Wearable device for reducing respiratory effort of a sleeping subject

Abstract

The present disclosure relates to the field of sleep and respiratory care. In particular, the present disclosure provides apparatuses and methods for reducing respiratory effort of a sleeping subject. The present disclosure also provides apparatuses and methods for treating snoring of a sleeping subject.

Description

Technical Field

[0001] This disclosure relates to the field of sleep and respiratory care. In particular, this disclosure provides apparatus and methods for reducing the breathing effort of a subject during sleep. This disclosure also provides apparatus and methods for treating snoring in a subject during sleep. Background Technology

[0002] Sleep-disturbed breathing (SDB), characterized by increased breathing effort, is a condition that affects sleep quality and leads to excessive daytime sleepiness, contributing to most road traffic accidents. Continuous positive airway pressure (CPAP) is the most effective treatment for SDB; however, it is limited to long-term adherence. There is an urgent need for new treatment methods and systems that are easily deployed on a large scale.

[0003] Electrical stimulation for treating sleep-induced diabetic dysplasia (SDB) in the upper airway has been investigated. The genioglossus muscle, a component of the tongue, is considered a major dilator of the upper airway and is used for specific targeting. Previous trials aimed to target the tongue unilaterally or bilaterally to move it further forward in the oral cavity to achieve more symmetrical tongue movement. Unilateral stimulation of the tongue via an implanted hypoglossal nerve stimulator has been shown to effectively reduce respiratory effort, but the associated cost and invasiveness of the proposed treatment limit its application to severe cases. Bilateral stimulation of the tongue has been proposed in an attempt to provide more symmetrical muscle tone to the genioglossus muscle, thereby increasing upper airway patency more significantly and consistently. To date, preferred bilateral stimulation has been examined using implanted hypoglossal nerve stimulation techniques.

[0004] However, the anatomy of the upper airway in Homo sapiens is complex, as are the functions required for chewing, swallowing, speech, and breathing. Upper airway obstruction is more common during sleep than in other primates because the human pharynx lacks rigid support except for the head and tail; it is anchored to the bony (upper) and cartilaginous (larynx) tail.

[0005] Therefore, the pharyngeal behavior during breathing in sleep is like a collapsible tube. On the other hand, most of the pharyngeal muscles are anchored directly or indirectly to the mandible via the hyoid bone, making it another type of mobile skeleton in humans. Targeting only the genioglossus muscle can prevent respiratory disturbances such as airway obstruction or collapse, and the associated increase in brainstem respiratory effort during sleep may fail because the pharynx can still collapse from other parts of the body besides the tongue. In fact, until now, bilateral genioglossus stimulators have not shown significant physiological and clinical benefits in a large proportion of patients. Therefore, it is necessary to address the problems and limitations of existing SDB treatments that are characterized by respiratory effort. Summary of the Invention

[0006] As stated above, it is necessary to address the problems and limitations of existing treatments for sleep-disordered breathing (SDB) characterized by respiratory effort. This disclosure relates to apparatus and methods for reducing respiratory effort in a sleep subject and / or preventing the occurrence of sleep-disordered breathing. In particular, this disclosure aims to provide transcutaneous electrical stimulation to the masseter, pterygoid, and / or temporalis muscles of the subject to modulate their contribution to sleep breathing activity and reduce the subject's respiratory effort during sleep. Furthermore, this disclosure aims to provide apparatus and methods for retraining the subject's brain via the provided electrical stimulation to reduce central respiratory drive in the masseter, pterygoid, and / or temporalis muscles.

[0007] One aspect of this disclosure relates to a wearable device for reducing respiratory effort in a subject during sleep, the device comprising:

[0008] - At least one left electrode, adapted to be positioned in electrical contact with a selected portion of the skin of the object, the selected portion extending from the movement point of the left masseter, pterygoid and / or temporalis muscles to the left posterior angle of the mandible;

[0009] - At least one right electrode adapted to be positioned in electrical contact with a selected portion of the skin of the object, the selected portion extending from the movement point of the right masseter, pterygoid and / or temporalis muscles to the right posterior angle of the mandible;

[0010] - A stimulator configured to apply transcutaneous electrical stimulation between a left electrode and at least one left masseter, pterygoid and / or temporalis muscle, and between a right electrode and at least one right masseter, pterygoid and / or temporalis muscle;

[0011] The applied electrical stimulation promotes the contraction of the stimulated masseter, pterygoid, and / or temporalis muscles on both sides, thereby controllably raising the subject's mandible and opening the upper airway.

[0012] One aspect of this disclosure relates to a wearable device for reducing respiratory effort in a subject during sleep, the device comprising:

[0013] - At least one left bipolar electrode is configured to be mounted on a selected portion of the subject's skin, the selected portion corresponding to the location of at least one left-sided target muscle including the left masseter, left pterygoid, and / or left temporalis muscle.

[0014] - At least one right bipolar electrode is configured to be mounted on a selected portion of the subject's skin, the selected portion corresponding to the location of at least one right-side target muscle including the right masseter, right pterygoid, and / or right temporalis muscle.

[0015] -The bipolar electrode includes at least two conductive elements, wherein the first conductive element is configured to be mounted at the movement point of the target muscle, and the second conductive element is configured to be mounted along the direction of the target muscle fibers;

[0016] - A stimulator configured to generate biphasic transcutaneous electrical stimulation to be applied between two conductive elements of a bipolar electrode; wherein the electrical stimulation promotes contraction of the target muscle to controllably elevate the subject's jaw, thereby reducing respiratory effort.

[0017] In one embodiment, the electrical stimulation is a biphasic and discontinuous current.

[0018] In one embodiment, the current intensity of the electrical stimulation is at least 1 mA to at most 50 mA, preferably 1 mA to 30 mA.

[0019] In one embodiment, the pulse frequency of the electrical stimulation is at least 1 Hz to at most 100 Hz, preferably 30 Hz to 50 Hz.

[0020] In one embodiment, the pulse width of the electrical stimulation is at least 100 μs to at most 400 μs, preferably 200 μs to 300 μs.

[0021] In one embodiment, the duration of electrical stimulation is from at least 1 second to at most 20 seconds, preferably from 5 seconds to 10 seconds.

[0022] In one embodiment, the stimulator is configured to generate the electrical stimulation according to at least one stimulation program, wherein the stimulation program is configured to generate electrical stimulation having a work cycle having a stimulation period of 1 to 20 seconds and / or a rest period of 1 to 20 seconds.

[0023] In one embodiment, the stimulator is configured to generate the electrical stimulation according to at least one stimulation program, wherein the stimulation program includes at least one muscle recruitment program configured to generate electrical stimulation defined by the following stimulation parameters: current intensity, between 5 mA and 10 mA, preferably between 6 mA and 10 mA; frequency, between 15 Hz and 50 Hz, preferably between 25 Hz and 45 Hz, more preferably between 30 Hz and 40 Hz; and pulse width, between 50 μs and 300 μs, preferably between 225 μs and 275 μs, more preferably between 200 μs and 250 μs.

[0024] In one embodiment, the stimulator is configured to generate the electrical stimulation according to at least one stimulation program, wherein the stimulation program includes at least one muscle rehabilitation program configured to generate electrical stimulation defined by the following stimulation parameters: current intensity, between 1 mA and 4 mA, between 2 mA and 4 mA; frequency, between 15 Hz and 50 Hz, preferably between 20 Hz and 45 Hz, more preferably between 30 Hz and 40 Hz; and pulse width, between 50 μs and 300 μs, preferably between 225 μs and 275 μs, more preferably between 200 μs and 250 μs.

[0025] In one embodiment, the stimulator is configured to generate the electrical stimulation according to at least one stimulation program, wherein the stimulation program includes at least one neuromuscular retraining program configured to generate electrical stimulation defined by the following stimulation parameters: current intensity, between 1 mA and 4 mA, between 2 mA and 4 mA; frequency, between 50 Hz and 150 Hz, preferably between 70 Hz and 130 Hz, even more preferably between 90 Hz and 110 Hz; and pulse width, between 500 μs and 1000 μs, preferably between 600 μs and 900 μs, even more preferably between 700 μs and 800 μs.

[0026] In one embodiment, the stimulator is configured to determine the current intensity based on the intensity determination procedure, wherein the current intensity is adjusted to a value between a stimulus perception threshold and a stimulus discomfort threshold.

[0027] In one embodiment, the stimulator is configured to selectively increase the intensity of electrical stimulation between at least two sleep periods; preferably, the electrical stimulation is increased by 1% to 25%.

[0028] In one embodiment, the stimulator is configured to selectively increase the intensity of electrical stimulation between each consecutive sleep period; preferably, the electrical stimulation is increased by 1% to 25%.

[0029] In one embodiment, the stimulator is configured to apply a timed electrical pre-stimulation current between the left and / or right electrodes and the target skin to reduce skin impedance.

[0030] In one embodiment, the stimulator is configured to apply a timed electrical pre-stimulation current between the left and / or right electrodes and the subject's skin, the current having a pulse width of approximately or less than 100 μm and / or a pulse frequency of approximately or greater than 100 Hz.

[0031] In one embodiment, the inter-electrode distance between at least two conductive elements of at least one electrode is between 15 mm and 25 mm, preferably between 16 mm and 24 mm, more preferably between 17 mm and 23 mm, even more preferably between 18 mm and 22 mm, even more preferably between 19 mm and 21 mm, and even most preferably about 20 mm.

[0032] In one embodiment, the diameter of at least one conductive element of at least one electrode is between 10 mm and 20 mm, preferably between 11 mm and 19 mm, more preferably between 12 mm and 18 mm, even more preferably between 13 mm and 17 mm, and even more preferably between 14 mm and 16 mm.

[0033] In one embodiment, the wearable device includes a sensing unit configured to record mandibular movements of an object and a processing unit operatively connected to the sensing unit; wherein the processing unit is configured to receive mandibular movement data from the sensing unit and to determine one or more mandibular features from the mandibular movement data. In one embodiment, the mandibular features include at least the position, rotation, or displacement of the mandible.

[0034] In one embodiment, the wearable device includes a sensing unit configured to record the movement of a subject's mandible and a processing unit operatively connected to the sensing unit; wherein the processing unit is configured to receive mandibular movement data from the sensing unit; and to determine one or more mandibular features from the mandibular movement data, preferably including at least the position, rotation, and / or displacement of the subject's mandible and / or head.

[0035] In one embodiment, the wearable device includes a sensing unit comprising at least one gyroscope and / or accelerometer configured to record jaw movements; wherein the sensing unit is mounted on the jaw of the subject.

[0036] In one embodiment, the wearable device includes a sensing unit mounted on a left electrode and / or a right electrode; preferably on the left masseter muscle and / or the right masseter muscle; preferably on a left electrode and / or a right electrode mounted on the left masseter muscle and / or the right masseter muscle.

[0037] In one embodiment, the processing unit is configured to receive respiratory activity data from the sensing unit and determine one or more respiratory features based on the respiratory activity data. In one embodiment, the respiratory features include at least sleep apnea characterized by increased breathing effort and / or sleep-disordered breathing.

[0038] In one embodiment, the processing unit is configured to determine a stimulus response from respiratory activity data, compare the stimulus response with a desired response, which includes a reduction in the respiratory effort of the sleeping subject, and adjust at least one stimulus parameter to achieve the desired response if a difference is determined between the stimulus response and the desired response. In one embodiment, the desired response includes adjusting at least one stimulus parameter, preferably adjusting the current intensity.

[0039] In one embodiment, the processing unit includes a breathing effort detection module configured to preferably detect an increase in breathing effort from one or more mandibular features in subject mandibular activity data, and to adjust one or more stimulation parameters and / or stimulation procedures to reduce breathing effort.

[0040] In one embodiment, when the breathing effort detection module detects an increase in breathing effort, it is configured to increase the current intensity by 10%, 20%, 30%, 40%, 50% or more, increase the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or decrease the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

[0041] In one embodiment, when the breathing effort detection module detects a decrease in breathing effort, it is configured to reduce the current intensity by 10%, 20%, 30%, 40%, 50% or more, reduce the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or increase the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

[0042] In one embodiment, the processing unit includes a respiratory disturbance detection module configured to preferably detect the presence of respiratory disturbance in mandibular movement data of a subject from one or more mandibular features, and to adjust one or more stimulation parameters and / or stimulation procedures to reduce, preferably prevent, the occurrence of respiratory disturbance.

[0043] In one embodiment, when a respiratory disturbance is detected, the respiratory disturbance detection module is configured to increase the current intensity by 10%, 20%, 30%, 40%, 50% or more, increase the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or decrease the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

[0044] In one embodiment, the processing unit includes a muscle fatigue detection module configured to preferably detect the presence of muscle fatigue in mandibular activity data of a subject from one or more mandibular features, and to adjust one or more stimulation parameters and / or stimulation procedures to reduce muscle fatigue.

[0045] In one embodiment, when muscle fatigue is detected, the muscle fatigue detection module is configured to reduce the current intensity by 10%, 20%, 30%, 40%, 50% or more, reduce the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or increase the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

[0046] In one embodiment, the muscle fatigue detection module is configured to terminate the recruitment process and / or initiate a rehabilitation process when muscle fatigue is detected.

[0047] In one embodiment, the muscle fatigue detection module is configured to detect the presence of fatigue in surrounding muscles or fibers; and, upon detection of fatigue in surrounding muscles or fibers, to adjust one or more stimulation parameters by reducing the current intensity preferably by 10%, 20%, 30%, 40%, 50% or more, preferably by activating stimulation defined by one or more stimulation parameters, which include a reduced current intensity of electrical stimulation.

[0048] In one embodiment, the muscle fatigue detection module is configured to detect the presence of fatigue in or on the spine; and when fatigue in or on the spine is detected, one or more stimulation parameters are adjusted by increasing the frequency, preferably by 10%, 20%, 30%, 40%, 50% or more, and / or increasing the pulse width of the electrical stimulation, preferably by activating stimulation defined by one or more stimulation parameters, which include the increased frequency and / or increased pulse width of the electrical stimulation.

[0049] In one embodiment, the processing unit is configured to receive sleep activity data from the sensing unit and determine one or more sleep features based on the sleep activity data. In one embodiment, the mandibular features include at least the subject's sleep state and / or sleep stage.

[0050] In one embodiment, the processing unit is configured to determine the sleep state of the subject based on sleep activity data, the sleep state including at least a waking state and / or a sleeping state; and to instruct the stimulator to initiate electrical stimulation during the sleeping state and / or terminate electrical stimulation during the waking state.

[0051] In one embodiment, the processing unit is configured to determine the subject's sleep stage based on sleep activity data, the sleep stage including at least a light sleep (N1) stage, a light sleep (N2) stage, a rapid eye movement (REM) stage, and / or a deep sleep (N3) stage; and instruct the stimulator to initiate electrical stimulation during the light sleep (N1 and / or N2) stage and / or the REM stage, and / or terminate electrical stimulation during the deep sleep (N3) stage.

[0052] In one embodiment, the processing unit includes a sleep stage determination module configured to determine the sleep stage of the object, which includes at least a waking state and a sleeping state, and to adjust one or more stimulation parameters and / or stimulation procedures when a change in the sleep stage is determined.

[0053] In one embodiment, when the sleep stage determination module detects a wakefulness stage, it is configured to preferably adjust one or more stimulation parameters and / or stimulation procedures and / or terminate electrical stimulation to reduce stimulation efficiency by terminating the recruitment procedure and / or reducing the current intensity by 10%, 20%, 30%, 40%, 50% or more, reducing the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or increasing the rest period in the work cycle by 10%, 20%, 30%, 40%, 50% or more.

[0054] In one embodiment, when the sleep stage determination module detects a sleep stage, it is configured to: preferably adjust one or more stimulation parameters and / or stimulation program and / or initiate electrical stimulation to improve stimulation efficiency by initiating a recruitment program and / or increasing the current intensity by 10%, 20%, 30%, 40%, 50% or more, increasing the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or reducing the rest period in the work cycle by 10%, 20%, 30%, 40%, 50% or more.

[0055] In one embodiment, the sleep stage determination module is further configured to determine a light sleep (N1 and / or N2) stage and / or a REM stage; and wherein, upon detecting a light sleep (N1 and / or N2) stage and / or a REM stage, the sleep stage determination module is configured to preferably adjust one or more stimulation parameters and / or initiate electrical stimulation to increase stimulation efficiency by increasing the current intensity by 10%, 20%, 30%, 40%, 50% or more, increasing the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or decreasing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

[0056] In one embodiment, the sleep stage determination module is further configured to determine a light sleep (N1 and / or N2) stage and / or a REM stage; and wherein, upon detecting a light sleep (N1 and / or N2) stage and / or a REM stage, the sleep stage determination module is configured to initiate a recruitment procedure and / or terminate a retraining procedure.

[0057] In one embodiment, the sleep stage determination module is further configured to determine a deep sleep (N3) stage; and wherein, upon detecting a deep sleep (N3) stage, the sleep stage determination module is configured to preferably adjust one or more stimulation parameters to reduce stimulation efficiency by decreasing the current intensity by 10%, 20%, 30%, 40%, 50% or more, decreasing the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or increasing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

[0058] In one embodiment, the sleep stage determination module is further configured to determine a deep sleep (N3) stage; and wherein, upon detecting a deep sleep (N3) stage, the sleep stage determination module is configured to terminate the recruitment process and / or initiate a retraining program.

[0059] In one embodiment, the processing unit is configured to determine the sleep state and / or stage by:

[0060] - Divide the mandibular movement data into specific time periods; and

[0061] - Apply mathematical models to assign sleep states and / or sleep stages to each period;

[0062] The mathematical model mentioned above includes the following steps:

[0063] - Extract at least one feature from the mandibular movement data of each recorded period;

[0064] - Track the values ​​of the extracted features at each period;

[0065] - Set feature-specific thresholds; and

[0066] - If the extracted feature value exceeds the feature-specific threshold, adjust the sleep state and / or sleep stage for the period.

[0067] In one embodiment, the sensing unit includes at least one gyroscope configured to record the jaw movements of an object.

[0068] In one embodiment, the sensing unit includes at least one gyroscope, at least one accelerometer, and optionally at least one magnetometer.

[0069] In one embodiment, the sensing unit is disposed on the left electrode and / or the right electrode.

[0070] In one embodiment, the wearable device includes a collar for accommodating a stimulator; wherein the collar is adapted to be placed around the neck of the subject and / or on the subject's shoulder.

[0071] In one embodiment, the left electrode and / or the right electrode are connected to the coil via a connecting cable, the length of which can be adjusted.

[0072] One aspect of this disclosure relates to a method for mounting electrodes on a selected portion of a subject's skin corresponding to a masseter muscle location, the method comprising the steps of:

[0073] (i) Identify the mandibular angle (Go), preferably the corner of the mandible;

[0074] (ii) Identify the zygomatic arch (Za), preferably the outer corner of the eye;

[0075] (iii) Identify the masseter muscle that extends from the angle of the mandible (Go) to the zygomatic arch (Za);

[0076] (iv) Identify a target stimulation area (S) on the masseter muscle, preferably extending from the angle of the mandible (Go) to approximately half the distance between the angle of the mandible (Go) and the zygomatic arch (Za) along the direction of the masseter muscle fibers; and

[0077] (v) The electrode is mounted on the target stimulation area (S).

[0078] In one embodiment of the method of installing the electrode, the electrode is a bipolar electrode comprising two conductive surfaces, wherein the first conductive element is preferably installed at the movement point of the masseter muscle adjacent to the angle of the mandible (Go), and the second conductive element is installed along the direction of the masseter muscle fibers, preferably at approximately half the distance between the angle of the mandible (Go) and the zygomatic arch (Za).

[0079] One aspect of this disclosure relates to a method for reducing the respiratory effort of a subject during sleep, the method comprising:

[0080] -A portion of the skin of a selected subject corresponding to the location of at least one left target muscle, including the left masseter, left pterygoid and / or left temporalis muscles, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the left target muscle and the second conductive element is installed along the direction of the left target muscle fibers.

[0081] -A portion of the skin of a selected subject corresponding to the location of at least one right target muscle, including the right masseter, right wing, and / or right temporalis muscle, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the right target muscle, and the second conductive element is installed along the direction of the right target muscle fibers.

[0082] - Biphasic transcutaneous electrical stimulation is applied between two conductive elements of left and right bipolar electrodes. This electrical stimulation promotes the contraction of target muscles to controllably elevate the subject's jaw, thereby reducing respiratory effort; wherein the electrical stimulation is generated according to a work cycle having a stimulation period of 1 to 20 seconds and / or a rest period of 1 to 20 seconds.

[0083] One aspect of this disclosure relates to a method for recruiting target muscles to reduce respiratory effort in a subject during sleep, the method comprising:

[0084] -A portion of the skin of a selected subject corresponding to the location of at least one left target muscle, including the left masseter, left pterygoid and / or left temporalis muscles, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the left target muscle and the second conductive element is installed along the direction of the left target muscle fibers.

[0085] -A portion of the skin of a selected subject corresponding to the location of at least one right target muscle, including the right masseter, right wing, and / or right temporalis muscle, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the right target muscle, and the second conductive element is installed along the direction of the right target muscle fibers.

[0086] - Biphasic transcutaneous electrical stimulation is applied between the two conductive elements of the left and right bipolar electrodes. This stimulation promotes the contraction of the target muscles to controllably elevate the subject's jaw, thereby reducing respiratory effort.

[0087] -The electrical stimulation is generated according to the following stimulation parameters: current intensity, between 5mA and 10mA, preferably between 6mA and 20mA; frequency, between 15Hz and 50Hz, preferably between 25Hz and 45Hz, more preferably between 30Hz and 40Hz; pulse width, between 50μs and 300μs, preferably between 225μs and 275μs, more preferably between 200μs and 250μs; and a work cycle having a stimulation period of 1 second to 20 seconds and / or a rest period of 1 second to 20 seconds.

[0088] One aspect of this disclosure relates to a method for rehabilitating the muscle function of a target muscle to reduce respiratory effort in a subject during sleep, the method comprising:

[0089] -A portion of the skin of a selected subject corresponding to the location of at least one left target muscle, including the left masseter, left pterygoid and / or left temporalis muscles, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the left target muscle and the second conductive element is installed along the direction of the left target muscle fibers.

[0090] -A portion of the skin of a selected subject corresponding to the location of at least one right target muscle, including the right masseter, right wing, and / or right temporalis muscle, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the right target muscle, and the second conductive element is installed along the direction of the right target muscle fibers.

[0091] - Biphasic transcutaneous electrical stimulation is applied between the two conductive elements of the left and right bipolar electrodes. This electrical stimulation promotes the contraction of the target muscles to controllably elevate the subject's jaw, thereby reducing respiratory effort.

[0092] -The electrical stimulation is generated according to the following stimulation parameters: current intensity, between 1 mA and 4 mA, preferably between 2 mA and 4 mA; frequency, between 15 Hz and 50 Hz, preferably between 20 Hz and 45 Hz, more preferably between 30 Hz and 40 Hz; pulse width, between 50 μs and 300 μs, preferably between 225 μs and 275 μs, more preferably between 200 μs and 250 μs; and a work cycle having a stimulation period of 1 second to 20 seconds and / or a rest period of 1 second to 20 seconds.

[0093] One aspect of this disclosure relates to a method for retraining neuromuscular circuits to reduce respiratory effort in a subject during sleep, the method comprising:

[0094] -A portion of the skin of a selected subject corresponding to the location of at least one left target muscle, including the left masseter, left pterygoid and / or left temporalis muscles, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the left target muscle and the second conductive element is installed along the direction of the left target muscle fibers.

[0095] -A portion of the skin of a selected subject corresponding to the location of at least one right target muscle, including the right masseter, right wing, and / or right temporalis muscle, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the right target muscle, and the second conductive element is installed along the direction of the right target muscle fibers.

[0096] - Biphasic transcutaneous electrical stimulation is applied between two conductive elements of a left bipolar electrode and a right bipolar electrode. This electrical stimulation promotes contraction of the target muscle to controllably elevate the subject's jaw, thereby reducing respiratory effort. The electrical stimulation is generated according to the following stimulation parameters: current intensity, between 1 mA and 4 mA, between 2 mA and 4 mA; frequency, between 50 Hz and 150 Hz, preferably between 70 Hz and 130 Hz, even more preferably between 90 Hz and 110 Hz; pulse width, between 500 μs and 1000 μs, preferably between 600 μs and 900 μs, more preferably between 700 μs and 800 μs; and a work cycle having a stimulation period of 1 second to 20 seconds and / or a rest period of 1 second to 20 seconds. Attached Figure Description

[0097] The following description of specific embodiments of this disclosure with accompanying drawings is merely exemplary in nature and is not intended to limit the teachings, their application, or uses.

[0098] In the accompanying drawings, the corresponding reference numerals indicate the following parts and features: stimulation area (S); superficial masseter muscle (SM); medial pterygoid muscle (MP); anterior temporalis muscle (AT); angle of mandible (Go); zygomatic arch (Za); wearable device (10); electrode (100); conductive element (110); connecting cable (150); wearable clothing (200), such as a hoop or headband.

[0099] Figure 1 This is an illustration of a stimulation area (S) on the target skin for positioning electrodes (100) according to a preferred embodiment of the present invention.

[0100] Figure 2 This is a schematic diagram of a wearable device (10) configured to stimulate the masseter muscle according to a preferred embodiment of the present invention.

[0101] Figure 3 This is a perspective view of a wearable device (10) configured to stimulate the masseter muscle according to another preferred embodiment of the present invention.

[0102] Figure 4 This is a perspective view of a wearable device (10) configured to stimulate the masseter muscle according to another preferred embodiment of the present invention.

[0103] Figure 5 This is a perspective view of a wearable device (10) configured to stimulate the masseter and / or temporalis muscles according to another preferred embodiment of the present invention.

[0104] Figure 6 This is a perspective view of a wearable device (10) configured for stimulating wing muscles according to another preferred embodiment of the present invention.

[0105] Figure 7 This is a side view of a skull with reference marks and lines for identifying stimulation areas (S) according to another preferred embodiment of the invention.

[0106] Figure 8 This is a side view of the head of a reference mark and line for identifying the stimulation region (S) according to another preferred embodiment of the present invention.

[0107] Figure 9 This is a placement guide illustrating a method for placing an electrode (100) on a stimulation region (S) according to another preferred embodiment of the invention.

[0108] Figure 10 This is a diagram of a bipolar electrode (100) according to a preferred embodiment of the present invention.

[0109] Figure 11 This is a schematic diagram illustrating the working principle of a wearable device (10) according to a preferred embodiment of the present invention.

[0110] Figure 12 The image shows jaw movements (MM data) recorded by a chin sensor for a sleep stage study discussed in Example 6.

[0111] Figure 13 The image shows jaw movements (MM data) recorded by a cheek sensor for a sleep stage study discussed in Example 6.

[0112] Figure 14 The frequency distribution of the standard deviation (SD) values ​​for sleep (light) and wakefulness (dark) states, as discussed in Example 6, is shown.

[0113] Figure 15 The sensitivity / specificity of all possible SD values ​​for detecting sleep and wakefulness states in sleep stage studies, as discussed in Example 6, are shown.

[0114] Figure 16 The frequency distribution of the maximum (MAX) values ​​for sleep (light) and wakefulness (dark) states, as discussed in Example 6, is shown.

[0115] Figure 17 The sensitivity / specificity for all possible maximum values ​​for detecting sleep and wakefulness, as discussed in Example 6, are shown.

[0116] Figure 18 The cutoff configuration parameters for a fixed cutoff model, as discussed in Example 6, are shown.

[0117] Figure 19 A table is shown with a data analysis algorithm configured for sobriety detection in a fixed cutoff model as discussed in Example 6.

[0118] Figure 20 A table is shown with a data analysis algorithm configured for balanced wakefulness / sleep state detection in a fixed cutoff model as discussed in Example 6.

[0119] Figure 21 A table with a data analysis algorithm is shown, which is configured for sleep state detection in a fixed cutoff model as discussed in Example 6.

[0120] Figure 22 The cutoff configuration parameters for a personalized cutoff model, as discussed in Example 6, are shown.

[0121] Figure 23 A table is shown with a data analysis algorithm configured for sobriety detection in a personalized cutoff model as discussed in Example 6.

[0122] Figure 24 A table is shown with a data analysis algorithm configured for balanced wakefulness / sleep state detection in a personalized cutoff model as discussed in Example 6.

[0123] Figure 25 A table with a data analysis algorithm is shown, which is configured for sleep state detection in a personalized cutoff model as discussed in Example 6.

[0124] Figure 26 A Bland-Altman plot comparing algorithmic data analysis of chin sensor data and cheek sensor data is shown.

[0125] Figure 27 A Bland-Altman plot showing a comparison of sleep / wake detection rules based on the standard deviation (SD) of chin sensor data and cheek sensor data.

[0126] Figure 28 A Bland-Altman plot showing a comparison of sleep / wake detection rules based on chin sensor data and the maximum value (MAX) of cheek sensor data. Detailed Implementation

[0127] This disclosure will be described with reference to specific embodiments, but is not limited thereto, but is defined only by the claims. Any reference numerals in the claims should not be construed as limiting their scope.

[0128] As used herein, the singular forms “a,” “an,” and “the” include both singular and plural references, unless the context clearly indicates otherwise.

[0129] As used herein, the terms “comprising,” “comprises,” and “comprised of” are synonymous with “including,” “includes,” “containing,” and “contains,” and are inclusive or open-ended, and do not exclude additional, unlisted members, elements, or method steps. The terms “comprising,” “comprises,” and “comprised of” also include embodiments “composed of” the stated members, elements, or method steps when referring to them.

[0130] The enumeration of numerical ranges by endpoints includes all numbers and fractions contained within each range, as well as the enumerated endpoints.

[0131] Furthermore, the terms first, second, third, etc., used in the specification and claims are used to distinguish similar elements and are not necessarily used to describe a sequence or chronological order, unless otherwise stated. It should be understood that the terms thus used are interchangeable where appropriate, and the embodiments of this disclosure described herein can operate in sequences other than those described or illustrated herein.

[0132] Unless otherwise defined, all terms used in this disclosure, including technical and scientific terms, have the meanings commonly understood by one of ordinary skill in the art to which this disclosure pertains. Further guidance, including definitions of the terms used in the specification, is provided to better understand the teachings of this invention. The terms or definitions used herein are for illustrative purposes only and are intended to aid in understanding the invention.

[0133] Throughout this specification, references to "one embodiment" or "embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout this specification do not necessarily refer to the same embodiment. Furthermore, in one or more embodiments, particular features, structures, or characteristics may be combined in any suitable manner, as will be apparent to those skilled in the art from this disclosure. Moreover, while some embodiments described herein include some but not all other features included in other embodiments, combinations of features from different embodiments should be within the scope of the invention and form different embodiments, as understood by those skilled in the art. For example, in the following claims and description, any claimed or described embodiment may be used in any combination.

[0134] The terms “left,” “right,” “front,” “rear,” “top,” “bottom,” “upper,” “lower,” etc. (if any) used in the specification and claims are for descriptive purposes and are not necessarily used to describe permanent relative positions. It should be understood that the terms thus used are interchangeable where appropriate, such that the embodiments described herein can operate in directions other than those shown or otherwise described herein. The term “coupled” as used herein is defined as a direct or indirect connection in an electrical or non-electrical (i.e., physical) manner. Objects described herein as “adjacent” to each other may be physically in contact with each other, very close to each other, or in the same general area or region as the phrase is used. The appearance of the phrases “in one embodiment” or “in one aspect” here does not necessarily refer to the same embodiment or aspect.

[0135] As used herein, the term "substantially" refers to the degree of completeness or near-completeness of an action, characteristic, property, state, structure, item, or result. For example, a "substantially" closed object means that the object is either completely closed or nearly completely closed. In some cases, the exact permissible deviation from absolute completeness may depend on the specific circumstances. However, in general, the degree of near-completeness will be the same as the overall result when absolute or complete completion is achieved. When "substantially" is used in a negative sense, it also applies to the complete or near-complete absence of an action, characteristic, property, state, structure, item, or result. For example, a composition that is "substantially free" of particles is either completely free of particles or nearly completely free of particles such that its effect is the same as being completely free of particles. In other words, a composition that is "substantially free" of a certain ingredient or element may still actually contain that ingredient or element, provided there is no measurable effect.

[0136] As used herein, the term "about" is used to provide flexibility for the endpoints of a numerical range by specifying that a given value can be "slightly above" or "slightly below" the endpoints. Unless otherwise stated, the use of the word "about" in relation to a particular number or range should also be understood to support such numerical terms or ranges in the absence of "about". For example, for convenience and brevity, a numerical range of "about 50 angstroms to about 80 angstroms" should also be understood to support a range of "50 angstroms to 80 angstroms". Furthermore, it should be understood that in this specification, even when the term "about" is used, support for actual numerical values ​​is provided. For example, listing "about" 30 should be interpreted as supporting not only values ​​slightly above and slightly below 30, but also the actual value of 30.

[0137] This specification may refer to apparatus, structures, systems, or methods that provide “improved” performance. It should be understood that, unless otherwise stated, such “improvement” is a measure of benefit obtained based on comparison with prior art apparatus, structures, systems, or methods. Furthermore, it should be understood that the degree of performance improvement may vary between the disclosed embodiments, or that the implementation of the improved performance is assumed to be generally applicable.

[0138] Furthermore, it should be understood that embodiments of this disclosure may include hardware, software, and electronic components or modules, which, for the purposes of discussion, may be illustrated and described as if most components were implemented solely in hardware. However, those skilled in the art will recognize that, in at least one embodiment, the electronic aspects of this disclosure may be implemented in software executable by one or more processing units (e.g., instructions stored on a non-transitory computer-readable medium), such as microprocessors and / or application-specific integrated circuits (“ASICs”). Therefore, it should be noted that the invention may be implemented using multiple hardware and software-based devices and multiple different structural components. For example, the “server” and “computing device” described in the specification may include one or more processing units, one or more computer-readable medium modules, one or more input / output interfaces, and various connections of connecting components (e.g., system buses).

[0139] As described above, there is a need to remedy the problems and limitations of existing treatments for sleep-disordered breathing characterized by respiratory effort (SDB). This disclosure relates to apparatus and methods for reducing respiratory effort in a sleeping subject and / or preventing the occurrence of sleep-disordered breathing. In particular, this disclosure aims to provide transcutaneous electrical stimulation to the muscles controlling jaw movement in a subject to modulate their contribution to sleep breathing activity and reduce respiratory effort in the subject during or after sleep.

[0140] Electrical stimulation of muscles can be applied during time-limited periods, referred to throughout this disclosure as stimulation periods. Stimulation periods according to this disclosure can be configured to achieve therapeutic effects, such as reducing the occurrence of sleep-disordered breathing or sleep-disordered breathing, or they can be configured for non-therapeutic purposes, such as reducing snoring or sleep-related noise, or improving sleep quality. The time limit of the period can be predetermined or variable.

[0141] Therefore, this disclosure relates to a wearable device for providing transcutaneous electrical stimulation to the muscles controlling jaw movement in a subject to reduce respiratory effort during sleep and / or prevent sleep-disordered breathing. Furthermore, this disclosure aims to provide retraining of the subject's brain through the provided electrical stimulation to reduce central respiratory drive in the stimulated muscles.

[0142] Furthermore, this disclosure also relates to wearable devices for monitoring the stimulus response of a sleeping subject, preferably in response to transcutaneous electrical stimulation provided by a wearable device disclosed herein for providing transcutaneous electrical stimulation. The wearable device can be configured to determine the stimulus response directly through the physiological response of the sleeping subject to electrical stimulation, or indirectly through the effects achieved by the electrical stimulation, such as a reduction in the subject's respiratory effort and / or the occurrence of sleep apnea.

[0143] Furthermore, this disclosure also relates to wearable devices for monitoring the respiratory activity of sleep subjects. The wearable device can be configured to identify sleep-disordered breathing characterized by increased respiratory effort and / or the occurrence of sleep-disordered breathing. The wearable device for monitoring the respiratory activity of sleep subjects can be linked to or combined with a wearable device for providing transcutaneous electrical stimulation as described herein.

[0144] Furthermore, this disclosure also relates to wearable devices for monitoring the sleep activity of a sleep subject. The wearable device can be configured to determine the sleep state of the subject, which may include a wakeful state and a asleep state, and / or the sleep stage of the sleep subject, which may include a light sleep (N1) stage, a light sleep (N2) stage, a rapid eye movement (REM) stage, and / or a deep sleep (N3) stage. The wearable device for monitoring the sleep activity of a sleep subject can be used to adjust transcutaneous electrical stimulation. The wearable device for monitoring the sleep activity of a sleep subject can be linked to or combined with a wearable device for providing transcutaneous electrical stimulation as described herein.

[0145] Selective electrical stimulation of the muscles controlling mandibular movement allows for the controlled movement of the mandible to an elevated anterior position during sleep, followed by stabilization in this position. The mandible can act as a lever to reinforce the entire pharyngeal muscle tissue, which is anchored to the mandibular arch and controls the opening of the upper airway. By finely adjusting the position of the mandible, the relationship between muscle fiber tension and its length, and between fiber force and its velocity, can be controlled. The genioglossus muscle anchors itself to the elevated position of the mandible, potentially further contributing to the opening of the upper airway. Additionally, attached muscles can elevate the hyoid bone to an even higher superior position. The functional result is pharyngeal dilation to essentially open the upper airway and instruct the brain to reduce the necessary respiratory effort.

[0146] Muscles used to control mandibular movement may include levator muscles (i.e., muscles that contract to elevate the mandible), including the upper bellies of the masseter, temporalis, medial pterygoid, and lateral pterygoid muscles, and / or depressor muscles (i.e., muscles that contract to lower the mandible), including the anterior belly of the digastric muscle, geniohyoid, mylohyoid, and lower bellies of the lateral pterygoid muscles. It should be understood that any reference to electrical stimulation of “muscle” as used herein refers to stimulation of the listed levator and / or depressor muscles. Embodiments of this disclosure may provide stimulation of a single muscle type, such as only the masseter, only the pterygoid, or only the temporalis. Figure 2 An example of stimulation of only the masseter muscle is shown in the figure. Figure 6 An example of stimulation of only the pterygoid muscles is shown. Another embodiment of this disclosure may provide dual stimulation of two different muscle types, such as the masseter and temporalis, the masseter and pterygoid, the temporalis and pterygoid, or the masseter and temporalis and pterygoid, sequentially or simultaneously, to achieve mandibular elevation and stabilization. Figure 5 An example of dual stimulation of the masseter and temporalis muscles is shown. Another embodiment of this disclosure may provide triple stimulation of three different muscle types, such as the masseter, temporalis, and pterygoid muscles, sequentially or simultaneously, to achieve mandibular elevation and stabilization.

[0147] Electrical stimulation of the muscles used to control mandibular movement can also have secondary effects on other muscles attached to the mandible. For example, the genioglossus is anchored to the mental spine (located on the inner surface of the midline of the mandible, the bony point on which the genioglossus hangs) on the medial side of the mandible—therefore, when the mandible is moved during elevation, stimulation according to this disclosure alters the spatial position of the anterior attachment point of the genioglossus. This may change the resting length of the genioglossus fibers by traction, a well-known condition that causes contraction of anchored fibers (myosal reflex). The risk of tongue dryness is minimal when the mouth is closed. Choking and gasping are avoided because the tongue remains in the anterior position of the oral cavity.

[0148] Furthermore, regarding the floor muscles (mylohyoid-geniohyoid-anterior belly of the digastric muscle): When the mandible elevates, it creates leverage on the floor muscles, which contract and stiffen the upper airway, while the position of the hyoid bone is adjusted by other posterior and inferior muscles. Essentially, the mandible is a movable bone with several upper airway muscle attachments from surrounding locations. The mandible moves with active muscle contractions. This movement causes the applied load to shift from one direction to other areas of the upper airway. The masseter muscle shifts the mandible to an upper and anterior position, which also allows another movable hyoid bone to improve upper airway patency. These muscles, directly or indirectly attached to the mandible, have an intricate relationship with the ultimate goal during sleep: ensuring local airflow circulation, while the diaphragm contracts and creates subatmospheric pressure in the upper airway.

[0149] It has been found that stimulation of the masseter, pterygoid, and / or temporalis muscles is particularly effective for controlling and stabilizing mandibular elevation, thus forming the preferred embodiments of this disclosure, particularly stimulation of the superficial masseter (SM), medial pterygoid (MP), and anterior temporalis (AT). More specifically, the masseter, pterygoid, and / or temporalis muscles are specifically designed for mandibular elevation, thereby closing the oral cavity. These muscles are highly specialized and trained to perform this task. They exhibit excellent endurance and resistance due to their unique fibromuscular isotypes not found in other muscle groups in the human body. They are also involved in other important life functions: chewing, swallowing, and speaking. When the masseter and / or temporalis muscles are stimulated, neurons develop in representative areas of the motor cortex, similar to tongue motor learning (neuroplasticity induced in the cortical motor control of the mandibular muscles—cortical neuroplasticity is the brain's ability to enhance specific skills through practice and adapt to or compensate for changes in sensory input).

[0150] Furthermore, focusing stimulation solely on the masseter, pterygoid, and / or temporalis muscles can reduce discomfort and decrease muscle fatigue. These effects can be observed, for example, when stimulation is focused on too many different muscles simultaneously and / or on muscles considered uncomfortable and / or easily fatigued (such as the tongue). Therefore, exclusive stimulation of the masseter, pterygoid, and / or temporalis muscles forms another preferred embodiment of this disclosure.

[0151] There are different methods to achieve electrical stimulation of muscles, each eliciting a unique physiological response, resulting in different technical effects and advantages. This disclosure envisions at least three different methods for achieving electrical stimulation, specifically, recruiting muscle fibers, rehabilitating muscle function, and retraining neuromuscular circuits (by stimulating muscles).

[0152] More specifically, muscle fiber recruitment refers to the direct and acute response of muscles to electrical stimulation, with directly measurable effects. Therefore, recruitment can be considered a "basic" procedure for controlling jaw movement during stimulation, but it typically does not provide a sustained effect after the stimulation process ends (i.e., when the stimulator is turned off).

[0153] Muscle function rehabilitation refers to training muscles through electrical stimulation, which may enhance the beneficial effects of stimulation over consecutive stimulation sessions. Therefore, rehabilitation can be considered an "advanced" program that can provide delayed and beneficial, sustained effects, but may require more than one session, such as multiple consecutive stimulations, to achieve those effects.

[0154] Retraining of neuromuscular circuits refers to the central effect of electrical stimulation on centrally driven processes (central neural circuits targeting respiratory activity in the motor branch of the trigeminal nerve in the brain of the subject), with the primary aim of achieving a sustained response after the stimulation period ends or is interrupted. Therefore, retraining can be considered an "advanced" procedure that provides a sustained effect after the stimulation period ends (i.e., when the stimulator is turned off), but may require more than one session, such as multiple consecutive stimulation periods, to achieve the desired effect.

[0155] Understandably, this initial overview of the stimulation methods is intended only to help the reader quickly grasp the differences between the methods. Throughout this disclosure, specific embodiments of each method will be discussed, for example, in the form of procedures to be performed by the stimulator disclosed herein.

[0156] During general stimulation, this disclosure provides a process for adjusting central respiratory drive to reduce the active effort required for breathing, thereby protecting the sleep subject from harmful sympathetic stress caused by respiratory disturbances. Furthermore, this disclosure provides a retraining process for central respiratory drive to reduce natural muscle drive and restore ventilation, a benefit that can persist after stimulation. These processes can also improve airflow, SpO2, noise, orofacial motor dysfunction, etc. Therefore, this disclosure can be applied to treat various disorders associated with sleep apnea characterized by respiratory effort (SDB), such as airway obstruction or collapse. Additionally, the device can help reduce the occurrence and / or intensity of snoring.

[0157] The mandibular elevation achieved by this disclosure can open the upper airway or upper respiratory tract by increasing the width of the upper airway and / or reducing its collapse. The degree of mandibular elevation can be expressed as a percentage of maximum protrusion capacity or / and millimeters (mm). The percentage of maximum protrusion capacity may be related to potential side effects, while the percentage or millimeters may be related to the effectiveness of opening the upper airway. Exemplary protrusion positions can include 10% to 90% of maximum mandibular protrusion.

[0158] It has been observed that recruiting and retraining muscles for controlling mandibular movement with “mild” transcutaneous electrical stimulation has not yielded sufficient results. However, this disclosure provides evidence that closing the mandible forcefully for a sufficiently long period can provide improved short-term and / or long-term outcomes. These outcomes can be therapeutic in nature (e.g., by reducing the occurrence of sleep-disordered breathing or sleep-disordered breathing) or they can be non-therapeutic (e.g., by reducing sleep-related noise levels or improving sleep quality). Advantageously, short-term and / or long-term effects can be combined to achieve an effective stimulus response by first recruiting stimulated muscles and then further retraining these stimulated muscles to improve stimulus response and / or achieve sustained effects after stimulation termination. In this way, synergistic effects beyond the benefits of local stimulation methods in the art can be achieved.

[0159] In the context of electrical stimulation, "sufficiently strong closure" refers to the electrical intensity experienced by a user in a quiet position before falling asleep at the onset of stimulation, a spontaneous (involuntary) tendency to close the mouth. The strength of the closure can be measured clinically using a dynamometer (minimum contractile force (F), minimum % of muscle fibers) or mandibular movements (amplitude variation, mandibular position). In the case of electrical stimulation, "sufficiently long closure" refers to the time the mandible is held in an elevated and forward position, which ensures air circulation. For example, the mandible can be raised to close the mouth during the stimulation phase of a work cycle, and then held elevated during the rest phase of the work cycle. The length of the closure can be measured clinically using an airflow meter (airflow amplitude (%)) or mandibular movements (time and frequency, mandibular position). The measurement of stimulation effects is discussed in Example 3.

[0160] The following provides an initial overview of various aspects of this disclosure, followed by a detailed description of specific embodiments. This initial overview is intended to help the reader quickly understand the technical concepts, but is not intended to identify its key or essential features, nor to limit the scope of the claimed subject matter. Those skilled in the art will understand that, unless otherwise stated, aspects can be combined. Thus, any particular embodiment of a particular aspect can be understood to constitute a particular embodiment of another aspect without requiring explicit discussion therein. For example, embodiments of the apparatus described below also form embodiments of the manufacture of the apparatus, the use of the apparatus, etc.

[0161] One aspect of this disclosure relates to a wearable device for reducing respiratory effort in a subject during sleep, the device comprising:

[0162] - At least one left electrode, adapted to be positioned in electrical contact with a selected portion of the subject's skin from the left muscle movement point to the left posterior angle of the mandible;

[0163] - At least one right electrode, adapted to be positioned in electrical contact with a selected portion of the subject's skin from the right muscle movement point to the right posterior angle of the mandible;

[0164] - A stimulator is configured to apply transcutaneous electrical stimulation from a left electrode to at least one left muscle and from the right electrode to at least one right muscle; wherein the applied electrical stimulation promotes contraction of the stimulated muscles on the left and right sides to controllably elevate the subject's jaw.

[0165] In one embodiment, at least one left electrode may be adapted to be positioned in electrical contact with a selected portion of the subject's skin, the selected portion extending from the left masseter, pterygoid, and / or temporalis muscle movement point to the left posterior angle of the mandible, and the stimulator is configured to apply transcutaneous electrical stimulation from the left electrode to at least one left masseter, pterygoid, and / or temporalis muscle.

[0166] In one embodiment, at least one right electrode may be adapted to be positioned in electrical contact with a selected portion of the subject's skin, the selected portion extending from the motility point of the right masseter, pterygoid, and / or temporalis muscles to the right posterior angle of the mandible, and the stimulator is configured to apply transcutaneous electrical stimulation from the right electrode to at least one right masseter, pterygoid, and / or temporalis muscle.

[0167] The electrodes, preferably left and right electrodes, can transmit electrical stimulation generated by the stimulator to the target muscles. According to one embodiment, two or more electrodes may be provided, at least one on each side of the mandible, particularly left and right electrodes, thereby enabling bilateral stimulation of the target muscles.

[0168] In one embodiment, the electrode may have a conductive element with a diameter between 10 mm and 20 mm, preferably between 11 mm and 19 mm, more preferably between 12 mm and 18 mm, even more preferably between 13 mm and 17 mm, and even more preferably between 14 mm and 16 mm, for example, about 15 mm. Typically, a circular conductive element, i.e., a conductive element with a circular surface area, can be used, but other geometries, such as elliptical elements, square elements, triangular elements, etc., are also contemplated. This allows coverage of the most prominent muscle volume to achieve an effective stimulation response. In another embodiment, a diameter of 10 mm or less can be used, and still allows coverage of the most prominent muscle mass to specifically stimulate smaller or narrower muscles, such as the surface of the temporalis muscle.

[0169] In one embodiment, the electrode may be a bipolar electrode, i.e., each electrode includes two conductive elements applied between the target stimulation area and the tendon. Figure 10 An example of a bipolar electrode with two adjacent conductive elements is shown. The distance between adjacent conductive elements of the bipolar electrode is defined as the interelectrode distance. The interelectrode distance has a significant impact on the comfort of stimulation. If comfort is improved, the patient may achieve a higher current intensity, thereby improving the effectiveness of treatment. In one embodiment, the interelectrode distance can be between 10 mm and 30 mm, preferably between 15 mm and 25 mm, preferably between 16 mm and 24 mm, more preferably between 17 mm and 23 mm, even more preferably between 18 mm and 22 mm, even more preferably between 19 mm and 21 mm, and even more preferably about 20 mm. Generally, a smaller interelectrode distance, such as 10 mm to 15 mm, can be selected for stimulating smaller muscles, and a larger interelectrode distance, such as 20 mm to 30 mm, can be selected for stimulating larger muscles, such as the temporalis muscle. Advantageously, adjacent surface electrodes can be aligned with the muscle fiber direction to stimulate the same motor unit twice, but spatially offset along the muscle.

[0170] In one embodiment, the electrodes can be repeatedly attached to the skin. Repeated attachment facilitates the reusability of the device during continuous sleep periods. During normal head and body movements, the electrodes can be easily attached to the appropriate position. The electrodes can be provided with an adhesive surface, which allows for easy attachment to the skin. Each electrode can be provided with a surface suitable for removable attachment to the skin. Advantageously, each electrode can be configured to ensure conductivity, thereby improving comfort and effectiveness.

[0171] In one embodiment, the electrode surface may be provided with an adhesive hydrogel to ensure low-resistance contact between the electrode and the skin. The electrode surface may be replaceable when the adhesive layer wears down due to repeated use, or the adhesive layer may be replenished alternatively. In an alternative embodiment, disposable electrodes may be considered. In another embodiment, electrodes with disposable, replaceable surfaces may be provided.

[0172] A stimulation device, or "stimulator" as used herein, typically includes a power source configured to generate an electric current and a controller operatively connected to said power source. The controller may control the power source to generate the current according to stimulation parameters disclosed herein to promote contraction of the stimulated muscle. The power source may be battery-operated, allowing the device to be worn freely during sleep. Electrodes may be connected to the stimulator via wires. Exemplary embodiments thereof will be described further below.

[0173] Bilateral electrodes can provide simultaneous stimulation to opposing left and right muscles. In some embodiments, the stimulation provided along the left and right electrodes can be equal. However, in other embodiments, the stimulation along the left and right electrodes can be different, allowing different programs to be programmed according to the type of treatment. Multiple controllers or a single controller can be used to perform unequal stimulation, and these controllers or single controllers are configured to perform separate stimulation programs for the left and right electrodes based on differences in anatomical structure; for example, in an object with more defined muscles on one side of the jaw.

[0174] The controller can be configured to execute the methods proposed herein. Embodiments can be implemented in code and can be stored on a storage medium having instructions stored thereon, which can be used to program the system to execute the instructions. For the purposes of this disclosure, the terms "code" or "program" cover a wide range of components and constructs, including application programs, drivers, processes, routines, methods, modules, and subroutines. Therefore, the terms "code" or "program" can be used to refer to any set of instructions that, when executed by a processing system, perform the desired operations. Furthermore, alternative embodiments may include processes using fewer than all disclosed operations, processes using additional operations, processes using the same operations in a different order, and processes in which the various operations disclosed herein are combined, subdivided, or otherwise modified. Those skilled in the art can implement the methods proposed herein as code or programs and will understand many modifications and variations thereon.

[0175] The way the generated current is used to percutaneously stimulate target muscles can be influenced by a variety of factors. Continuous low-current application generally requires less force than intermittent stimulation because maintaining an open upper airway is easier than reopening an obstructed one. Nevertheless, it is beneficial to avoid prolonged, continuous stimulation, as this can adversely affect muscle fatigue and sleep quality. Therefore, selecting optimal stimulation parameters, including current intensity (mA), pulse frequency (Hz), pulse width (μs), and / or stimulation duration (e.g., continuous, intermittent, triggered), is crucial for promoting effective muscle responses while avoiding adverse effects. Furthermore, the choice of specific stimulation parameters can also elicit different physiological responses, particularly in recruiting muscle fibers, rehabilitating muscle function, and retraining neuromuscular circuits (through muscle stimulation).

[0176] A pulsed current can be formed by applying a regular stimulation pattern with a controlled rhythm. In one embodiment, the current is a biphasic current, characterized by one or more single stimulation parameters, such as biphasic current intensity, pulse frequency, pulse width, and / or stimulation duration. Depending on specific factors of the subject, such as age, weight, skin type, etc., different combinations of signal parameters tend to be suitable for different subjects. For example, biphasic currents may be particularly suitable for muscle recruitment, rehabilitation, and / or retraining. However, as mentioned above, some stimulation parameters carry the risk of inducing muscle fatigue or affecting sleep quality. Various stimulation parameters are listed below, which have been found to offer a particularly good trade-off between effectiveness and the risk of side effects.

[0177] In a typical embodiment, the current intensity can be selected from at least 1 mA to at most 50 mA, or 1 mA to 45 mA, or 1 mA to 40 mA, or 1 mA to 35 mA, more preferably from 1 mA to 30 mA, or 1 mA to 25 mA, or 5 mA to 25 mA, and even more preferably from 10 mA to 20 mA, or 15 mA to 20 mA, or 10 mA to 15 mA. Variations in signal intensity can affect muscle contractility. The stimulation intensity can typically be a primary stimulation parameter adjusted according to the subject's needs and discomfort threshold.

[0178] In a general embodiment, the pulse frequency can be selected between at least 1 Hz and at most 100 Hz, more preferably between 10 Hz and 90 Hz, or 10 Hz and 85 Hz, or 10 Hz and 80 Hz, or 15 Hz and 75 Hz, or between 15 Hz and 70 Hz, even more preferably between 20 Hz and 60 Hz, or 25 Hz and 55 Hz, more preferably between 30 Hz and 50 Hz, and even more preferably about 40 Hz, for example, 35 Hz and 45 Hz. Variations in the signal frequency may affect muscle contractile force. To achieve proper contraction, a suitable frequency can be selected within the wide range described above, and a preferred narrow range is more suitable.

[0179] In general embodiments, the pulse width can be selected between at least 50 μs and at most 1000 μs, preferably between 100 μs and 500 μs, or between 100 μs and 400 μs, more preferably between 125 μs and 375 μs, or between 150 μs and 350 μs, or between 175 μs and 325 μs, even more preferably between 200 μs and 300 μs, and even more preferably about 250 μs, for example, between 225 μs and 275 μs. Variations in the signal pulse width may affect the muscle contraction time. The signal pulse width can also be varied according to the needs and discomfort threshold of the subject.

[0180] The duration of stimulation can be biphasic, thus consisting of two repetitive phases or periods, specifically a stimulation period (i.e., an "on" period) followed by a non-stimulatory rest period (i.e., a "off" period); the difference between the stimulation period and the rest period is defined as a work cycle. In one embodiment, the stimulation period can be between at least 1 second and at most 20 seconds, or between 1 second and 15 seconds, or between 1 second and 10 seconds, more preferably between 2 seconds and 8 seconds, even more preferably between 3 seconds and 7 seconds, even more preferably between 4 seconds and 6 seconds, even more preferably 5 seconds. In one embodiment, the rest period can be between at least 1 second and at most 20 seconds, or between 1 second and 15 seconds, or between 1 second and 10 seconds, more preferably between 2 seconds and 8 seconds, even more preferably between 3 seconds and 7 seconds, even more preferably between 4 seconds and 6 seconds, even more preferably 5 seconds. The duration of the stimulation and rest periods can be symmetrical, such as 5 seconds of stimulation followed by 5 seconds of rest, or asymmetrical, such as 5 seconds of stimulation followed by 10 seconds of rest or 10 seconds of stimulation followed by 5 seconds of rest. The duration and / or relative ratio of the stimulation and rest periods can be adjusted for specific physiological effects. For example, the stimulation period can be increased and / or the rest period decreased to promote muscle stimulation. Conversely, the stimulation period can be decreased and / or the rest period increased to reduce muscle fatigue.

[0181] The specified values ​​provided above offer general guidelines for selecting one or more stimulation parameters suitable for achieving a physiological response from a sleeping subject. However, by selecting more specific stimulation parameters, the physiological response can be directed toward a particular physiological effect. Those skilled in the art will understand that these stimulation parameters can be executed in the form of an executable stimulation program by the wearable stimulation device disclosed herein. At least three different stimulation programs are envisioned in this disclosure for achieving electrical stimulation, specifically recruiting muscle fibers, rehabilitating muscle function, and retraining neuromuscular circuits. However, it should be understood that the wearable device of this disclosure is not limited to these three different stimulation programs.

[0182] In one embodiment, stimulation for muscle fiber recruitment, referred herein as a “recruitment procedure,” may include transcutaneous electrical stimulation (as opposed to rehabilitation and retraining procedures) at low frequencies with high current intensity and narrow pulse width. This recruitment procedure is designed to provide a direct and acute muscle response with directly measurable effects for controlling mandibular movement during stimulation, but typically does not provide sustained effects after the stimulation process (i.e., when the stimulator is turned off).

[0183] The exact parameters of the recruitment procedure are subject-specific; they depend on the subject's bodily response to stimulation and the degree of discomfort perceived. In one embodiment, the current intensity of the recruitment procedure can be selected between 5 mA and 10 mA, preferably between 6 mA and 10 mA, such as 7 mA, 8 mA, or 9 mA. In a specific embodiment, the frequency of the recruitment procedure can be selected between 10 Hz and 50 Hz, preferably 15 Hz to 50 Hz, or 20 Hz to 50 Hz, or 25 Hz to 45 Hz, or 25 Hz to 45 Hz, or 30 Hz to 40 Hz, such as 30 Hz. In one embodiment, the pulse width of the recruitment procedure can be selected between 25 μs and 300 μs, preferably 50 μs to 275 μs, 50 μs to 250 μs or 75 μs to 275 μs, or 100 μs to 275 μs, 125 μs to 275 μs, 150 μs to 275 μs, 175 μs to 275 μs, 200 μs to 275 μs or 200 μs to 250 μs; for example 210 μs, 220 μs, 230 μs, 240 μs or 250 μs.

[0184] In one embodiment, stimulation for rehabilitating muscle function, referred to herein as a "rehabilitation program," may include transcutaneous electrical stimulation (as opposed to recruitment and retraining programs) at low frequencies with low current intensity and narrow pulse width. The purpose of the rehabilitation program may be to improve muscle function of the stimulated muscles, such as improving contractility and / or reducing perceived discomfort. The rehabilitation program can provide an improved muscle response to the stimulation, which may enhance the beneficial effects of the stimulation over multiple, preferably consecutive, time periods.

[0185] The exact parameters of the rehabilitation program are subject-specific; they depend on the subject's physical response to stimulation and the degree of discomfort perceived, such as whether the subject suffers from a muscular or respiratory disorder. In one embodiment, the current intensity of the rehabilitation program can be selected between 1 mA and 4 mA, preferably between 2 mA and 4 mA, for example, 3 mA. In one embodiment, the frequency of the rehabilitation program can be selected between 10 Hz and 50 Hz, preferably between 15 Hz and 50 Hz, or 20 Hz to 50 Hz, or 25 Hz to 45 Hz, or 25 Hz to 45 Hz, or 30 Hz to 40 Hz, for example, 30 Hz. In one embodiment, the pulse width of the rehabilitation procedure can be selected between 25 μs and 300 μs, preferably between 50 μs and 275 μs, 50 μs and 250 μs, or 75 μs and 275 μs, or 100 μs and 275 μs, 125 μs and 275 μs, 150 μs and 275 μs, 175 μs and 275 μs, or 200 μs and 270 μs; for example, 210 μs, 220 μs, 230 μs, 240 μs, or 250 μs.

[0186] In one embodiment, stimulation for retraining neuromuscular circuits, referred to herein as a "retraining procedure," may include transcutaneous electrical stimulation (as opposed to recruitment and rehabilitation procedures) at a higher frequency with low current intensity and a wide pulse width. The retraining procedure may be designed to retrain neuromuscular circuits to alter the central effects of stimulation on central drives, i.e., it targets central neural circuits involved in respiratory activity of the trigeminal motor branch of the subject's brain. The retraining procedure may achieve a sustained response after the termination or even interruption of a time period, but may require multiple, preferably consecutive, time periods.

[0187] The exact parameters of the recruitment procedure are subject-specific; they depend on the subject's physical response to stimulation and the degree of perceived discomfort, such as whether the subject suffers from a muscle or respiratory disorder. In one embodiment, the current intensity of the retraining procedure can be selected between 1 mA and 4 mA, preferably between 2 mA and 4 mA, for example, 3 mA. In one implementation, the frequency of the retraining procedure can be selected between 50 Hz and 150 Hz, preferably between 60 Hz and 140 Hz, or 70 Hz and 130 Hz, or 80 Hz and 120 Hz, or 90 Hz and 110 Hz, for example, 100 Hz. In one embodiment, the pulse width of the retraining procedure can be selected between 500 μs and 1000 μs, preferably between 550 μs and 950 μs, more preferably between 600 μs and 900 μs, even more preferably between 650 μs and 850 μs, even more preferably between 700 μs and 800 μs; for example, 750 μs.

[0188] The stimulator can be configured to set the intensity of electrical stimulation based on a stimulation intensity parameter determined according to a stimulation perception threshold and a stimulation discomfort threshold. The current intensity of transcutaneous electrical stimulation may depend on the subject's sensitivity threshold and habits. Optimal stimulation intensity can provide a user-personalized program to adapt to variations in subject-specific parameters, such as skin conductivity, muscle thickness, fat or adipose tissue thickness, etc. In one embodiment, the current intensity of electrical stimulation is adjusted to a value between the stimulation perception threshold and the stimulation discomfort threshold. For example, the current intensity can be set at half the stimulation perception threshold and the stimulation discomfort threshold, i.e., half (1 / 2) of the sum of the stimulation perception threshold (in milliamperes (mA)) and the stimulation discomfort threshold (in mA). Alternatively, depending on the type of treatment, the current intensity parameter can be set to one-quarter (1 / 4) or three-quarters (3 / 4) of the stimulation perception threshold and the stimulation discomfort threshold.

[0189] Stimulation intensity parameters can be determined via user input. In one embodiment, the stimulator can be configured to connect to an input device, such as a smartphone, and receive object-specific input from said input device. The input device can prompt the user to input a stimulation perception threshold and a stimulation discomfort threshold. The stimulation perception threshold corresponds to the lowest intensity of electrical stimulation at which the object still perceives the electrical stimulation to promote target muscle contraction, and the stimulation discomfort threshold corresponds to the highest intensity of electrical stimulation at which the object feels a certain degree of discomfort, such as muscle pain, due to the pulsed current, which may affect sleep quality.

[0190] The stimulator can be equipped with a stimulation intensity determination procedure configured to automatically determine optimal stimulation intensity parameters. For example, the stimulator can set a predefined intensity based on object-specific parameters (e.g., age or gender), then gradually increase the current until the object reports a perceived discomfort event, and then gradually decrease the current until the object reports a lack of perceived stimulation. The stimulator can then calculate the optimal stimulation intensity parameters based on the reported discomfort and perception thresholds. Alternatively, the stimulator can be selectively operated by the user to apply stimulation intensity based on user input. If the optimal intensity parameters are known, for example, from previous time intervals, this allows the user to quickly set up the device. Those skilled in the art will understand that detection procedures can also be provided for other stimulation parameters (e.g., pulse frequency or width).

[0191] The stimulator can be configured to selectively increase the intensity of electrical stimulation based on device and / or user feedback. Repeated periods of transcutaneous electrical stimulation can reduce muscle responses over time, thereby increasing the stimulation perception threshold. Furthermore, the subject may become accustomed to the electrical stimulation, thereby increasing the stimulation discomfort threshold. To avoid the need for user recalibration, the stimulator can be configured to automatically adjust the stimulation intensity between at least two sleep periods. Preferably, the stimulation intensity is adjusted between each and every two consecutive sleep periods. Alternatively, the stimulation intensity can be adjusted when a specific therapeutic goal is achieved, such as a decrease in the percentage of snoring intensity or an increase in the percentage of muscle strength. In one embodiment, the stimulator can automatically increase the stimulation intensity at a fixed rate, such as an increase of 1% to 25% per sleep period. Alternatively, the user can be prompted to manually adjust the stimulation intensity.

[0192] The stimulator can be configured to apply a pre-stimulatory current to improve the response of stimulated muscles to transcutaneous electrical stimulation. Specifically, the stimulator can be configured to apply a time-limited high-frequency current from the left and / or right electrodes to the subject's skin to reduce skin impedance. Skin typically exhibits a certain resistivity to the passage of current, which may decrease over time. However, in certain subject groups with higher skin resistivity (e.g., older adults or people of color), a decrease in skin resistance may take longer to occur. Furthermore, high resistivity means that the current is primarily established on the skin surface, producing an unpleasant sensation.

[0193] Therefore, it is beneficial to reduce skin impedance and ensure an appropriate muscle response to electrical stimulation by implementing a pre-stimulation protocol that reduces skin impedance. For example, the pre-stimulation protocol can be applied when the device is first activated and / or just before the subject enters a target sleep cycle. In one embodiment, the pre-stimulation protocol can be a pre-stimulation current with a low pulse width and a high frequency (depending on power capability and the subject's perceived discomfort threshold) for a limited time (e.g., one to five minutes). For example, the pre-stimulation current can be a current with a pulse width of 100 μs and a pulse frequency of 100 Hz, applied by electrodes for one to two minutes.

[0194] The stimulator can determine and adjust stimulation parameters using preset programs provided on the stimulator's storage device. Adhering to preset programs may be suitable for embodiments requiring continuous stimulation throughout the sleep cycle. Nevertheless, the stimulator can also be configured to deliver stimulation based on data from the sensing unit.

[0195] The aim of stimulating the masseter, pterygoid, and / or temporalis muscles is to position the mandible in a manner that allows for normal breathing and reduces respiratory effort. Therefore, for optimal stimulation, electrodes should be advantageously placed on these muscles. Identifying these muscles can be difficult, especially for untrained individuals using wearable devices at home. Nevertheless, methods for positioning electrodes on the superficial masseter and temporalis muscles can be developed based on anatomical landmarks, particularly the zygomatic arch (Za) and the angle of the mandible (Go). Using anatomical landmarks as a reference ensures greater reproducibility in electrode positioning on the target muscles. Reproducibility in electrode positioning can be advantageous for longitudinal stimulation to ensure stimulation of specific muscle regions (the spatial distribution of motor unit action potentials is not uniform throughout the muscle's extension).

[0196] In one embodiment, a method for placing electrodes on the masseter muscle may include the following steps:

[0197] (i) Identify the mandibular angle, preferably the corner of the mandible;

[0198] (ii) Identify the zygomatic arch, preferably the outer corner of the eye;

[0199] (iii) Identify the masseter muscle that extends from the angle of the mandible toward the zygomatic arch;

[0200] (iv) Identify the target stimulation area on the masseter muscle, preferably extending from the angle of the mandible to half the distance between the angle of the mandible and the zygomatic arch along the direction of the muscle fibers;

[0201] (v) Optionally, the electrode according to this disclosure is placed on the target stimulation area.

[0202] In one embodiment, the electrode is a bipolar electrode comprising two conductive surfaces, wherein the first conductive element is preferably mounted near the angle of the mandible at the movement point of the masseter muscle, and the second conductive element is mounted along the direction of the masseter muscle fibers, preferably along the muscle fiber direction at half the distance between the angle of the mandible and the zygomatic arch. Figure 9 An example of a method for placing electrodes on the masseter muscle is shown in the figure.

[0203] Advantageously, electrodes can be placed on the muscle belly, at the midpoint of the muscle, or along the direction of the muscle fibers, as determined by palpation or visual observation. Nevertheless, the different tissue-muscle interfaces between electrodes exhibit anisotropic characteristics, thus it is desirable for the electrodes to be placed in the same orientation as the muscle fibers. This allows a pair of electrodes to pick up the diffusion of action potentials from the same bundle of muscle fibers, thereby picking up the corresponding muscle volume and improving stimulation efficiency.

[0204] Advantageously, the surface electrodes can be placed along the muscle fibers on the most prominent areas during muscle contraction. Preferably, the electrode surface can be positioned close to the main motor neuron of the muscle (close to the motor point of the muscle), allowing energy to be distributed along the length of the fiber and conducted from the main motor point by the axons of the motor neuron. By directly transferring energy to the motor neurons, the electrodes can reduce the dissipation of current through the skin (dermis) to other muscles of the head (such as the orbicularis oculi, lip muscles, etc.), which may contract and elevate the eyelids or lips and other sensory endings that cause discomfort (such as paresthesia).

[0205] Understandably, the exact anatomy of the target muscle is unique and therefore varies between subjects. Therefore, any suggestion to locate surface electrodes based on anatomical landmarks that are not closely related to the muscle of interest or are not personalized disregards the principle that electrodes can be advantageously placed parallel to the muscle fibers and on their maximum volume. Bipolar surface electrodes can be advantageously placed between the nerve innervation area and the tendon insertion, directly depending on the anatomy of the muscle to be stimulated. The nerve innervation areas of the masseter, pterygoid, and / or temporalis muscles are often extensive, hindering electrode placement in the suggested optimal anatomical area. Surface electrodes can be placed in one or two different locations based on ease of palpation (using palpation during muscle contraction) and specific anatomical references / landmarks (zygomatic arch and angle of the mandible) to guide the subject in daily procedures and ensure the quality of stimulation. This can further improve stimulation efficiency and reduce discomfort due to regional side effects.

[0206] The sensing unit, or "sensor" as used herein, can record data related to various activities of the object, such as respiratory activity / effort and / or stimulus response. After recording, the sensed data can be processed by a processing unit, particularly a data analysis unit, which is operatively connected to the stimulator, for example via a data link, or alternatively is part of the stimulator, such as a controller. The stimulator can be adapted for this purpose to receive feedback from the data analysis unit in the form of instructions to adjust the stimulation. The data link can be a wired or wireless connection.

[0207] Advantageously, the sensor can be mounted on at least one electrode of the wearable device, allowing for direct monitoring of the stimulation effect. However, the sensor can also be positioned at another site on the object, such as the chin or chest, depending on the activity and sensitivity to be measured. Embodiments of the sensor are envisioned below, which may be particularly well-suited for integration with this device for transcutaneous stimulation of target muscles.

[0208] Advantageously, the sensing unit can be integrated into the wearable device to provide transcutaneous electrical stimulation to the muscles controlling jaw movement in a subject, thereby reducing the subject's respiratory effort during sleep and / or preventing sleep-disordered breathing. This has the advantage of allowing data to be recorded during stimulation, thus reducing the chance of potential time delays or stimulation program mismatches. Furthermore, the wearable device for monitoring and / or analyzing the respiratory activity of a sleep subject may include the integrated sensing unit.

[0209] The wearable device disclosed herein may include a sensing unit configured to record the jaw and / or head movements of an object and record the movements as jaw movement data, the jaw movement data including one or more jaw features, such as the position, rotation, or displacement of the object's jaw, and / or one or more head features, such as the position, rotation, or displacement of the object's head.

[0210] In one embodiment, mandibular movement data can also provide information about the effectiveness of stimulation, particularly the muscular response of the subject to the applied stimulation, which can be determined based on obtained mandibular features, such as displacement of the mandible and / or head during sleep or changes in respiratory function and / or central drive.

[0211] In one embodiment, mandibular movement data can also provide information about the subject's muscle fatigue, which can be determined based on obtained mandibular features, such as displacement of the mandible and / or head or changes in respiratory effort and / or central drive during sleep.

[0212] In one embodiment, mandibular movement data can also provide information about snoring or sleep-related noise and / or the general sleep quality of the subject, which may be related to mandibular features, such as displacement of the mandible and / or head during sleep.

[0213] In one embodiment, a sensing unit may be configured to record mandibular movements, and a processing unit may be operatively connected to the sensing unit; wherein the processing unit is configured to receive mandibular movement data from the sensing unit; and to determine from the mandibular movement data one or more respiratory features indicating the subject's respiratory activity and / or one or more sleep features indicating the subject's sleep activity. The inventors have determined that mandibular data can be correlated with respiratory and / or sleep parameters, for example, directly through the detection of specific mandibular movement features based on thresholds or indirectly through pattern recognition of the mandibular movement data. Exemplary embodiments of such a configuration will be further discussed below.

[0214] The sensor may include at least one gyroscope configured to record rotational movements of the subject's mandible. The recorded rotational movement data can be linked to various mandibular movement categories comprising a set of rotation values ​​that may indicate at least one rate, rate variation, frequency, and / or amplitude of mandibular rotation associated with that movement category. As described above, the recorded rotational movements can be analyzed to determine mandibular activity data, respiratory activity data, and / or sleep activity data. Advantageously, the gyroscope is positioned on the left and / or right electrodes, allowing it to be placed alongside the electrodes and reducing the complexity of the device.

[0215] Compared to other sensing devices commonly used in the art (e.g., accelerometers, force / pressure sensors, or magnetic sensors), providing a gyroscope in a sensing device is particularly suitable for recording mandibular movements. For example, accelerometers can only measure linear acceleration and are therefore unsuitable for measuring mandibular rotational displacement. Furthermore, during respiration, accelerometers can be affected by body or head movements (such as chest or trachea), making it difficult to distinguish the source of the data and adding unnecessary noise and complexity to the system. This negatively impacts diagnostics based on the measurement data stream. The inventors have discovered that mandibular rotation recorded by a gyroscope carries the necessary information for accurate evaluation of mandibular activity data, respiratory activity data, and / or sleep activity data as described above.

[0216] In a preferred embodiment, the sensing device may include at least one gyroscope, at least one accelerometer, and optionally at least one magnetometer. The inventors have found that accelerometers are particularly suitable for measuring head movements and position. Adding an accelerometer to this system allows for the differentiation between head movements and jaw movements, thereby enabling a more accurate assessment of jaw behavior during sleep. Furthermore, the provision of a magnetometer allows for the assessment of the orientation of the sensing unit, much like a compass, to determine the direction of the movements recorded by the gyroscope and / or accelerometer. Therefore, the preferred embodiment may be particularly suitable for recording jaw movements.

[0217] In some embodiments, the sensor may also include devices selected from a list, including oxygen sensors (e.g., pulse oximeters), temperature sensors (e.g., thermometers), sound sensors (e.g., microphones), muscle activity sensors (e.g., electromyography units), brain activity sensors, heart activity sensors, and blood sensors (e.g., pulsed photoplethysmography). Providing additional sensing devices can allow the sensor to be customized for patient-specific purposes, such as snoring detection.

[0218] Furthermore, the wearable devices described herein can also be used in conjunction with other systems or methods. These systems can be therapeutic in nature, such as respiratory devices (CPAP, BiPAP, adaptive support ventilation), devices for stimulating specific nerves and / or other muscles (whether percutaneous or implanted), or devices for correcting body and / or head posture and / or position during sleep. In some embodiments, an alarm can be connected to the system, and / or the system can be connected to or equipped with devices that have alarm functionality.

[0219] The wearable device disclosed herein may include a processing unit, also referred to as a data analysis unit, configured to receive mandibular movement data from the sensing unit; and to determine one or more mandibular features, such as the position, rotation, or displacement of the subject's mandible, and / or one or more head features, such as the position, rotation, or displacement of the subject's head, from the mandibular movement data.

[0220] In one embodiment, the wearable device may include a sensing unit configured to record the respiratory activity of a subject and a processing unit operatively connected to the sensing unit; wherein the processing unit is configured to receive respiratory activity data from the sensing unit; and to determine one or more respiratory characteristics from the respiratory activity data, such as the frequency or intensity of breathing, the occurrence of sleep apnea marked by increased breathing effort, and / or the occurrence of respiratory disturbances, such as airway obstruction or collapse.

[0221] In some embodiments, respiratory activity data can also provide feedback to the device about the effect of stimulation, but can also trigger the device to initiate specific procedures for treating respiratory disorders. In certain embodiments, respiratory activity data can also provide information about a subject's snoring, which can be correlated with respiratory characteristics, such as increased breathing effort during sleep.

[0222] Wearable devices may include a sensing unit configured to record a subject's sleep activity and a processing unit operatively connected to the sensing unit; wherein the processing unit is configured to receive sleep activity data from the sensing unit and determine one or more sleep characteristics based on the sleep activity data, such as sleep state detection, identification of specific sleep stages, and / or assessment of sleep quality. Sleep activity data may provide feedback to the device regarding the effect of stimulation, but may also trigger the device to target specific sleep states or stages. Sleep quality parameters may include, for example, total sleep time (TST), sleep onset latency (SOL), wake time after sleep onset (WASO), wakefulness or arousal index, sleep efficiency (SE), the ratio of REM sleep to non-REM sleep latency, REM sleep latency, and other sleep quality indicators.

[0223] The data analysis unit can be configured to obtain multiple values ​​from one or more sensing data as described above, such as jaw movement data, respiratory activity data, and / or sleep activity data, and to match the obtained values ​​with predefined categories. Preferably, the sensing data is sampled at a specific sampling rate, which may range, for example, from 1.0 to 100.0 Hz, or 2.0 to 50.0 Hz, or 5.0 to 25.0 Hz, preferably 10.0 Hz. Values ​​from the sampled or unsampled sensing data may include one or more of the following mathematical processes: discretization, time averaging, normalization, (fast) Fourier transform, etc. Many modifications and variations thereto will be understood by those skilled in the art.

[0224] Matching can be fully or partially automated by providing a machine learning model, enabling the data analysis unit to learn multiple statistical and / or physical measures to capture the characteristics of signals in the frequency and time domains and identify rotational signal patterns for specific events, such as sleep stages, respiratory effort, muscle fatigue, etc. In one embodiment, the machine learning model can be selected from a list of models including extreme gradient boosting, deep neural networks, convolutional neural networks, and random forests. The inventors have found these models particularly suitable for classifying recorded jaw movement data, respiratory activity data, and / or sleep activity data into corresponding categories. However, many modifications and variations will be understood by those skilled in the art. The provision of the machine learning model can therefore provide automated interpretation of relevant information and / or matching of feature data with sleep disturbance events.

[0225] In one embodiment, the data analysis unit, preferably using recorded mandibular movement data, can be configured to determine the effectiveness of the stimulus without requiring subject feedback, particularly during the subject's sleep. The effectiveness of the stimulus can be determined when irregular mandibular movements decrease over time, preferably in synchronization with selected stimulation parameters of the applied electrical stimulation. On the other hand, a high incidence of irregular mandibular movements may indicate that the subject's muscles are not responding adequately to the applied electrical stimulation, thus potentially requiring adjustment of one or more stimulation parameters, for example, by increasing the current intensity.

[0226] In one embodiment, preferably through recorded mandibular movement data, the sensing unit can be configured to determine muscle fatigue without requiring subject feedback, particularly during the subject's sleep. Muscle fatigue can be determined when the mandibular height decreases over time, but the stimulation parameters remain constant within a specific time period or sleep stage.

[0227] In one embodiment, muscle fatigue can be determined more accurately by tracking the displacement of the jaw, preferably by means of an accelerometer, and / or by tracking central drive and / or respiratory effort, preferably by means of a gyroscope. Therefore, embodiments including a sensing unit comprising an accelerometer and a gyroscope are considered, preferably with the accelerometer and gyroscope mounted in the same location.

[0228] In one embodiment, the following parameters can allow the determination of the type of muscle fatigue:

[0229] Muscle fatigue can be identified when obvious mouth closure (usually in the form of significant mandibular displacement in recorded accelerometer data) and / or a decrease in central drive / respiratory force (usually derived from peak-to-peak amplitude of recorded gyroscope data) can be observed.

[0230] • When no obvious mouth closure (typically indicated by a decrease in mandibular displacement in recorded accelerometer data) and / or an increase in central drive / respiratory force (typically indicated by an increase in peak-to-peak amplitude in recorded gyroscope data) can be observed, peripheral muscle and / or fiber fatigue can be identified.

[0231] • When no obvious mouth closure (usually manifested as a decrease in mandibular displacement in recorded accelerometer data) and / or a decrease in central drive / breathing force (usually indicated by a decrease in peak-to-peak amplitude in recorded gyroscope data) can be observed, spinal or vertebral fatigue can be identified.

[0232] Analysis of the recorded data can be used to provide a feedback loop for wearable devices to improve control of the subject's jaw by adjusting one or more stimulation parameters, thereby advantageously enhancing device effectiveness. In one embodiment, the wearable device may include a processing unit operatively connected to a stimulator and configured to determine a stimulation response from the sensed data and compare the stimulation response with a desired response. Furthermore, the processing unit may be configured to adjust at least one electrical stimulation parameter to achieve the desired response when the difference between the stimulation response and the desired response is determined, or alternatively, to determine an adjustment to at least one electrical stimulation parameter to achieve the desired response and provide the adjustment to the stimulator as instructed. In one embodiment, the stimulation intensity may be adjusted. Nevertheless, the pulse frequency, pulse width, and / or stimulation duration may also be adjusted. Exemplary embodiments of a respiratory feedback loop may be discussed below.

[0233] In one embodiment, the processing unit may be configured to determine a mandibular response to a stimulus from mandibular movement data and compare the mandibular stimulus response with a desired response, which includes elevation of the subject's mandible to open the upper airway. In one embodiment, the processing unit may be configured to determine a stimulus response based on respiratory activity data and compare the respiratory stimulus response with a desired response, which includes a reduction in the sleep subject's respiratory effort. In one embodiment, the processing unit may be configured to determine a sleep response to a stimulus based on sleep activity data and compare the sleep stimulus response with a desired response, which includes an improvement in the sleep subject's sleep quality. Furthermore, the device may be configured to determine other responses, such as a reduction in snoring.

[0234] Analysis of mandibular movement data can be used to track muscle fatigue. Wearable devices can be equipped with a muscle fatigue detection module configured to determine muscle fatigue in the subject's mandibular movement data and preferably adjust one or more stimulation parameters of the electrical stimulation. Different stimulation parameters exist, which can be adjusted individually or in combination to tailor neuromuscular electrical stimulation for optimal effects, particularly improving mouth closure and / or reducing or preventing muscle fatigue. These parameters may include current intensity, pulse width and frequency, work cycle, stimulation of different target muscles, continuous stimulation period as a target function, targets for specific time periods or sleep stages, amplitude and drive response of the monitored accelerometer. For example, if muscle fatigue is detected, the current intensity can be reduced preferably by 10%, 20%, 30%, 40%, 50% or more, and / or the work cycle can be modified, particularly by increasing the rest period of the work cycle preferably by 10%, 20%, 30%, 40%, 50% or more; for example, from 5 seconds to 10 seconds. Alternatively, upon detection of muscle fatigue, the detection module can temporarily interrupt the electrical stimulation to allow muscle recovery, for example by providing a 1-minute or 2-minute rest. Once the stimulus is restarted, the muscle fatigue detection module can determine whether the stimulus response has improved, and if not, provide another, preferably longer, rest.

[0235] In one embodiment, the muscle fatigue detection module can be configured to change one or more stimulation programs, particularly recruitment programs, rehabilitation programs, and / or retraining programs, upon detection of a specific sleep stage. The period can typically be initiated by recruitment and / or rehabilitation programs. However, since these programs can cause muscle fatigue (due to relatively narrow pulses and / or high current intensities), the muscle fatigue module can be configured to switch the stimulator to a retraining program (with relatively wide pulses and / or lower current intensities) to reduce muscle fatigue, for example, when central fatigue is detected.

[0236] In one embodiment, the muscle fatigue detection module can be configured to determine the type of muscle fatigue, particularly peripheral muscle and / or fiber fatigue, and / or spinal or supraspinous fatigue. Methods for muscle fatigue detection have been discussed earlier in this disclosure. In one embodiment, when detecting peripheral muscle and / or fiber fatigue, the muscle fatigue detection module may preferably reduce the current intensity and / or increase the simulated pulse width by activating a procedure defined by a lower current intensity and / or a wider pulse width compared to the present procedure. In one embodiment, when detecting spinal or supraspinous fatigue, the muscle fatigue detection module may increase the simulated frequency and / or pulse width, preferably by activating a procedure defined by a higher frequency and / or a wider pulse width compared to the present procedure.

[0237] In a particular embodiment, the processing unit can be configured to detect poor muscle contraction and adjust the time period to begin the rehabilitation program. To clarify, in the presence of mild illness without severe apnea or hypoventilation episodes, there is time to rehabilitate the target muscles. Therefore, rather than adjusting one or more stimulation parameters to improve the efficiency of electrical stimulation (e.g., by increasing current intensity and / or frequency), it is preferable to reduce electrical stimulation, thereby building muscle fiber strength to accept stronger stimulation. This can alleviate discomfort for subjects at risk of muscle fatigue or those highly sensitive to higher current intensities that would interrupt training. Advantageously, this functionality can be included in a wearable device to be activated as needed, such as when a clinician diagnoses poor masseter contraction or certain accessory conditions. Furthermore, rehabilitation programs can be proposed to subjects sensitive to current intensities above 2 mA, particularly when stimulation prevents the subject from falling asleep and / or waking the subject after a ramp phase.

[0238] The wearable device may include a breathing effort detection module configured to determine the level of breathing effort in a subject's breathing data. In one embodiment, the breathing effort detection module may be configured to detect increased breathing effort in the subject's breathing data and adjust one or more stimulation parameters and / or stimulation procedures to reduce breathing effort. Stimulation may be adjusted based on recorded breathing effort / central drive, preferably by increasing the efficiency of stimulation when an increase in breathing effort / central drive is detected and / or by decreasing the efficiency of stimulation when a decrease in breathing effort / central drive is detected.

[0239] In one embodiment, the respiratory distress detection module can be configured to detect, preferably, higher frequencies and / or higher amplitudes (peak-to-peak amplitudes) indicating an increase in respiratory effort compared to a baseline value, and preferably by adjusting one or more stimulation parameters to promote stimulation while maintaining the same frequency and pulse width but increasing the current intensity, more preferably by increasing the current intensity by 10%, 20%, 30%, 40%, 50% or more, and / or reducing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more. This can improve the efficiency of stimulation and / or reduce respiratory effort / central drive. The baseline value can be a standard value, such as based on the expected population average, but preferably a personalized value based on the subject's respiratory profile. Advantageously, the baseline value starts as a standard value at the beginning of the time period and is adjusted based on the recorded data.

[0240] In one embodiment, the respiratory distress detection module can be configured to detect, preferably, lower frequencies and / or lower amplitudes (peak-to-peak amplitudes) indicating a reduction in respiratory effort compared to a baseline value, and preferably by maintaining the same frequency and pulse width but reducing the current intensity, more preferably by adjusting one or more stimulation parameters to reduce stimulation by reducing the current intensity by 10%, 20%, 30%, 40%, 50% or more, and / or increasing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more. This can improve the subject's comfort and / or reduce the chance of muscle fatigue.

[0241] Analysis of respiratory activity data can be used to selectively focus on specific respiratory disturbances, such as airway obstruction or collapse. Wearable devices may include a respiratory disturbance detection module configured to determine the presence of a respiratory disturbance in the subject's respiratory data, enabling the initiation or adjustment of electrical stimulation when a respiratory disturbance is detected. Stimulation can be adjusted based on the detection of a respiratory disturbance (e.g., airway obstruction or collapse), preferably by increasing the efficiency of stimulation when the amplitude, frequency, and / or duration of one or more detected respiratory disturbances increases, and / or decreasing the efficiency of stimulation when the amplitude, frequency, or duration of one or more detected respiratory disturbances decreases.

[0242] In one embodiment, the respiratory disturbance detection module can be configured to detect a higher frequency, higher amplitude (peak-to-peak amplitude), and / or increased duration of respiratory disturbance compared to a baseline value, and preferably by adjusting one or more stimulation parameters to promote stimulation by maintaining the same frequency and pulse width but increasing the current intensity, more preferably by increasing the current intensity by 10%, 20%, 30%, 40%, 50%, or more, and / or reducing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50%, or more. This can improve the efficiency of stimulation and / or reduce, preferably prevent, the occurrence of further respiratory disturbance. The baseline value can be a standard value, such as based on a expected population average, but preferably a personalized value based on the subject's respiratory profile. Advantageously, the baseline value starts as a standard value at the beginning of the time period and is adjusted based on recorded data.

[0243] In one embodiment, the respiratory disturbance detection module can be configured to detect a lower frequency, lower severity, and / or reduced duration of respiratory disturbance compared to a baseline value, and preferably by maintaining the same frequency and pulse width but reducing the current intensity, more preferably by reducing the current intensity by 10%, 20%, 30%, 40%, 50%, or more, and / or increasing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50%, or more, to reduce stimulation. This can improve the subject's comfort and / or reduce the chance of muscle fatigue.

[0244] Analysis of respiratory activity data can be used to selectively focus on snoring and / or sleep-related noise. Wearable devices may include a snoring detection module configured to determine the occurrence of snoring / sleep-related noise, allowing electrical stimulation to be initiated or adjusted when such noise is detected. Snoring detection may optionally be threshold-based, e.g., when a specific volume level is exceeded. Stimulation can be adjusted based on recorded snoring or sleep-related noise, preferably by increasing the efficiency of stimulation when an increase in snoring / sleep-related noise is detected and / or by decreasing the efficiency of stimulation when a decrease in snoring / sleep-related noise is detected, preferably by maintaining the same frequency and pulse width but increasing the current intensity, more preferably by increasing the current intensity by 10%, 20%, 30%, 40%, 50% or more, and / or reducing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more. This can improve the efficiency of stimulation and / or reduce, preferably prevent, further snoring / sleep-related noise.

[0245] Wearable devices can be equipped with a sleep stage determination module configured to determine the subject's wakefulness and sleep state, allowing electrical stimulation to begin when the subject falls asleep and terminate when the subject wakes up. Some subjects may perceive electrical stimulation as distracting from falling asleep. Detection of at least the wakefulness and sleep stages allows the subject to fall asleep more easily before stimulation begins. Furthermore, electrical stimulation can be initiated gradually to avoid waking the subject due to device activation, for example, by gradually increasing the stimulation intensity.

[0246] Wearable devices can be equipped with a sleep stage determination module configured to identify one or more sleep stages of a subject, allowing electrical stimulation to be initiated, adjusted, and / or terminated when the subject enters a specific sleep stage. Accurate sleep stage detection can improve stimulation response, thereby increasing the efficiency of sessions used for therapeutic or non-therapeutic purposes. Furthermore, accurate sleep stage detection can improve the safety and comfort of sessions, particularly by reducing or preventing stimulation during deep sleep (e.g., N3) and / or during wakefulness or wakefulness. This allows the device to focus stimulation on specific sleep stages of the subject, enabling the subject to easily fall asleep or remain awake even in deeper stages. Additionally, accurate sleep stage detection can reduce or prevent muscle fatigue, particularly by reducing or preventing stimulation during specific deep sleep (e.g., N3) and / or providing variable stimulation during lighter sleep, such as by gradually increasing / decreasing current intensity.

[0247] The sleep detection module can be configured to detect specific sleep stages based on the following classifications (which increase computational complexity):

[0248] -2-class (i.e., binary) rating is used to detect whether a subject is awake or asleep;

[0249] -3 categories of rating are used to classify sleep stages, including the subject's wakefulness, light sleep (N1 and N2) stages, and / or non-light sleep (N1 and N2) stages;

[0250] -3 categories of rating are used to classify sleep stages, including the subject's wakefulness, deep sleep (N3) stage and / or non-deep sleep (N1) stage;

[0251] -3 categories of rating are used to classify sleep stages, including the subject's wakefulness, REM sleep stage and / or non-REM sleep stage;

[0252] -4 categories of rating are used to classify sleep stages, including the subject's wakefulness, light sleep (N1 and N2) stages, deep sleep (N3) stages, and / or REM sleep stages;

[0253] -5 categories of rating are used to classify sleep stages, including the subject's wakefulness, N1 sleep stage, N2 sleep stage, N3 sleep stage, and / or REM sleep stage.

[0254] Those skilled in the art will understand that, depending on the required complexity of data processing, data analysis can be performed by a processing unit located on the wearable device, or, if more complex calculations are required, by performing calculations on an external device connected to the wearable device, such as the object's smartphone or server. Nevertheless, for convenience in this disclosure, it will be assumed that all necessary calculations can be performed by the sleep stage determination module disclosed herein.

[0255] In one embodiment, the sleep stage determination module can be configured to determine the occurrence of light sleep (N1 and / or N2) stages and / or REM stages, and to initiate or adjust applied electrical stimulation when the subject enters said light sleep (N2 and / or N1) stages and / or REM stages. It has been found that muscles are more sensitive to retraining purposes during light sleep (N1 and / or N2) stages, thus allowing for adjustment of one or more stimulation parameters, such as increased stimulation intensity. Light sleep (N1 and / or N2) stages and / or REM stages can be associated with specific mandibular condylar rotations and can therefore be determined based on mandibular movement data. Furthermore, the risk of apnea / hypopnea increases during light sleep (N1 and / or N2) and REM sleep stages (compared to deep N3 sleep), primarily due to reduced or highly variable compensatory drives directed towards pharyngeal muscle tissue, resulting in lower efficiency (REM sleep).

[0256] The N3 sleep stage is typically characterized by stable jaw movements. Therefore, in one embodiment, the sleep stage determination module can be configured to determine N3 based on stable peak-to-peak amplitude and / or respiratory rate. Upon detecting the N3 sleep stage, the sleep stage determination module can be configured to switch to a rehabilitation procedure, preferably by maintaining the same frequency and pulse width but reducing the current intensity, more preferably by reducing the current intensity by 10%, 20%, 30%, 40%, 50%, or more, and / or increasing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50%, or more. Alternatively, after detecting the N3 sleep stage, the sleep stage determination module can be configured to switch to a retraining procedure, preferably by increasing the frequency and pulse width and optionally decreasing the current intensity, preferably by increasing the frequency by 10%, 20%, 30%, 40%, 50% or more, increasing the pulse width by 10%, 20%, 30%, 40%, 50% or more, increasing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or decreasing the current intensity by 10%, 20%, 30%, 40%, 50% or more.

[0257] A typical characteristic of REM sleep is unstable jaw movements. Therefore, in one embodiment, the sleep stage determination module can be configured to determine REM based on unstable peak-to-peak amplitude and / or respiratory rate. After detecting a REM sleep stage, the sleep stage determination module can be configured to switch to a recruitment program, preferably by maintaining the same frequency and pulse width but increasing the current intensity, more preferably by increasing the current intensity by 10%, 20%, 30%, 40%, 50% or more, and / or reducing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more. Alternatively, if the stimulator is already operating in a recruitment program, one or more parameters of the recruitment program can be adjusted to increase stimulation, preferably by increasing the current intensity by 10%, 20%, 30%, 40%, 50% or more, and / or reducing the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

[0258] In one embodiment, the sleep stage determination module can be configured to gradually increase during the N1 sleep stage in anticipation of the next sleep stage to prevent inappropriate awakenings. In adults, typical N1 sleep stages are relatively short and light; sleep stages may deepen within minutes. Therefore, the sleep stage determination module can be configured according to a ramp algorithm, preferably detecting a predetermined amount of continuous sleep using the sleep stage sensor disclosed herein. Once a specific sleep stage is detected, the ramp algorithm can adjust one or more stimulation parameters over a specific time length, for example, by linearly increasing the current intensity from 0% to 100% over 20 minutes.

[0259] In one embodiment, the sleep stage determination module can be configured to determine the occurrence of a deep sleep (N3) stage and terminate the applied electrical stimulation when the subject enters the deep sleep (N1) stage. It has been found that during deep sleep (N3), the risk of accidents and severe SDB is reduced because central motor control of ventilation is stabilized at the levers of the upper airway muscles (stability driven by chemotherapy and pneumatic pressure), and upper airway patency (via premotor neurons of cranial nerves V, XII, and VII) is optimized by neurons regulating respiration. Therefore, during deep sleep (N3), electrical stimulation can be reduced or alternatively terminated, which allows the stimulated muscles to relax and prevent muscle fatigue. The deep sleep (N3) stage may also be associated with specific mandibular condylar rotation and can therefore be determined from mandibular movement data.

[0260] In one embodiment, the sleep state or stage of an object can be determined by the following procedure:

[0261] - Divide the sensing data into specific time periods, such as 30 seconds, wherein the sensing data is preferably selected from jaw movement data, respiratory activity data, and / or sleep activity data, and

[0262] - Apply mathematical models to assign sleep states to each period;

[0263] The mathematical model mentioned above includes the following steps:

[0264] - Extract at least one feature from the sensor data of each recorded period;

[0265] - Track the values ​​of the extracted features at each period;

[0266] - Set feature-specific thresholds; and

[0267] - If the extracted feature value exceeds the feature-specific threshold, the sleep state of the period is adjusted.

[0268] Typical features extracted from recorded sensor data by the sleep detection model may include maximum and minimum values ​​(e.g., mandibular movement data recorded by a gyroscope), mean, median, and standard deviation. Preferably, the sleep detection model extracts multiple features to improve the sensitivity and reliability of the sleep detection module. The inventors have found that mandibular movement recorded by a gyroscope can provide particularly reliable detection of wakefulness. In particular, specific thresholds for the following features have been determined. A wakefulness state can be determined when the standard deviation of the gyroscope norm exceeds the threshold of at least 1.10 to at most 1.50, preferably 1.15 to 1.25, more preferably about 1.20, for example, 1.17. A wakefulness state can be determined when the maximum value of the gyroscope norm exceeds the threshold of at least 14.0 to at most 15.0, preferably 14.1 to 14.9, or 14.2 to 14.8, more preferably 14.3 to 14.5, or 14.3 to 14.4.

[0269] Indicators related to sleep-disordered breathing may include the hourly rate of respiratory effort and cumulative duration during sleep. The analysis unit can be configured to report object-specific parameters being interpreted. Reports may include output to devices such as computers or smartphones. Reports may also include visual or textual reports providing object-specific parameters, such as in the form of sleep graphs.

[0270] In one embodiment, the sleep detection module can be configured to change one or more stimulation programs, particularly recruitment programs, rehabilitation programs, and / or retraining programs, when a specific sleep stage is detected. The period can typically be initiated by a recruitment program and / or rehabilitation program to be applied during the initial sleep stages (e.g., N1, N2). However, in deeper sleep stages, particularly N3, ventilation and the muscular pharyngeal wall (specifically for airway patency) are generally more stable, thus requiring less electrical stimulation to produce a beneficial response. Therefore, the sleep detection module can be configured to switch the stimulator to a retraining program to prevent potential muscle fatigue and / or conserve the wearable device's battery.

[0271] Wearable devices may include clothing, particularly wearable garments, configured to hold at least a portion of a stimulator and / or support electrodes. In one embodiment, the wearable device may include a loop configured to be positioned around at least a portion of a subject's neck. In one embodiment, the loop may be rigid, allowing it to rest on the subject's shoulders. An example of such an embodiment is as follows: Figure 2 As shown. In another embodiment, the loop can be flexible, allowing it to fit around the subject's neck, advantageously providing pressure on the neck so that the loop is held in place around the neck during sleep. An example of this embodiment is shown below. Figure 4As shown. In one embodiment, the wearable device may include a headband configured to be placed around at least a portion of an object's head. The headband may be similarly rigid, flexible, or a combination of both. An example of this embodiment is shown below. Figure 5 As shown.

[0272] The garment can have a curved, rigid body, allowing it to wrap around a part of the body, preferably around the neck or head. Advantageously, the garment has a semi-circular or arched shape, which improves the ergonomics of the design and prevents it from slipping off during sleep. The garment can be designed with gaps to allow for easier fitting around the neck.

[0273] Preferably, the garment body can be rigid enough to protect the internal electronics, yet flexible enough to ensure conformity with the movement of the wearer. In one embodiment, the garment has a rigid polymer core covered by a silicone shell. Silicon is a material particularly well-suited to ensuring pleasant contact with the skin. These components can, for example, be 3D printed or molded for larger-scale production. The interior of the garment can be textured to enhance comfort in contact with the wearer's skin, but also to provide sufficient surface friction to prevent the garment from shifting due to body rotation during sleep. In one embodiment, the garment is covered with a fabric such as polyester or polyamide to allow the material to breathe, as it may be in contact with the skin for extended periods.

[0274] In one embodiment, the garment can be configured to (gently) press against a body part of the subject, particularly the neck and / or head, to generate pressure. This has the advantage that the garment can be more easily secured in place, for example, while sleeping. Furthermore, the pressure can extend to the electrodes, causing them to press against the target stimulation area. The pressure on the electrodes can improve skin contact, reduce skin resistance, and / or bring the stimulation closer to motor nerves. Therefore, this can increase the stimulation response and / or reduce local side effects or discomfort.

[0275] Electrodes can be electrically connected to the garment using connecting cables. In one embodiment, the wearable device may be provided with flexible cables of adjustable length to facilitate easier placement of the electrodes on the subject's skin and / or in response to the subject's movements, such as head or body rotation. Adjustment of the flexible cable length prevents the electrodes from being detached from the subject's skin. The garment may be provided with a cable housing adapted to tension the cable and / or retract excess cable, for example, by winding the cable into said housing. Optionally, a locking mechanism may be provided on the garment to secure the cable at different lengths. Alternatively, the cable may be rigid, but this may reduce sleep quality. The cable may be configured to allow current to travel from the stimulator configured within the garment to the electrodes. An example of this embodiment is as follows: Figure 2As shown. The electrodes can be detachably attached to the cable to allow for the replacement of used or defective electrodes. In another embodiment, the cable can be integrated into a housing, which can be part of a garment. An example of this embodiment is shown below. Figure 5 As shown.

[0276] The clothing may also include a battery pack and an optional plug to allow the battery to be charged when the device is not in use (typically during the day). Optionally, the clothing may have user interface buttons, such as a power button. Additionally, a display may be provided that notifies the user of one or more actions, such as the selected program, information about battery life, or charging time.

[0277] Wearable devices can be configured to connect to an output device, such as a smartphone, and transmit data to the output device. The output device may have analytics software, such as an application, configured to analyze the received data and optionally determine various features from the data. The wearable device may include storage for storing stimulus data, such as an overview of stimulus parameters generated by a stimulator, which can be exported to the output device for analysis. In embodiments where the wearable device is equipped with sensors, it may include storage for storing sensed data, which can similarly be exported to the output device for analysis.

[0278] The output device can be configured to determine object-specific profiles, which can be used, for example, to adjust one or more single-pulse-specific parameters of the pulse current or to adjust one or more single-feature-specific thresholds of the sleep detection module. Furthermore, object-specific profiles can be used to provide user feedback in the form of games or questionnaires, for example, investigating neurocognitive, quality-of-life, mood, and other bio / physiological measurements, to promote improved sleep quality.

[0279] Furthermore, the output device can be configured to send the received data to a dedicated data analysis device, such as an external server, which is configured to determine more complex features from the received information, for example, through a machine learning model.

[0280] One aspect of this disclosure relates to a method for reducing respiratory effort in a subject during sleep, the method comprising:

[0281] - Select the portion of the target skin from the left muscle (preferably the masseter, pterygoid, and / or temporalis) movement point to the left posterior angle of the mandible, and position the left electrode on the selected skin portion; and select the portion of the target skin from the right muscle (preferably the masseter, pterygoid, or temporalis) movement point to the right posterior angle of the mandible, and position the right electrode on the selected skin portion.

[0282] - Transcutaneous electrical stimulation is applied from the left electrode to at least one left muscle, preferably the masseter, pterygoid and / or temporalis muscles, and transcutaneous electrical stimulation is applied from the right electrode to at least one right muscle, preferably the masseter, pterygoid and / or temporalis muscles.

[0283] The applied electrical stimulation promotes the contraction of the stimulated muscles on the left and right sides, preferably the masseter, pterygoid and / or temporalis muscles, to controllably elevate the subject's mandible, thereby opening the upper airway.

[0284] One aspect of this disclosure relates to a method for reducing respiratory effort in a subject, the method comprising: a sensor configured to detect jaw movements in the subject during sleep; the method comprising:

[0285] - The sensor outputs a signal indicating mandibular movement;

[0286] - The signal indicating mandibular movement is received by the signal processing unit;

[0287] - The signal processing unit processes the signal indicating mandibular movement to determine mandibular movement data;

[0288] - The stimulator is actuated by the signal processing unit using a control signal generated by the signal processing unit based on determined mandibular movement data;

[0289] - An electrical stimulus is generated by a stimulator, characterized by one or more stimulation parameters adapted to promote contraction of preferred masseter, pterygoid, and / or temporalis muscles to controllably elevate the subject's mandible, thereby opening the upper airway.

[0290] One aspect of this disclosure relates to a method for reducing respiratory effort in a subject, the method comprising: a sensor configured to detect jaw movements in the subject during sleep; the method comprising:

[0291] The sensor outputs a signal indicating mandibular movement;

[0292] - The signal indicating mandibular movement is received by the signal processing unit;

[0293] - The signal processing unit processes the signal indicating mandibular movement to determine respiratory activity data;

[0294] - Optionally, the signal processing unit determines the occurrence of sleep-disordered breathing marked by increased breathing effort;

[0295] - Optionally, the occurrence of sleep-disordered breathing is determined by the signal processing unit;

[0296] - The stimulator is actuated by the signal processing unit by means of a control signal generated by the signal processing unit based on determined respiratory activity data, optionally based on determined sleep disorder breathing and / or determined sleep breathing disorder;

[0297] - An electrical stimulus is generated by a stimulator, characterized by one or more stimulation parameters adapted to promote contraction of preferred masseter, pterygoid, and / or temporalis muscles to controllably elevate the subject's mandible, thereby opening the upper airway.

[0298] One aspect of this disclosure relates to a method for reducing respiratory effort in a subject, the method comprising: a sensor configured to detect jaw movements in the subject during sleep; the method comprising:

[0299] - The sensor outputs a signal indicating mandibular movement;

[0300] - The signal indicating mandibular movement is received by the signal processing unit;

[0301] - The signal processing unit processes the signal indicating mandibular movement to determine sleep activity data;

[0302] - Optionally, the sleep state is determined by the signal processing unit, the sleep state including a waking state and a sleeping state;

[0303] - Optionally, the signal processing unit determines the sleep stage, which includes at least one stage selected from light (N1) sleep stage, light (N2) sleep stage, deep (N3) sleep stage N3 and / or REM sleep;

[0304] - The stimulator is actuated by the signal processing unit using a control signal generated by the signal processing unit based on determined sleep activity data, optionally based on a determined sleep state and / or a determined sleep stage;

[0305] - An electrical stimulus is generated by a stimulator, characterized by one or more stimulation parameters adapted to promote contraction of preferred masseter, pterygoid, and / or temporalis muscles to controllably elevate the subject's mandible, thereby opening the upper airway.

[0306] In some preferred embodiments, the method for reducing a subject's breathing effort as described above may further include:

[0307] - The generated electrical stimulation is transmitted to the left electrode via a stimulator. The left electrode is positioned on a selected portion of the subject's skin, the selected portion being the area from the movement point of the left-side muscles (preferably the masseter, pterygoid, and / or temporalis muscles) to the left posterior angle of the mandible.

[0308] - The generated electrical stimulation is transmitted to the right electrode via a stimulator, the right electrode being positioned on a selected portion of the subject's skin, the selected portion being the area from the movement point of the right-side muscles (preferably the masseter, pterygoid, and / or temporalis muscles) to the right posterior angle of the mandible;

[0309] - Transcutaneous electrical stimulation is applied via the left electrode to at least one left-side muscle (preferably the masseter, pterygoid, and / or temporalis muscles) to promote contraction of the left-side muscles (preferably the masseter, pterygoid, and / or temporalis muscles), and

[0310] - Transcutaneous electrical stimulation is applied to at least one right-side muscle (preferably the masseter, pterygoid, and / or temporalis) via the right electrode to promote contraction of the right-side muscle (preferably the masseter, pterygoid, and / or temporalis); wherein the stimulated muscles on the left and right sides (preferably the masseter, pterygoid, and / or temporalis) can controllably elevate the subject's mandible, thereby opening the upper airway.

[0311] One aspect of this disclosure relates to a method for reducing the respiratory effort of a subject during sleep, the method comprising:

[0312] -A portion of the skin of a selected subject corresponding to the location of at least one left target muscle, including the left masseter, left pterygoid, and / or left temporalis muscles, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the left target muscle, and the second conductive element is installed along the direction of the left target muscle fibers.

[0313] -A portion of the skin of a selected subject corresponding to the location of at least one right target muscle, including the right masseter, right wing, and / or right temporalis muscle, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the right target muscle, and the second conductive element is installed along the direction of the right target muscle fibers.

[0314] - Biphasic transcutaneous electrical stimulation is applied between two conductive elements of left and right bipolar electrodes. This electrical stimulation promotes the contraction of target muscles to controllably elevate the subject's jaw, thereby reducing respiratory effort; wherein the electrical stimulation is generated according to a work cycle having a stimulation period of 1 to 20 seconds and / or a rest period of 1 to 20 seconds.

[0315] One aspect of this disclosure relates to a method for reducing the respiratory effort of a subject during sleep, the method comprising:

[0316] -A portion of the skin of a selected subject corresponding to the location of at least one left target muscle, including the left masseter, left pterygoid, and / or left temporalis muscles, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the left target muscle, and the second conductive element is installed along the direction of the left target muscle fibers.

[0317] -A portion of the skin of a selected subject corresponding to the location of at least one right target muscle, including the right masseter, right wing, and / or right temporalis muscle, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the right target muscle, and the second conductive element is installed along the direction of the right target muscle fibers.

[0318] - Biphasic transcutaneous electrical stimulation is applied between two conductive elements of left and right bipolar electrodes. This electrical stimulation promotes the contraction of target muscles to controllably elevate the subject's jaw, thereby reducing respiratory effort; wherein the electrical stimulation is generated according to a work cycle having a stimulation period of 1 to 20 seconds and / or a rest period of 1 to 20 seconds.

[0319] One aspect of this disclosure relates to a method for recruiting target muscles to reduce respiratory effort in a subject during sleep, the method comprising:

[0320] -A portion of the skin of a selected subject corresponding to the location of at least one left target muscle, including the left masseter, left pterygoid, and / or left temporalis muscles, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the left target muscle, and the second conductive element is installed along the direction of the left target muscle fibers.

[0321] -A portion of the skin of a selected subject corresponding to the location of at least one right target muscle, including the right masseter, right wing, and / or right temporalis muscle, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the right target muscle, and the second conductive element is installed along the direction of the right target muscle fibers.

[0322] - Biphasic transcutaneous electrical stimulation is applied between the two conductive elements of the left and right bipolar electrodes. This electrical stimulation promotes the contraction of the target muscles to controllably elevate the subject's jaw, thereby reducing respiratory effort.

[0323] - The electrical stimulation is generated according to the following stimulation parameters: current intensity, between 5mA and 10mA, preferably between 6mA and 10mA; frequency, between 15Hz and 50Hz, preferably between 25Hz and 45Hz, more preferably between 30Hz and 40Hz; pulse width, between 50μs and 300μs, preferably between 225μs and 275μs, more preferably between 200μs and 250μs; and a work cycle having a stimulation period of 1 second to 20 seconds and / or a rest period of 1 second to 20 seconds.

[0324] One aspect of this disclosure relates to a method for rehabilitating the muscle function of a target muscle to reduce respiratory effort of a subject during sleep, the method comprising:

[0325] -A portion of the skin of a selected subject corresponding to the location of at least one left target muscle, including the left masseter, left pterygoid, and / or left temporalis muscles, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the left target muscle, and the second conductive element is installed along the direction of the left target muscle fibers.

[0326] -A portion of the skin of a selected subject corresponding to the location of at least one right target muscle, including the right masseter, right wing, and / or right temporalis muscle, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the right target muscle, and the second conductive element is installed along the direction of the right target muscle fibers.

[0327] - Biphasic transcutaneous electrical stimulation is applied between the two conductive elements of the left and right bipolar electrodes. This electrical stimulation promotes the contraction of the target muscles to controllably elevate the subject's jaw, thereby reducing respiratory effort.

[0328] -The electrical stimulation is generated according to the following stimulation parameters: current intensity, between 1 mA and 4 mA, preferably between 2 mA and 4 mA; frequency, between 15 Hz and 50 Hz, preferably between 20 Hz and 45 Hz, more preferably between 30 Hz and 40 Hz; pulse width, between 50 μs and 300 μs, preferably between 225 μs and 275 μs, more preferably between 200 μs and 250 μs; and a work cycle having a stimulation period of 1 second to 20 seconds and / or a rest period of 1 second to 20 seconds.

[0329] One aspect of this disclosure relates to a method for retraining neuromuscular circuits to reduce respiratory effort in a subject during sleep, the method comprising:

[0330] -A portion of the skin of a selected subject corresponding to the location of at least one left target muscle, including the left masseter, left pterygoid, and / or left temporalis muscles, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the left target muscle, and the second conductive element is installed along the direction of the left target muscle fibers.

[0331] -A portion of the skin of a selected subject corresponding to the location of at least one right target muscle, including the right masseter, right wing, and / or right temporalis muscle, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the right target muscle, and the second conductive element is installed along the direction of the right target muscle fibers.

[0332] - Biphasic transcutaneous electrical stimulation is applied between two conductive elements of left and right bipolar electrodes. This electrical stimulation promotes the contraction of target muscles to controllably elevate the subject's jaw, thereby reducing respiratory effort. The electrical stimulation is generated according to the following stimulation parameters: current intensity, between 1 mA and 4 mA, between 2 mA and 4 mA; frequency, between 50 Hz and 150 Hz, preferably between 70 Hz and 130 Hz, even more preferably between 90 Hz and 110 Hz; pulse width, between 500 μs and 1000 μs, preferably between 600 μs and 900 μs, even more preferably between 700 μs and 800 μs; and a work cycle having a stimulation period of 1 second to 20 seconds and / or a rest period of 1 second to 20 seconds.

[0333] One aspect of this disclosure relates to treating snoring in a subject. Treatment of snoring can be considered as a reduction in snoring intensity, such as halving the snoring intensity, or complete prevention of snoring, such as a complete reduction in snoring intensity. Therefore, preventing snoring can also be considered as reducing snoring. In some preferred embodiments, the methods described above for reducing the breathing effort of a subject can be methods for treating snoring in a subject. The inventors have found that applying transcutaneous electrical stimulation to the masseter, pterygoid, and / or temporalis muscles to controllably elevate the subject's jaw, thereby opening the upper airway, can prevent snoring or at least reduce the intensity of the subject's snoring.

[0334] In one embodiment, a method for treating snoring may include:

[0335] - Select the portion of the subject's skin from the movement point of the left muscle (preferably the masseter, pterygoid, and / or temporalis) to the left posterior angle of the mandible, and position the left electrode on the selected skin portion; and select the portion of the subject's skin from the movement point of the right muscle (preferably the masseter, pterygoid, or temporalis) to the right posterior angle of the mandible, and position the right electrode on the selected skin portion.

[0336] - Transcutaneous electrical stimulation is applied from the left electrode to at least one left muscle, preferably the masseter, pterygoid and / or temporalis muscles, and transcutaneous electrical stimulation is applied from the right electrode to at least one right muscle, preferably the masseter, pterygoid and / or temporalis muscles.

[0337] The applied electrical stimulation promotes the contraction of the stimulated muscles on the left and right sides (preferably the masseter, pterygoid, and / or temporalis muscles) to controllably elevate the subject's jaw, thereby opening the upper airway and reducing and / or preventing snoring.

[0338] A sensor configured to detect snoring can be provided to the subject. As mentioned above, snoring signals can be obtained from jaw movement data or through a dedicated snoring sensor (e.g., a microphone provided on or near the subject).

[0339] In one embodiment, a method for treating snoring may include:

[0340] - The signal indicating snoring is received by the signal processing unit;

[0341] - The signal indicating snoring is processed by the signal processing unit;

[0342] - The stimulator is actuated by the signal processing unit using a control signal generated by the signal processing unit based on a signal indicating snoring;

[0343] - An electrical stimulation is generated by a stimulator, characterized by one or more stimulation parameters adapted to promote contraction of preferred masseter, pterygoid, and / or temporalis muscles to controllably elevate the subject's mandible, thereby opening the upper airway and reducing or preventing snoring.

[0344] One aspect of this disclosure relates to a method for treating snoring in a subject during sleep, the method comprising:

[0345] -A portion of the skin of a selected subject corresponding to the location of at least one left target muscle, including the left masseter, left pterygoid, and / or left temporalis muscles, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the left target muscle, and the second conductive element is installed along the direction of the left target muscle fibers.

[0346] -A portion of the skin of a selected subject corresponding to the location of at least one right target muscle, including the right masseter, right wing, and / or right temporalis muscle, and at least one left bipolar electrode comprising at least two conductive elements is installed on the selected skin portion, wherein the first conductive element is installed at the movement point of the right target muscle, and the second conductive element is installed along the direction of the right target muscle fibers.

[0347] - Biphasic transcutaneous electrical stimulation is applied between two conductive elements of left and right bipolar electrodes. This electrical stimulation promotes the contraction of target muscles to controllably elevate the subject's jaw, thereby reducing or preventing snoring; wherein the electrical stimulation is generated according to a work cycle having a stimulation period of 1 to 20 seconds and / or a rest period of 1 to 20 seconds.

[0348] One aspect of this disclosure relates to a method for assisting in characterizing the respiratory effort of a subject, the method comprising a sensor configured to detect jaw movements of the subject during sleep, the method comprising the steps of:

[0349] - The sensor outputs a signal indicating jaw movement;

[0350] - The signal indicating mandibular movement is received via a data analysis unit;

[0351] - N mandibular movement categories are stored in a memory unit included in the data analysis unit, where N is an integer greater than 1; at least one of the N mandibular movement categories indicates sleep apnea.

[0352] Each j-th (1≤j≤N) mandibular movement category consists of a j-th group of rotation values, and each j-th group of rotation values ​​indicates at least one mandibular rotation rate;

[0353] Associated with class j;

[0354] - Sampled mandibular movement data are obtained by sampling mandibular movement data during the sampling period using sampling elements included in the data analysis unit;

[0355] - Multiple mandibular movement values ​​are derived from the sampled mandibular movement data using the data analysis unit; and

[0356] - The data analysis unit matches the mandibular movement value with the N mandibular movement categories, wherein at least one of the N mandibular movement categories indicates sleep apnea.

[0357] In some implementations, at least one of the N jaw movement categories indicates sleep-disordered breathing marked by increased breathing effort.

[0358] In some implementations, at least one of the N mandibular movement categories indicates sleep-disordered breathing.

[0359] One aspect of this disclosure relates to a method for assisting in characterizing the respiratory effort of a subject, the method comprising a sensor including a gyroscope configured to detect jaw movements of the subject during sleep, the method comprising the steps of:

[0360] - A signal indicating mandibular movement is output via a sensor (preferably a gyroscope);

[0361] - The signal indicating mandibular movement is received via a data analysis unit;

[0362] - N mandibular movement categories are stored in a memory unit included in the data analysis unit, where N is an integer greater than 1; at least one of the N mandibular movement categories indicates sleep apnea.

[0363] Each j-th (1≤j≤N) mandibular movement category consists of a j-th group of rotation values, and each j-th group of rotation values ​​indicates at least one mandibular rotation rate;

[0364] Associated with class j;

[0365] - Sampled mandibular movement data are obtained by sampling mandibular movement data during the sampling period using sampling elements included in the data analysis unit;

[0366] - Multiple mandibular movement values ​​are derived from the sampled mandibular movement data using the data analysis unit; and

[0367] - The data analysis unit matches the mandibular movement value with the N mandibular movement categories, wherein at least one of the N mandibular movement categories indicates sleep apnea.

[0368] Example

[0369] To better illustrate the features, advantages, and characteristics of the present invention, some preferred embodiments are disclosed as examples with reference to the accompanying drawings. However, the scope of this disclosure is by no means limited to the illustrative examples described below.

[0370] Example 1: Wearable device design

[0371] refer to Figure 2 A wearable device (10) according to an embodiment of the present disclosure is shown. The wearable device (10) includes at least one left electrode (100) and at least one right electrode (not shown). Each electrode (100) is connected to a garment (200), specifically a loop, via at least one connecting cable (150). The loop may house a stimulator and any auxiliary devices, such as a power supply configured to power the stimulator, such as a battery pack, and a controller for controlling the stimulation generated by the power supply. The connecting cable (150) then provides an electrical connection between the electrode (100) and the stimulator.

[0372] Reference Figure 3The following illustrates a wearable device (10) according to another embodiment of the present disclosure. The wearable device (10) also includes at least one left electrode (100) and at least one right electrode (not shown), which are connected to a garment (200), specifically the loop, via a rigid housing extending laterally from the loop. The connecting housing allows one or more cables to be integrated therein. The loop can be configured to press (gently) against the neck of an object, thereby holding it in place. Furthermore, the loop can be configured to generate pressure on the electrodes, which can increase stimulation response and / or reduce discomfort.

[0373] Reference Figure 5 The following illustrates a wearable device (10) according to another embodiment of the present disclosure. The wearable device (10) also includes at least one left electrode (100) and at least one right electrode (not shown), which are connected to the garment (200), particularly the headband, via a rigid housing extending downward from the headband. The loop can be configured to (gently) press against the head of the subject to hold it in place.

[0374] Example 2: Stimulus Zone

[0375] To achieve optimal stimulus response and / or reduce stimulus discomfort, each electrode (100) of the wearable device can be positioned to make electrical contact with a selected portion of the target skin. Preferred skin portions include... Figure 1 As shown, its range extends from the point of motion of the masseter muscle of the object to the posterior angle of the object's mandible.

[0376] To locate the region of interest on the superficial masseter (SM) muscle, a straight line can be drawn from easily accessible anatomical landmarks. (See reference...) Figure 7 These markers can be identified. Specifically, Figure 7 A shows a reference line TL V TL H Side view of the skull and masseter line (ML). The thin line indicates the intersection point from the angle of the mandible (Gonion, Go) to approximately 40% of the length of the masseter line (ML). Figure 7 B further shows a lateral view of the deep facial plane, demonstrating the anterior temporalis (AT) and superficial masseter (SM) muscles and their relationship to the anatomical landmarks and reference lines used. Further references Figure 8 The same markings are drawn on the faces of human subjects. Specifically, Figure 8 A shows TL with the same reference line. V TL H And a side view of the ML object header. Additionally... Figure 8 B shows the placement of electrodes on the AT and SM muscles.

[0377] In a clinical setting, electrodes can be optimally placed by palpation on the superficial masseter (SM), the angle of the mandible (located at the mandibular angle), and the main body of the zygomatic bone to determine anatomical reference landmarks. The superficial masseter line is drawn from these reference landmarks, connecting the angle of the mandible on the soft tissue to the midpoint between the posterior inferior border of the zygomatic bone and the zygomatic arch; these two points can also be identified by palpation.

[0378] The line is aligned with the fiber direction of the superficial masseter muscle, consistent with its origin and insertion. The superficial masseter muscle is covered by a tendinous layer extending from the zygomatic bone to 1 / 3 to 1 / 2 of its length. Placing electrodes in the tendinous region is not recommended; therefore, the reference point is located 40% of the length of the straight line from the angle of the mandible (Go). The electrode is placed along this reference line, with its placement on the marker corresponding to 40% of that line.

[0379] After all reference points and lines have been laid out, the subject may be asked to clench their teeth to confirm whether any adjustments to the suggested anatomical landmarks are needed.

[0380] Surface electrodes are advantageously placed along the muscle fibers on the most prominent areas during muscle contraction to improve stimulus response. The electrode placement can be verified by palpating the muscle during contraction, allowing for any necessary corrections.

[0381] In a home environment, optimal electrode placement on the preferred stimulation area (S) can be achieved by following easier-to-use user guide steps. (Reference) Figure 9 This placement guide will be discussed as a method that includes the following steps:

[0382] · Figure 9 (i) Identify the mandibular angle (Go); preferably at the outer corner of the mandible;

[0383] · Figure 9 (ii) Identify the zygomatic arch (Za); preferably at the outer corner of the eye;

[0384] · Figure 9 (iii) Identify the muscle extending from Go to Za; preferably, contract the muscle by clenching the teeth;

[0385] · Figure 9 (iv) Identify the target stimulation area (S), which extends from Go to the center of the identified muscle as determined along the direction of the muscle fibers;

[0386] · Figure 9 (v) Place at least one electrode on the stimulation area (S), preferably a bipolar electrode, with one electrode placed near the angle of the mandible (Go) and the other electrode placed near the center of the identified muscle, defined along the direction of the muscle fibers. Figure 9 An example of a bipolar electrode is shown in the figure.

[0387] It is understood that variations of the above method can be developed to identify the same target stimulus by recognizing different anatomical landmarks. Nevertheless, this method provides a particularly easy-to-follow guide for home and / or clinical applications of wearable devices, and thus forms the preferred embodiment of this disclosure.

[0388] Example 3: Stimulation effect

[0389] To evaluate the feasibility of electrical stimulation on target stimulation areas (as defined in Example 2), numerous research protocols have been established on different subjects with various stimulation parameters. The recorded data will be discussed below.

[0390] short-term effects

[0391] The efficacy of transcutaneous electrical stimulation with high current intensity at low frequencies with narrow pulse widths was verified to determine whether muscle fiber recruitment could provide a direct and acute response to prevent sleep disorders.

[0392] One subject was selected for nighttime stimulation. The subject was a 53-year-old female volunteer with a BMI of 26.2 kg / m². 2 Sleep stages were monitored using laboratory polysomnography. Airflow was measured using pressure sensors and thermistors.

[0393] Electrical stimulation of the masseter muscle was achieved using two electrodes, one placed above the motor point of the masseter muscle and the other on the posterior angle of the mandible. The electrodes consisted of bipolar surface electrodes, spaced 20 mm apart, with a conductive area diameter of 14 mm, and were backed with a viscous wet gel and foam. Stimulation consisted of a biphasic pulsed current at a frequency of 40 Hz, a current intensity of 7 mA, a pulse width of 250 μs, and an activation cycle of 5 seconds of stimulation followed by a 5-second rest.

[0394] The results showed that electrical stimulation elicited a direct muscle response, causing the jaw to elevate sufficiently to maintain good airflow during any sleep stage, particularly the N2 stage. Therefore, sleep disorders can be prevented by applying electrical stimulation.

[0395] Long-term effects

[0396] Two subjects were selected for nighttime stimulation. The first subject was a 61-year-old male volunteer with a BMI of 24.8 kg / m². The second subject was a 38-year-old male volunteer with a BMI of 29.8 kg / m². Respiratory event index (OAHI) and sleep fragmentation index (ArI) were measured in laboratory polysomnography at baseline (week 0), one week after stimulation (week 1), and one week after stimulation was discontinued (week 2).

[0397] Electrical stimulation of the masseter muscle was achieved using two electrodes, one placed above the motor point of the masseter muscle and the other on the posterior angle of the mandible. The electrodes consisted of bipolar surface electrodes, 20 mm apart, with a conductive area diameter of 14 mm, backed by a viscous wet gel and foam. Stimulation consisted of a biphasic pulsed current at a frequency of 40 Hz, a pulse width of 250 μs, an activation cycle of 5 seconds of stimulation followed by a 5-second rest, and current intensities of 6 mA and 8 mA, respectively.

[0398] The results for the first object are shown in the table below:

[0399] Week 0 31.7 39.8 Week 1 12.6 23.2 Week 2 22.4 32.1

[0400] Data from the first subject showed a 60.3% decrease in OAHI after one week of stimulation (week 1). Following the week without stimulation (week 2), OAHI remained 29.3% lower than baseline (week 0).

[0401] The results for the second object are shown in the table below:

[0402] Week 0 15.6 38.3 Week 1 3.4 23.6 Week 2 11.4 30.2

[0403] Data from the second subject showed that a 78.2% decrease in OAHI was observed one week after stimulation (week 1). Following the week without stimulation (week 2), OAHI was still 26.9% lower than baseline (week 0).

[0404] The results showed that electrical stimulation induced muscle retraining with a delayed response effect, which improved the beneficial effects of stimulation during continuous stimulation and provided sustained effects even after stimulation was terminated.

[0405] Respiratory events

[0406] Six subjects were selected for nighttime stimulation. Compared with baseline values, the respiratory event index (OAHI - obstructive apnea-hypopnea index) and sleep fragmentation index (ArI - arousal index) were reduced in laboratory polysomnography two weeks after stimulation.

[0407] Electrical stimulation of the masseter muscle was achieved using two electrodes, one placed above the masseter's motor point and the other on the posterior angle of the mandible. Bipolar surface electrodes, with a 20mm distance between electrodes, a 14mm diameter conductive area, and a viscous wet gel and foam backing, were implanted on the faces of awake volunteers with normal occlusion. Participants were assigned to one of two stimulation protocols, varying the duration of rest periods during nighttime stimulation (Protocol A: 5 seconds on / 5 seconds off, no pause throughout the night; Protocol B: 5 seconds on / 5 seconds off, 1 minute pause after every 1 minute of stimulation throughout the night). The results are shown in Table 1 below.

[0408] Table 1: Electrical stimulation parameters and stimulation response

[0409]

[0410] The results shown in Table 1 above indicate that transcutaneous electrical stimulation applied to the masseter muscle is effective in significantly reducing the occurrence of respiratory events and the arousal index. The reduction in respiratory events and the arousal index was even more significant in the group that did not pause for one minute after each minute of stimulation.

[0411] Example 4: Stimulus parameters

[0412] Using various stimulation parameters and electrode settings, the achievement of electrical stimulation on the target stimulation area was evaluated on different subjects. The results are discussed throughout Example 4.

[0413] Electrode type

[0414] Bipolar surface electrodes were implanted on the face of a normally occlusal, awake volunteer. Electrical stimulation was applied using biphasic pulsed currents at a frequency of 40 Hz, with a pulse width of 250 μs and an activation cycle of 5 seconds followed by a 5-second rest. Jaw closure force was assessed using an intrusive pressure sensor (FUTEK Advanced Sensor Technology, Irvine, California, USA). Electrodes were positioned on the masseter and temporalis muscles according to the preferred method described in Example 2. The results are shown in Table 2 below.

[0415] Table 2: Electrical stimulation parameters and stimulation response

[0416]

[0417]

[0418] The results shown in Table 2 above indicate that the bipolar surface electrode with an electrode spacing of 20 mm, a conductive area diameter of 14 mm, and a viscous wet gel and foam backing, mounted on the masseter muscle, provided the highest level of comfort (visual score of 9 out of 10), while also stimulating a strong closing force (42 Nm) in the jaw. Similar results were obtained for the same bipolar surface electrode mounted on the masseter and temporalis muscles.

[0419] Electrode positioning

[0420] Bipolar surface electrodes with an inter-electrode distance of 20 mm, a conductive area diameter of 14 mm, and a viscous wet gel and foam backing were installed on the faces of conscious volunteers with normal occlusion. Electrical stimulation was applied using biphasic pulsed current at a frequency of 40 Hz, with a pulse width of 250 μs, and an activation cycle of 5 seconds followed by a 5-second rest. The jaw closure force was assessed using an intrusive pressure sensor (FUTEK Advanced Sensor Technology, Irvine, California, USA). The results are shown in Table 3 below.

[0421] Table 3: Electrical stimulation parameters and stimulation response

[0422]

[0423]

[0424] The results shown in Table 3 above indicate that, according to the method described in Example 2, bipolar surface electrodes mounted on the target stimulation areas of the masseter muscle and optionally the temporalis muscle provided the highest reported comfort level (visual score of 9 out of 10) while also stimulating a strong closing force (42 Nm) in the jaw.

[0425] Stimulation parameters

[0426] Bipolar surface electrodes with an inter-electrode distance of 20 mm, a conductive area diameter of 14 mm, and a viscous wet gel and foam backing were installed on the face of awake volunteers with normal occlusion. The bipolar surface electrodes were installed on the target stimulation area of ​​the masseter muscle according to the method described in Example 2. Electrical stimulation was applied in the form of biphasic pulsed current with an activation cycle of 5 seconds of stimulation followed by 5 seconds of rest. The jaw closure force was assessed using an intrusive pressure sensor (FUTEK Advanced Sensor Technology, Irvine, California, USA). The electrodes were positioned on the masseter and temporalis muscles according to the preferred method described in Example 2. The results are shown in Table 4 below.

[0427] Table 4: Electrical stimulation parameters and stimulation response

[0428]

[0429]

[0430] The results in Table 4 above indicate that electrical stimulation with a frequency of 40 Hz and a pulse width of 250 μs provides the highest reported comfort (visual score of 9 out of 10) while also stimulating strong closure force (42 Nm) in the jaw.

[0431] It should be understood that the embodiments given in Tables 2-4 of Embodiment 3 form preferred embodiments of the wearable device of this disclosure.

[0432] Example 5: Sensor unit feedback

[0433] The wearable device (10) of this disclosure may be provided with a sensing unit configured to record mandibular movements of a subject. For example, the sensing unit may include a gyroscope and / or accelerometer mounted on at least one electrode (100), preferably both the gyroscope and / or accelerometer are mounted on at least one electrode (100). Mandibular movements may refer to any change in the position of the subject's mandible or any rotation or displacement of the subject's mandible. Mandibular movements can be recorded as mandibular activity data by the sensing unit.

[0434] Furthermore, the sensing unit can also be configured to record data related to the subject's respiratory or sleep activities. Respiratory activity data can refer to any data related to the subject's breathing, such as respiratory rate or intensity. Respiratory activity data can also be derived from or combined with jaw movement data. Similarly, sleep activity data can refer to any data related to the subject's sleep, such as sleep-related movements. Sleep activity data can also be derived from or combined with jaw movement data. Respiratory activity data can also be combined with sleep activity data.

[0435] Data on jaw movement, respiratory activity, and sleep activity can be analyzed to provide feedback loops to the stimulator, thereby improving stimulation effectiveness and reducing the occurrence of drawbacks. Figure 11 The present disclosure provides an exemplary operating principle of a feedback loop according to a preferred embodiment of the present disclosure. Several exemplary embodiments found particularly suitable for the invention are given below. However, it should be understood that the various embodiments described in this disclosure can be combined in any suitable manner, as will be apparent to those skilled in the art from this disclosure.

[0436] - In one particular embodiment, mandibular movement data can be analyzed to determine a stimulus response that may include elevation and stabilization of the subject's mandible, and to instruct the stimulator to adjust one or more stimulus parameters to control the elevation and stabilization of the subject's mandible. Mandibular movement data can also be used to determine the occurrence of muscle fatigue.

[0437] - In a particular embodiment, respiratory activity data can be analyzed to identify sleep apnea marked by increased breathing effort, and the stimulator can be instructed to adjust one or more stimulation parameters to reduce breathing effort.

[0438] - In a particular embodiment, respiratory activity data can be analyzed to identify sleep apnea and instruct the stimulator to adjust one or more stimulation parameters to reduce the intensity of sleep apnea or prevent further sleep apnea.

[0439] - In certain embodiments, sleep activity data can be analyzed to determine sleep states, such as wakefulness and sleep. The stimulator can be instructed to initiate electrical stimulation when the subject falls asleep and to terminate electrical stimulation when the subject wakes up.

[0440] - In a particular embodiment, sleep activity data can be analyzed to determine sleep stages, which may include light sleep (N1), light sleep (N2), REM sleep, and / or deep sleep (N3). The stimulator can be instructed to initiate electrical stimulation when the subject enters a light sleep (N1), light sleep (N2), and / or REM sleep stage, and to terminate electrical stimulation when the subject enters a deep sleep (N3) sleep stage.

[0441] Example 6: Sleep Stage Detection

[0442] To evaluate the feasibility of a sleep stage determination module, a research protocol was established based on the following parameters. Mandibular movement data were collected from 30 participants, each with a "chin sensor" and a "cheek sensor." The cheek sensor was located in the preferred target stimulation area discussed in Embodiment 2 of this disclosure, i.e., at the same location as the electrodes. This study aimed to identify differences in sleep analysis quality based on MM data obtained from the chin sensor and cheek sensor. These results can be used to evaluate the feasibility of implementing a precise sleep stage determination module in the wearable device disclosed herein.

[0443] Main objectives

[0444] - Detect sleep / wake status from MMs derived from the cheeks with sufficient performance.

[0445] - Determine the sleep / wake detection rules for cheek MM data, which can effectively approximate the sleep / wake algorithm analysis from chin sensors.

[0446] Assumption

[0447] - The difference in total sleep time (TST) between the cheek and chin MM sensors was not greater than the expected value of inter-rater variability (~85%).

[0448] Applying simple detection rules to MM features derived from the cheeks should be able to detect sleep and wakefulness with >75% accuracy.

[0449] method

[0450] A prospective study of consenting adult patients involved a single nighttime laboratory polysomnography (PSG) session, supplemented by simultaneous recording of jaw movements (MM) using two devices. The data sample of 30 participants was obtained through recruitment during routine practice in a sleep laboratory over a 3-month period.

[0451] The research device consists of two coin-sized devices, which are attached by sleep technicians to the participant's chin (between the sublabial sulcus and the premental point) and cheek (surface of the masseter muscle), respectively.

[0452] Results and Processing

[0453] exist Figure 12 The image shows MM data of a single selected participant recorded using a chin sensor, and... Figure 13 The image shows the corresponding MM data recorded using a cheek sensor. These figures indicate the occurrence of sleep states and obstructive breathing events relative to nighttime (x-axis). The MM data is divided into three parts based on the awake and asleep states recorded by the sensors. The MM data shows the occurrence of obstructive breathing events—differences may be attributed to algorithm calibration.

[0454] The collected MM data is automatically transmitted to a cloud-based infrastructure at the end of the night and analyzed using a dedicated machine learning algorithm. This algorithm analyzes time-series data from the cheek device to accurately identify consecutive 30-second periods of the raw MM signal as either awake or asleep, based on relevant and non-redundant features. Each 30-second period is summarized by 11 features extracted from the gyroscope specifications:

[0455] a. Standard deviation

[0456] b. The difference between the minimum value and the minimum value in the adjacent 30-second window

[0457] c. The difference between the maximum value and the maximum value in the adjacent 30-second window

[0458] d. Difference between the median and the median in the adjacent 30-second window

[0459] e. The difference between the first quartile and the Q1 value in the adjacent 30-second window.

[0460] f. The difference between the third quartile and the Q3 value in the adjacent 30-second window

[0461] For the purposes of this study, gyroscope data were chosen because it is more sensitive to sleep / wake cycles; accelerometer data were not considered. Normalized histograms were constructed to investigate the distribution of these features during sleep and wakefulness.

[0462] Sleep / wake tags derived from the algorithm are extracted from the chin sensor. Relevant features are extracted from the corresponding raw MM signal sequences and used as input data for the algorithm to determine whether they are related to wakefulness or sleep.

[0463] Then, MM features derived from the cheeks were used to optimally classify sleep / wake labels derived from the chin. This study selected two features with the highest discriminative power: the standard deviation (SD) and maximum value (MAX) of the MM data recorded by the gyroscope. Reference Figures 14-17 The processed data is shown. Specifically, Figure 14 The frequency distribution of SD values ​​for sleep (light) and wakefulness (dark) states is shown. Figure 15 The sensitivity / specificity of all possible SD values ​​for detecting sleep and wakefulness are shown. Figure 16 The frequency distribution of MAX values ​​for sleep (light) and wakefulness (dark) states is shown. Finally, Figure 17 The sensitivity / specificity for all possible maximum values ​​for detecting sleep and wakefulness are shown.

[0464] Data Analysis

[0465] The data analysis algorithm can be configured to automatically detect sleep and wakefulness by considering sensitivity / specificity values ​​and processed MM features derived from the cheeks. Furthermore, the cutoff used to optimize sleep / wakefulness detection can remain universal (i.e., the same cutoff across all individuals). Figure 18 Or personalized (i.e., adjusting the cutoff time based on the individual's sleep pattern). Figure 22 The cutoff value will affect Total Sleep Time (TST), which is the amount of time an individual actually sleeps during their planned sleep period. By comparing chin TST data values ​​with cheek TST data, cheek SD, and cheek MAX values, the following parameters can be determined: Diff_TST refers to the percentage difference between "chin data" and "cheek data"; Diff_TST1 refers to the percentage difference between "chin data" and "cheek SD"; and Diff_TST2 refers to the percentage difference between "chin data" and "cheek MAX". This data analysis algorithm can be implemented as a configuration of the sleep detection module of this disclosure.

[0466] Data analysis algorithms can be implemented in three different ways:

[0467] - Awake state detection: By limiting sensitivity to 0.9 and maximizing specificity, data analysis algorithms can be configured to optimize awake state detection. For example, this configuration can maximize patient comfort by preventing stimulation during awake and / or light sleep stages. However, episodes occurring during sleep may be misclassified as awake and cessation of stimulation (thus reducing stimulation efficiency).

[0468] - Balanced wakefulness / sleep state detection: The data analysis algorithm can be configured to balance the detection of wakefulness and sleep states by achieving a balance between specificity and sensitivity. This configuration is designed to accommodate sufficient subject comfort while still providing adequate stimulus length.

[0469] - Sleep state detection: By limiting specificity to 0.9 and maximizing sensitivity, data analysis algorithms can be configured to optimize sleep state detection. This configuration can, for example, maximize stimulation efficiency by preventing respiratory episodes. However, awakening episodes may be misclassified as sleep and continued stimulation (thus reducing subject comfort).

[0470] Model 1 - Fixed Cutoff

[0471] In the first model, a cutoff value for optimizing sleep / wake state detection was selected, regardless of inter-individual differences. A single optimal cutoff value was used for each patient. Cutoff configuration parameters are as follows: Figure 18 As shown.

[0472] refer to Figure 19-21 Let's discuss the choice of cutoff data. Specifically, Figure 19 A table showing a data analysis algorithm configured for wakefulness detection is presented, which yields a 45% difference in total sleep time (TST) and 50% of subjects having a stimulation duration of less than 4 hours. Figure 20 A table showing a data analysis algorithm configured for balancing wakefulness / sleep state detection is presented, which yields a TST difference of approximately 15%, with 6.5% of subjects experiencing stimulation durations of less than 4 hours. Figure 21 A table is shown with a data analysis algorithm configured for sleep state detection, which yields a TST difference of ~7% and 0% of subjects with a stimulation duration of less than 4 hours.

[0473] Model 2 - Personalization Deadline

[0474] In the second model, a cutoff value for optimizing sleep / wake state detection has been individually selected for each object, thus personalizing sleep / wake detection to their own sleep patterns. A different optimal cutoff value is used for each object. The cutoff configuration parameters are as follows: Figure 22 As shown.

[0475] refer to Figures 23-25 Let's discuss the choice of cutoff data. Specifically, Figure 23 A table showing a data analysis algorithm configured for wakefulness detection is presented, which yields a total sleep time (TST) difference of ~44%, with 43.5% of subjects experiencing stimulation duration of less than 4 hours. Figure 24 A table is shown with a data analysis algorithm configured for balancing wakefulness / sleep state detection, which yields a TST difference of ~15%, with 0% of subjects having a stimulation duration of less than 4 hours. Figure 25 A table is shown with a data analysis algorithm configured for sleep state detection, which yields a TST difference of ~4.5% and 0% of subjects with a stimulation duration of less than 4 hours.

[0476] in conclusion

[0477] Based on the above results, it appears that personalized optimization of the sleep / wake detection cutoff used for sleep detection can provide better results in sleep and wake recognition. This process results in a lower variability in total sleep time (TST) than the 4.5% TST of the reference chin sensor. Bland-Altman analysis shows that the distribution of the variance is relatively tight, with a systematic bias close to 0.

[0478] For comparison, the analysis provides three Bland-Altman plots for the following paired variables:

[0479] - Figure 26 The comparison between chin sensor data and cheek sensor data is shown.

[0480] - Figure 27 A comparison of sleep / wake detection rules based on chin sensor data and standard deviation (SD) based on cheek sensor data is shown.

[0481] - Figure 28 A comparison of sleep / wake detection rules based on chin sensor data and the maximum value (MAX) of cheek sensor data is shown.

[0482] In summary, these data demonstrate that sleep / wake phases can be detected by integrating an MM recording device into a wearable device and mounting it near the stimulation zone. The primary purpose of this device is to detect sleep and wakefulness phases in order to actively guide the stimulator, thereby initiating stimulation when the patient falls asleep and terminating stimulation when the patient wakes up.

[0483] discuss

[0484] To reduce the computational complexity of the algorithm analysis, we envision extracting simple features (standard deviation, maximum, minimum, average, median, etc.) of the MM signal within each 30-second period of the signal, and applying a simple formula to optimally classify the MM signal originating from the cheek into wakefulness and sleep labels defined by the reference MM signal originating from the chin.

[0485] Standard deviation and maximum value appear to be the most discriminative values ​​for detecting sleep / wake labels. To optimize the detection threshold, three different scenarios can be considered:

[0486] 1. Maximize detection of wakefulness and mistakenly detect certain sleep episodes as quiet wakefulness (stimulation only begins when the patient is clearly asleep, thus limiting the time window when treatment is effective). This situation achieves comfort by minimizing stimulation during wakefulness.

[0487] 2. Balance detection of wakefulness and sleep, ensuring that most stimulation is limited to true sleep and that stimulation is applied for most of the duration of sustained sleep.

[0488] 3. Detecting sleep to the maximum extent possible, and mistakenly detecting quiet wakefulness as sleep (stimulation may begin when the patient is quietly awake, potentially disrupting the transition from wakefulness to sleep). This situation enhances therapeutic effectiveness by maximizing stimulation time.

[0489] Based on the evaluation data, the third option (sleep optimization) appears to be the preferred choice for the following reasons:

[0490] • The TST difference between the cheek and chin MM sensors was not greater than the expected value of inter-rater variability (~85%).

[0491] • Applying simple detection rules to MM features derived from the cheeks allows for the detection of sleep and wakefulness with >75% accuracy, just as initially assumed.

[0492] • Scenario 3 resulted in a TST difference of approximately 4.5%, with 0% of subjects experiencing stimulation durations shorter than 4 hours (in clinical practice, it is recommended to treat obstructive sleep apnea (OSA) for 4 hours daily).

[0493] accomplish

[0494] Given this data, the following recommendations can be made for implementation in wearable device functionality:

[0495] 1. The stimulator has two different activation modes: manual mode, where the user decides when to start stimulation; and smart mode, which starts stimulation based on the user's MM (masturbation point).

[0496] 2. Manual mode should be fully programmable:

[0497] a. Users should be able to decide to begin stimulation directly.

[0498] b. Users should be able to decide to delay the start of stimulation (e.g., stimulation will begin 20 minutes after activation).

[0499] c. Users should be able to decide how to begin stimulation by gradually increasing the current intensity to the optimal level.

[0500] 3. The functions of the intelligent mode are as follows:

[0501] a. In the first intended scenario, the MM signal will be processed for a period of 30 seconds. This time window should be programmable.

[0502] b. Different features should be extracted from the 30-second period. Features should be programmable. Standard deviation and maximum value should be extracted first.

[0503] c. The 30-second period should overlap with the programmable interval and be non-continuous to ensure that the user does not have to wait 30 seconds to stop the stimulus if they should. As a primary intention, the 30-second period should be refreshed every second.

[0504] d. The intelligent stimulation mode will be implemented using a fixed standard deviation and a maximum threshold that has the highest sleep / wake discrimination value for the selected scenario (i.e., optimal sleep detection) as reported above.

[0505] The selected thresholds are as follows:

[0506] - If the standard deviation of the gyroscope specification is >1.17, wakefulness is detected.

[0507] - If the maximum value of the gyroscope specification is >14.35, wakefulness is detected.

[0508] e. Predefined sleep / wake thresholds executed in intelligent stimulation mode should be programmable and personalized for each patient. These thresholds should be modified based on the first stimulation night to optimize sleep or wakefulness detection for any given user. A first night with fixed parameters can be used to differentiate between sleep and wakefulness to extract a cutoff point suitable for each patient.

[0509] 4. The intelligent mode should also be programmable:

[0510] a. Users should be able to decide to start intelligent stimulation directly (i.e., sleep / wake detection using detection rules will start directly after startup).

[0511] b. Users should be able to decide to delay the start of smart stimulation (i.e., sleep / wake detection using detection rules will begin 20 minutes after startup).

[0512] c. Users should be able to decide to start intelligent stimulation in a manner that gradually increases to the optimal current intensity (i.e., sleep / wake detection using detection rules will begin after a programmable delay (in minutes) after startup, and the current will gradually increase to the optimal intensity).

[0513] 5. Upon waking in either activation mode, stimulation will resume after a programmable delay (in minutes) and without wakefulness detection.

[0514] It should be understood that the embodiments presented in Example 6 form preferred embodiments of the wearable devices of this disclosure.

Claims

1. A wearable device (10) for reducing breathing effort in a subject during sleep, the device comprising: - At least one left bipolar electrode is configured to be mounted on a selected portion of the skin of the object, the selected portion corresponding to the location of at least one left target muscle including the left masseter, left pterygoid and / or left temporalis muscle; - At least one right bipolar electrode is configured to be mounted on a selected portion of the skin of the object, the selected portion corresponding to the location of at least one right target muscle, including the right masseter, right pterygoid and / or right temporalis muscle, opposite to the left target muscle. - wherein the at least one left bipolar electrode and the at least one right bipolar electrode include at least two conductive elements (110) with an inter-electrode distance between 10 mm and 30 mm, wherein the position and orientation of the conductive elements (110) are adjusted in such a way that the first conductive element (110) is configured to be installed at the movement point of the target muscle, and the second conductive element (110) is configured to be installed along the direction of the target muscle fibers; - A stimulator configured to generate biphasic transdermal electrical stimulation to be applied between the two conductive elements (110) of the at least one left bipolar electrode and the at least one right bipolar electrode; -The stimulator is configured to generate electrical stimulation according to at least one stimulation program, including the following stimulation parameters: current intensity between 1 mA and 50 mA, frequency between 1 Hz and 100 Hz, pulse width between 50 µs and 1000 µs, and a work cycle having a stimulation period of 1 second to 20 seconds and / or a rest period of 1 second to 20 seconds; wherein at least the frequency, the pulse width, and the work cycle are equal between the left bipolar electrode and the right bipolar electrode; - In this process, applying the electrical stimulation causes simultaneous contraction of the target muscles that lift the subject's jaw, thereby reducing respiratory effort.

2. The wearable device (10) according to claim 1, wherein, The stimulation procedure includes at least one muscle recruitment procedure configured to generate electrical stimulation defined by the following stimulation parameters: - Current intensity, between 5 mA and 10 mA; - Frequency, between 15 Hz and 50 Hz; and - Pulse width, between 50μs and 300μs.

3. The wearable device (10) according to claim 2, wherein, The stimulation program includes at least one muscle rehabilitation program configured to generate electrical stimulation defined by the following stimulation parameters: - Current intensity, between 1 mA and 4 mA; - Frequency, between 15 Hz and 50 Hz; and - Pulse width, between 50μs and 300μs.

4. The wearable device (10) according to claim 3, wherein, The stimulation program includes at least one neuromuscular retraining program configured to generate electrical stimulation defined by the following stimulation parameters: - Current intensity, between 1 mA and 4 mA; - Frequency, between 50 Hz and 150 Hz; and - Pulse width, between 500μs and 1000μs.

5. The wearable device (10) according to claim 1, wherein, The inter-electrode distance between at least two conductive elements (110) of at least one of the at least left bipolar electrode and at least one right bipolar electrode is between 15 mm and 25 mm.

6. The wearable device (10) according to claim 1, wherein, The diameter of at least one conductive element (110) of at least one of the at least left bipolar electrode and at least one right bipolar electrode is between 10 mm and 20 mm.

7. The wearable device (10) according to claim 4, comprising a sensing unit configured to record jaw movements of the subject and a processing unit operatively connected to the sensing unit; wherein, The processing unit is configured to receive mandibular movement data from the sensing unit and to determine one or more mandibular features based on the mandibular movement data.

8. The wearable device (10) according to claim 7, wherein, The sensing unit includes at least one gyroscope and / or accelerometer configured to record jaw movements; wherein the sensing unit is mounted on the jaw of the object.

9. The wearable device (10) according to claim 7, wherein, The sensing unit is mounted on at least one of the at least left bipolar electrode and the at least right bipolar electrode.

10. The wearable device (10) according to claim 7, wherein, The processing unit includes a breathing effort detection module configured to detect an increase in breathing effort in the subject's mandibular movement data and to adjust one or more stimulation parameters and / or stimulation procedures to reduce breathing effort.

11. The wearable device (10) according to claim 10, wherein, When an increase in respiratory effort is detected, the respiratory effort detection module is configured to increase the current intensity by 10%, 20%, 30%, 40%, 50% or more, increase the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or decrease the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

12. The wearable device (10) according to claim 10, wherein, When a decrease in respiratory effort is detected, the respiratory effort detection module is configured to reduce the current intensity by 10%, 20%, 30%, 40%, 50% or more, reduce the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or increase the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

13. The wearable device (10) according to claim 7, wherein, The processing unit includes a respiratory disturbance detection module configured to detect the presence of respiratory disturbance in the subject's mandibular movement data and adjust one or more stimulation parameters and / or stimulation procedures to reduce the occurrence of respiratory disturbance.

14. The wearable device (10) according to claim 13, wherein, When a respiratory disturbance is detected, the respiratory disturbance detection module is configured to increase the current intensity by 10%, 20%, 30%, 40%, 50% or more, increase the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or decrease the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

15. The wearable device (10) according to claim 7, wherein, The processing unit includes a muscle fatigue detection module configured to detect the presence of muscle fatigue in the subject's jaw movement data and to adjust one or more stimulation parameters and / or stimulation procedures to reduce muscle fatigue.

16. The wearable device (10) according to claim 15, wherein, When muscle fatigue is detected, the muscle fatigue detection module is configured to reduce the current intensity by 10%, 20%, 30%, 40%, 50% or more, reduce the stimulation period of the work cycle by 10%, 20%, 30%, 40%, 50% or more, and / or increase the rest period of the work cycle by 10%, 20%, 30%, 40%, 50% or more.

17. The wearable device (10) according to claim 15, wherein, When muscle fatigue is detected, the muscle fatigue detection module is configured to terminate the recruitment process and / or initiate the rehabilitation process.

18. The wearable device (10) according to claim 15, wherein, The muscle fatigue detection module is configured to detect the presence of fatigue in surrounding muscles or fibers. And when fatigue of surrounding muscles or fibers is detected, one or more stimulation parameters can be adjusted by reducing the current intensity.

19. The wearable device (10) according to claim 15, wherein, The muscle fatigue detection module is configured to detect the presence of fatigue in or on the spine; and when fatigue in or on the spine is detected, to adjust one or more stimulation parameters by increasing the frequency and / or increasing the pulse width of the electrical stimulation.

20. The wearable device (10) according to claim 7, wherein, The processing unit includes a sleep stage determination module configured to determine the sleep stage of the object, the sleep stage including at least a waking state and a sleeping state, and to adjust one or more stimulation parameters and / or stimulation programs when a change in sleep stage is determined.

21. The wearable device (10) according to claim 20, wherein, When a wakefulness phase is detected, the sleep stage determination module is configured to adjust one or more stimulation parameters and / or stimulation program and / or terminate the electrical stimulation to reduce stimulation efficiency.

22. The wearable device (10) according to claim 20, wherein, When a sleep stage is detected, the sleep stage determination module is configured to adjust one or more stimulation parameters and / or stimulation programs and / or initiate the electrical stimulation to increase stimulation efficiency.

23. The wearable device (10) according to claim 20, characterized in that, The sleep stage determination module is further configured to determine light sleep N1 and / or N2 stages and / or REM stages; and, wherein, upon detecting the light sleep N1 and / or N2 stages and / or REM stages, the sleep stage determination module is configured to adjust one or more stimulation parameters and / or initiate the electrical stimulation to increase stimulation efficiency.

24. The wearable device (10) according to claim 20, wherein, The sleep stage determination module is further configured to determine light sleep N1 and / or N2 stages and / or REM stages; and, wherein, upon detecting the light sleep N1 and / or N2 stages and / or REM stages, the sleep stage determination module is configured to initiate the recruitment procedure and / or terminate the retraining procedure.

25. The wearable device (10) according to claim 20, wherein, The sleep stage determination module is further configured to determine a deep sleep N3 stage; and, when the deep sleep N3 stage is detected, the sleep stage determination module is configured to adjust one or more stimulation parameters to reduce stimulation efficiency.

26. The wearable device (10) according to claim 20, wherein, The sleep stage determination module is further configured to determine a deep sleep N3 stage; and wherein, upon detecting the deep sleep N3 stage, the sleep stage determination module is configured to terminate the recruitment process and / or initiate the retraining process.

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