GB2621222A

GB2621222A - Method and system for estimating cardiovascular fitness and maximum heart rate for a user

Info

Publication number: GB2621222A
Application number: GB2308178.9A
Authority: GB
Inventors: Simpson Clare
Original assignee: Prevayl Innovations Ltd
Current assignee: Prevayl Innovations Ltd
Priority date: 2022-06-07
Filing date: 2023-06-01
Publication date: 2024-02-07
Also published as: GB202208306D0; GB202308178D0

Abstract

Method and system for estimating cardiovascular fitness for a user comprises: obtaining cardiac activity data for a user during a plurality of stages of an exercise, the plurality of stages comprising an activity stage and a rest stage following the activity stage 1604. A heart rate recovery value is determined from the cardiac activity data 1606. The cardiovascular fitness is estimated using a comparison of the heart rate recovery value to a threshold heart rate recovery value 1608. The estimated cardiovascular fitness is output to the user 1610. A peak heart rate may be determined and compared to an existing maximum heart rate for the user, a stored maximum heart rate for the user may then be updated. Also disclosed is a method for estimating cardiovascular fitness wherein a VO2 max value is determined from the cardiac activity data; cardiovascular fitness is estimated using a comparison of the VO2 max value to a threshold VO2 max value.

Description

METHOD AND SYSTEM FOR ESTIMATING CARDIOVASCULAR FITNESS AND MAXIMUM HEART

RATE FOR A USER

[0001] The present disclosure is directed towards a method and system for estimating cardiovascular fitness and maximum heart rate for a user.

BACKGROUND

[0002] Wearable articles, such as garments, incorporating sensors are wearable electronics used to measure and collect information from a wearer. Such wearable articles are commonly referred to as 'smart clothing'. It is advantageous to measure biosignals of the wearer during exercise, or other scenarios.

[0003] It is known to provide a garment, or other wearable article, to which an electronic device (i.e., an electronics module, and/or related components) is attached in a prominent position, such as on the chest or between the shoulder blades. Advantageously, the electronic device is a detachable device. The electronic device is configured to process the incoming signals, and the output from the processing is stored and/or output to a user in a suitable way.

[0004] A sensor senses a biosignal such as electrocardiogram (ECG) signals and the biosignals are coupled to the electronic device, via an interface. The sensors may be coupled to the interface by means of conductors which are connected to terminals provided on the interface to enable coupling of the signals from the sensor to the interface.

[0005] Electronics modules for wearable articles such as garments are known to communicate with user electronic devices over wireless communication protocols such as Bluetooth 0 and Bluetooth 0 Low Energy. These electronics modules are typically removably attached to the wearable article, interface with internal electronics of the wearable article, and comprise a Bluetooth 0 antenna for communicating with the user electronic device.

[0006] The electronic device includes drive and sensing electronics comprising components and associated circuitry, to provide the desired functionality. The drive and sensing electronics include a power source to power the electronic device and the associated components of the drive and sensing circuitry.

[0007] 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 heartrate. Among professional medical staff, individual signals have names such as "the QRS complex," which is the largest part of an ECG signal and is a collection of Q, R, and S signals, including the P and T waves.

[0008] Typically, the detected ECG signals can be displayed as a trace to a user for information along with other metrics derived from the ECG signals. The user may be a clinician who is looking to assess cardiac health, a lay user using the electronics module as a fitness or health and wellness assessment device, or a trainer that is looking to improve the performance of the user. 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. The IBI values can be used to derive measures of the heart rate and heart rate variability.

[0009] Heart rate recovery is a measure of how fast a user's heart rate declines following peak exercise.

Heart rate recovery is an indicator of cardiovascular fitness. It is known to measure heart rate recovery following a workout. However, it can be challenging for a user to determine their cardiovascular fitness from heart rate recovery values.

[0010] V02 max is a measure of the maximum amount of oxygen that the body can utilise during intense exercise. V02 max is an indicator of cardiovascular fitness. V02 max is typically measured in a laboratory setting using gas analysis equipment although it is also known to estimate V02 max either from the resting and peak heartrates of the user or their heart rate recovery. However, it can be challenging for a user to determine their cardiovascular fitness from V02 max values.

[0011] Maximum heart rate is the fastest rate at which the heart can beat during maximal effort exercise.

It is known to estimate maximum heart rate from factors such as age or sex. It is also known to determine a user specific maximum heart rate in a controlled laboratory setting. It is desirable to provide a simpler approach for calculating a user specific maximum heart rate that does not require a laboratory setting.

SUMMARY

[0012] According to the present invention, there is provided a method, computer readable medium and system as set forth in the appended claims. Other features of the invention will be a pparent from the dependent claims, and the description which follows.

[0013] According to a first aspect of the disclosure, there is provided a computer-implemented method of estimating a cardiovascular fitness of a user. The method comprises obtaining cardiac activity data for the user during a plurality of stages of an exercise. The plurality of stages of exercise comprising an activity stage and a rest stage following the activity stage. The method comprises determining, from the cardiac activity data, a heart rate recovery value for the user according to a determination of a decrease in the heart rate of the user during the rest stage. The method comprises estimating the cardiovascular fitness of the user using a comparison of the determined heart rate recovery value to a threshold heart rate recovery value. The method comprises outputting the estimate of the cardiovascular fitness.

[0014] Advantageously, the method calculates a heart rate recovery value for a user. The user performs an activity stage followed (e g, immediately) by a rest stage (also known as recovery), A heart rate recovery value is calculated for the user and compared to a threshold heart rate recovery value to generate an estimate of the cardiovascular fitness. The estimate of the cardiovascular fitness provides an intuitive indication of the cardiovascular fitness of the user that would not be obtainable from direct inspection of the heart rate recovery value. The user is able to easily determine whether their heart rate recovery value is indicative of good cardiovascular fitness and may be able to easily compare their heart rate recovery value to previous values recorded for the user so as to determine whether their cardiovascular fitness is improving.

[0015] The estimate of the cardiovascular fitness may be output via a user electronic device. The output may comprise one or a combination of visual, audible, and haptic outputs.

[0016] Determining the heart rate recovery value may comprise: determining a heart rate of the user during the activity stage and a heart rate of the user during the rest stage; and calculating the heart rate recovery value for the user using the difference between the heart rate of the user during the activity stage and the heart rate of the user during the rest stage. The heart rate recovery value is therefore indicative of how the heart rate of the user decreases during the rest stage.

[0017] The heart rate of the user during the activity stage may represent the heart rate of the user at the end of the activity stage.

[0018] The heart rate of the user during the rest stage may represent the heart rate of the user 30 seconds or more after the end of the activity stage, 1 minute or more after the end of the activity stage, 2 minutes or more after the end of the activity stage, or 3 minutes or more after the end of the activity stage.

[0019] The heart rate of the user during the rest stage may represent the heart rate of the user between seconds and 3 minutes after the end of the activity stage.

[0020] The heart rate of the user during the rest stage may represent the heart rate of the user between 1 minutes and 2 minutes after the end of the activity stage.

[0021] The activity stage may comprise a period of high intensity activity. In the period of high intensity activity, the user may be performing activities intended to raise their heartrate towards their maximum heartrate value.

[0022] The method may comprise prompting the user to perform the plurality of stages of exercise. The user may be prompted to perform a fitness test comprising the plurality of stages of exercise.

[0023] The method may further comprise: generating a plurality of instructions for the user to transition between the plurality of stages of the exercise; and outputting the plurality of instructions.

[0024] The cardiac activity data may comprise heartbeat data samples representative of the heartbeat activity of the user.

[0025] 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.

[0026] The method may further comprise generating a health recommendation from the estimated cardiovascular fitness.

[0027] The method may further comprise outputting the generated health recommendation The generated health recommendation may be output via a user electronic device. The generated health recommendation may be output by one or a combination of visual, audible, and haptic outputs.

[0028] The threshold heart rate recovery value may be a user specific threshold heart rate recovery value.

[0029] Advantageously, the heart rate recovery value is compared to a user specific threshold to generate the cardiovascular fitness. The cardiovascular fitness is thus highly relevant to the user and enables the user to easily determine whether their cardiovascular fitness is improving.

[0030] The threshold heart rate recovery value may be determined from a heart rate recovery value calculated previously calculated for the user. The heart rate recovery value may be calculated from a fitness test previously performed by the user. Advantageously, the user is able to follow trends in their cardiovascular fitness and determine whether their cardiovascular fitness is improving over time.

[0031] The threshold heart rate recovery value may be selected according to at least one of the age, gender, height, weight, or fitness level of the user.

[0032] The method may further comprise determining, from the cardiac activity data, a peak heart rate of the user during the activity stage.

[0033] The method may comprise using the peak heart rate of the user to estimate a V02 max value for the user. The V02 max value may be determined from the peak heart rate and a resting heart rate of the user. The peak heart rate may be divided by the resting heart rate to determine the V02 max value.

[0034] The method may comprise comparing the V02 max value for the user to a threshold V02 max value so as to generate a cardiovascular fitness for the user.

[0035] The method may further comprise comparing the peak heart rate value to a current maximum heart rate value for the user; and if the peak heart rate value is greater than the current maximum heart rate value, replacing the current maximum heart rate value with the peak heart rate value.

[0036] Advantageously, if the peak heart rate value is greater than the current maximum heart rate value stored for the user, the current maximum heart rate value is replaced by the peak heart rate value. This provides a more reliable and accurate estimation of the users maximum heart rate. The maximum heart rate value is useable in deriving a number of metrics for the user.

[0037] If the peak heart rate value is greater than the current maximum heart rate value, the method may comprise notifying the user that the current maximum heart rate value can be updated, and in response to receiving a user instruction, replacing the current maximum heart rate value with the peak heart rate value.

[0038] The method may further comprise establishing a communication session with a wearable electronics module, and receiving the cardiac activity data from the electronics module.

[0039] The method may comprise any of the features of the methods of the fourth, seventh and tenth

aspects of the present disclosure described below.

[0040] 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.

[0041] According to a third aspect of the disclosure, there is provided a system for estimating the cardiovascular fitness of a user, 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 cardiac activity data for a user during a plurality of stages of an exercise, the plurality of states comprising an activity stage and a rest stage following the activity stage; determining, from the cardiac activity data, a heart rate recovery value for the user according to a determination of a decrease in the heart rate of the user during the rest stage; estimating the cardiovascular fitness of the user using a comparison of the determined heart rate recovery value to a threshold heart rate recovery value; and outputting the estimate of the cardiovascular fitness [0042] The operations performed by the processor may comprise any of the features of the first aspect

of the disclosure.

[0043] The system may comprise a user electronic device, and wherein the user electronic device comprises the processor and the memory.

[0044] The system may comprise the wearable electronics module.

[0045] According to a fourth aspect of the disclosure, there is provided a computer-implemented method of estimating the cardiovascular fitness of a user. The method comprises obtaining cardiac activity data for the user. The method comprises estimating a V02 max value for the user from the cardiac activity data. The method comprises estimating the cardiovascular fitness of the user using a comparison of the determined V02 max value to a threshold V02 max value.

[0046] Advantageously, the method estimates a V02 max value for a user who has performed an activity.

A V02 max value is estimated for the user and compared to a threshold heart rate recovery value to generate an estimate of the cardiovascular fitness. The cardiovascular fitness provides an intuitive indication of the cardiovascular fitness of the user that would not be obtainable from direct inspection of the heart rate recovery value. The user is able to easily determine whether their heart rate recovery value is indicative of good cardiovascular fitness and may be able to easily compare their heart rate recovery value to previous values recorded for the user so as to determine whether their cardiovascular fitness is improving.

[0047] The cardiac activity data may be obtained while the user is performing an activity. The activity may be a high intensity activity.

[0048] The method may comprise prompting the user to perform an activity. The method may comprise prompting the user to perform a fitness test.

[0049] The method may further comprise determining, from the cardiac activity data, a peak heart rate of the user.

[0050] The V02 max value may be determined from the peak heart rate and a resting heart rate for the user.

[0051] The method may further comprise comparing the peak heart rate value to a current maximum heart rate value for the user; and if the peak heart rate value is greater than the current maximum heart rate value, replacing the current maximum heart rate value with the peak heart rate value.

[0052] If the peak heart rate value is greater than the current maximum heart rate value, the method may comprise notifying the user that the current maximum heart rate value can be updated, and in response to receiving a user instruction, replacing the current maximum heart rate value with the peak heart rate value.

[0053] The obtaining may comprise obtaining cardiac activity data for the user during a plurality of stages of an exercise comprising an activity stage and a rest stage follows the activity stage.

[0054] The method may further comprise determining, from the cardiac activity data, a heart rate of the user during the activity stage and a heart rate of the user during the rest stage.

[0055] The method may further comprise calculating a heart rate recovery value for the user using the difference between the heart rate of the user during the activity stage and the heart rate of the user during the rest stage.

[0056] The V02 max value may be estimated from the heart rate recovery value.

[0057] Estimating the cardiovascular fitness of the user may further comprise comparing the determined heart rate recovery value to a threshold heart rate recovery value.

[0058] The determined V02 max value may be used to generate a first cardiovascular fitness estimate for the user and the heart rate recovery value may be used to generate a second cardiovascular fitness estimate for the user. The determined V02 max value and the heart rate recovery value may be combined to generate the estimate of the cardiovascular fitness for the user.

[0059] The threshold V02 max value may be a user specific threshold V02 max value.

[0060] The threshold V02 max value may be determined from a previously determined V02 max value for the user [0061] The threshold V02 max value may be selected according to at least one of the age, gender, height, weight, or fitness level of the user.

[0062] The method may further comprise outputting the estimated cardiovascular fitness [0063] The method may further comprise generating a health recommendation from the estimated cardiovascular fitness.

[0064] The method may further comprise outputting the generated health recommendation.

[0065] The method may further comprise establishing a communication session with a wearable electronics module, and receiving the cardiac activity data from the electronics module.

[0066] The method may comprise any of the features of the methods of the first, seventh and tenth

aspects of the present disclosure.

[0067] 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.

[0068] According to a sixth aspect of the disclosure, there is provided a system for determining a cardiovascular fitness for a user, 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 cardiac activity data for a user; estimating a V02 max value for the user from the cardiac activity data; and estimating the cardiovascular fitness of the user using a comparison of the determined V02 max value to a threshold V02 max value.

[0069] The operations performed by the processor may further comprise establishing a communication session with a wearable electronics module, and receiving the cardiac activity data from the electronics module.

[0070] The system may comprise a user electronic device, and wherein the user electronic device comprises the processor and the memory.

[0071] The system may comprise the wearable electronics module.

[0072] The operations performed by the processor may comprise any of the features of the fourth aspect

of the disclosure.

[0073] According to a seventh aspect of the disclosure, there is provided a computer-implemented method of estimating a V02 max value for a user. The method comprises prompting a user to adopt a resting position. The method comprises obtaining cardiac activity data for the user while in the resting position. The method comprises calculating, from the cardiac activity data, a resting heart rate for the user. The method comprises prompting the user to perform an activity. The method comprises obtaining cardiac activity data for the user during the activity. The method comprises calculating, from the cardiac activity data, a peak heart rate for the user.

[0074] The method may further comprise estimating a V02 max value for the user from the resting heart rate and the peak heart rate.

[0075] Estimating the V02 max value may comprise dividing the peak heart rate by the resting heart rate.

[0076] The method may comprise comparing the determined V02 max value to a threshold V02 max value so as to generate a cardiovascular fitness for the user.

[0077] The method may further comprise establishing a communication session with a wearable electronics module, and receiving the cardiac activity data from the electronics module.

[0078] The method may further comprise outputting the estimated cardiovascular fitness.

[0079] The method may further comprise generating a health recommendation from the estimated cardiovascular fitness.

[0080] The method may further comprise outputting the generated health recommendation.

[0081] The threshold V02 max value may be a user specific threshold V02 max value.

[0082] The threshold V02 max value may be determined from a V02 max value estimated during a fitness test previously performed by the user.

[0083] The threshold V02 max value may be selected according to at least one of the age, gender, height, weight, or fitness level of the user.

[0084] The method may comprise any of the features of the methods of the first, fourth and tenth aspects

of the present disclosure.

[0085] According to an eighth aspect of the present 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.

[0086] According to a ninth aspect of the present disclosure, there is provided a system for estimating a V02 max value for a user, 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: prompting a user to adopt a resting position; obtaining cardiac activity data for the user while in the resting position; calculating, from the cardiac activity data, a resting heart rate for the user; prompting the user to perform an activity; obtaining cardiac activity data for the user during the activity; calculating, from the cardiac activity data, a peak heart rate for the user.

[0087] The operations may further comprise estimating a V02 max value for the user from the resting heart rate and the peak heart rate.

[0088] The operations performed by the processor may further comprise establishing a communication session with a wearable electronics module, and receiving the cardiac activity data from the electronics module.

[0089] The system may comprise a user electronic device, and wherein the user electronic device comprises the processor and the memory.

[0090] The system may comprise the wearable electronics module.

[0091] The operations performed by the processor may comprise any of the features of the seventh

aspect of the disclosure.

[0092] According to a tenth aspect of the disclosure, there is provided a computer-implemented method of determining a maximum heart rate for a user, the method comprising: obtaining cardiac activity data for a user; determining, from the cardiac activity data, a peak heart rate value for the user; comparing the peak heart rate value to a current maximum heart rate value for the user; and if the peak heart rate value is greater than the current maximum heart rate value, replacing the current maximum heart rate value with the peak heart rate value.

[0093] If the peak heart rate value is greater than the current maximum heart rate value, the method may comprise notifying the user that the current maximum heart rate value can be updated, and in response to receiving a user instruction, replacing the current maximum heart rate value with the peak heart rate value.

[0094] The method may comprise prompting the user to perform the activity. The user may be prompted to perform a series of activity stages. The series of activity stages may comprise a high intensity activity stage. Cardiac activity data for the user may be obtained during the series of activity stages.

[0095] The method may comprise any of the features of the methods of the first, fourth and seventh

aspects of the present disclosure.

[0096] 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.

[0097] According to a twelfth aspect of the disclosure, there is provided a system for determining a maximum heart rate for a user, 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 cardiac activity data for a user; determining, from the cardiac activity data, a peak heart rate value for the user; comparing the peak heart rate value to a current maximum heart rate value for the user; and if the peak heart rate value is greater than the current maximum heart rate value, replacing the current maximum heart rate value with the peak heart rate value.

[0098] The operations may comprise prompting the user to perform the activity.

[0099] The operations performed by the processor may further comprise establishing a communication session with a wearable electronics module, and receiving the cardiac activity data from the electronics module.

[0100] The system may comprise a user electronic device, and wherein the user electronic device comprises the processor and the memory.

[0101] The system may comprise the wearable electronics module.

[0102] The operations performed by the processor may comprise any of the features of the tenth aspect

of the disclosure.

[0103] In the above examples of the present disclosure, the cardiac activity data may be derived 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 includes photoplethysmography (PPG) signals, ballistocardiogram (BOG) signals, and electromagnetic cardiogram (EMCG) signals.

BRIEF DESCRIPTION OF THE DRAWINGS

[0104] 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.

[0105] FIG. 1 illustrates an example system in accordance with aspects of the present disclosure.

[0106] FIG. 2 illustrates a schematic for an example electronics module in accordance with aspects of

the present disclosure.

[0107] FIG. 3 illustrates an example wearable article in accordance with aspects of the present

disclosure.

[0108] FIG. 4 illustrates an example wearable assembly comprising an electronics module and wearable article in accordance with aspects of the present disclosure.

[0109] FIG. 5 illustrates a schematic for an example electronics module in accordance with aspects of

the present disclosure.

[0110] FIG. 6 illustrates an example analogue-to-digital frontend of an electronics module according to

aspects of the present disclosure.

[0111] FIG. 7 illustrates an example user electronic device according to aspects of the present disclosure.

[0112] FIG. 8 to FIG. 15 illustrate example pages of an application running on a user electronic device

according to aspects of the present disclosure.

[0113] FIG. 16 illustrates a flow diagram for an example method according to aspects of the present

disclosure.

[0114] FIG. 17 to FIG. 20 illustrate example pages of an application running on a user electronic device

according to aspects of the present disclosure.

[0115] FIG. 21 to FIG. 23 illustrate flow diagrams for example methods according to aspects of the

present disclosure.

DETAILED DESCRIPTION

[0116] 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.

[0117] 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.

[0118] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0119] FIG. 1 shows a system according to aspects of the present disclosure. The system comprises a wearable assembly 102 and a user electronic device 104. The wearable assembly 102 is worn by a user who in this example is the wearer 106 of the wearable assembly 102.

[0120] The wearable assembly 102 comprises a wearable article 108 which, in this is example, is in the form of a garment. Other forms of wearable article, such as wristbands/smart watches, necklaces, bracelets, and glasses are possible.

[0121] The wearable assembly 102 comprises an electronics module 110. The electronics module 110 is releasably coupled to the wearable article 108. The wearable article 108 comprises an electronics module holder (not shown) arranged to removably retain the electronics module 110. The electronics module holder enables the electronics module 110 to be attached and removed from the wearable article 108.

[0122] The electronics module 110 can be removed from the wearable article 108 so that the wearable article 108 can be washed without damaging the internal electronics of the electronics module 110. The electronics module 110 can also be removed from the wearable article 108 for charging In other examples, the electronics module 110 is integrally formed with the wearable article 108.

[0123] Generally, the electronics module 110 comprises all of the components required for data transmission and processing. In this way, the manufacture of the wearable article may be simplified. In addition, it may be easier to clean a wearable article 108 which has fewer electronic components attached thereto or incorporated therein. Furthermore, the removable electronics module 110 may be easier to maintain or troubleshoot than embedded electronics. The electronics module 110 may comprise flexible electronics such as a flexible printed circuit (FPC).

[0124] 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 110 may be inserted and removed from the pocket. The pocket may be formed from fabric layers of the wearable article 108.

[0125] The present disclosure is not limited to electronics module holders in the form pockets.

[0126] The electronics module 110 may be configured to be releasably mechanically coupled to the wearable article 108. The mechanical coupling of the electronics module 110 to the wearable article 108 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 110 in a particular orientation with respect to the wearable article 108 when the electronics module 110 is coupled to the wearable article 108. This may be beneficial in ensuring that the electronics module 110 is securely held in place with respect to the wearable article 108 and/or that any electronic coupling of the electronics module 110 and the wearable article 108 can be optimized. The mechanical coupling may be maintained using friction or using a positively engaging mechanism, for example.

[0127] The electronics module 110 is arranged to wirelessly communicate data to the user electronic device 104. Various protocols enable communication between the electronics module 110 and the user electronic device 104. Example communication protocols include Bluetooth 0, Bluetooth 0 Low Energy, and near-field communication (NFC).

[0128] The system also comprises a remote server 112 which may be in communication with the user electronic device 104 and/or the electronics module 110.

[0129] FIG. 2 shows a simplified diagram of an example electronics module 110 according to aspects of the present disclosure. The electronics module 110 comprises a controller 202 and a sensing interface 204 communicatively coupled to the controller 202.

[0130] The sensing interface 204 in this example comprises a first electrical contact 206 and a second electrical contact 208. The sensing interface 204 receives measurement signals from the electrical contacts 206, 208. The measurement signals, or a processed version thereof, are provided to the controller 202. The measurement signals may be any form of biosignal as described above. The sensing interface 204 is therefore able to receive physiological signals from a wearer of the electronics module 110.

[0131] The controller 202 is able to process the signals received from the sensing interface 204 The controller 202 may control a wireless communicator (not shown) of the electronics module 110 to transmit data to an external device such as user electronic device 104 of FIG. 1.

[0132] FIG. 3 shows a simplified diagram of an example wearable article 108. The wearable article 108 comprises a fabric layer 302.

[0133] A first communication interface 304 is provided on the fabric layer 302. The first communication interface 304 is accessible from the electronics module holder of the wearable article 108.

[0134] The first communication interface 304 is communicatively coupled to a first sensor 306 via a first communication pathway 308. The first communication interface 304, first sensor 306 and first communication pathway 308 form a first sensing unit of the wearable article 108. The first sensor 306 is in the form of an electrode. The first sensor 306 may be provided on the wearable article 108 such that it faces the skin surface of the wearer when the wearable article 108 is worn. This enables the first sensor 306 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.

[0135] A second communication interface 310 is provided on the fabric layer 302. The second communication interface 310 is accessible from the electronics module holder of the wearable article 108.

[0136] The second communication interface 310 is communicatively coupled to a second sensor 312 via a second communication pathway 314. The second communication interface 310, second sensor 312, and second communication pathway 314 form a second sensing unit of the wearable article 108. The second sensor 312 is in the form of an electrode. The second sensor 312 may be provided on the wearable article 108 such that it faces the skin surface of the wearer when the wearable article 108 is worn. This enables the second sensor 312 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.

[0137] In this example, the first sensor 306 and second sensor 312 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 108 may include any combination of different types of sensors.

[0138] FIG. 4 shows a simplified diagram of an electronics module 110 coupled to a wearable article 108 to form an example wearable assembly 102. The electronics module 110 is positioned inside an electronics module holder 402 of the wearable article 108 which in this example is in the form of a pocket.

[0139] The first communication interface 304 and the second communication interface 310 are provided on a first surface of fabric layer 404 such that they are located within the pocket space. The first sensor 306 and the second sensor 312 are provided on a second surface of fabric layer 406 that opposes the first surface of fabric layer 404. The first sensor 306 and second sensor 312 are arranged such that they face towards the skin surface of the wearer of the wearable article 108. The first and second communication pathways are not shown in FIG 4 but as discussed above in relation to FIG 3, couple the sensors to their respective communication interfaces 304, 310.

[0140] The electronics module 110 is positioned within the pocket space. The first electrical contact 206 of the electronics module 110 contacts and is electrically coupled to the first communication interface 304. The second electrical contact 208 of the electronics module 110 contacts and is electrically coupled to the second communication interface 310. The electronics module 110 is therefore coupled to the first sensor 306 and the second sensor 312 via the communication pathways, communication interfaces 304, 310, and electrical contacts 206, 208.

[0141] FIG. 5 shows a simplified schematic diagram for an example electronics module 110 as shown in FIG. 4. It will be appreciated that not all of the components shown in FIG. 5 are required and additional components may also be provided.

[0142] The electronics module 110 comprises a controller 202 and a sensing interface 204 as described in FIG. 4. The sensing interface 204 comprises a first electrical contact 206 and a second electrical contact 208. The controller 202 is communicatively coupled to the sensing interface 204 and is operable to receive signals from the sensing interface 204 for further processing.

[0143] The sensing interface 204 comprises electrical contacts 206, 208 in this example. This means that the communicative coupling in this example is a conductive coupling formed by direct contact between the electrical contacts 206, 208 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.

[0144] The sensing interface comprises an analogue-to-digital front end 616 (FIG. 6) that couples signals received from the electrical contacts 206, 208 to the controller 202 and optionally an electrostatic discharge (ESD) protection circuit.

[0145] The electronics module 110 further comprises a power source 502 and a power receiving interface 504.

[0146] The power source 502 may comprise one or a plurality of power sources. The power source 502 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 502 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.

[0147] The power receiving interface 504 is operable to receive power from an external power store for charging the power source. The power receiving interface 504 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 206, 208 may also function as the power receiving interface 504 to enable power to be received from the external power store.

[0148] The power receiving interface 504 may also be coupled to the controller 202 to enable direct communication between the controller 202 and an external device if required.

[0149] The electronics module 110 further comprises a wireless communicator 506. The wireless communicator 506 may utilise any communication protocol such as used for communication over: a wireless wide area network (WVVAN), a wireless metro area network (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN), Bluetooth Low Energy, Bluetooth 0 Mesh, Thread, Zigbee, IEEE 802.15.4, 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.

[0150] The electronics module 110 further comprises a sensor 508. The sensor 508 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 110.

[0151] FIG. 6 is a schematic illustration of the component circuitry for the analogue-to-digital front end 616 of the sensing interface 204.

[0152] In the example described herein, the analogue-to-digital front end 616 is an integrated circuit (IC) chip which converts the raw analogue biosignal received via the contacts 206, 208 into a digital signal for further processing by the controller 202. 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. [0153] The analogue-to-digital front end 616 includes inputs 602, 612 and an outputs 604, 614.

[0154] Raw biosignals are input to the analogue-to-digital front end 616, where received signals are processed in an ECG channel 606 and a bioimpedance (BIOZ) channel 608 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.

[0155] The output digital signals may be decimated to reduce the sampling rate prior to being passed to a serial programmable interface 610 of the analogue-to-digital front end 616. Signals are output to the controller via the serial programmable interface 610.

[0156] The digital signal values output to the controller 202 are stored in a FIFO data buffer. The controller 202 performs operations to generate biological metrics from the digital signal values. The operations are performed in real-time while the ADC analogue-to-digital front end 616 are outputting new digital signals to the controller 202.

[0157] 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 (1131) values can be determined by the controller 202.

[0158] 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.

[0159] The controller 202 can also be configured to apply digital signal processing (DSP) to the digital signal from the analogue-to-digital front end 616.

[0160] The DSP may include noise filtering additional to that carried out in the analogue-to-digital front end 616 and may also include additional processing to determine further information about the signal from the analogue-to-digital front end 616.

[0161] The controller 202 is configured to send the biosignals to the user electronic device 104. The biosignals sent to the user electronic device 104 in this example comprise the inter-beat interval (IBI) values representing the time differences between successive R peaks in the measured ECG signal.

[0162] Referring to FIG. 7, there is shown a schematic diagram of a user electronic device 104 according to an example aspect of the present disclosure. The user electronic device 104 is in the form of a mobile phone or tablet and comprises a controller 702, a memory 704, a wireless communicator 706, a display 708, a user input unit 710, a capturing device in the form of a camera 712 and an inertial measurement unit 714. The controller 702 provides overall control to the user electronic device 104. The controller 702 includes a processor and a memory.

[0163] The user input unit 710 receives inputs from the user such as a user credential.

[0164] The memory 704 stores information for the user electronic device 104.

[0165] The display 708 is arranged to display a user interface for applications operable on the user electronic device 104. The display 708 may be a presence-sensitive display and therefore may comprise the user input unit 710 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 710.

[0166] The inertial measurement unit 714 provides motion and/or orientation detection and may comprise an accelerometer and optionally one or both of a gyroscope and a magnetometer.

[0167] The controller 702 is configured to launch an application which is configured to display insights derived from the biosignal data processed by the analogue-to-digital front end 616 of the electronics module 110, input to electronics module 110 controller 202, and then transmitted from the electronics module 110. The transmitted data is received by the wireless communicator 706 of the user electronic device 104 and input to the controller 702. 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 102 of FIG. 1).

[0168] User electronic devices 104 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 104 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 300 may include a head-mounted device such as an Augmented Reality, Virtual Reality or Mixed Reality head-mounted device. The user electronic device 104 may be desktop PC, workstations, television apparatus or a projector, e.g., arranged to project a display onto a surface.

[0169] The controller 702 is configured to launch an application which establishes a communication session with the electronics module 110, receives sensor data from the electronics module 110, and processes the sensor data to generate insights for the wearer.

[0170] FIG. 8 to FIG. 15 show a series of pages of an example application run by the user electronic device 104 and which may be displayed on the display 708 of the user electronic device 104 according to aspects of the present disclosure. The application is used to guide a user through tests, such as a fitness test, to estimate the cardiovascular fitness of the user.

[0171] FIG. 8 shows a menu page 802 of the application. The menu page 802 displays a plurality of interface elements in the form of a workout button 804, a recovery test button 806, a guided breathing button 808, and a fitness test button 810. The different buttons allow the user to perform different activities and receive different insights based on the data received from the electronics module 110.

[0172] The workout button 804 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.

[0173] The recovery test button 806 takes the user to a recovery test page so that they may perform a recovery test. In a recovery test, 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.

[0174] An example recovery test 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 recovery test may be a form of orthostatic heart rate (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.

[0175] The guided breathing button 808 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.

[0176] The fitness test button 810 takes the user to a fitness test page so that the user may perform a fitness test. In a fitness test, the user is prompted to perform a series of activities.

[0177] In response to interacting with the fitness test button 810, the controller 702 of the user electronic device 104 determines whether the user electronic device 104 is in communication with an electronics module.

[0178] If a communication session has not been established, the user is taken to a page (not shown) which displays an interface element to enable the user to connect to their electronics module 110. In response to selecting the interface element, the user is prompted to tap their user electronic device 104 against the electronics module 110 to trigger a pairing process between the user electronic device 104 and the electronics module 110.

[0179] Once a communication session has been established with the electronics module 110, the user is taken to page 902 as shown in FIG. 9.

[0180] The page 902 may display connection information (not shown) for the electronics module 110 connected to the user electronic device 104. The connection information may include the identity of the electronics module 110 and a battery status of the electronics module 110.

[0181] The page 902 displays the activities that the user is prompted to perform during the fitness test along with the time duration of each activity. The activities include periods of high intensity activity, periods of low/moderate intensity activity and periods of rest which are also known as periods of recovery.

[0182] High intensity activities are intended to raise the user's heart rate towards their peak or maximal value. High intensity activities include running and sprinting. Generally, a high intensity activity is intended to take the user to at least 80% of their maximum heart rate.

[0183] Low/moderate intensity activities are not intended to raise the user's heart rate towards their peak or maximal value. Generally, a low/moderate intensity activity is intended to take the user to at most 80% of their maximum heart rate. Typically, low/moderate intensity activities are intended to take the user to between 10% and 70% of their maximum heart rate. Low/moderate intensity activities include walking and jogging.

[0184] Recovery refers to when the user is at rest. The user may be standing, sitting, lying down or walking at low speed. During the period of rest, the users heart rate is expected to drop and, eventually, return to a value near the resting heart rate of the user. The rate of decrease of the heart rate during the period of rest is referred to as the heart rate recovery [0185] In this example, the fitness test comprises: [0186] 1. A warm-up for 3 minutes. This activity stage is a period of low intensity activity. The user is prompted to begin with a steady walk. 30 seconds into the warm-up the user is prompted to increase their walking speed. 1 minute into the warm-up the user is prompted to begin a steady jog. The user is instructed to maintain the steady jog until the end of the 3 minute workout.

[0187] 2. High intensity activity for 3 minutes. This activity stage is a period of high intensity activity. The user is prompted to increase their pace. 30 seconds into the high intensity activity, the user is prompted to start running. The user is prompted to continue running until the final 30 seconds of the high intensity activity. For the final 30 seconds the user is prompted to sprint.

[0188] 3. Low intensity activity for 2 minutes. This activity stage is a period of low intensity activity. The user is prompted to return to a steady jog.

[0189] 4. High intensity activity for 3 minutes. This activity stage is a period of high intensity activity. The user is prompted to increase their pace. 30 seconds into the high intensity activity, the user is prompted to start running. The user is prompted to continue running until the final 30 seconds of the high intensity activity. For the final 30 seconds the user is prompted to sprint.

[0190] 5. Recovery for 2 minutes. This is a rest stage, i.e., a period of rest. The user is prompted to stop, stand still, and recover.

[0191] 6. Low intensity activity for 1 minute. This activity stage is a period of low intensity activity. The user is prompted to start walking to cooldown.

[0192] The page 902 also displays a start button 904 to begin the fitness test Once the start button 904 is selected, the fitness test starts.

[0193] FIG. 10 to FIG. 15 show pages displayed during the fitness test.

[0194] Each page includes text 1002 indicating the stage of the fitness test, text 1004 indicating the type of activity being performed, a timer 1006 indicating the time remaining in stage, a fitness instruction 1008, a current heart rate 1010 for the user, a peak heart rate 1012 for the user during the stage, and text 1014 indicating the next stage for the fitness test.

[0195] The fitness instruction 1008 may be updated during the stages to guide the user to perform different activities and/or increase/decrease their activity level.

[0196] At the same time as guiding the user through the fitness test, the user electronic device 104 is receiving physiological data from the electronics module 110. In this example, the physiological data includes cardiac activity data and, in particular, a sequence of heartbeat data samples for the user representative of the heartbeat activity of the user. 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 202 of the electronics module 110 from digital signal values received from the analogue-to-digital front end 616.

[0197] The cardiac activity data is used to calculate the current heart rate 1010 and peak heart rate 1012 during each stage The cardiac activity data is also used to determine a cardiovascular fitness for the user. The cardiovascular fitness may be derived from one or both of a heart rate recovery value for the user and a determined V02 max value for the user.

[0198] FIG. 16 shows an example computer-implemented method 1600 of estimating a cardiovascular fitness for the user from a heart rate recovery value determined during the fitness test.

[0199] Step 1602 comprises prompting a user to perform a fitness test comprising a plurality of exercise stages. The plurality of stages comprise an activity stage followed by a rest stage. The fitness test may be the fitness test as described in FIG. 10 to FIG. 15 but is not limited to this example. The prompts may be audible, visual, or haptic prompt or may be a combination of any of audible, visual, and haptic prompts.

[0200] The method may comprise generating a plurality of instructions for the user to transition between the plurality of stages of the exercise; and outputting the plurality of instructions so as to prompt the user to perform the fitness test.

[0201] Step 1604 comprises obtaining cardiac activity data for the user during the plurality of exercise stages including the activity stage and the rest stage.

[0202] The cardiac activity data is obtained from the electronics module 110 as described above. The obtained cardiac activity values comprise a series of IBI values which are converted into heart rate values. IBI values representing four seconds of cardiac activity may be used to generate each heart rate value.

[0203] Step 1606 comprises determining, from the cardiac activity data, a heart rate recovery value for the user according to a determination of a decrease in the heart rate of the user during the rest stage.

[0204] In some examples, determining the heart rate recovery value involves determining, from the cardiac activity data, a heart rate of the user during the activity stage and a heart rate of the user during the rest stage. The heart rate recovery value is then determined according to the difference between the heart rate during the activity stage and the heart rate during the rest stage.

[0205] The heart rate of the user during the activity stage may represent the heart rate of the user at the end of the activity stage. The activity may be a high intensity activity.

[0206] The heart rate of the user during the rest stage may represent the heart rate of the user after 30 seconds or more of the start of the rest stage (30 seconds or more following the activity stage). The heart rate of the user during the rest stage may represent the heart rate of the user 1 minute following the activity stage. The heart rate of the user during the rest stage may represent the heart rate of the user 2 minutes after the activity stage.

[0207] Step 1608 comprises estimating the cardiovascular fitness of the user using a comparison of the determined heart rate recovery value to a threshold heart rate recovery value.

[0208] In one example, the threshold heart rate recovery value is non-specific for the user. The threshold heart rate recovery value may be determined according to population norms. The threshold heart rate recovery may be specific for any one or a combination of the age, gender, height, weight, or fitness level of the user.

[0209] In some examples, the determined heart rate recovery value may be compared to a plurality of threshold heart rate recovery values. Comparing the determined heart rate recovery value to a plurality of threshold heart rate values allows for a more informed insight into the cardiovascular fitness of the user.

[0210] A first threshold value may represent the lower limit for excellent cardiovascular fitness. If the determined heart rate recovery value is greater than or equal to the first threshold value, then the user is determined to have excellent cardiovascular fitness. The first threshold value may be 30 for example.

[0211] A second threshold value may represent the lower limit for good cardiovascular fitness. If the determined heart rate recovery value is greater than or equal to the second threshold value but less than the first threshold value, then the user is determined to have good cardiovascular fitness. The second threshold value may be 15 for example. If the determined heart rate recovery value is less than the second threshold value, then the user is determined to have poor cardiovascular fitness [0212] In another example, the threshold heart rate recovery value is user specific. The threshold heart rate recovery value is determined from a heart rate recovery value calculating during a fitness test previously performed by the user. This allows for the user to determine whether their cardiovascular fitness is improving over time.

[0213] Step 1610 comprises outputting the estimate of the cardiovascular fitness. The output may be via the user electronic device 104. The output may be in the form of one or a combination of visual, audible, and haptic feedback.

[0214] FIG. 17 shows an example summary screen page 1702 that is displayed to the user at the end of the fitness test. The summary screen page 1702 displays metrics based on the cardiac activity data received from the electronics module 110 during the fitness test.

[0215] The page 1702 displays a plot 1704 of the user's heart rate during the rest stage. The plot 1704 shows the user's heart rate at the end of the high intensity activity stage 1706, the user's heart rate 1 minute into the rest stage 1708 and the user's heart rate 2 minutes into the rest stage 1710. 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.

[0216] The page 1702 additionally displays cardiovascular fitness information 1712 for the user which includes the estimate of the cardiovascular fitness as explained above.

[0217] FIG. 18 shows an example cardiovascular fitness information 1712 which is displayed to a user with excellent cardiovascular fitness. The user's heart rate recovery value (difference between heart rate and end of high intensity activity and heart rate 1 minute into rest stage) is 35 bpm. The heart rate recovery value is greater than the first threshold value described above in relation to FIG. 16. The cardiovascular fitness is therefore determined to be excellent.

[0218] The cardiovascular fitness information 1712 includes the users heart rate recovery value 1802, the estimated cardiovascular fitness ("excellent") 1804 and a health recommendation 1806. In this example, the health recommendation 1806 states that the user's heart rate recovery is above average indicating high cardiovascular fitness. The user is recommended to continue to include a balance of high intensity workouts and proper recovery each week to maintain the excellent level of fitness.

[0219] FIG. 19 shows an example cardiovascular fitness information 1712 displayed to a user with good cardiovascular fitness. The user's heart rate recovery value is 28 bpm. The heart rate recovery value is less than the first threshold value and greater than the second threshold value described above in relation to FIG. 16. The cardiovascular fitness is determined to be good.

[0220] The cardiovascular fitness information 1712 displays the user's heart rate recovery value 1902, the estimated cardiovascular fitness ("good") 1904, and a health recommendation 1906. In this example, the health recommendation 1906 states that the user's heart rate recovery is within a healthy range indicating good cardiovascular fitness. The user is recommended to challenge themselves to include two to three high intensity workouts per week balanced with proper recovery to further improve their score.

[0221] FIG. 20 shows an example cardiovascular fitness information 1712 displayed to a user with poor cardiovascular fitness. The users heart rate recovery value is 14 bpm. The heart rate recovery value is less than the second threshold value described above in relation to FIG. 16. The cardiovascular fitness is determined to be poor.

[0222] The cardiovascular fitness information 1712 displays the user's heart rate recovery value 2002, the estimated cardiovascular fitness ("poor') 2004, and a health recommendation 2006. In this example, the health recommendation 2006 states that the user's heart rate recovery indicates that their cardiovascular fitness can be improved. The user is recommended to perform at least 150 minutes of moderate to high intensity exercise each week to improve their fitness. The user is also advised to consult their GP before starting a new exercise programme.

[0223] The summary screen page 1702 of FIG. 17 additionally displays a plot 1714 of the user's heart rate during the fitness test. The plot 1714 identifies the user's peak heart rate values 1716, 1718 during the high intensity activity stages. 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.

[0224] The summary screen page 1702 additionally displays the user's average heart rate 1720 and peak heart rate 1722 during the fitness test.

[0225] The average heartrate of the user over the duration of the fitness test is derived, by the user electronic device 104, using the cardiac activity data received from the electronics module. 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.

[0226] 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.

[0227] The peak heart rate is the highest heart rate for the user during the fitness test.

[0228] Importantly, in this example, the peak heart rate 1722 is compared to a current maximum heart rate value for the user. The current maximum heart rate value may have been determined previously for the user such as during a previous performance of a fitness test or may be predetermined and set according to population norms. The maximum heart rate may be determined according to factors such as the age and gender of the user.

[0229] In this example, the peak heart rate determined during the fitness test (189 BPM) is greater than the current maximum heart rate value for the user. The summary screen page 1702 displays a prompt 1724 to the user to update their maximum heart rate value to reflect their peak heart rate determined during the fitness test. Selecting the prompt 1724 replaces the current maximum heart rate value with the peak heart rate value. User input is not required in all examples and the peak heart rate value may automatically replace the current maximum heart rate value if it is determined to be greater than the current maximum heart rate value in some examples.

[0230] Advantageously, the present disclosure provides a simple method for providing an accurate estimation of the maximum heart rate of the user that does not rely solely on population norms or on laboratory based testing. The maximum heart rate is able to be updated as the cardiovascular fitness of the user improves. The maximum heart rate is a variable that is used in a number of health insights such as in calculating the calorie consumption and heartrate training zone that the user is in.

[0231] Beneficially, updating the maximum heart rate value for the user from the fitness test can provide an accurate estimate of the maximum heartrate of the user which is specific to the user and has a high degree of confidence. This improves on methods which use a default maximum 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 maximum heartrate. Beneficially, this approach also enables the maximum heart rate value used in calculations to adapt based on physical changes of the user.

[0232] By way of example, the maximum heartrate 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.

[0233] In the above examples, the cardiovascular fitness is estimated from the heart rate recovery value.

This is not required in all examples. The cardiovascular fitness may be estimated from other metrics such as the V02 max of the user. The cardiovascular fitness may also be estimated from a combination of the heart rate recovery and the V02 max of the user.

[0234] FIG. 21 shows an example method 2100 of estimating a V02 max value for a user.

[0235] Step 2102 comprises prompting a user to perform a fitness test comprising an activity stage. The fitness test may be as described above but of course other fitness tests are possible. The activity stage may be a period of high intensity activity.

[0236] Step 2104 comprises obtaining cardiac activity data for the user during the fitness test.

[0237] Step 2106 comprises determining, from the cardiac activity data, a peak heart rate for the user during the activity stage.

[0238] Step 2108 comprises estimating a V02 max value for the user from the peak heart rate and a resting heart rate for the user. The V02 max value may be determined by dividing the peak heart rate by the resting heart rate. The V02 max value may be determined according to the formula: VO2max = 15 x peak heart rate / resting heart rate.

[0239] The determined V02 max value may be compared to a threshold V02 max value to estimate the cardiovascular fitness.

[0240] In one example, the threshold V02 max value is non-specific for the user. The threshold V02 max value may be determined according to population norms. The threshold V02 max value may be specific for any one or a combination of the age, gender, height, weight, or fitness level of the user.

[0241] In some examples, the determined V02 max value may be compared to a plurality of threshold V02 max values. Comparing the determined V02 max value to a plurality of threshold V02 max values allows for a more informed insight into the cardiovascular fitness of the user.

[0242] A first threshold value may represent the lower limit for excellent cardiovascular fitness. If the determined V02 max value is greater than or equal to the first threshold value, then the user is determined to have excellent cardiovascular fitness.

[0243] A second threshold value may represent the lower limit for good cardiovascular fitness. If the determined V02 max value is greater than or equal to the second threshold value but less than the first threshold value, then the user is determined to have good cardiovascular fitness. If the determined V02 max value is less than the second threshold value, then the user is determined to have poor cardiovascular fitness.

[0244] In another example, the threshold V02 max value is user specific. The threshold V02 max value is determined from a V02 max value estimated during a fitness test previously performed by the user. This allows for the user to determine whether their cardiovascular fitness is improving over time.

[0245] In the above example, the V02 max value is estimated from the peak heart rate of the user determined during the fitness test and a resting heart rate for the user. The resting heart rate may be predetermined based on factors such as the age of the user or, in some examples, derived from previous fitness tests performed by the user.

[0246] The resting heart rate may be determined during a test in which the user is prompted to adopt a resting position. The test may be a recovery test or guided breathing test as described above in relation to FIG. 8.

[0247] FIG. 22 shows an example method 2200 for determining the resting and peak heart rates of the user for estimating V02 max.

[0248] Step 2202 comprises prompting a user to perform a first test during which the user adopts a resting position [0249] Step 2204 comprises obtaining cardiac activity data for the user during the first test [0250] Step 2206 comprises calculating, from the cardiac activity data, a resting heart rate for the user.

[0251] The first test may be a recovery test.

[0252] In a recovery test, the user electronic device 104 prompts the user to adopt a first, resting, position.

The first position may be a sitting position or lying dawn position for example. While the user is in the first position, the user electronic device 104 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, I B I, values representing the time between successive heartbeats.

[0253] The user electronic device 104 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 104 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.

[0254] While the user is in the second position, the user electronic device 104 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 104 receives heartbeat samples for a second time period of three minutes (other time ranges are possible).

[0255] 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 greater than 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.

[0256] The second time period is usually desired to commence quickly after the first time period.

Typically, the second time period commences between 1 and 10 seconds after the first time period.

[0257] 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 greater than 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.

[0258] The user electronic device 104 determines a measure of the average heartrate of the user over the first time period. This value provides an accurate indication of the resting heart rate and may be used to set the resting heart rate of the user.

[0259] The first test may be a guided breathing exercise.

[0260] In a guided breathing exercise, the user electronic device 104 prompts the user to exhale and inhale in a controlled manner over a time. The time span may be 5 minutes for example. The prompt may be audible, visual, or haptic prompt or may be a combination of any of audible, visual, and haptic prompts. The user electronic device 104 may also prompt the user to hold their breath between exhales and inhales.

[0261] The user electronic device 104 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 110 in wireless communication with the user electronic device 104.

[0262] The user electronic device 104 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. The measure of the heartrate of the user can be used to set a resting heartrate for the user.

[0263] Setting the resting heartrate from the first test is beneficial as it provides a more 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.

[0264] Step 2208 comprises prompting the user to perform a second test during which the user performs an activity stage. The second test may be a fitness test as described above.

[0265] Step 2210 comprises obtaining cardiac activity data for the user during the second test.

[0266] Step 2212 comprises calculating, from the cardiac activity data, a peak heart rate for the user.

[0267] Step 2214 comprises estimating a V02 max value for the user from the resting heart rate and the peak heart rate.

[0268] In the above example, the V02 max value is determined according to the peak and resting heart rates of the user. This is not required in all examples. The V02 max value may also be estimated from the heart rate recovery of the user.

[0269] The user-specific determinations of resting and peak heart rates are not required to be used in estimating the V02 max value in all examples. These user-specific heart rate values may be used in other calculations for deriving insights about the user.

[0270] As described above, the present disclosure provides a beneficial method for determining the maximum heart rate of the user. This may be performed in isolation to determining the cardiovascular fitness of the user.

[0271] FIG. 23 shows an example method 2300 of determining a maximum heart rate for the user.

[0272] Step 2302 comprises prompting a user to perform an activity. The activity may comprise a series of activities The series of activities may comprise the fitness test as described above [0273] Step 2304 comprises obtaining cardiac activity data for the user during the activity.

[0274] Step 2306 comprises determining, from the cardiac activity data, a peak heart rate value for the user.

[0275] Step 2308 comprises comparing the peak heart rate value to a current maximum heart rate value for the user. The current maximum heart rate value is a prestored maximum heart rate value which may be predetermined based on factors such as the age of the user or obtained from a previous fitness test performed by the user.

[0276] Step 2310 comprises, if the peak heart rate value is greater than the current maximum heart rate value, replacing the current maximum heart rate value with the peak heart rate value.

[0277] In summary, there is provided a method and system for estimating cardiovascular fitness and maximum heart rate for a user. Cardiac activity data may be obtained for a user during a plurality of stages of an exercise, the plurality of stages comprising an activity stage and a rest stage following the activity stage. A heart rate recovery value may be determined from the cardiac activity data. The cardiovascular fitness may be estimated using a comparison of the heart rate recovery value to a threshold heart rate recovery value. A V02 max value may be determined from the cardiac activity data. The cardiovascular fitness may be estimated using a comparison of the V02 max value to a threshold V02 max value. The estimated cardiovascular fitness may be output to the user. A peak heart rate may be determined and compared to an existing maximum heart rate for the user. The maximum heart rate may then be updated.

[0278] 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.

[0279] 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.

[0280] 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.

[0281] 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.

[0282] 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

CLAIMS1. A computer-implemented method of estimating the cardiovascular fitness of a user, the method comprising: generating a plurality of instructions for a user to transition between a plurality of stages of an exercise, the plurality of stages comprising an activity stage and a rest stage following the activity stage, outputting the plurality of instructions to the user; obtaining cardiac activity data for the user during the plurality of stages of the exercise; determining, from the cardiac activity data, a heart rate of the user during the activity stage and a heart rate of the user during the rest stage; and calculating a heart rate recovery value for the user using the difference between the heart rate of the user during the activity stage and the heart rate of the user during the rest stage, estimating the cardiovascular fitness of the user using a comparison of the determined heart rate recovery value to a threshold heart rate recovery value; and outputting the estimate of the cardiovascular fitness.
2. The computer-implemented method of claim 1, wherein estimating the cardiovascular fitness comprises comparing the determined heart rate recovery value to a plurality of threshold heart rate recovery values.
3. The computer-implemented method of claim 1 or 2, wherein the heart rate of the user during the activity stage represents the heart rate of the user at the end of the activity stage.
4. The computer-implemented method of any one of claims 1 to 3, wherein the heart rate of the user during the rest stage represents the heart rate of the user between 30 seconds and 3 minutes after the end of the activity stage.
5. The computer-implemented method of any one of claims 1 to 4, wherein the heart rate of the user during the rest stage represents the heart rate of the user between 1 minute and 2 minutes after the end of the activity stage.
6. The computer-implemented method of any one of claims 1 to 5, wherein the threshold heart rate recovery value is a user specific threshold heart rate recovery value.
7. The computer-implemented method of claim 6, wherein the threshold heart rate recovery value is determined from a heart rate recovery value previously calculated for the user.
8. The computer-implemented method of any one of claims 1 to 6, wherein the threshold heart rate recovery value is selected according to at least one of the age, gender, height, weight, or fitness level of the user.
9. The computer-implemented method of any one of claims 1 to 8, further comprising determining, from the cardiac activity data, a peak heart rate of the user during the activity stage.
10. The computer-implemented method of claim 9, further comprising using the peak heart rate of the user to determine a V02 max value for the user.
11. The computer-implemented method of claim 10, wherein estimating the cardiovascular fitness further comprises comparing the V02 max value for the user to a threshold V02 max value.
12. The computer-implemented method of any one of claims 9 to 11, further comprising comparing the peak heart rate value to a current maximum heart rate value for the user; and if the peak heart rate value is greater than the current maximum heart rate value, replacing the current maximum heart rate value with the peak heart rate value.
13. The computer-implemented method of claim 12, wherein if the peak heart rate value is greater than the current maximum heart rate value, the method comprises notifying the user that the current maximum heart rate value can be updated, and in response to receiving a user instruction, replacing the current maximum heart rate value with the peak heart rate value.
14. The computer-implemented method of any one of claims 1 to 13, further comprising establishing a communication session with a wearable electronics module, and receiving the cardiac activity data from the electronics module.
15. 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.
16. A system for estimating a cardiovascular fitness for a user, 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: generating a plurality of instructions for a user to transition between a plurality of stages of an exercise, the plurality of stages comprising an activity stage and a rest stage following the activity stage, outputting the plurality of instructions to the user; obtaining cardiac activity data for a user during the plurality of stages of the exercise; determining, from the cardiac activity data, a heart rate of the user during the activity stage and a heart rate of the user during the rest stage; and calculating a heart rate recovery value for the user using the difference between the heart rate of the user during the activity stage and the heart rate of the user during the rest stage; estimating the cardiovascular fitness of the user using a comparison of the determined heart rate recovery value to a threshold heart rate recovery value; and outputting the estimate of the cardiovascular fitness.
17. The system of claim 16, wherein the operations performed by the processor further comprise establishing a communication session with a wearable electronics module, and receiving the cardiac activity data from the electronics module
18. The system of claim 16 or 17, wherein the system comprises a user electronic device, and wherein the user electronic device comprises the processor and the memory.
19. The system of any one of claims 16 to 18, wherein the system comprises the wearable electronics module.
20. A computer-implemented method of estimating a cardiovascular fitness for a user, the method comprising: generating a plurality of instructions for a user to transition between a plurality of stages of an exercise, the plurality of stages comprising an activity stage and a rest stage following the activity stage, outputting the plurality of instructions to the user; obtaining cardiac activity data for a user during the plurality of stages of the exercise; determining a V02 max value for the user from the cardiac activity data; estimating the cardiovascular fitness of the user using a comparison of the determined V02 max value to a threshold V02 max value; and outputting the estimate of the cardiovascular fitness.
21. The computer-implemented method of claim 20, further comprising determining, from the cardiac activity data, a peak heart rate of the user.
22. The computer-implemented method of claim 21, wherein the V02 max value is determined from the peak heart rate and a resting heart rate for the user.
23. The computer-implemented method of claim 21 or 22, further comprising comparing the peak heart rate value to a current maximum heart rate value for the user; and if the peak heart rate value is greater than the current maximum heart rate value, replacing the current maximum heart rate value with the peak heart rate value.
24. The computer-implemented method of any one of claims 20 to 23, wherein the threshold V02 max value is a user specific threshold V02 max value.
25. The computer-implemented method of claim 24, wherein the threshold V02 max value is determined from a previously determined V02 max value for the user.