and HRsecond are compared to historic measures of the heartrate for the user when in the first and second positions. In examples, a two week moving average of historic heartrate data for the user is compared to the values of HRfirst and HRsecond. The two week moving average is just one example and other time windows can be used to calculate the historic heartrate variability for the user. If HRfirst is higher than the historic heartrate for the user when in the first position, then this indicates that the user is stressed. If HRsecond is higher than the historic heartrate variability for the user when in the first position, then this indicates that the user is stressed.

[0371] In an example implementation, a stress score is initialised to an initial value of 0. [0372] If HRVfirst is lower than the corresponding historic heartrate variability then the stress score is increased, e.g., by 1 . If HRVfirst is higher than the corresponding historic heartrate variability then the stress score is decreased, e.g., by 1. If HRVfirst is substantially the same as the corresponding historic heartrate variability, then the stress score is neither increased nor decreased.

[0373] If HRVsecond is lower than the corresponding historic heartrate variability then the stress score is increased, e.g., by 1. If HRVsecond is higher than the corresponding historic heartrate variability then the stress score is decreased, e.g., by 1 . If HRVsecond is substantially the same as the corresponding historic heartrate variability, then the stress score is neither increased nor decreased.

[0374] If HRfirst is higher than the corresponding historic heartrate then the stress score is increased, e.g., by 1. If HRfirst is lower than the corresponding historic heartrate then the stress score is decreased, e.g., by 1. If HRfirst is substantially the same as the corresponding historic heartrate then the stress score is neither increased nor decreased.

[0375] If HRsecond is higher than the corresponding historic heartrate then the stress score is increased, e.g., by 1. If HRsecond is lower than the corresponding historic heartrate then the stress score is decreased, e.g., by 1 . If HRsecond is substantially the same as the corresponding historic heartrate then the stress score is neither increased nor decreased.

[0376] A stress condition is then determined to be present if the stress score is greater than 0. A stress condition is determined to not be present if the stress score is less than or equal to 0. It will be appreciated that this is just one example of determining whether a stress condition is present. A different scoring system may be used. The scoring system may apply different weights to different comparisons, e.g., such that HRV has a greater effect on the overall stress score.

[0377] It will be appreciated that the stress score does not need to be determined from all of HRVfirst, HRVsecond, HRfirst, and HRsecond. Only HRV measures may be used to determine whether a stress condition is present. Only HR measures may be used to determine whether a stress condition is present. In addition, data from both the first and second positions is not required in all examples. The present of a stress condition may be determined based only on data obtained when the user is in the first position or the second position if desired.

[0378] It is also not required that the stress condition be detected from a bodycheck operation. A stress condition may be detected in other situations such as during a workout by, for example, comparing the HRV of the user to historic HRV values of the user when conducting similar workouts.

[0379] The value of HRfirst may also provide an accurate indication of the resting heartrate and may be used to set the resting heartrate of the user.

[0380] At least some of the example embodiments described herein may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as ‘component,’ ‘module’ or ‘unit’ used herein may include, but are not limited to, a hardware device, such as circuitry in the form of discrete or integrated components, a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks or provides the associated functionality. In some embodiments, the described elements may be configured to reside on a tangible, persistent, addressable storage medium and may be configured to execute on one or more processors. These functional elements may in some embodiments include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables.

[0381] Although the example embodiments have been described with reference to the components, modules and units discussed herein, such functional elements may be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive. Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of others.

[0382] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0383] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0384] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A computer-implemented method of generating a health metric for a user, the method comprising: prompting a user to exhale and inhale in a controlled manner over a time span as part of a guided breathing exercise; obtaining a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span; calculating a measure of the heartrate variability of the user from the heartbeat data samples; and generating a health metric for the user according to a comparison between the measure of the heartrate variability of the user and historic heartrate variability values of the user when performing guided breathing exercises.

2. The computer-implemented method of claim 1 , wherein the heartbeat data samples comprise inter-beat interval, IBI, values representing the time between successive heartbeats.

3. The computer-implemented method of claim 1 or 2, wherein generating the health metric comprises comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user when performing guided breathing exercises.

4. The computer-implemented method of any one of claims 1 to 3, further comprising outputting the measure of the heartrate variability to the user.

5. The computer-implemented method of any one of claims 1 to 4, further comprising outputting the health metric to the user.

6. The computer-implemented method of any one of claims 1 to 5, further comprising calculating a measure of the heartrate of the user from the heartbeat data samples.

7. The computer-implemented method of any one of claims 1 to 6, further comprising outputting the measure of the heartrate of the user.

8. The computer-implemented method of claim 6 or 7, wherein generating the health metric further comprises comparing the measure of the heartrate of the user to historic average heartrate values of the user when performing guided breathing exercises.

9. The computer-implemented method of claim 8, wherein generating the health metric further comprises comparing the measure ofthe heartrate of the userto a measure of the average historic heartrate of the user when performing guided breathing exercises.

10. The computer-implemented method of any preceding claim, further comprising: calculating a measure of the heartrate of the user from the heartbeat data samples; and setting a resting heartrate for the user using the measure of the heartrate.

11 . The computer-implemented method of claim 10, further comprising using the resting heartrate to set a heartrate reserve for the user.

12. The computer-implemented method of any preceding claim, wherein prior to prompting the user to exhale and inhale in a controlled manner over the time span, the method comprises: obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user over the time span; determining from heartbeat data samples whether a stress condition is present; and in response to determining that a stress condition is present, prompting the user to exhale and inhale in a controlled manner over the time span.

13. The computer-implemented method of claim 12, wherein determining from the heartbeat data samples whether a stress condition is present comprises: determining a measure of the heartrate variability of the user from the heartbeat data samples; and determining, from the measure of the heartrate variability, whether the stress condition is present.

14. The computer-implemented method of claim 13, wherein determining, from the measure of the heartrate variability, whether the stress condition is present comprises comparing the measure of the heartrate variability to one or more historic measures of heartrate variability for the user.

15. The computer-implemented method of claim 14, wherein determining, from the measure of the heartrate variability, whether the stress condition is present comprises comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user.

16. The computer-implemented method of any of claims 13 to 15, wherein obtaining the sequence of heartbeat data samples comprises obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user when in a first position and obtaining a sequence of heartbeat data samples for a user representative of the heartbeat activity of the user when in a second position.

17. The computer-implemented method of claim 16, wherein determining from the heartbeat data samples whether a stress condition is present comprises: determining from the heartbeat data samples a measure of the heartrate variability of the user when in the first position; determining from the heartbeat data samples a measure of the heartrate variability of the user when in the second position; and determining, from the measure of the heartrate variability when in the first position and from the measure of the heartrate variability when in the second position, whether the stress condition is present.

18. The computer-implemented method of any one of claims 1-17, further comprising establishing a communication session with a wearable electronics module; and receiving the heartbeat data samples from the electronics module during the time span.

19. A computer-readable medium having instructions recorded thereon which, when executed by a processor, cause the processor to perform the method as claimed in any preceding claim.

20. A system comprising a processor and a memory, the memory storing instructions which when executed by the processor cause the processor to perform operations comprising: prompting a user to exhale and inhale in a controlled manner over a time span as part of a guided breathing exercise; obtaining a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user over the time span; calculating a measure of the heartrate variability of the user from the heartbeat data samples; and generating a health metric for the user according to a comparison between the measure of the heartrate variability of the user and historic heartrate variability values of the user when performing guided breathing exercises.

21 . The system of claim 20, wherein the heartbeat data samples comprise inter-beat interval, I Bl , values representing the time between successive heartbeats.

22. The system of claim 20 or 21 , wherein generating the health metric comprises comparing the measure of the heartrate variability to a measure of the average historic heartrate variability value of the user when performing guided breathing exercises.

23. The system of any one of claims 20 to 22, wherein the operations performed by the processor further comprise outputting the measure of the heartrate variability to the user.

24. The system of any one of claims 20 to 23, wherein the operations performed by the processor further comprise calculating a measure of the heartrate of the user from the heartbeat data samples.

25. The system of claim 24, wherein generating the health metric further comprises comparing the measure of the heartrate of the user to historic average heartrate values of the user when performing guided breathing exercises.

26. The system of claim 25, herein generating the health metric further comprises comparing the measure of the heartrate of the user to a measure of the average historic heartrate of the user when performing guided breathing exercises.

27. The system of any one of claims 20 to 26, wherein the operations performed by the processor further comprise establishing a communication session with a wearable electronics module; and receiving the heartbeat data samples from the electronics module during the time span.

28. The system of claim 27, wherein the system comprises a user electronic device, and wherein the user electronic device comprises the processor and the memory.

29. The system of claim 28, wherein the system comprises the wearable electronics module.