Patent Description:
Utilizing guided breathing to regulate a user or subject's breathing rate, or amount of breaths taken per minute, can be beneficial in a number of health fields. For example, guided breathing can be used in several clinical applications, potentially leading to more effective or quicker treatments of conditions, including: asthma, stress, anxiety, insomnia, panic disorder, recurrent abdominal pain, chronic obstructive pulmonary disease, chronic hyperventilation, hypertension, and congestive heart failure, among others. Guided breathing may also be utilized to assist people in falling asleep and for meditation or relaxation purposes.

<CIT>, <CIT>, <CIT>, and <CIT> describe systems for guided breathing.

Many guided breathing exercises start at a rate that matches a user's current measured breathing rate. However, many users find starting at their current measured breathing rate to be uncomfortable. When the starting breathing rate is uncomfortable for a user, the guided breathing exercise is difficult to follow, which may result in the overall guided breathing exercise being unpleasant. Therefore, there is a need for a starting breathing metric for guided breathing exercises that is more comfortable for users to follow.

Aspects of the present disclosure provide methods, apparatuses, and systems for dynamic starting rates for guided breathing. According to an aspect, a user's initial breathing metric is determined. A multiplier is then determined, where the multiplier varies as a function of the initial breathing metric within a range. The level of intensity of the multiplier may vary, and may be a dynamic feature based on the determination of the user's initial breathing metric. Once the multiplier is determined, the multiplier is applied to the user's initial breathing metric to determine a starting breathing metric for guided breathing. The starting breathing metric is slower than or equal to the user's initial breathing metric.

In an aspect, a method for determining a starting breathing metric for guided breathing comprises determining an initial breathing metric of a user, determining a multiplier, wherein the multiplier varies as a function of the initial breathing metric within a range, and applying the multiplier to the initial breathing metric of the user.

The breathing metric may comprise one of a breaths per minute rate of the user or a breathing period of the user. Determining the initial breathing metric of the user may comprise measuring a current breathing rate of the user. According to the invention, the breathing metric comprises a breathing period of the user, and when the initial breathing metric of the user is determined to be between a first value and a second value higher than the first value, the multiplier varies in a linearly decreasing manner, and when the initial breathing metric of the user is determined to be between the second value and a third value higher than the second value, the multiplier is constant. The range may be between about <NUM> seconds and about <NUM> seconds. The multiplier may vary between about <NUM> and about <NUM>. When the breathing metric comprises a breaths per minute rate of the user, the multiplier may be lower when the initial breathing metric of the user is higher as compared to when the initial breathing metric is lower. When the breathing metric comprises a breathing period of the user, the multiplier may be higher when the initial breathing metric of the user is lower as compared to when the initial breathing metric is higher.

Determining the initial breathing metric of the user comprises measuring a current breathing rate of the user and converting the measured current breathing rate of the user to a breathing period, determining the multiplier comprises determining the multiplier based on the breathing period of the user, and applying the multiplier to the initial breathing metric of the user comprises applying the ratio to the breathing period of the user to provide a modified breathing period. The modified breathing period may be used as the starting breathing metric for the guided breathing, and the starting breathing metric may be in units of breaths per minute rate or period of a breath in seconds.

In yet another aspect, a stimulus output system comprises at least one transducer configured to output a guiding stimulus to a user, and a processor, the processor configured to determine a starting breathing metric for the guiding stimulus by determining a starting breathing metric for guided breathing comprises determining an initial breathing metric of a user, determining a multiplier, wherein the multiplier varies as a function of the initial breathing metric within a range, and applying the multiplier to the initial breathing metric of the user.

The breathing metric may comprise one of a breaths per minute rate of the user or a breathing period of the user. Determining the initial breathing metric of the user may comprise measuring a current breathing rate of the user. According to the invention, the breathing metric comprises a breathing period of the user, and when the initial breathing metric of the user is determined to be between a first value and a second value higher than the first value, the multiplier varies in a linearly decreasing manner, and when the initial breathing metric of the user is determined to be between the second value and a third value higher than the second value, the multiplier is constant. The range may be between about <NUM> seconds and about <NUM> seconds. The multiplier may vary between about <NUM> and about <NUM>. When the breathing metric comprises a breaths per minute rate of the user, the multiplier may be lower when the initial breathing metric of the user is higher as compared to when the initial breathing metric is lower. When the breathing metric comprises a breathing period of the user, the multiplier may be higher when the initial breathing metric of the user is lower as compared to when the initial breathing metric is higher. The initial breathing metric of the user may be estimated using a biometric sensor.

In another aspect, a wearable audio device comprises at least one speaker configured to output a guiding stimulus to a user, and a processor, the processor configured to determine a starting breathing metric for the guiding stimulus by determining a starting breathing metric for guided breathing comprises determining an initial breathing metric of a user, determining a multiplier, wherein the multiplier varies as a function of the initial breathing metric within a range, and applying the multiplier to the initial breathing metric of the user.

All examples and features mentioned herein can be combined in any technically possible manner.

<FIG> illustrates an example stimulus output system <NUM> in a sleeping environment, according to an aspect. The stimulus output system <NUM> may be used to determine a dynamic starting breathing metric, and to non-linearly alter a guiding stimulus from the dynamic starting breathing metric to a target breathing metric for non-linear guided breathing. The stimulus output system <NUM> may be an audio system.

The stimulus output system <NUM> includes headphones <NUM> and a smartwatch <NUM>, which are shown as being worn by a subject or user. A headphone <NUM> refers to a device that fits around, on, or in an ear and that radiates acoustic energy into the ear canal. Headphones <NUM> are sometimes referred to as earphones, earpieces, headsets, earbuds, or sport headphones, and can be wired or wireless. The headphones <NUM> may comprise one or more of: a processing unit, a transceiver, one or more biosensors, one or more speakers, one or more systems configured to output any combination of haptics, lighting and audio, and one or more microphones. The headphones <NUM> may comprise an interface configured to receive input from a subject or user. A smartwatch <NUM> may be any type of wearable computer designed to be worn on a wrist of a subject or user, such as a fitness tracker. The smartwatch <NUM> may comprise one or more of: a processing unit, a transceiver, one or more biosensors, one or more speakers, one or more haptic systems, and one or more microphones. The smartwatch <NUM> may comprise an interface configured to receive input from a subject or user.

The stimulus output system <NUM> further includes a bedside unit <NUM> and a smartphone <NUM>. The smartphone <NUM> may be a mobile phone, tablet, phablet, or laptop computer. The smartphone <NUM> may comprise one or more of: a processing unit, a transceiver, one or more biosensors, one or more speakers, one or more haptic systems, one or more light sources, and one or more microphones. The smartphone <NUM> may comprise an interface configured to receive input from a subject or user. The bedside unit <NUM> may be a stationary smart device, such as a smart speaker. The bedside unit <NUM> may have any shape and size capable of fitting on a surface in the sleeping environment, such as a dresser, desk, or night table. The bedside unit <NUM> may comprise one or more of: a processing unit, a transceiver, one or more biosensors, one or more speakers, one or more haptic systems, one or more light sources, and one or more microphones. In one embodiment, the bedside unit <NUM> comprises one or more contactless biosensors, such as a radio frequency (RF) sensor, a radar sensor, or an under-bed accelerometer and/or microphone. The bedside unit <NUM> may comprise an interface configured to receive input from a subject or user.

The headphones <NUM>, the smartwatch <NUM>, the bedside unit <NUM>, and the smartphone <NUM> may each include any wired or wireless communication means suitable for use with any other device <NUM>-<NUM> disposed in the sleeping environment, such as WiFi, Bluetooth, Near Field Communications (NFC), USB, micro USB, or any suitable wired or wireless communications technologies known to one of ordinary skill in the art. For example, the headphones <NUM> may comprise one or more speakers while the bedside unit <NUM> comprises one or more biosensors in communication with the one or more speakers of the headphones <NUM>. Furthermore, the stimulus output system <NUM> may include one or more of the devices <NUM>-<NUM>, and is not required to include each device <NUM>-<NUM> shown. Thus, each device <NUM>-<NUM> in the stimulus output system <NUM> may be optionally included, and only one device <NUM>-<NUM> is needed for guiding breathing exercises and for determining a starting breathing metric for such guided breathing exercises.

The devices <NUM>-<NUM> of the stimulus output system <NUM>, either alone or in combination, are configured to: determine a starting breathing metric for guided breathing by determining an initial breathing metric of a user, determining a multiplier, wherein the multiplier varies as a function of the initial breathing metric within a range, and applying the multiplier to the initial breathing metric of the user. The stimulus output system <NUM> may output a guided breathing stimulus to a user in the form of audio, haptics, lights, etc..

<FIG> illustrates example components of a stimulus output device <NUM>, in accordance with certain aspects of the present disclosure. According to an example, the stimulus output device <NUM> is a wireless wearable audio device. The stimulus output device <NUM> may be an audio output device. The stimulus output device <NUM> may be used in a stimulus output system, such as the stimulus output system <NUM> of <FIG>. For instance, the stimulus output device <NUM> may be any device <NUM>-<NUM> in the stimulus output system <NUM> of <FIG>. In one example, the stimulus output device <NUM> is the headphones <NUM> of <FIG>. In another example, the stimulus output device <NUM> is the bedside unit <NUM> of <FIG>. The stimulus output device <NUM> may be used to determine a dynamic starting breathing metric, and to non-linearly alter a guiding stimulus from the dynamic starting breathing metric to a target breathing metric for non-linear guided breathing.

The stimulus output device <NUM> includes a memory and processor <NUM>, communication unit <NUM>, a transceiver <NUM>, a biosensor <NUM>, and an audio output transducer or speaker <NUM>. The memory may include Read Only Memory (ROM), a Random Access Memory (RAM), and/or a flash ROM. The memory stores program code for controlling the memory and processor <NUM>. The memory and processor <NUM> control the operations of the stimulus output device <NUM>. Any or all of the components in <FIG> may be combined into multi-function components.

The processor <NUM> controls the general operation of the stimulus output device <NUM>. For example, the processor <NUM> performs process and control for audio and/or data communication. The processor <NUM> is configured to determine a starting breathing metric for guided breathing by determining an initial breathing metric of a user, determining a multiplier, wherein the multiplier varies as a function of the initial breathing metric within a range, and applying the multiplier to the initial breathing metric of the user. The processor <NUM> is configured to measure, receive, calculate, or detect at least one biosignal parameter of the subject. In combination with the audio output transducer <NUM>, the processor <NUM> is configured to output a guiding stimulus. The processor <NUM> is further configured to alter the guiding stimulus. The processor <NUM> may be further configured to receive input from a subject or user, such as input regarding an initial breathing metric and a final breathing metric. In at least one example, the processor <NUM> is disposed on another device in an audio system, such as a smartphone, and is in communication with the stimulus output device <NUM>.

The communication unit <NUM> facilitates a wireless connection with one or more other wireless devices, such as with other devices in an audio system. For example, the communication unit <NUM> may include one or more wireless protocol engines such as a Bluetooth engine. While Bluetooth is used as an example protocol, other communication protocols may also be used. Some examples include Bluetooth Low Energy (BLE), NFC, IEEE <NUM>, WiFi, or other local area network (LAN) or personal area network (PAN) protocols. The stimulus output device <NUM> may receive audio files wirelessly via the communication unit <NUM>. Additionally or alternatively, the communication unit <NUM> may receive information associated with a subject's biosignal parameters, obtained via a contactless sensor. Examples of contactless sensors include a radio frequency (RF) sensor, a radar sensor, or an under-bed accelerometer.

The transceiver <NUM> transmits and receives information via one or more antennae to exchange information with one or more other wireless devices. The transceiver <NUM> may be used to communicate with other devices in an audio system, such as a bedside unit, a smartphone, and/or a smartwatch. The transceiver <NUM> is not necessarily a distinct component.

The stimulus output device <NUM> includes the audio output transducer <NUM>, which may be also known as a driver or speaker. In some examples, more than one output transducer <NUM> is used. The transducer <NUM> (that may be part of a microphone) converts electrical signals into sound and converts sound into electrical signals. The transducer <NUM> is configured to output a guiding stimulus to a user or subject. The transducer <NUM> outputs audio signals, including adjusted audio signals in an effort to regulate a user's breathing. For example, the transducer <NUM> may be configured to adjust audio signals in response to a subject's biosignal parameters. In at least one example, the transducer <NUM> is disposed on another device in an audio system, such as a bedside unit, and is in communication with the stimulus output device <NUM>.

The stimulus output device <NUM> optionally includes one or more microphones <NUM>. In an aspect, the microphones <NUM> are used to convert noises into electrical signals. In at least one example, one or more microphones <NUM> are disposed on another device in an audio system, such as a bedside unit, and are in communication with the stimulus output device <NUM>. The microphone <NUM> may be used to approximate or measure a user's breathing metric, such as breaths per minute rate.

The stimulus output device <NUM> optionally includes one or more biosensors <NUM> used to determine, sense, measure, monitor, or calculate a biosignal parameter of a subject wearing the stimulus output device <NUM>.

According to an aspect when the stimulus output device <NUM> is headphones, only one earpiece (ear tip, ear cup) of the stimulus output device <NUM> includes the biosensor <NUM>. In an aspect, neither earpiece includes a biosensor <NUM>. Instead, a biosensor <NUM>, not on the stimulus output device <NUM>, may remotely detect a biosignal parameter of the subject. In an example, the biosensor <NUM> detects a subject's heartrate or heart rate variability (HRV) with a sensor disposed on the wrist, such as by utilizing a smartwatch. In an example, the biosensor <NUM> may be a contactless biosensor. The contactless biosensor is configured to report detected biosignal parameters to the processor <NUM>, for example, via the communication unit <NUM>. In at least one example, the biosensor <NUM> is disposed on another device in an audio system, such as a smartwatch, and is in communication with the stimulus output device <NUM>.

<FIG> illustrates communication between certain modules of an example stimulus output device <NUM>; however, aspects of the disclosure are not limited to the specific illustrated example. According to aspects, any module <NUM>-<NUM> is configured to communicate with any other module in the stimulus output device <NUM>. In one example, all modules <NUM>-<NUM> are connected to and communicate with each other. The stimulus output device <NUM> may output a guided breathing stimulus to a user in the form of audio, haptics, lights, etc..

<FIG> illustrates an example method <NUM> for determining a dynamic starting breathing metric for guided breathing. <FIG> illustrates an exemplary diagram <NUM> that may be utilized to determine a multiplier to apply to a breathing metric to determine a dynamic starting breathing metric for guided breathing. A breathing metric may comprise one of a breathing rate or a breathing period. A breathing period is an amount of time in seconds from a beginning of one inhale to an end of a next exhale. A breathing rate, or breaths per minute rate (BrPM) (e.g. breath rate per minute or breathing rate per minute), is the amount or number of breaths a subject takes in one minute. The terms "breaths per minute rate", "breath rate per minute", "breathing rate", and "breathing rate per minute" as used herein may be used interchangeably. The method <NUM> and the diagram <NUM> may each individually be utilized with the stimulus output system <NUM> of <FIG> and/or the stimulus output device <NUM> of <FIG>.

At <NUM>, an initial breathing metric of a user is determined. The initial breathing metric may be determined by measuring the current breathing rate or breathing period of the user. In one embodiment, a biometric sensor, such as the biometric sensor <NUM> of <FIG>, may be used to estimate or measure the breathing rate of the user. In other embodiments, the breathing metric may be determined based on historical data, demographic data, preference data, or the like. For example, a user's breathing rate or breathing period may be measured using a biometric sensor every day for one or more days around the same time each day to gather historical data. Based on the collected historical data, the user's breathing metric may be determined or estimated, such as by averaging the breathing metrics collected. As another example, a user may input their demographic data, such as race, height, weight, known medical conditions, diet, etc. into an interface. The demographic data may then be analyzed to approximate the user's initial breathing metric. If the breathing metric is determined in units of breaths per minute rate (i.e., breathing rate), the breathing metric may be converted to units of period of a breath in seconds (i.e., breathing period) prior to continuing to <NUM>.

At <NUM>, a multiplier is determined, the multiplier varying as a function of the initial breathing metric within a range. The multiplier may vary linearly as a function of breaths per minute rate such that the higher the user's initial breathing rate is, the higher the multiplier. The range for the varying function of the multiplier may be between about a <NUM> second period to about a <NUM> second period.

<FIG> illustrates an exemplary diagram <NUM> that may be utilized to determine the multiplier. The diagram <NUM> may be used as a look up table and illustrates two conditions for determining the multiplier. While <FIG> shows the highest multiplier being <NUM>, the multiplier may be higher, such as <NUM>, as described below in <FIG>. The multiplier may be a ratio of the user's initial breathing metric divided by a preselected starting breathing metric found to be a comfortable starting breathing metric for the user. While the diagram <NUM> illustrates multipliers for both a breathing period (BP) and a breathing rate (BR) along the y-axis, only one unit of multiplier is needed. The multiplier may be determined for either a breathing rate or a breathing period of a user, regardless of the unit of the multiplier.

Under condition <NUM> in the diagram <NUM>, a user's initial breathing metric is multiplied by the same multiplier regardless of what the user's initial breathing metric is. As shown in the diagram <NUM>, the multiplier under condition <NUM> is always <NUM> for breathing periods (i.e., about <NUM> for breathing rates). Similarly, while not shown on the diagram <NUM>, one BrPM may be subtracted from the user's initial breathing metric, or one second may be added, regardless of what the user's initial breathing metric is.

Under condition <NUM> in the diagram <NUM>, the multiplier varies linearly as a function of breaths per minute rate from a first value to a second value, and then becomes constant from the second value to a third value. For example, when the first value is about a <NUM> second period or higher and the second value is about an <NUM> second period, the multiplier varies in a decreasing linear manner. When the second value is about an <NUM> second period and the third value is about a <NUM> second period, the multiplier is constant at <NUM>. When the multiplier varies in a decreasing linear manner, the higher the user's initial breathing rate is, the lower the multiplier. Similarly, when the multiplier varies in a decreasing linear manner, the lower the user's initial breathing period is, the higher the multiplier. For example, if a user's initial breathing metric is about <NUM> seconds, a multiplier of <NUM> is selected (i.e., a multiplier of about <NUM> for a corresponding breathing rate of <NUM> BrPM). However, when a user's initial breathing metric is about <NUM> seconds, a multiplier of about <NUM> is selected (i.e., a multiplier of about <NUM> for a corresponding breathing rate of <NUM> BrPM).

At <NUM>, the multiplier determined at <NUM> is applied to the initial breathing metric of the user to determine a starting breathing metric for guided breathing. The starting breathing metric is slower than or equal to the user's initial breathing metric. Under condition <NUM> in the diagram <NUM>, if a user's initial breathing metric is determined to be a <NUM> second period, the user's determined starting metric would be a <NUM> second period, or about <NUM> breaths per minute. Under condition <NUM> in the diagram <NUM>, if a user's initial breathing metric is determined to be a <NUM> second period, the user's determined starting metric would be a <NUM> second period, or about <NUM> breaths per minute. In one aspect, the starting breathing metric is bound such that the starting breathing rate never starts lower than about <NUM> seconds (i.e., <NUM> BrPM) and never starts higher than about <NUM> seconds (i.e., <NUM> BrPM). Once the starting breathing metric is determined, it may be used as the breathing metric to start a guided breathing exercise as the starting breathing metric for a guided breathing stimulus.

While referred to as a multiplier, the multiplier may be applied to the initial breathing metric through any mathematical operation or function, including but not limited to, addition, subtraction, multiplication, or division. In one example, the initial breathing metric in terms of breathing rate per minute may be subtracted by <NUM> for all values of breathing rate per minute. In another example, if the multiplier is determined to be <NUM> in <NUM>, the initial breathing metric of the user may be multiplied by <NUM> if the initial breathing metric is in units of a breathing period, or the initial breathing metric may be divided by <NUM> if the initial breathing metric is in units of breaths per minute rate. Conversely, if the multiplier is determined to be <NUM> in <NUM>, the initial breathing metric of the user may be divided by <NUM> if the initial breathing metric is in units of a breathing period, or the initial breathing metric may be multiplied by <NUM> if the initial breathing metric is in units of breaths per minute rate. Thus, regardless of the unit of the multiplier, the multiplier may be applied to both a breathing rate and a breathing period of a user.

<FIG> illustrates an exemplary chart <NUM> for various levels of intensities of multipliers, and <FIG> illustrates a corresponding diagram <NUM>. The chart <NUM> and the diagram <NUM> may be utilized with the stimulus output system <NUM> of <FIG>, the stimulus output device <NUM> of <FIG>, and or the method <NUM> of <FIG>. The chart <NUM> and the diagram <NUM> illustrate various levels of intensities or severities for determining multipliers for condition <NUM> described above in <NUM>. As shown in the chart <NUM>, various intensities or severities, such as mild, medium, and strong, may be selected for determining the rate at which the multiplier may decreasingly vary (i.e., the slope of the line for condition <NUM>). The mild level <NUM> determines a lower, or weaker, intensity to apply to a user's initial breathing metric while the strong level <NUM> determines a higher, or steeper, intensity. The chart <NUM> further illustrates a fixed multiplier of <NUM>, relating to condition <NUM> above, for comparison. While the chart <NUM> is shown in units of breathing rate, the chart <NUM> may be in units of breathing period.

In the chart <NUM>, the mild level <NUM> starts at a multiplier of about <NUM> for an initial breathing rate of about <NUM> breaths per minute, the medium level <NUM> starts at a multiplier of about <NUM> for an initial breathing rate of about <NUM> breaths per minute, and the strong level <NUM> starts at a multiplier of about <NUM> for an initial breathing rate of about <NUM> breaths per minute. The diagram <NUM> illustrates each of the levels of intensities starting at a high breathing rate of about <NUM> breaths per minute. In the diagram <NUM>, the mild level <NUM> starts at a multiplier of about <NUM> for an initial breathing rate of about <NUM> breaths per minute, the medium level <NUM> starts at a multiplier of about <NUM> for an initial breathing rate of about <NUM> breaths per minute, and the strong level <NUM> starts at a multiplier of about <NUM> for an initial breathing rate of about <NUM> breaths per minute. Like in the diagram <NUM>, if a user's initial breathing period is determined to be about <NUM> or <NUM> breaths per minute, the multiplier no longer decreases linearly, and is instead constant at <NUM>.

The level of intensity may be user selected or may be predetermined. In one embodiment, the level of intensity is a dynamic feature that is selected based on the user's initial breathing metric. For instance, the lower the user's initial breathing metric, the lower the level of intensity of the multiplier, and the higher the user's initial breathing metric, the higher the level of intensity of the multiplier. For example, if a user's initial breathing metric is determined to be about <NUM> BrPM to about <NUM> BrPM, the mild intensity may be selected. Similarly, if the user's initial breathing metric is determined to be about <NUM> BrPM to about <NUM> BrPM, the medium intensity may be selected. If the user's initial breathing metric is determined to be about <NUM> BrPM or higher, the strong intensity may be selected. If the user's initial breathing metric is determined to be about <NUM> BrPM of lower, the constant multiplier of <NUM> is selected.

By determining a starting breathing metric for guided breathing different from a user's current breathing metric, the guided breathing will start at a more comfortable pace, which may help the user reach a target breathing metric quicker. Additionally, by starting the guided breathing at a more comfortable pace, a user may be more encourage to complete the guided breathing, as the guided breathing will feel smoother than a guided breathing exercise started at the user's current breathing metric, helping the user reach their target breathing metric quicker. As such, the overall guided breathing experience will be more efficient and beneficial to a user, as the guided breathing experience will be more comfortable and easier for the user to follow.

Aspects of the present disclosure provide methods, apparatuses, and systems for dynamic starting rates for guided breathing. According to aspects, the audio device or system described herein is also configured to non-linearly alter a guiding stimulus with a non-linear breath rate per minute or breaths per minute rate sequence to align with a final or target breathing period, as described in <CIT> entitled "Non-Linear Breath Entrainment," filed on January <NUM>, <NUM>.

In the preceding, reference is made to aspects presented in this disclosure. However, the scope of the present disclosure is not limited to specific described aspects. Aspects of the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "component," "circuit," "module" or "system. " Furthermore, aspects of the present disclosure may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.

More specific examples of a computer readable storage medium include: an electrical connection having one or more wires, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the current context, a computer readable storage medium may be any tangible medium that can contain, or store a program.

Claim 1:
A method (<NUM>) for determining a starting breathing metric for guided breathing, comprising:
determining (<NUM>) an initial breathing metric of a user;
determining (<NUM>) a multiplier, wherein the multiplier varies as a function of the initial breathing metric within a range; and
applying (<NUM>) the multiplier to the initial breathing metric of the user;
wherein the initial breathing metric comprises a breathing period of the user, and wherein:
when the initial breathing metric of the user is determined to be between a first value and a second value higher than the first value, the multiplier varies in a linearly decreasing manner, and
when the initial breathing metric of the user is determined to be between the second value and a third value higher than the second value, the multiplier is constant.