WO2016181148A2

WO2016181148A2 - Apparatus and method for determining, visualising or monitoring vital signs

Info

Publication number: WO2016181148A2
Application number: PCT/GB2016/051359
Authority: WO
Inventors: Thomas Blacklay MOLE
Original assignee: Mole Thomas Blacklay
Priority date: 2015-05-12
Filing date: 2016-05-11
Publication date: 2016-11-17
Also published as: GB2538261A; WO2016181148A3; GB201508107D0

Abstract

Apparatus for determining and/or visualising and/or monitoring vital signs such as the respiratory rate and/or heart rate of a user, the apparatus comprising an accelerometer and a processor; wherein the accelerometer is contained within a housing and configured to generate, in use, when the housing is placed in contact with the user's upper body, a signal in response to motion of the user's body; and the processor is configured to receive the signal from the accelerometer and to process the signal to determine, and optionally cause display of, the vital sign. The apparatus may be implemented by a suitably-programmed mobile device (e.g. a smart phone having a built-in accelerometer). Embodiments enable user input, which is intended to be provided at specific times across a plurality of breaths or heartbeats, to cause the processor to provide an indication as to whether the user is concentrating on his or her breathing or heartbeat. This may be used to engender a state of mindfulness on the part of the user, for example to provide therapy to counter the effects of stress, anxiety, pain, depression or addiction disorders, or other psychiatric conditions. The apparatus may also be used for diagnostic purposes, for example identifying respiratory rate associated with a respiratory problem, or identifying heart rate characteristic associated with a heart-related problem.

Description

APPARATUS AND METHOD FOR DETERMINING, VISUALISING

OR MONITORING VITAL SIGNS

Field of the Invention

The present invention relates to apparatus and a method for determining and/or visualising and/or monitoring vital signs. It is particularly applicable, but by no means limited, to determining, visualising or monitoring one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of a human user. Embodiments of the invention are also particularly applicable, but by no means limited, to applications involving the self-awareness of a user, for example related to cognitive training.

The term "user" as used herein is intended to refer to the person whose breathing (or respiratory cycle more generally) is being determined and/or visualised and/or monitored. Whilst the present apparatus and method may be employed by the user, it should be appreciated that the apparatus and method may alternatively be provided to (or employed on) the user by someone else, such as a healthcare professional.

The methods described herein are typically performed ex vivo.

Background to the Invention

Dedicated equipment for determining and/or visualising and/or monitoring the vital signs of a user is generally available in hospitals, medical centres and the like. However, for a variety of purposes, there is a desire to be able to determine and/or visualise and/or monitor the breathing of a user elsewhere, away from hospitals, medical centres and the like, in places where dedicated equipment is unavailable.

For example, a user may wish to determine, visualise and/or monitor his or her own respiratory cycle at home or elsewhere (e.g. after a period of exercise), to determine, visualise and/or monitor his or her breathing rate, and how this tracks changes over time or under different or changing physiological and psychological states. This may be for diagnostic, therapeutic or research purposes, in order to check or monitor the regularity and pace of his or her breathing (e.g. if irregularities are suspected), or simply for the sake of curiosity or amusement. The user may also wish to determine, visualise and/or monitor his or her heart rate, or the variability of the heart rate. Again, this may be for diagnostic purposes (e.g. if irregularities are suspected), or simply for the sake of curiosity or amusement. A healthcare professional may also wish to carry out such determining, visualising or monitoring in respect of a person's respiratory cycle or heart rate, away from a hospital, medical centre and the like - for example to carry out an assessment or diagnosis in an emergency situation at the person's home, or elsewhere, where conventional specialist equipment is unavailable.

Other reasons for which the user may wish to visualise or determine their respiratory cycle and heart rate, and for which the present work is particularly applicable, relate to therapeutic applications. For example, through visualising in real-time a user's own respiratory cycle, and thereby getting the user to concentrate on their own breathing, "respiratory interoception", the user may achieve stress relief, achieve relaxation, induce and improve sleep and enhance well-being and so on.

Such benefits can realised by engendering a state of moment-by-moment attention and concentration on their own breathing, engendering qualities of "mindfulness". This has been a common cognitive training method for humans over the last two millennia, and is considered to be beneficial to those suffering from stress, anxiety, sleep problems, increased impulsivity, pain, depression or addiction disorders, and other psychiatric conditions. Further, for people not suffering from such conditions, achieving a state of mindfulness is considered to be beneficial for improving, for example, one or more of their mental resilience, ability to concentrate, and memory.

There is therefore a desire to help a user to concentrate on his or her own breathing, in order to help the user achieve a state of mindfulness. To this end, there is also a desire to provide objective feedback to the user to indicate whether they are concentrating on their breathing, and to provide an objective measure of the extent to which they are concentrating on their breathing - and when their mind is not focused and wandering. Background art is provided in WO 2009/097548 A1 , which discloses an apparatus, system and method for non-contact monitoring of respiratory and/or cardiac functions that is used to provide biofeedback to a monitored subject. Examples of the non- contact techniques disclosed include the use of radiated energy (e.g. ultrasonic, radio frequency, infrared, laser, etc.) to identify cardiac and respiratory waveforms. Accordingly, specialist apparatus is required, and safety precautions (e.g. in respect of the use of lasers) may need to be taken.

Further general background art is provided in a Master of Science thesis by Vikram Chandrasekaran of the University of North Texas, entitled "Measuring Vital Signs Using Smart Phones" (available at:

http://digital.library.unt.edU/ark:/67531/metadc33139/m2/1/high_res_d/thesis.pdf).

Summary of the Invention

According to a first aspect of the invention there is provided apparatus for visualising, in real time, the respiratory cycle of a user, the apparatus comprising an accelerometer, a processor and display means; wherein the accelerometer is contained within a housing and configured to generate, in use, when the housing is placed in contact with the user's body, a signal in response to motion of the user's body due to respiration; and the processor is configured to receive the signal from the accelerometer, to process the signal, and to cause the display means to display, in real time, a visual representation of the user's respiratory cycle. For example, this visual representation may be scaled in a manner easily interpretable by humans, for example to show a whole recent respiratory cycle, or a predetermined number of recent respiratory cycles.

The term "processor" as used herein should be interpreted broadly, to encompass a general purpose processor, the processor of an application specific integrated circuit, a microprocessor, a digital signal processor, a controller, a microcontroller, a state machine, and so on. The term "processor" may also refer to a plurality of such processing devices in combination.

The term "display means" as used herein should be interpreted broadly, to encompass any means capable of displaying a visual representation of the user's respiratory cycle (or other vital signs, as discussed below). Thus, the term "display means" not only encompasses high resolution liquid crystal displays and the like, that are capable of displaying graphical images, but alternatively (if adequate for the application in question) could be provided simply by a light emitting diode (LED) or an array of LEDs, and so on.

The term "real-time" as used herein should be interpreted broadly, to allow, if necessary, a short period (e.g. a few seconds or thereabouts, such as 0.5, 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, or 30 or more seconds) of inherent latency "constraints" in acquiring sufficient accelerometer data to provide an accurate analysis of breathing cycles, as those skilled in the art will appreciate. The duration of the latency period may be variable, dependent on the respiratory rate, as those skilled in the art will also appreciate. Such an interpretation is consistent with analogous "real-time" cognitive assessment systems using functional magnetic resonance imaging (fMRI) scanners, which similarly have a few seconds latency and are also termed "real-time".

The term "visual representation" as used herein should also be interpreted broadly, to encompass not only a graphical substantially-sinusoidal waveform that corresponds to the cyclical motion of the user's body due to respiration, but also simpler visual indications. For example, one or more light emitting diodes, lamps, display icons, graphical/artistic characters, etc. that illuminate and subsequently go off, or move, in such a manner as to represent the cyclical nature of the user's respiration, may be used. One such example would be a moving graphical/artistic character, such as a flying bird, whose motion corresponds to the cyclical motion of the user's body due to respiration.

Through using the accelerometer and processing the signal generated by the accelerometer, such apparatus provides a way of visualising the respiratory cycle of a user, that may advantageously be used as an alternative to conventional hospital or medical centre equipment for respiratory or cardiac monitoring.

According to certain embodiments, the processor is further configured to determine the user's respiratory rate, based on the signal received from the accelerometer. Thus, a quantitative measure (e.g. numerical) of the user's respiratory rate may be obtained (e.g. by the user or a healthcare professional). In some embodiments, the quantitative measure of the user's respiratory rate is for diagnostic purposes.

The processor may be further configured to cause the display means to display the user's respiratory rate. Moreover, the processor may be configured to cause the display means to display the user's respiratory rate in real time, thereby providing the user (or healthcare professional, for example) with the quantitative information in a substantially-immediate, substantially-continuous manner, so that he or she can appreciate not only the respiratory rate at any given moment, but also how the rate changes over time.

In addition to (or instead of) respiratory rate, the processor may be configured to determine the depth of breathing of the user, based on the signal received from the accelerometer. For example, a measure of the user's depth of breathing can be obtained by functions of the amplitude of the waveform. This depth of breathing may hence serve as a proxy measure of traditional measurements of 'tidal volume' in conventional pulmonary function tests. The processor may be configured to cause the display means to display a measure of the depth of breathing of the user, e.g. in real time.

The processor may be configured to determine the regularity of the user's breathing, based on the signal received from the accelerometer. The processor may be configured to cause the display means to display a measure of the regularity of the user's breathing, e.g. in real time.

The processor may be configured to cause the visual representation of the user's respiratory cycle to be displayed as a graphical waveform in real time. This is particularly beneficial for helping the user to concentrate on his or her own breathing by aiding intuitive visual learning, motivation and engagement.

The processor may be further configured to identify substantially periodic deflections of relatively small amplitude within the signal received from the accelerometer, and to use the time period between such deflections to determine the heart rate of the user. Thus, by virtue of the accelerometer signal providing both respiratory information and heart rate information, the heart rate may advantageously be determined without the use of a separate heart rate sensor. The determined heart rate may be used, for example, for diagnostic, prognostic or research purposes. The processor may be further configured to cause the display means to display a visual representation of the user's heart rate, e.g. in real time. The visual representation of the user's heart rate may for example be a quantitative measure (e.g. a number of beats per minute) or a graphical representation (e.g. a flashing or moving image or symbol) or even simply a flashing light (e.g. LED).

More particularly with respect to heart rate, according to a second aspect of the invention there is provided apparatus for determining the heart rate of a user, the apparatus comprising an accelerometer and a processor; wherein the accelerometer is contained within a housing and configured to generate, in use, when the housing is placed in contact with the user's body, a signal in response to motion of the user's body; and the processor is configured to receive the signal from the accelerometer, to process the signal and identify substantially periodic deflections of relatively small amplitude within the signal, and to use the time period between such deflections to determine the user's heart rate.

The processor may be further configured to cause display means to display a visual representation of the user's heart rate, e.g. in real time. The visual representation of the user's heart rate may for example be a quantitative measure (e.g. a number of beats per minute) or a graphical representation (e.g. a flashing or moving image or symbol) or even simply a flashing light (e.g. LED).

With both the first and second aspects of the invention, the processor may for example be configured to perform waveform analysis in the frequency domain, on the signal received from the accelerometer, in order to identify the substantially periodic deflections of relatively small amplitude. In effect, such analysis in the frequency domain advantageously enables both the frequency of the respiratory rate and the frequency of the heart rate to be extracted from the accelerometer signal. The processor may be further configured to determine a measure of the variability of the user's heart rate, by evaluating temporal dispersion between successive determinations of the user's heart rate. This measure of the variability of the user's heart rate may be used, for example, for diagnostic, prognostic or research purposes.

The processor may be further configured to cause the visual display to display the measure of the variability of the user's heart rate, e.g. in real time. This measure may be displayed quantitatively or by using some kind of graphical representation. The processor may be further configured to calculate and output (e.g. to the user, or to a healthcare professional), after a plurality of respiratory cycles, average readings of one or more of the user's respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability as determined during the said plurality of respiratory cycles. This information may then be used, for example, for diagnostic, prognostic or research purposes. For example, heart rate variability may be used as an indicator of whether the user has a relatively stressful or chaotic lifestyle. In turn, this can be used as an indicator as to whether the user would be likely to be able to stop smoking, for example. According to presently-preferred embodiments, the apparatus further comprises a user interface operable to receive instances of user input during use of the accelerometer as described above. The user interface may be, for example, responsive to touch operations, or button presses or such like. Alternatively, the user interface may be responsive to speech/sound or non-contact gesture input, so as not to risk subjecting the accelerometer to undesirable vibrations arising from physical contact between the user and the user interface, which could in some cases affect the sensitivity of the accelerometer in respect of the user's respiratory cycle (although it should nevertheless be noted that embodiments which use a touch-based user interface have been found to work entirely satisfactorily). Further, across a plurality of breaths or heartbeats, the processor is further configured to: determine, in accordance with a response rule, a plurality of timepoints when instances of user input are to be expected; receive instances of user input via the user interface; and determine, in respect of each instance of received user input, whether the user input is synchronised with a timepoint at which an instance of user input is to be expected. The term "synchronised" in this context should be interpreted broadly, to encompass a situation in which instances of user input are offset by a substantially consistent period (which may be either positive or negative) relative to the expected times, as well as a situation in which instances of user input substantially coincide with the expected times.

Such a determination as to whether the instances of user input substantially coincide with the expected times can be used as a way of helping or encouraging the user to concentrate on his or her own breathing or heartbeat, for example for therapeutic purposes. In particular, such a technique may be used for the purpose of engendering a state of high interoceptive concentration or mindfulness on the part of the user.

More generally, according to a third aspect of the invention there is provided apparatus for generating data related to the self-awareness of a user, the apparatus comprising an accelerometer, a processor and a user interface; wherein the accelerometer is contained within a housing and configured to generate, in use, when the housing is placed in contact with the user's body, a signal in response to motion of the user's body due to respiration; the user interface is operable to receive instances of user input; and the processor is configured to: receive the signal from the accelerometer and process the signal to determine waveform data representative of the user's respiratory cycle, determine, in accordance with a response rule, a plurality of timepoints relative to the user's respiratory cycle when instances of user input are to be expected; receive instances of user input via the user interface; and determine, in respect of each instance of received user input, whether the user input is synchronised with a timepoint at which an instance of user input is to be expected.

In relation to all of the above aspects and embodiments, the processor may be further configured to divide the user's respiratory cycle into temporal segments and, in determining in respect of each instance of received user input whether the user input is synchronised with a timepoint at which an instance of user input is to be expected, the processor may be configured to determine whether the received instance of user input is within the temporal segment for which the instance of user input is to be expected.

The processor may be further configured to provide output to the user, in response to each instance of user input, the output being in dependence on the result of determining whether the user input is synchronised with a timepoint at which an instance of user input is to be expected. Providing feedback to the user in such a manner helps the user to maintain concentration on his or her own breathing or heart beat by providing rapid and repeated feedback to reinforce learning over an extended period of time, and thereby accelerates the learning and acquisition of mindfulness skills on the part of the user. In some embodiments, accelerated learning and acquisition of mindfulness is particularly advantageous for therapeutic purposes. In some embodiments, accelerated learning and acquisition of mindfulness is for non- therapeutic purposes.

Further, the processor may be configured to provide output (e.g. to the user, or to a healthcare professional), after a plurality of respiratory cycles, in respect of the proportion of instances of user input which were synchronised with timepoints at which instances of user input were expected - thereby providing a quantitative measure of the degree of concentration or mindfulness of the user during the plurality of respiratory cycles. Such a quantitative measure may subsequently be used by a healthcare professional to diagnose a mental condition, such as anxiety or panic attacks, or may be used by the user as a measure of a component of mindfulness he or she reached (e.g. as part of a therapeutic exercise), or simply for the purpose of amusement or interest. For example, the user may be deemed to have sufficiently concentrated, or to have achieved a state of mindfulness, if said proportion of instances is greater than or equal to 0.6, or greater than or equal to 0.7, or greater than or equal to 0.8, or greater than or equal to 0.9. According to a fourth aspect of the invention there is provided apparatus for monitoring one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of a user, the apparatus comprising an accelerometer and a processor; wherein the accelerometer is contained within a housing and configured to generate, in use, when the housing is placed in contact with the user's body, a signal in response to motion of the user's body due to respiration; and the processor is configured to: receive the signal from the accelerometer and process the signal to determine a value representative of one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of the user; and issue a notification if the determined value reaches a threshold. As those skilled in the art will appreciate, in some cases the threshold in question may be reached as a result of an increase in the determined value, whereas in other cases the threshold may be reached as a result of a decrease in the determined value. Such a notification may be sent in the form of an alert message, e.g. by short message service (SMS) or other wireless means, to a healthcare professional, and may be used to provide an "early warning" indication of a deterioration in one or more of the user's clinical condition or vital signs (such as, for example, their respiratory rate). Alternatively, the notification could be sounding an alarm to alert a nearby person.

In certain embodiments the processor may be configured to issue a first notification if the determined value reaches a first threshold, and a second notification if the determined value reaches a second threshold. For example, the first and second notifications may be sent to different people, or to different categories or people. For example, in a hospital context, the user reaching the first threshold may indicate a moderately serious problem, and consequently the first notification may be sent to a nurse, whereas reaching the second threshold may indicate a more severe problem, and consequently the second notification may be sent to a doctor. Additional thresholds and corresponding notifications may also be provided. For example, reaching a third threshold may indicate an extremely serious problem, and consequently a third notification may be sent to an emergency response/resuscitation team.

According to presently-preferred embodiments, the apparatus is a mobile device of unitary form. Further, the user interface may be integrated with the visual display, as a touch screen. In such a manner, the apparatus may be a suitably-programmed mobile phone (e.g. a smart phone) or tablet device. This provides the advantage that the physical hardware needed for implementing an embodiment of the present invention is readily available, subject to being programmed with appropriate software to cause the processor to function as described above.

However, variants in which the display means is provided in or on a separate housing from that of the accelerometer, or in which the user interface is provided in or on a separate housing from that of the accelerometer, are also possible.

According to a fifth aspect of the invention there is provided a method for visualising, in real time, the respiratory cycle of a user, the method being performed by a processor that is coupled to an accelerometer, the accelerometer being within a housing that is in contact with the user's body, the method comprising: receiving a signal generated by the accelerometer in response to motion of the user's body due to respiration; processing the signal; and causing display means to display in real time a graphical representation of the user's respiratory cycle. The user's respiratory rate, depth of breathing, regularity of breathing, heart rate, and variability of the heart rate, may also be determined, visualised, or monitored as mentioned above.

According to a sixth aspect of the invention there is provided a method for determining the heart rate of a user, the method being performed by a processor that is coupled to an accelerometer, the accelerometer being within a housing that is in contact with the user's body, the method comprising: receiving a signal generated by the accelerometer in response to motion of the user's body; processing the signal and identifying substantially periodic deflections of relatively small amplitude within the signal; and using the time period between such deflections to determine the user's heart rate.

The method of the fifth or sixth aspects may further comprise calculating and outputting, after a plurality of respiratory cycles (for plausible consistency and artefact removal), average readings of one or more of the user's respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability as determined during the said plurality of respiratory cycles.

The method may further comprise: determining, in accordance with a response rule, a plurality of timepoints when instances of user input are to be expected; receiving, via a user interface, instances of user input (e.g. touch operations, or button presses or such like) across a plurality of breaths or heartbeats; and determining, in respect of each instance of received user input, whether the user input is synchronised with a timepoint at which an instance of user input is to be expected.

According to a seventh aspect of the invention there is provided a method for generating data related to the self-awareness of a user, the method being performed by a processor that is coupled to an accelerometer and a user interface, the accelerometer being within a housing that is in contact with the user's body, the method comprising: receiving a signal generated by the accelerometer in response to motion of the user's body due to respiration; processing the signal to determine waveform data representative of the user's respiratory cycle; determining, in accordance with a response rule, a plurality of timepoints relative to the user's respiratory cycle when instances of user input are to be expected; receiving instances of user input via the user interface; and determining, in respect of each instance of received user input, whether the user input is synchronised with a timepoint at which an instance of user input is to be expected.

In relation to the sixth or seventh aspect, the method may further comprise dividing the user's respiratory cycle into temporal segments; and, in determining in respect of each instance of received user input whether the user input is synchronised with a timepoint at which an instance of user input is to be expected, the method may comprise determining whether the received instance of user input is within the temporal segment for which the instance of user input is to be expected.

The method may further comprise providing feedback output to the user, in response to each instance of user input, the output being in dependence on the result of determining whether the user input is synchronised with a timepoint at which an instance of user input is to be expected.

The method may further comprise, after a plurality of respiratory cycles, providing output (e.g. to the user, or to a healthcare professional) in respect of the proportion of instances of user input which were synchronised with the timepoints at which instances of user input were expected. Such a proportion may be defined, for example, by:

b— a

P =

total number of breaths where b is the number of breaths the user is deemed to have concentrated on (i.e. the number of breaths with time-appropriate responses), and a is the number of breaths the user is deemed not to have concentrated on (i.e. the number of breaths with time- inappropriate responses).

According to an eighth aspect of the invention there is provided a method for monitoring one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of a user, the method being performed by a processor that is coupled to an accelerometer, the accelerometer being within a housing that is in contact with the user's body, the method comprising: receiving a signal generated by the accelerometer in response to motion of the user's body due to respiration; processing the signal to determine a value representative of one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of the user; and issuing a notification if the determined value reaches a threshold. As discussed above, the method may further comprise issuing a first notification if the determined value reaches a first threshold (e.g. to indicate a moderately serious problem), and a second notification if the determined value reaches a second threshold (e.g. to indicate a more severe problem). The present method and apparatus may be for use in therapy or diagnosis. The term "therapy" as used herein should be interpreted broadly, in that it need not fully cure the condition or ailment in question, but may alleviate at least some of the symptoms of said condition or ailment.

The therapy may comprise engendering a state of mindfulness on the part of the user, for example to counter the effects of stress, anxiety, pain, depression or addiction disorders. Diagnosis may comprise identifying whether the user is in a state of mindfulness, based on the instances of user input received via the user interface, and following an evaluation of, for example, the proportion of instances of user input which were time- appropriate to the user's respiratory cycle, as discussed above - i.e. quantifying interoceptive performance associated with mindfulness.

Alternatively, diagnosis may comprise identifying respiratory rate associated with a respiratory problem, or identifying heart rate characteristic associated with a heart- related problem. Such diagnosis may be performed by comparing the measurements obtained (e.g. the above-mentioned quantitative measure of mindfulness, and/or the measured respiratory rate, and/or the measured depth of breathing, and/or the measured regularity of breathing, and/or the measured heart rate, and/or the measured heart rate variability) with one or more corresponding reference values. Such reference values may have been obtained from the user himself/herself, for example when resting or in a normal/healthy condition, or alternatively the reference values may be in respect of a population average (e.g. derived from a population whose age, weight and gender correspond to, or are similar to, those of the user). The respiratory problem may be one or more of: respiratory arrest, respiratory depression/failure, asthma, bronchitis, shortness of breath, apnoea (which is typically characterised by a period of suspended breathing followed by a pronounced intake of breath), emphysema, and chronic obstructive pulmonary disease. For example, the present method and apparatus may be used to detect and monitor apnoeic episodes associated with obstructive sleep apnoea, or respiratory depression due to the effects of drugs or sedation, or to monitor against sudden infant death syndrome (so-called "cot death").

The heart rate characteristic may be an elevated rate, a reduced rate, or an irregular rate.

The heart-related problem may be one or more of: arrhythmia, atrial fibrillation, atrial flutter, sick sinus syndrome, tachycardia, ventricular fibrillation, premature contractions, long QT syndrome, heart block, syncope, myocardial infarction, heart failure, and heart valve problems.

Dependent on the diagnosis, the method may further comprise recommending or administering treatment (e.g. medication) to the user, or recommending a change in lifestyle to the user.

The present method is by no means limited to diagnostic or therapeutic applications. For example, for "healthy" people it may be beneficial for improving one or more of their stress-levels, relaxation, mental resilience, ability to concentrate, or memory, or simply to promote a state of relaxation. Thus, in some embodiments, the apparatus, methods and uses of the invention are not therapeutic. In some embodiments, the apparatus, methods and uses of the invention are not diagnostic. According to a further aspect of the invention there is provided a computer program or set of instruction code which, when executed by a processor of an apparatus (e.g. a mobile device) having an accelerometer, causes the apparatus to become configured as the apparatus in accordance with the first, second, third or fourth aspect of the invention, or causes the processor to perform the method in accordance with the fifth, sixth, seventh or eighth aspect of the invention. Such a computer program or set of instruction code may, for example, be provided as a software application or "app" that may be downloaded from a remote server onto a mobile device via a network (e.g. the Internet). As those skilled in the art will appreciate, other ways of transferring a computer program or set of instruction code to such apparatus are of course possible, such as by using a direct cable connection or a portable data carrier of some form (e.g. a memory card or memory stick).

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, and with reference to the drawings in which:

Figure 1 illustrates a first embodiment of an accelerometer-based real-time feedback system responsive to breathing, incorporating a wired connection between the units; Figure 2 illustrates a variant of the embodiment of Figure 1 , incorporating wireless communication between the units;

Figure 3 illustrates a second embodiment of an accelerometer-based real-time feedback system responsive to breathing, incorporating wired connections between the units;

Figure 4 illustrates a variant of the embodiment of Figure 3, incorporating wireless communication between the units;

Figure 5 illustrates a third embodiment of an accelerometer-based real-time feedback system responsive to breathing, in this case being a unitary (single-unit) device;

Figure 6 illustrates a fourth embodiment of an accelerometer-based real-time feedback system responsive to breathing, in this case being an appropriately- programmed handheld device such as a "smart phone" having a built-in accelerometer;

Figure 7 illustrates an accelerometer-based device such as that of Figure 6 in use by a human subject in a recumbent position, with the device placed on their abdomen;

Figure 8 illustrates an accelerometer-based device such as that of Figure 6 receiving user input at certain times during the user's respiratory cycle;

Figure 9 illustrates a display screenshot showing a smoothed accelerometer waveform and the remaining time in respect of a certain breathing exercise;

Figure 10 illustrates diagrammatic waveform modelling of the respiratory cycle;

Figure 1 1 illustrates sample raw sinusoidal accelerometer-based waveform data generated from a human subject;

Figure 12 illustrates use of the accelerometer-based waveform data to obtain heart rate and heart rate variability measurements;

Figure 13 is a diagrammatic representation of how an embodiment of an Interoceptive Concentration Training System cyclically measures attention to provide real-time feedback, and also concentration metrics, and also the effect of a distractor on the user's ability to provide interoceptive attention;

Figure 14 shows diagrammatic representations of different performances of a user using an Interoception Concentration Training System, in which the response mode is specified to require user input during every peak inhalation; Figure 15 is an operational flow diagram in respect of a real-time feedback Interoceptive Concentration Training System;

Figure 16 presents results obtained from users using the Interoceptive Concentration Training System for 20.0 minutes; and

Figure 17 illustrates a method for Accelerometer-Enhanced Mindfulness

Training, in accordance with the present work.

In the figures, like elements are indicated by like reference numerals throughout. Detailed Description of Preferred Embodiments

Example systems

Overview of example systems

The present work provides a number of embodiments of accelerometer-based realtime feedback systems, wherein the accelerometer is responsive to the motion of a user's body due to respiration. In each case the system includes a unit containing an accelerometer. In use, the user places the accelerometer-containing unit in a position where changes in the pitch (i.e. angle of inclination) of the unit during - and due to - respiration are detectible by the accelerometer. For example, the user may adopt a reclined/recumbent position, with the accelerometer rested on or close to the user's waist or umbilicus. The user may remain clothed, with the accelerometer placed on the outside of his or her clothing. In use, a processor is configured to receive a signal (which may be either analogue or digital) generated by the accelerometer representative of changes in the pitch of the accelerometer-containing unit due to the user's breathing. The processor processes this signal and causes display means to display, in real time, a visual representation of the user's respiratory cycle.

The processor may also cause the respiratory rate to be determined and displayed in real time. Additionally, or alternatively, the signal obtained from the accelerometer may be processed to determine the user's heart rate, from which a measure of the variability of the heart rate may also be determined. The processor may also cause the heart rate, and/or the measure of the variability of the heart rate, to be determined and displayed in real time.

Each of the presently-preferred systems also includes a user interface of some kind, comprising one or more buttons or other touch input means. In use, user input from the user interface is received and processed by the processor. In certain operational modes the user is required to provide touch input to the user interface in a manner that is in synchronicity with a specific time, or certain specific times, during the user's respiratory cycle. Examples of such operational modes are discussed in greater below. By causing the user to concentrate on his breathing and to provide touch input to the user interface in this manner, this provides the user with "Interoceptive Attentional Training" or "Interoceptive Concentration Training" - an important component of so-called "mindfulness therapies", which may be used, for example, to provide therapy to the user to counter the effects of stress, anxiety, pain, depression or addiction disorders, or other psychiatric conditions. In accordance with one presently-preferred embodiment, an accelerometer-based real-time feedback system may be provided by a pre-existing handheld device such as a "smart phone" or tablet device having a built-in accelerometer, but programmed with new control software. However, in accordance with other embodiments a number of alternative multi-unit and single-unit function-specific systems may be provided, i.e. that comprise new hardware and are specifically configured for the present purpose. Such systems will first be described. Multi-unit systems

Figure 1 illustrates a first embodiment of an accelerometer-based real-time feedback system 1 responsive to breathing. The system 1 includes an accelerometer- containing unit 10 that comprises an accelerometer 12, a user interface 18, memory 14 and a processor 16. The processor 16 is in data communication with the accelerometer 12, memory 14 and user interface 18, and is configured to supply an output signal to a visual display unit 20 which is connected to the accelerometer- containing unit 10 via port 13 and a cable 26. In use, the accelerometer-containing unit 10 is rested on or close to a user's waist or umbilicus, with the user in a reclined/recumbent position, such that changes in the pitch of the unit 10 during respiration are detectible by the accelerometer 12. The processor 16 is configured to receive data generated by the accelerometer 12, representative of changes in the pitch of the unit 10 due to the user's breathing, and to process that data to generate real-time data representative of the user's respiratory cycle.

The visual display unit 20 comprises a display screen 22 on which, in real time, a graphical representation 24 of the user's respiratory cycle is displayed, under the control of the processor 16, using the data obtained from the accelerometer 12. As mentioned above, one or more physiological measurements derived from the signal generated by the accelerometer 12 may also be displayed on the display screen 22.

The user interface 18 comprises one or more buttons or other touch input means. In use, user input from the user interface 18 is received and processed by the processor 18. Examples of operational modes, in which the user is required to provide touch input to the user interface 18 in a manner that is in synchronicity with a specific time or certain specific times during the user's respiratory cycle, are discussed in greater detail below.

Figure 2 illustrates a variant of the embodiment of Figure 1 , incorporating wireless communication between the units. In the variant system 2 as illustrated, the accelerometer-containing unit 10 (including user interface 18), and its manner of operation, are substantially as described above in relation to Figure 1 , but with the unit 10 comprising a wireless transmitter 15 instead of cable port 13. The visual display unit 20 is also substantially as described above in relation to Figure 1 , but comprising a wireless receiver. The processor 16 of the accelerometer-containing unit 10 is configured to cause a wireless signal 27 to be sent from the wireless transmitter 15 to the visual display unit 20, to cause the visual display unit 20 to display a graphical representation 24 of the user's respiratory cycle, optionally together with one or more physiological measurements derived from the signal generated by the accelerometer 12, as mentioned above.

Figure 3 illustrates a second embodiment of an accelerometer-based real-time feedback system 3 responsive to breathing. The system 3 comprises a control unit

1 1 , a visual display unit 20, and an accelerometer 12 as a separate unit from the control unit 1 1. The control unit 11 comprises a user interface 18, a memory 14 and a processor 16. The processor 16 is in data communication with the memory 14 and user interface 18, and is configured to supply an output signal to the visual display unit 20 which is connected to the control unit 1 1 via port 13 and a cable 26. Similarly, the accelerometer 12 is connected to the control unit 1 1 via port 17 and a cable 28.

As with the embodiments described above, in use the accelerometer 12 is placed on or close to a user's waist or umbilicus (or alternatively may be attached/clipped to his or her clothing in such a position), with the user in a reclined/recumbent position, such that changes in the pitch of the accelerometer 12 are detectible by the accelerometer

12. The processor 16 is configured to receive data generated by the accelerometer 12, representative of changes in its pitch due to the user's breathing, to process that data to generate real-time data representative of the user's respiratory cycle, and to cause the visual display unit 20 to display a graphical representation 24 of the user's respiratory cycle, optionally together with one or more physiological measurements derived from the signal generated by the accelerometer 12, as mentioned above.

The visual display unit 20 is substantially as described above in relation to Figure 1. Similarly, the user interface 18 and its manner of operation are substantially as described above in relation to Figure 1 (apart from the user interface 18 being provided in a separate unit from the accelerometer 12).

Figure 4 illustrates a variant of the embodiment of Figure 3, incorporating wireless communication between the units. In the variant system 4 as illustrated, the accelerometer 12 and the control unit 1 1 , and their manner of operation, are substantially as described above in relation to Figure 3, but with the unit 1 1 comprising a wireless transmitter 15 instead of cable port 13, and a wireless receiver 19 instead of cable port 17. The visual display unit 20 is substantially as described above in relation to Figure 3, but comprising a wireless receiver. The accelerometer 12 is also substantially as described above in relation to Figure 3, but comprising a wireless transmitter. The control unit 1 1 is configured to receive a wireless signal 29 from the accelerometer 12 via wireless receiver 19. The processor 16 of the control unit 1 1 is configured to cause a wireless signal 27 to be sent from the wireless transmitter 15 to the visual display unit 20, to cause the visual display unit 20 to display a graphical representation 24 of the user's respiratory cycle, optionally together with one or more physiological measurements derived from the signal generated by the accelerometer 12, as mentioned above.

In the examples given in Figures 3 and 4, the processor 16 and memory 14 and contained within the same unit 1 1 as the user interface 18, whilst the accelerometer 12 is provided as a separate unit. However, as those skilled in the art will appreciate, in alternative embodiments the accelerometer 12 may be provided in the same unit as the processor 16 and memory 14, whilst the user interface 18 may be provided as a separate unit. A plurality of processors and memories, distributed throughout the various units, may also be employed, as those skilled in the art will also appreciate.

With those embodiments in which the accelerometer 16 is provided in a different unit from the user interface 18, the accelerometer 16 may be subjected to less interference (e.g. vibrations) when the user provides input (e.g. tapping) to the user interface 18. However, this is not critical to the successful operation of the present embodiments, and embodiments in which the accelerometer 16 is provided in the same unit as the user interface 18 also work entirely satisfactorily.

Single-unit system with user interface separate from the display screen

Figure 5 illustrates a third embodiment of an accelerometer-based real-time feedback system responsive to breathing. The system 5 is formed as a unitary (single-unit) device comprising an accelerometer 12, a user interface 18, a memory 14, a processor 16 and a display screen 22. The processor 16 is in data communication with the accelerometer 12, memory 14, user interface 18 and display screen 22. In use, the device 5 is rested on or close to a user's waist or umbilicus, with the user in a reclined/recumbent position, such that changes in the pitch of the device 5 during respiration are detectible by the accelerometer 12. The processor 16 is configured to receive data generated by the accelerometer 12, representative of changes in the pitch of the device due to the user's breathing, to process that data to generate realtime data representative of the user's respiratory cycle, and to cause the display screen 22 to display a graphical representation 24 of the user's respiratory cycle. As mentioned above, one or more physiological measurements derived from the signal generated by the accelerometer 12 may also be displayed on the display screen 22.

The user interface 18 is separate from the display screen 22. The user interface 18 and its manner of operation are substantially as described above in relation to Figure 1.

Single-unit system with user interface integrated in the display screen (e.g. a "smart phone" or tablet device)

Figure 6 illustrates a fourth embodiment of an accelerometer-based real-time feedback system responsive to breathing. The system 30 is formed as a unitary (single-unit) device, comprising an accelerometer 12, a memory 14, a processor 16 and a display screen 32 having an integral touch-sensitive user interface (i.e. a touch screen). The processor 16 is in data communication with the accelerometer 12, memory 14 and display screen/user interface 32. In use, the device 30 is rested on or close to a user's waist or umbilicus, with the user in a reclined/recumbent position, such that changes in the pitch of the device 30 during respiration are detectible by the accelerometer 12. The processor 16 is configured to receive data generated by the accelerometer 12, representative of changes in the pitch of the device due to the user's breathing, to process that data to generate real-time data representative of the user's respiratory cycle, and to cause the display screen/user interface 32 to display a graphical representation 24 of the user's respiratory cycle. As mentioned above, one or more physiological measurements derived from the signal generated by the accelerometer 12 may also be displayed on the display screen/user interface 32. The manner of user interaction with the user interface aspect of the display screen is substantially as described above in relation to Figure 1 , and is also described in greater detail below. As with all the above-described embodiments, examples of operational modes, in which the user is required to provide touch input to the user interface in a manner that is in synchronicity with a specific time or certain specific times during the user's respiratory cycle, are discussed in greater detail below.

The device 30 may be a suitably-programmed pre-existing mobile handheld device such as a smart phone or tablet device, taking advantage of the device's built-in accelerometer 12 and integral display screen/user interface 32. The program (or set of instruction code) executed by the device 30 may, for example, be provided as a software application or "app" that is downloaded from a remote server onto the device 30 via a network (e.g. the Internet).

Operational details

The following operational details will primarily be described in relation to the above- described fourth embodiment (being a suitably-programmed mobile device 30 such as a smart phone or table device) functioning as an Interoceptive Concentration Training System, although those skilled in the art will appreciate that the operational details may readily be applied or adapted to any of the embodiments described herein.

Device placement

As shown in Figure 7, the mobile device 30 (containing an accelerometer) is placed in a position on the upper body of the user 34 where pitch changes during - and due to - respiration of the user 34 are detectible by the accelerometer. For example, the user 34 may adopt a reclined/recumbent position, with the device (accelerometer) 30 close to the user's waist or umbilicus. A position just underneath the ribs is preferable, where the device (accelerometer) 30 tilts the most during inhalation and exhalation. The user should keep the device 30 in that position for the duration of the exercise.

As shown in Figure 8, if user input is required at certain times during the user's respiratory cycle, e.g. for the purposes of mindfulness therapy, then the user may position one or more fingers 36, 37 close to (or lightly on) the touch screen 32 of the device 30, to lightly tap on the touch screen 32 at the times as required by the exercise. Response mode specification

The subject (i.e. user) or a healthcare professional chooses a response mode to determine the specific time or times during the respiratory cycle which require attentional assessment and user input (e.g. touching on the touch screen 32), such as at the point of maximum inhalation during each breath. Requiring such input from the user encourages the user to concentrate on his or her breathing, and can thereby help to engender a state of state of mindfulness on the part of the user.

Depending on the response mode chosen, the processor applies a corresponding response rule, to determine whether each received instance of user input is synchronised with a timepoint at which user input is to be expected in accordance with the response rule, and to provide objective feedback to the user at each instance of user input, and at the end of the exercise. The time duration of an initial practice phase, and whether feedback sounds are generated, may also be specified.

In certain embodiments, various alternative response modes (having corresponding response rules used by the processor) can be provided for use. These may include specifying different response patterns required from users. Such response patterns could include responses on consecutive breaths, or on alternate breaths, or on breaths increasing in separation (e.g. every 1 st, 2nd, 4th, 8th breath, etc.).

In addition, response patterns could specify different user inputs to indicate different respiratory phases such as a two-finger touch-screen tap for every other breath and a single-tap for every breath. Or an alternative input could be used to indicate user awareness of a previously incorrect or absent response - to indicate their meta- awareness of mind-wandering. Different combinations of these different response patterns could be used.

Further permutations include the absence of any user input during breathing, with the device simply serving as a vital sign monitoring or recording device or a training timer. In alternative embodiments intended to engender a state of mindfulness, the user may be required to provide user input (e.g. tapping on the touch screen) synchronised with their heartbeat, or a response pattern based on their heartbeat, rather than their breathing.

Instructions

In a typical exercise the subject (i.e. user) is instructed to direct their attention to breathing-related sensations and to provide user input (e.g. via screen tapping or button pressing) at specific times during their respiratory cycle according to the specified response mode above. With reference to Figure 9, the overall exercise may comprise one or more phases or levels (38), each of which may last for a predetermined length of time. An indication of the time remaining in any given phase may be provided on the display screen 32 (e.g. in the form of a countdown timer 39). Real-time respiratory and cardiac waveform display

The user starts the system and, as shown in Figure 10, cyclical abdominal movements associated with respiration are uniquely exploited using the accelerometer. A single-plane input is selected from the accelerometer to generate a real-time substantially sinusoidal waveform: During inhalation, the abdomen expands causing the pole of the device nearest the user's feet to be changed in position relative to the pole of the device nearest the user's head. During exhalation, the abdomen falls and the reverse pitch change occurs.

The evolving waveform is displayed on the screen (e.g. as shown in Figure 1 1 ) and continually re-scaled in real time to fill the screen to account for individual differences in the magnitude of accelerometer pitch changes during breathing.

Respiratory rate, heart rate and heart-rate variability measurements may also be generated and displayed on the screen in real time.

With regard to heart rate and heart-rate variability measurements, and with reference to Figure 12, since the accelerometer is placed on the abdomen, transmitted arterial pulsations are detectible by the accelerometer as minor pitch deflections (highlighted in circles for illustration purposes) superimposed on the larger respiratory cycle deflections. Both heart rate and respiratory rate can be derived by temporal calculations of successive respiratory cycles and employing waveform analysis in the frequency domain (since the heart rate and respiratory rate are of different frequency). This involves decomposition of the waveform into component respiratory and cardiac waveforms that periodically recur and have characteristic shapes and amplitudes of deflection. Acceptable frequencies ranges are further constrained by physiologically plausible limits to increase reliability. For example, respiratory rate detection is constrained between e.g. 3-40 breaths per minute, whilst heart rate detection is constrained between e.g. 30 and 150 beats per minute.

A measure of heart rate variability can also be derived from the varying temporal dispersion between successive transmitted pulsations.

The detection of heart rate and heart-rate variability in the above-described manner is particularly suited to thin/non-obese subjects, for whom the motion of the body (minor pitch deflections) due to the heart beats can be more readily detected by an accelerometer.

Respiratory cycle modelling

With reference back to Figure 10, as the waveform emerges during breathing, the waveform is segmented algorithmically into the different respiratory phases (e.g. T₀- T₇). As those skilled in the art will appreciate, the use of these segments is, in effect, a form of quantisation, to determine whether user input (as discussed below) falls within the temporal segment (T₀-T₇) in which the user input is expected. The current respiratory phase of the breathing is detected in relation to preceding and subsequent waveform patterns. In order to most accurately determine what part of the respiratory cycle any one timepoint represents, adjacent, neighbouring points are also analysed and their amplitudes compared. This allows determination of the timepoint's relative position in terms of larger trends of deflections making up the respiratory cycle.

In one embodiment, a graphical indication may be added to the displayed respiratory waveform in real time to indicate when the user input is expected. Real-time feedback

Based on the response mode selected by the user previously, by applying a corresponding response rule the system will expect user responses (e.g. touch operations) to be received during certain phases of the respiratory cycle. Thus, when the user is concentrated on their breathing, the user provides a "time-appropriate" user input such as a screen-tap. Feedback is given to the user (e.g. through audio or vibrations) when their responses are time-appropriate to enable real-time learning reinforcement and accelerated skill acquisition. The user remains able to provide time-appropriate responses until mind-wandering or distraction occurs. When they fail to concentrate on their breath, this results in a time-inappropriate user input that was guessed by the user, or absence of any input because the user was inattentive and distracted and unable to use interoception to temporally guide their response. This is illustrated for example in Figures 13 and 14, in which the small dots superimposed on the waveforms represent instances of user input received across multiple respiratory cycles. Time-inappropriate responses trigger feedback to the user to also enable real-time learning reinforcement and accelerated acquisition of concentration skills.

In more detail, Figure 13 illustrates that, in an example of time-appropriate responses (outcome (b)), each instance of user input is correctly synchronised with a point of maximum inhalation, whereas in the examples of time-inappropriate responses (outcome (a)), the instances of user input are either random (upper waveform, indicating guessing and lack of concentration) or absent (indicating a lack of response when required, and again lack of concentration). Figure 13 also illustrates schematically the effect of a distractor in causing the user to transition from time- appropriate responses to time-inappropriate responses, and how the user may transition back from time-inappropriate responses to time-appropriate responses by focusing or refocusing their attention on their breathing.

Figure 14 shows some further examples of user input. In example (I), the user input exhibits perfect attention, with each instance of user input being correctly synchronised with a point of maximum inhalation (i.e. a breathing-response correlation). On the other hand, in example (II) the user input exhibits complete inattention, with the instances of user input falling at random times across the plurality of respiratory cycles (i.e. no breathing-response correlation, and only random, time- inappropriate responses). Example (III) illustrates the effect of a period of inattention, where a user whose inputs were initially synchronised with points of maximum inhalation becomes distracted or otherwise loses concentration for a few cycles (and thus there is a loss in breathing-response correlation), before the user regains concentration again and the breathing-response correlation is re-established. The final example in Figure 14 depicts a user who mostly exhibits inattention (i.e. absence of input), but who, for a while, achieves a period of attention (i.e. a gain of breathing- response correlation). It should be noted that the associated respiratory phase of any single timepoint along the generated waveform is determined by analysing other preceding and subsequent timepoints. Hence, when using the system, there may be a short latency of a few seconds (less than a whole breath's duration) where future timepoints are sampled to confirm with greater accuracy what point in the respiratory cycle the original waveform timepoint related to.

Output measures

The system provides both cross-sectional (at a single timepoint during training) and longitudinal measures (measuring changes during a training session) of multiple psychophysiological measures. These measures comprise physiological indices (e.g. respiratory rate, proxies of respiratory tidal volume, heart rate, heart rate variability) and psychological indices (e.g. interoceptive accuracy [temporal latency between expected target response time and the actual response time], duration of sustained concentration (maximum length of time-appropriate responses), duration of mind- wandering (maximum length of time-appropriate responses)).

As shown in Figure 13, a "concentration metric" may be obtained in respect of the responses obtained from the user throughout the course of an exercise. More particularly, the concentration metric may be defined as a proportion P of the user's breaths in which the user provided input in synchronisation with his or her respiratory cycle, i.e. such that he or she was concentrating on his breathing. The proportion P may be defined as:

b— a

P =

total number of breaths where b is the number of breaths the user is deemed to have concentrated on (i.e. the number of breaths with time-appropriate responses), and a is the number of breaths the user is deemed not to have concentrated on (i.e. the number of breaths with time- inappropriate responses). The time-inappropriate responses may be due to the user guessing, or simply not providing a response when required, due to lack of concentration.

The proportion P provides a quantitative measure that may subsequently be used by a healthcare professional to diagnose a mental condition, or may be used by the user as a measure of the state of mindfulness he or she reached. For example, depending on the parameters of the exercise, the user may be deemed to have sufficiently concentrated, or to have achieved a state of mindfulness, if the said proportion P is greater than or equal to 0.6, or greater than or equal to 0.7, or greater than or equal to 0.8, or greater than or equal to 0.9.

Operation

Computing processes involved in the Interoceptive Concentration Training System when performing an exercise are shown in Figure 15. Taking (in step S1 ) a single- plane input from the accelerometer 12, the processor 16 creates (step S3) a waveform 24 for real-time display on the display screen 22. The waveform 24 is rescaled (step S3) in real time to fit the display screen 22, and optimal smoothing is applied to increase the signal to noise ratio. In step S4 the waveform 24 is analysed for component frequencies, from which the respiratory rate, heart rate and heart rate variability are determined, as mentioned above. One or more of the respiratory rate, heart rate and heart rate variability may be displayed in real time on the display screen 22. In step S5 the waveform 24 is labelled into different respiratory cycle phases (e.g. T₀- T₇ as discussed above).

In step S6, current timepoint analysis is performed, to determine whether touch input received (S7) from the user via the user interface is synchronised with the expected user input as determined (S8) by the processor by applying response rules corresponding to the user response mode that is in operation. If the touch input received from the user via the user interface is synchronised with the expected user input then, in step S9, real-time feedback of a positive nature is outputted to the user (e.g. playing a positive sound). However, if the touch input received from the user is not synchronised with the expected user input then, in step S10, real-time feedback of a negative nature is outputted to the user (e.g. playing a negative sound).

In step S1 1 a determination is made as to whether or not the duration of time for which the exercise lasts is complete. If it is not, then a subsequent timepoint is analysed (step S12) and the computing process continues. However, if the duration of time is complete then, in step S13, averaged physiological readings (e.g. respiratory rate, heart rate and heart rate variability) obtained for the duration of the training period may be displayed, and the exercise ends.

Example results

The effects (anxiolytic psychological benefits) of the present Interoceptive Concentration Training System on external subjects are shown in Figure 16. The graph includes n=14 data with healthy volunteers randomised to either 20 minutes utilising the Interoceptive Concentration Training System (n=7) as embodied by a suitably-programmed mobile device (for which the results are labelled "app"), or subjected to an alternative recreational control activity (listening to music). The graph shows that superior relaxation and stress reduction was demonstrated in the group utilising the Interoceptive Concentration Training System, compared to those who listened to music.

Accelerometer-Enhanced Mindfulness Training

Figure 17 illustrates a method for Accelerometer-Enhanced Mindfulness Training, in accordance with the present work, and which employs a number of the principles described above. This may be regarded as a method for determining and visualising mindful breathing. On the one hand, it enables determination of mindfulness present in successive breaths. On the other hand, it enables visualisation of mindful breathing (respiratory interoception) that can be used for the enhancement of mindfulness training. The method illustrated in Figure 17 can be used to enhance both training and research. More particularly, the method illustrated in Figure 17 depicts a method for determining effectiveness of mindful breathing by measuring the psychological and physiological results of training in real-time. It will of course be appreciated that, in practice, visualizations of the accelerometer data, user input data and mindfulness data need not be limited to the particular visualization shown in Figure 17, and can be varied as desired (e.g. to be displayed in multiple formats). In more detail, Figure 17 illustrates a series of waveforms 41a, 41 b, 41 c, 41d from successive breaths during a mindful breathing exercise, visually segmented and aligned contiguously (waveforms 41 a-41d being the first four breaths identified).

The broken line 42 denotes, for each breath, the mindful breath target response point, close to the point of peak inhalation, at which the user is required to tap their smartphone screen (or provide other user input) to demonstrate mindful breathing.

The shaded circles in the illustration denote (with the exception of the two darker- shaded circles that are exactly on the broken line 42) received instances of user input.

Circle 43 is an example of user input in respect of a mindful breath. Here, the screen- tap (or other user input) occurred near the point of peak inhalation, demonstrating appropriate concentration on the user's breathing. Circle 44 is an example of user input in respect of an unmindful breath. Here, the screen-tap (or other user input) is present but far from the point of peak inhalation, demonstrating inattention in respect of the user's breathing.

The two darker-shaded circles that are exactly on the broken line 42 denote points at which user input was absent or forgotten, again demonstrating inattention in respect of the user's breathing.

Arrow 45 indicates a measure of mindfulness precision in respect of the corresponding circle (i.e. instance of user input) at the beginning of said arrow. The temporal distance of the circle (instance of user input) from the peak (broken line 42) represents the user's respiratory interoceptive precision.

Waveform 46 shows transmitted abdominal heartbeat deflections which provide heart rate and heart rate variability physiology in real time.

Arrow 47 is a marker of respiratory tidal volume which can be determined in real time based on the magnitude of the accelerometer pitch changes during breathing. Finally, the broken double-headed arrow 48 denotes the temporal separation between successive waveform troughs, which may be used to generate respiratory rate data in real time. Alternatively, the temporal separation between successive waveform peaks may be used for the same purpose. It will therefore be understood that the present work provides a method of (and corresponding apparatus/system for) accelerometer-enhanced mindfulness training. That is, it uses an accelerometer to measure, feed back, and ultimately enhance, in real time, a much-needed health training intervention. Following on from this, it is to be noted that, whilst many parts of the present disclosure relate to specific physical aspects of the apparatus/system, in a more general sense the present work covers the use of accelerometers to measure, feed back, visualise or enhance meditation training (e.g. in respect of mindful breathing). Applications, including (but not limited to) therapy and diagnosis

Embodiments of the present method may be employed in any of the following (non- limiting) ways: (1 ) Obtaining a visualisation of the user's respiratory cycle and/or heart rate, without any user input (e.g. tapping) being provided, and without any quantitative output being given, may be used for amusement or interest, or to enable a user or healthcare professional to qualitatively assess the overall form, regularity and pace of the user's respiratory cycle and/or heart rate (e.g. for diagnostic purposes), or to help the user concentrate on his or her breathing or heart rate. The latter may have therapeutic benefits (e.g. to counter the effects of stress, anxiety, impulsive/compulsive disorders, post-traumatic stress disorder, pain, depression or addiction disorders, or other psychiatric conditions) and may lead the user to reach a state of mindfulness. In the absence of user input and corresponding feedback from the system, the likelihood of the user reaching a state of mindfulness is reduced. For a "healthy" user, helping them to concentrate on their breathing or heart rate may also be beneficial from the point of view of improving one or more of their mental resilience, ability to concentrate, or memory, or for achieving a state of relaxation.

(2) In addition to the examples given as (1) above, obtaining a quantitative output in respect of respiratory rate and/or depth of breathing and/or regularity of breathing and/or heart rate and/or variability of heart rate (either continuously and/or as average reading(s) at the end of an exercise) may be used for diagnostic or monitoring purposes. For example, this information may enable a healthcare professional to identify a respiratory rate characteristic associated with a respiratory problem, or to identify a heart rate characteristic associated with a heart-related problem. Such diagnosis may be performed by comparing the measurements obtained (e.g. the measured respiratory rate, and/or depth of breathing, and/or regularity of breathing, and/or the measured heart rate, and/or the measured heart rate variability) with one or more corresponding reference values. The reference values may have been obtained from the user himself/herself, for example when resting or in a normal/healthy condition, or alternatively the reference values may be in respect of a population average (e.g. derived from a population whose age, weight and gender correspond to, or are similar to, those of the user).

The respiratory problem may be, for example, one or more of: respiratory arrest, respiratory depression/failure, asthma, bronchitis, shortness of breath, apnoea, emphysema, and chronic obstructive pulmonary disease. Apnoeic episodes associated with obstructive sleep apnoea, or respiratory depression due to the effects of drugs or sedation, may be detected.

The heart rate characteristic may be an elevated rate, a reduced rate, or an irregular rate. The heart-related problem may be one or more of: arrhythmia, atrial fibrillation, atrial flutter, sick sinus syndrome, tachycardia, ventricular fibrillation, premature contractions, long QT syndrome, heart block, syncope, myocardial infarction, heart failure, and heart valve problems. Dependent on the condition diagnosed by the present method, the method may further comprise recommending or administering treatment (e.g. medication or therapy) to the user, or recommending a change in lifestyle to the user.

(3) In addition to the examples given as (1 ) and (2) above, enabling user input (e.g. tapping) via a user interface, comparing each instance of user input with a timepoint at which an instance of user input is to be expected, and providing feedback to the user during the course of the exercise in respect of the time-appropriateness of each response, helps the user concentrate on his or her breathing or heartbeat, which may have therapeutic benefits (e.g. to counter the effects of stress, anxiety, pain, depression or addiction disorders, or other psychiatric conditions) and may help the user to achieve mindfulness. Information as to the time-appropriateness of the user's response, either during the exercise or afterwards (e.g. as an "concentration metric" proportion P, as discussed above) may also be used for diagnostic purposes, e.g. prompting a healthcare professional to recommend or administer a treatment (e.g. medication or therapy) to the user, or to recommend a change in lifestyle to the user, if the results of the exercise indicate that the user has not been able to concentrate on his or her own breathing or heartbeat to a sufficient level.

(4) Further embodiments may be used for monitoring purposes. In such cases, the apparatus comprises an accelerometer and a processor. The accelerometer is contained within a housing and configured to generate, in use, when the housing is placed in contact with the user's body, a signal in response to motion of the user's body due to respiration, as described above. For such embodiments a user interface is not essential (but may optionally be included). Furthermore, a visual display is not essential (but may optionally be included). The processor is configured to receive the signal from the accelerometer and to process the signal to determine a value representative of one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of the user. The processor is further configured to issue a notification if the determined value reaches a threshold. Such a notification may be sent in the form of an alert message, e.g. by short message service (SMS) or other wireless means, to a healthcare professional, and may be used to provide an "early warning" indication of a deterioration in one or more of the user's vital signs (such as, for example, their respiratory rate). Alternatively, the notification could be sounding an alarm to alert a nearby person.

The monitoring process may comprise issuing a first notification if the determined value reaches a first threshold, and a second notification if the determined value reaches a second threshold. For example, the first and second notifications may be sent to different people, or to different categories or people. For example, in a hospital context, the user reaching the first threshold may indicate a moderately serious problem, and consequently the first notification may be sent to a nurse, whereas reaching the second threshold may indicate a more severe problem, and consequently the second notification may be sent to a doctor. Additional thresholds and corresponding notifications may also be provided. For example, reaching a third threshold may indicate an extremely serious problem, and consequently a third notification may be sent to an emergency response/resuscitation team.

Summary

The present work provides inter alia the following:

1. Accelerometer-based vital sign detection (e.g. of respiratory rate and/or depth of breathing and/or regularity of breathing and/or heart rate and/or heart-rate variability) and real-time display thereof.

2. Application of the above to provide real-time feedback for specific training in quantitative respiratory interoception (a critical component of current "mindfulness" therapies effective for mood, anxiety and drug addictions, as well as to aid one or more of mental resilience, ability to concentrate, memory, or relaxation, for "healthy" people).

3. A training system that is beneficial when used for e.g. 20 minutes on healthy people, showing dramatic relaxation effects.

4. An accelerometer-based heart rate and heart-rate variability detection device. APPENDICES

In certain embodiments three data files are automatically generated (in CSV format) once an exercise is complete, respectively containing Metadata, Labels and Waveform values. Explanations of these follow below, as Appendices 1 -3, to provide detail in respect of the programming/encoding aspects of the software used in these embodiments.

APPENDIX 1: "METADATA FILE"

This contains metadata summarising the settings selected for the session and the chosen user response mode, in certain embodiments these being as follows:

VARIABLE DESCRIPTION

SessionJD Text to identify the practice session

Response_pattern The user-defined response pattern expected

AlternativeTapl nputEvery Whether alternative input is expected at certain times (e.g. double finger screen-tap)

SoundsOnOffRealTimeFeedback Whether sounds are played when users

provide time-appropriate or time-inappropriate responses

LongestDurationOfConcentration Longest period of uninterrupted

synchronisation

AverageDurationOfConcentration Mean period of uninterrupted synchronisation

Total NoOf Errors A count of all the time inappropriate or absent user responses

AverageDeviationOfTapFromTarget Average time offset of when they tapped to when they were expected to tap. Positive values indicate late responses, negative values indicate premature responses. This value was used so that users that consistently perceived their breath earlier or later than the computed expected time but did this consistently, were not penalised for this discrepancy.

StartTime Date and time of starting practice session

EndTime Date and time of ending practice session TotalTime Duration of the session

SyncTime Total time spent with the user's responses synchronised with their breathing

APPENDIX 2: "LABEL FILE"

This file lists the points along the generated waveform that correspond to different parts of the respiratory cycle. It also specifies the response from the user and classifies it as correct or incorrect. It has a list of all breath, tap and interruption events and associated details.

In certain embodiments the "column headings" in the "label file" are:

VARIABLE DESCRIPTION

event Type of event that took place: breath, tap or interruption

ticks When the event took place - can be

cross-referenced with waveform roll values data and with other events synchronisation Was the user-input appropriately synced to the breathing pattern when this event took place

Correct Was the user input correct in terms of timing and the type of input expected.

BreathJnhalationVsExhalation For breathing events, was the breath an inhalation or exhalation

Breath_TypeofTouchscreenlnputTapped Was a single finger-tap or double finger- tap expected

Breath_TypeofTouchscreenlnputExpected Was a single finger-tap or double finger- tap actually performed

Breath_CorrespondingBreathPresent Was there a corresponding breath

identified

Breath_CorrespondingBreathTime When was a corresponding breath

identified Tap_Fingersllsed How many fingers were used

Tap_CorrespondingBreath Was a corresponding breath found

Tap_BreathingTime When did the corresponding breath

happen

APPENDIX 3: "WAVEFORM-VALUES FILE"

This file contains a list of roll values (in radians) alongside the tick number (which increments approximately 20x a second when the phone is correctly oriented) and a corresponding timestamp (in seconds, to ms precision). When visualised it produces a sinusoidal pattern. A timestamp per tick is included because it's possible that the ticks will drift, and not be precisely 20 per second, so if it is necessary to calculate the time between two events the corresponding timestamps should be used. This data is considered sufficient to recreate exactly how a given exercise proceeded.

Claims

1. Apparatus for visualising, in real time, the respiratory cycle of a user, the apparatus comprising an accelerometer, a processor and display means;

wherein the accelerometer is contained within a housing and configured to generate, in use, when the housing is placed in contact with the user's body, a signal in response to motion of the user's body due to respiration; and

the processor is configured to receive the signal from the accelerometer, to process the signal, and to cause the display means to display, in real time, a visual representation of the user's respiratory cycle.

2. Apparatus as claimed in claim 1 , wherein the processor is further configured to determine the respiratory rate of the user, based on the signal received from the accelerometer.

3. Apparatus as claimed in claim 2, wherein the processor is further configured to cause the display means to display the respiratory rate of the user.

4. Apparatus as claimed in claim 3, wherein the processor is configured to cause the display means to display the respiratory rate of the user in real time.

5. Apparatus as claimed in any preceding claim, wherein the processor is further configured to determine the depth of breathing of the user, based on the signal received from the accelerometer.

6. Apparatus as claimed in claim 5, wherein the processor is further configured to cause the display means to display a measure of the depth of breathing of the user.

7. Apparatus as claimed in claim 6, wherein the processor is configured to cause the display means to display the measure of the depth of breathing of the user in real time.

8. Apparatus as claimed in any preceding claim, wherein the processor is further configured to determine the regularity of breathing of the user, based on the signal received from the accelerometer.

9. Apparatus as claimed in claim 8, wherein the processor is further configured to cause the display means to display a measure of the regularity of breathing of the user.

10. Apparatus as claimed in claim 9, wherein the processor is configured to cause the display means to display the measure of the regularity of breathing of the user in real time.

1 1. Apparatus as claimed in any preceding claim, wherein the processor is configured to cause the visual representation of the user's respiratory cycle to be displayed as a waveform in real time.

12. Apparatus as claimed in any preceding claim, wherein the processor is further configured to identify substantially periodic deflections of relatively small amplitude within the signal received from the accelerometer, and to use the time period between such deflections to determine the heart rate of the user.

13. Apparatus as claimed in claim 12, wherein the processor is further configured to cause the display means to display a visual representation of the heart rate of the user.

14. Apparatus as claimed in claim 13, wherein the processor is configured to cause the display means to display the visual representation of the heart rate of the user in real time.

15. Apparatus for determining the heart rate of a user, the apparatus comprising an accelerometer and a processor;

wherein the accelerometer is contained within a housing and configured to generate, in use, when the housing is placed in contact with the user's body, a signal in response to motion of the user's body; and the processor is configured to receive the signal from the accelerometer, to process the signal and identify substantially periodic deflections of relatively small amplitude within the signal, and to use the time period between such deflections to determine the heart rate of the user.

16. Apparatus as claimed in claim 15, wherein the processor is further configured to cause display means to display a visual representation of the heart rate of the user.

17. Apparatus as claimed in claim 16, wherein the processor is configured to cause the display means to display a visual representation of the heart rate of the user in real time.

18. Apparatus as claimed in any of claims 12 to 17, wherein the processor is configured to perform waveform analysis in the frequency domain, on the signal received from the accelerometer, in order to identify the substantially periodic deflections of relatively small amplitude.

19. Apparatus as claimed in any of claims 12 to 18, wherein the processor is further configured to determine a measure of the variability of the heart rate of the user, by evaluating temporal dispersion between successive determinations of the heart rate of the user.

20. Apparatus as claimed in claim 19, wherein the processor is further configured to cause the display means to display the measure of the variability of the heart rate of the user.

21. Apparatus as claimed in claim 20, wherein the processor is configured to cause the display means to display the measure of the variability of the heart rate of the user in real time.

22. Apparatus as claimed in any preceding claim, wherein the processor is further configured to calculate and output, after a plurality of respiratory cycles, average readings of one or more of the user's respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability as determined during the said plurality of respiratory cycles.

23. Apparatus as claimed in any preceding claim, further comprising a user interface operable to receive instances of user input, and wherein, across a plurality of breaths or heartbeats, the processor is further configured to:

determine, in accordance with a response rule, a plurality of timepoints when instances of user input are to be expected;

receive instances of user input via the user interface; and

determine, in respect of each instance of received user input, whether the user input is synchronised with a timepoint at which an instance of user input is to be expected.

24. Apparatus for generating data related to the self-awareness of a user, the apparatus comprising an accelerometer, a processor and a user interface;

wherein the accelerometer is contained within a housing and configured to generate, in use, when the housing is placed in contact with the user's body, a signal in response to motion of the user's body due to respiration;

the user interface is operable to receive instances of user input; and

the processor is configured to:

receive the signal from the accelerometer and process the signal to determine waveform data representative of the user's respiratory cycle,

determine, in accordance with a response rule, a plurality of timepoints relative to the user's respiratory cycle when instances of user input are to be expected;

receive instances of user input via the user interface; and

25. Apparatus as claimed in claim 23 or claim 24,

wherein the processor is further configured to divide the user's respiratory cycle into temporal segments,

and wherein, in determining in respect of each instance of received user input whether the user input is synchronised with a timepoint at which an instance of user input is to be expected, the processor is configured to determine whether the received instance of user input is within the temporal segment for which the instance of user input is to be expected.

26. Apparatus as claimed in any of claims 23 to 25, wherein the processor is further configured to provide output to the user, in response to each instance of user input, the output being in dependence on the result of determining whether the user input is synchronised with a timepoint at which an instance of user input is to be expected.

27. Apparatus as claimed in any of claims 23 to 26, wherein the processor is further configured to provide output, after a plurality of respiratory cycles, in respect of the proportion of instances of user input which were synchronised with timepoints at which instances of user input were expected.

28. Apparatus for monitoring one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of a user, the apparatus comprising an accelerometer and a processor;

the processor is configured to:

receive the signal from the accelerometer and process the signal to determine a value representative of one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of the user; and

issue a notification if the determined value reaches a threshold.

29. Apparatus as claimed in claim 28, wherein the processor is configured to issue a first notification if the determined value reaches a first threshold, and a second notification if the determined value reaches a second threshold.

Apparatus as claimed in any preceding claim, being a mobile device of unitary

31. Apparatus as claimed in claim 30 when dependent on any of claims 23 to 27, wherein the user interface is integrated with the visual display, as a touch screen.

32. Apparatus as claimed in claim 31 , being a mobile phone or tablet device.

33. Apparatus as claimed in any of claims 1 to 14 or 16 to 22, wherein the display means is provided in or on a separate housing from that of the accelerometer.

34. Apparatus as claimed in any of claims 23 to 27 or 33, wherein the user interface is provided in or on a separate housing from that of the accelerometer.

35. A method for visualising, in real time, the respiratory cycle of a user, the method being performed by a processor that is coupled to an accelerometer, the accelerometer being within a housing that is in contact with the user's body, the method comprising:

receiving a signal generated by the accelerometer in response to motion of the user's body due to respiration;

processing the signal; and

causing display means to display in real time a graphical representation of the user's respiratory cycle.

36. A method as claimed in claim 35, further comprising determining the respiratory rate of the user, based on the signal received from the accelerometer.

37. A method as claimed in claim 36, further comprising causing the display means to display the respiratory rate of the user.

38. A method as claimed in claim 37, wherein the respiratory rate of the user is displayed in real time.

39. A method as claimed in any of claims 35 to 38, further comprising determining the depth of breathing of the user, based on the signal received from the accelerometer.

40. A method as claimed in claim 39, further comprising causing the display means to display a measure of the depth of breathing of the user.

41. A method as claimed in claim 40, wherein the measure of the depth of breathing of the user is displayed in real time.

42. A method as claimed in any of claims 35 to 41 , further comprising determining the regularity of breathing of the user, based on the signal received from the accelerometer.

43. A method as claimed in claim 42, further comprising causing the display means to display a measure of the regularity of breathing of the user.

44. A method as claimed in claim 43, the measure of the regularity of breathing of the user is displayed in real time.

45. A method as claimed in any of claims 35 to 44, further comprising causing the visual representation of the user's respiratory cycle to be displayed as a waveform in real time.

46. A method as claimed in any of claims 35 to 45, further comprising identifying substantially periodic deflections of relatively small amplitude within the signal received from the accelerometer, and using the time period between such deflections to determine the heart rate of the user.

47. A method as claimed in claim 46, further comprising causing the display means to display a visual representation of the heart rate of the user.

48. A method as claimed in claim 47, wherein the visual representation of the heart rate of the user is displayed in real time.

49. A method for determining the heart rate of a user, the method being performed by a processor that is coupled to an accelerometer, the accelerometer being within a housing that is in contact with the user's body, the method comprising: receiving a signal generated by the accelerometer in response to motion of the user's body;

processing the signal and identifying substantially periodic deflections of relatively small amplitude within the signal; and

using the time period between such deflections to determine the heart rate of the user.

50. A method as claimed in claim 49, further comprising causing display means to display a visual representation of the heart rate of the user.

51. A method as claimed in claim 50, wherein the representation of the heart rate of the user is displayed in real time.

52. A method as claimed in any of claims 46 to 51 , further comprising performing waveform analysis in the frequency domain, on the signal received from the accelerometer, in order to identify the substantially periodic deflections of relatively small amplitude.

53. A method as claimed in any of claims 46 to 52, further comprising determining a measure of the variability of the heart rate of the user, by evaluating temporal dispersion between successive determinations of the heart rate of the user.

54. A method as claimed in claim 53, further comprising causing the display means to display the measure of the variability of the heart rate of the user.

55. A method as claimed in claim 54, wherein the measure of the variability of the heart rate of the user is displayed in real time.

56. A method as claimed in any of claims 35 to 55, further comprising calculating and outputting, after a plurality of respiratory cycles, average readings of one or more of the user's respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability as determined during the said plurality of respiratory cycles.

57. A method as claimed in any of claims 35 to 56, further comprising: determining, in accordance with a response rule, a plurality of timepoints when instances of user input are to be expected;

receiving instances of user input via a user interface, across a plurality of breaths or heartbeats; and

determining, in respect of each instance of received user input, whether the user input is synchronised with a timepoint at which an instance of user input is to be expected.

58. A method for generating data related to the self-awareness of a user, the method being performed by a processor that is coupled to an accelerometer and a user interface, the accelerometer being within a housing that is in contact with the user's body, the method comprising:

processing the signal to determine waveform data representative of the user's respiratory cycle;

determining, in accordance with a response rule, a plurality of timepoints relative to the user's respiratory cycle when instances of user input are to be expected;

receiving instances of user input via the user interface; and

59. A method as claimed in claim 57 or claim 58, further comprising:

dividing the user's respiratory cycle into temporal segments;

and wherein, in determining in respect of each instance of received user input whether the user input is synchronised with a timepoint at which an instance of user input is to be expected, the method comprises determining whether the received instance of user input is within the temporal segment for which the instance of user input is to be expected.

60. A method as claimed in any of claims 57 to 59, further comprising providing output to the user, in response to each instance of user input, the output being in dependence on the result of determining whether the user input is synchronised with a timepoint at which an instance of user input is to be expected.

61. A method as claimed in any of claims 57 to 60, further comprising, after a plurality of respiratory cycles, providing output in respect of the proportion of instances of user input which were synchronised with timepoints at which instances of user input were expected.

62. A method for monitoring one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of a user, the method being performed by a processor that is coupled to an accelerometer, the accelerometer being within a housing that is in contact with the user's body, the method comprising:

processing the signal to determine a value representative of one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of the user; and

issuing a notification if the determined value reaches a threshold.

63. A method as claimed in claim 62, further comprising issuing a first notification if the determined value reaches a first threshold, and a second notification if the determined value reaches a second threshold.

64. A method as claimed in any of claims 35 to 63, being performed by the processor of a mobile device of unitary form.

65. A method as claimed in claim 64, being performed by the processor of a mobile phone or tablet device.

66. A method as claimed in any of claims 35 to 65, for use in therapy or diagnosis.

67. Apparatus as claimed in any of claims 1 to 34 for use in therapy or diagnosis.

68. Use of apparatus as claimed in any of claims 1 to 34 in therapy or diagnosis.

69. Use of apparatus as claimed in any of claims 1 to 34 in a method of visualising the respiratory cycle of a user.

70. Use of apparatus as claimed in any of claims 1 to 34 or 69 in a method of determining the heart rate of a user.

71. Use of apparatus as claimed in any of claims 1 to 34, 69 or 70 in a method of generating data related to the self-awareness of a user.

72. Use of apparatus as claimed in any of claims 1 to 34, 69 or 70 in a method of monitoring one or more of the respiratory rate, depth of breathing, regularity of breathing, heart rate, and heart rate variability of a user.

73. The method of claim 66, apparatus of claim 67, or use of any of claims 68 to 71 , wherein the therapy comprises engendering a state of mindfulness on the part of the user.

74. The method of claim 66, apparatus of claim 67, or use of any of claims 68 to 71 , or the method, apparatus or use of claim 73, wherein the therapy comprises countering the effects of stress, anxiety, pain, depression or addiction disorders.

75. The method of claim 66, apparatus of claim 67, or use of any of claims 68 to 71 , when dependent on any of claims 23 to 27 or 57 to 61 , for diagnosis of whether the user is in a state of mindfulness.

76. The method or use of claim 75, wherein the user is identified as not being in a state of mindfulness.

77. The method or use of claim 75, wherein the user is identified as being in a state of mindfulness.

78. The method of claim 66, apparatus of claim 67, or use of any of claims 68 to 71 , wherein the diagnosis comprises identifying respiratory rate characteristic associated with a respiratory problem, or identifying heart rate characteristic associated with a heart-related problem.

79. The method, apparatus or use of claim 78, wherein said respiratory problem is one or more of: respiratory arrest, respiratory depression/failure, asthma, bronchitis, shortness of breath, apnoea, emphysema, and chronic obstructive pulmonary disease.

80. The method, apparatus or use of claim 78, wherein said heart rate characteristic is an elevated rate, a reduced rate, or an irregular rate.

81. The method, apparatus or use of claim 78 or claim 80, wherein said heart- related problem is one or more of: arrhythmia, atrial fibrillation, atrial flutter, sick sinus syndrome, tachycardia, ventricular fibrillation, premature contractions, long QT syndrome, heart block, syncope, myocardial infarction, heart failure, and heart valve problems.

82. The method or use of any of claims 75 to 81 , further comprising, dependent on the diagnosis, recommending or administering treatment to the user, or recommending a change in lifestyle to the user.

83. A computer program or set of instruction code which, when executed by a processor of an apparatus having an accelerometer, causes the apparatus to become configured as the apparatus of any of claims 1 to 34 or 67.

84. A computer program or set of instruction code which, when executed by a processor of an apparatus having an accelerometer, causes the processor to perform the method of any of claims 35 to 66 or any of claims 73 to 82.

85. Apparatus substantially as herein described with reference to and as illustrated in any combination of the accompanying drawings.

86. A method substantially as herein described with reference to and as illustrated in any combination of the accompanying drawings.

87. A computer program or set of instruction code substantially as herein described with reference to and as illustrated in any combination of the accompanying drawings.

88. Use of apparatus substantially as herein described with reference to and as illustrated in any combination of the accompanying drawings.