Apparatus, system and method for treating sleep disorders

Abstract

A system for managing a sleep disorder of a subject is provided, the system comprising: a sensor assembly for detecting movement and / or the orientation of part or all of the body of the subject and / or movement of the subject during sleep; an emitter for stimulating the subject to change the orientation of their body; and a processor configured to: receive a signal from the sensor assembly, the signal comprising data relating to the orientation and / or movement of the subject; process the data received from the sensor assembly; and transmit a signal to the emitter to apply a stimulus to the subject to provoke the subject to alter the orientation of part or all of their body. The system may also comprise a sensor for detecting sounds emitted by the subject while sleeping. A method for managing a sleep disorder of a subject is also provided, the method comprising: i) sensing the position in which the subject is sleeping; ii) determining if the position is related to a sleep disorder; and iii) if the position is related to a sleep disorder, applying a stimulus to the subject to provoke the subject to change their sleeping position.

Description

APPARATUS, SYSTEM AND METHOD FOR TREATING SLEEP DISORDERSThe present invention relates to an apparatus for sensing and treating sleep disorders. In a further aspect, the present invention relates to a system for sensing and treating sleep disorders. In a still further aspect, the present invention relates to a method for treating sleep disorders.There are a number of disorders which can affect a person while sleeping, leading to disruptions in the sleep pattern and / or a reduced quality of sleep. Detecting and addressing these disorders can be problematic.Snoring is a significant sleep disorder that affects both the person snoring and their partner. Figures for the number of people in the population that snore vary. For example, the British Snoring and Sleep Apnoea Association (BSSAA) reports that 1.5% of the UK adult population snore. It estimates that there are approximately 15 million snorers in the UK and that snoring affects up to 30 million people in the UK. The BSSAA indicates that the majority of snorers are male. It suggests that 58% of snorers are between 50 and 59 years of age. In one of the largest prevalence studies to date, a Hungarian population survey of 12,643 people was conducted and 50% self-reported being loud snorers (Torzsa, P. et aL, ‘Socio-demographic characteristics, health behaviour, co-morbidity and accidents in snorers: A population survey’, Sleep and Breathing, 15, pages 809 to 818 (2011 )). The sample was subdivided into loud and habitual snorers and further by gender. 37% of males self-identified as loud snorers with breathing pauses and 23% as habitual snorers, whereas in females, 21% identified as loud snorers with breathing pauses and 21% as habitual snorers.Many snorers might have obstructive sleep apnoea (OSA), a more serious condition associated with breathing interruptions during sleep.The best practice for diagnosing snoring and / or OSA is in-laboratory polysomnography (PSG), which involves an overnight sleep study. Home sleep apnoea testing (HSAT) is a less expensive alternative for screening individuals with a high probability of OSA.For many snorers, their snoring depends upon their position while sleeping. Many snorers only snore, or their snoring is worse, when sleeping on their backs. Consequently, it has been suggested for snorers to adopt different sleeping positions and to employ means preventing sleeping on their backs. In addition, a range of different devices have been proposed and marketed for reducing or preventing snoring. Such devices include: small plastic inserts inserted into the front of the nose which may slightly improve the nasal airway; adhesive plastic strips applied to the outside of the nose which pull the airway open or stop it from collapsing; sprays for the throat to lubricate the palate; adhesive strips to prevent the mouth falling open; and pillows to keep the neck in the best position to stop the airway collapsing. Mandibular advancement devices are also known. These are devices worn by the snorer over their teeth and act to prevent the jaw slipping back or to bring the jaw forward. This is intended to reduce the tendency of the back of the tongue to cause a narrowing of the airway. It is known to provide MADs that are adjustable and / or are custom formed to fit the individual. Devices of this kind are typically fitted by orthodontists and some dentists.The health risks associated with snoring can be significant. Snoring, especially loud snoring, significantly increases a person’s chances of having high blood pressure, high blood sugar, unhealthy cholesterol levels, and even heart attacks and strokes. Snoring may be as a result of the body not getting enough oxygen. This lack of oxygen can, in turn, strain the heart and blood vessels, leading to health issues associated with these organs.There is a need for an improved technique for reducing or preventing a person from snoring.A second sleep disorder is Bruxism, that is grinding of the teeth. A person may grind their teeth while awake (awake Bruxism or AB) or while sleeping (sleep Bruxism or SB). Clearly, a person is likely to be largely or completely unaware of their actions while asleep. The occurrence of sleep Bruxism in the population is significant, with estimates ranging from 6 to 91%, depending upon the diagnostic criteria being used. Studies using polysomnography (PSG) report a prevalence of around 7.4%, while self-reported data suggest a higher prevalence of 12.5% (Beddis, H., et al. ‘Sleep bruxism: An overview for clinicians’, Br DentJ, 225, pages 497 to 501 (2018). The prevalence of bruxism does not differ significantly between sexes and tends to decrease with age (Kanclerska, J. et al.,‘Polysomnographic Evaluation of Sleep Bruxism Intensity and Sleep Architecture in Nonapneic Hypertensives: A Prospective, Observational Study’, J Clin Med, 11 , (2022)). In children, the prevalence of SB decreases with age, with estimates ranging from 3.5 to 8.5% in children under five years old (Huynh, N., et al., ‘Sleep bruxism in children and adolescents — A scoping review’, Journal of Oral Rehabilitation, vol. 51 , pages 103 to 109 (2024).Teeth grinding can cause a number of adverse effects, including face, neck and shoulder pain, a painful jaw, which can in turn lead to temporomandibular disorder (TMD), worn-down or broken teeth, which can cause increased sensitivity and loss of teeth and fillings, headaches, earache and, of course, disturbed sleep.Treatments of Bruxism typically focus on managing symptoms, as no definitive cure exists. Actions to prevent a person grinding their teeth while asleep include wearing a mouth guard or mouth splint, which are primarily worn to prevent damage to teeth. Behavioural therapies may assist in reducing Bruxism and sometimes medications such as muscle relaxants may result in a reduction. Botulinum toxin (Botox) injections to reduce muscle activity are also being explored for severe cases of Bruxism.There is a need for an improved technique for reducing or preventing Bruxism.Further, the position in which a person sleeps can, in certain circumstances, be considered to be a disorder.In particular, research has shown that the position in which a pregnant woman sleeps can affect the likelihood of a stillbirth. Heazell, A.E.P., et al. ‘Association between maternal sleep practices and late stillbirth - findings from a still birth case-control study’, BJOG An International Journal of Obstetrics and Gynaecology, November 2017, pages 254 to 262 investigated maternal sleep practices. They report that a supine going-to-sleep position is associated with late stillbirth, with an increased risk of stillbirth of 2.3 times after 28 weeks gestation being associates with the mother sleeping on her back. Heazell et al. report that their study suggests that 3.7% of stillbirths after 28 weeks of pregnancy were linked to the mother going to sleep on her back.Despite a wealth of advice about pregnancy throughout history, the importance of the sleep position of a mother during pregnancy, in particular during the third trimester, has only emerged recently with modern obstetrics. Stillbirth is defined as the loss of a baby after 20 weeks of pregnancy. An estimated 2.64 million babies die before birth globally each year. In the UK, recent data from the Office of National Statistics shows the stillbirth rate at approximately 4.0 per 1 ,000 total births in 2022. The total number of stillbirths in 2022 was reported as 2,433 across England and Wales. Efforts to reduce stillbirth rates, including initiatives like the Saving Babies' Lives Care Bundle, have targeted various risk factors. Nevertheless, disparities persist, with higher stillbirth rates observed in more deprived areas and among specific ethnic groups. The UK government has set a goal to halve the 2010 stillbirth rate by 2025, aiming to reach 2.6 per 1 ,000 births. However, achieving this goal will require sustained efforts to address both medical and social determinants of health, which continue to influence stillbirth outcomes across different demographics and regions.Lying supine in the third trimester of pregnancy can compromise maternal haemodynamics. Aortocaval compression from the gravid-enlarged uterus impairs venous blood return to the heart, reducing maternal cardiac output, uterine perfusion, and oxygenation of the foetus and placenta. The adverse impact on foetal well-being is frequently shown in labour as abnormalities in electronic foetal monitoring.Further research has showed that women who reported supine positioning when falling asleep had double the stillbirth risk of those who fell asleep in a left lateral position (adjusted odds ratio 2.31 (95% confidence interval 1.04 to 5.11 )). By full term, this risk increased to 10-fold (10.26 (3.00 to 35.04)) (McCowan, L. M. E., et aL, ‘Going to sleep in the supine position is a modifiable risk factor for late pregnancy stillbirth; Findings from the New Zealand multicentre stillbirth case-control study’, PLoS One 12, (2017)). The risk of stillbirth with a supine sleep position is further increased for growth-restricted foetuses with pre-existent compromised placental perfusion (5.5 (1 .36 to 22.5)).Cronin, R. S. et aL, ‘An Individual Participant Data Meta-analysis of Maternal Going- to-Sleep Position, Interactions with Fetal Vulnerability, and the Risk of Late Stillbirth’, EClinicalMedicine 10, pages 49 to 57 (2019) reported that going to sleep lying on the back from 28 weeks of pregnancy increased the risk of stillbirth by 2.6 times. Specifically, the adjusted odds ratio (aOR) for stillbirth when sleeping supine was 2.63, indicating a morethan twofold increase in risk compared to sleeping on either side. No difference in risk was observed between left and right-side sleeping positions. This heightened risk occurred regardless of the other known risk factors for stillbirth. However, the risk is additive, meaning that going to sleep on the back adds to other stillbirth risk factors, for example, a baby who is growing poorly in the womb.A second group of people who will benefit from sleep positional therapy, in particular not sleeping supine, that is on their back, are people affected by Obstructive Sleep Apnoea (OSA). The earliest studies on sleep breathing disorders recognised the aggravating effect of the supine body position on breathing abnormalities during sleep.OSA is a common sleep disorder characterised by repeated airway obstruction during sleep, leading to intermittent hypoxia and fragmented sleep. Its prevalence ranges from 9 to 38% in the general population, increasing with age, obesity, and certain anatomical features. Men are more commonly affected than women, with a ratio of about 2:1 . From the early 1980’s it was becoming more apparent to researchers that OSA and its severity is affected by sleep position. To confirm these findings, Joosten et al. found that the most striking feature of obstructive respiratory events is that they are at their most severe and frequent in the supine sleeping position: indeed, more than half of all OSA patients can be classified as experiencing supine related OSA. Existing evidence points to supine-related OSA being attributable to unfavourable airway geometry, reduced lung volume, and an inability of airway dilator muscles to compensate as the airway collapses adequately (Joosten, S. A., et aL, ‘Supine position related obstructive sleep apnea in adults: Pathogenesis and treatment’, Sleep Medicine Reviews, Vol. 18, pages 7 to 17 (2014). It has since been concluded that OSA can be categorised into positional OSA and non-positional OSA based on positional dependency during sleep.Positional therapy (PT) is a viable alternative for patients with OSA. The therapy aims to reduce airway collapses or partial blockages that occur when lying on the back. By avoiding the supine position, this therapy seeks to decrease the frequency of sleep apnoea events and improve overall sleep quality. This therapy focuses on preventing supine sleep and promoting lateral (side-lying) sleep, yielding multiple health benefits.More generally, a study by Levendowski et al. explored the inter-relationships between neurodegenerative disease (NDD), age, sex, diagnosis of obstructive sleep apnoea, snoring, and duration of sleep time with the head in the supine and non-supine positions (Levendowski, D. J. et aL, ‘Head position during sleep: Potential implications for patients with neurodegenerative disease’ Journal of Alzheimer’s Disease, 67, pages 631 to 638, (2019). It was found that the frequency of supine sleep was significantly greater in the NDD group than in the NC group and remained significant after controlling for age, sex, snoring, and obstructive sleep apnoea diagnosis.The effect of sleeping position on the cortical activities of a person is not fully understood. Xu et al. showed that sleep onset latency (SOL) was affected by both sleep position preference (SPP) and lying poses (Xu, D., et aL, ‘Lying posture affects sleep structures and cortical activities: a simultaneous EEG-fMRI imaging of the sleeping and waking brain’, Brain Imaging Behav., 2021 , Aug, 15(4). It was noted that SOL in a supine position was significantly shorter than that in a lateral posture. The correlation analysis between SPP and sleep parameters indicated that individuals who prefer supine had less SOL and N2 sleep durations. In the supine posture, the brain activities in the left praecuneus and anterior cingulate cortex were greater than those when lying in the lateral position. Finally, it was also found that the right putamen was sensitive to habitual sleep posture in the awake state. Participants who prefer to lie supine tended to have higher putamen activity. This study may help understand the contribution of lying posture to brain activity and its relationship with posture preference in sleep.Further, Spironelli et al. studied the effects of body position on resting-state EEG activity in 32 young women (Spironelli, C., et aL, ‘Supine posture inhibits cortical activity: Evidence from Delta and Alpha EEG bands’, Neuropsychologia 89, pages 125 to 131 (2016). It was found that the supine position induced a steady inhibition of cortical activity in the resting state. These results indicate clear-cut differences at rest between the seated and supine positions, thus supporting the view that the role of body position in the differences found between brain metabolic methods (fMRI and PET) in which participants lie horizontally and EEG-MEG-TMS techniques with participants in a seated position, has been largely underestimated so far.In summary, the relationship between sleep positions and health outcomes is multifaceted, impacting respiratory, neurological, and cortical activities. There seems to bea significant link between prolonged supine sleep (>2 hours) and neurodegenerative disease (NDD). Further findings indicate that sleep posture impacts brain activity differently, potentially influencing cognitive health and sleep quality. Individuals who prefer the supine position exhibit shorter sleep onset latency (SOL) but altered sleep architecture, such as reduced N2 sleep duration. These variations may influence overall sleep quality and brain recovery during sleep. Research has demonstrated that the supine position inhibits cortical activity at rest. This inhibition underscores the significant effect of body posture on brain function, as different positions (seated vs. supine) can alter outcomes in neurological and imaging studies like EEG or fMRI.There is therefore a need for an improved technique for monitoring and managing the position adopted by a person, in particular pregnant women, during sleep.US 2016 / 367203 concerns a system and method of detecting sleep disorders. An apparatus for detecting sleep disorders, such as obstructive sleep apnea, is disclosed. The apparatus includes a housing insertable into an ear canal of a subject. A sensor is disposed within the housing and measures a position of the head of the subject relative to an axis of gravity. A transducer in the housing is responsive to the sensor and is capable of creating a stimulus detectable by the subject under certain conditions. In various embodiments, a controller receives signals corresponding to a pitch angle and a roll angle of the head of the subject measured by the sensor, determines if the pitch and roll angles correspond to a sleep apnea inducing position, and causes the transducer to generate a stimulus upon determining that the head of the subject is in the sleep apnea inducing position more than a predetermined threshold number of times. Various parameters of the stimulus may be modified with successive stimulus generation until a non-sleep apnea inducing position is detected.US 11298048 discloses a sleep position trainer with non-movement timer. The sleep position trainer has a normal operational mode for alerting when a posture of the body detected by a position sensor corresponds with an undesired body posture. The sleep position trainer further comprises a non-movement timer for timing a non-movement period of the user wearing the sleep position trainer. An output signal is sent to an alert unit when a posture of the body detected by the position sensor corresponds with a body posture when a threshold value of the non-movement timer of at least 15 minutes is exceeded.A positional snoring and sleep apnea prevention system is disclosed in US 2022 / 062030. The system comprises a headband, a sensor, for example an accelerometer, and a vibrating pad. The sensor may be integrated on a front portion of the headband so as to contact the forehead, while the vibrating pad may be integrated on a rear portion of the headband, contacting the back of the head. The sensor may act as a forehead level, thereby measuring the position of the head of the user and sending a signal to the vibrating pad to initiate head repositioning when the head is in an undesirable position.More recently, US 2023 / 191058 discloses a control system for controlling a respiratory support system for supplying therapy gas to a subject. The control system comprises processing circuitry coupled to an interface for receiving an indication of a combination of the orientation of the head of the subject and the orientation of their torso. The indication is based on orientation data provided by a sensing system configured to detect the orientation of the head and torso. The control system further comprises a machine-readable medium storing instructions. When executed by the processing circuitry, the instructions cause the processing circuitry to identify, from parameter information associated with each of a set of different combinations of head orientation and torso orientation, a parameter value of the therapy gas for the respiratory support system to use in supplying the therapy gas to the subject for the indicated combination of the orientation of the head and torso. The respiratory support system is caused to supply the therapy gas with the identified parameter value.In general, there is a need for improvements in the management and prevention of sleep disorders in general and the aforementioned disorders of OSA, snoring, Bruxism and infant stillbirths in particular.According to a first aspect of the present invention, there is provided a system for managing a sleep disorder of a subject, the system comprising: a sensor assembly for detecting movement and / or the orientation of part or all of the body of the subject and / or movement of the subject during sleep; an emitter for stimulating the subject to change the orientation of their body; anda processor configured to: receive a signal from the sensor assembly, the signal comprising data relating to the orientation and / or movement of the subject; process the data received from the sensor assembly; and transmit a signal to the emitter to apply a stimulus to the subject to provoke the subject to alter the orientation of part or all of their body.The system of the first aspect of the present invention advantageously allows a range of sleeping disorders to be managed. For example, the system is operable to manage any sleeping disorder that arises from the position or orientation in which the subject is lying while sleeping.As discussed above, one such disorder arises with pregnant women sleeping in a supine position, especially in the third trimester of pregnancy. The system of the first aspect of the invention may be used to manage this disorder, in particular to reduce or eliminate the time a pregnant woman spends in a supine position and encourage lying in a different, non-supine position.Snoring is also a sleep disorder that can be affected by the position in which the subject is sleeping. The BSSAA reports that body position plays an important role during sleep and can often make the difference between the subject having a good night's sleep or not. For subjects who suffer from obstructive sleep apnoea (OSA), this is a particular problem. The BSSAA reports that several studies have found that subjects who sleep in the supine position are more likely to snore or have increased apnoeas than those who sleep in a lateral position (on the side).Bruxism is a further sleep disorder that can be affected by the position in which the subject is sleeping. Kuang, B. et aL, ‘The effect of sleep position on sleep bruxism in adults with obstructive sleep apnoea’, Journal of Oral Rehabilitation, 2024, 51 , pages 1207 to 1212, report on the effects of sleep position on Bruxism. Sleep Bruxism is defined as a repetitive jaw-muscle activity and is characterised by the subject clenching or grinding their teeth and / or bracing or thrusting their mandible. Sleep Bruxism is diagnosed when therhythmic masticatory muscle activity (RMMA) index is at least two events per hour of sleep. The study performed by Kuang et al. showed that the RMMA index of sleepers in a supine position is significantly higher that the RMMA index of subjects sleeping in a non-supine position.The system of the first aspect of the present invention is operable to manage the position in which the subject is sleeping, which in turn manages sleeping disorders that are dependent upon or related to sleeping in a particular position, such as the disorders discussed above.The system comprises a sensor assembly for sensing the orientation of the body of the subject and / or movement of the subject during sleep. References herein to the orientation or movement of the ‘body’ of the subject are to the orientation and / or movement of the whole or one or more parts of the body, for example determining if the person is lying in a supine position or determining the movement and / or orientation of one or more parts of the body, for example the head and / or torso of the person. References to the ‘body’ of the subject include the head and the torso and all limbs. Separate parts of the body, such as the head and the torso, are referred to individually, as required.In one embodiment, the sensor assembly is configured and operable to sense the movement and / or the orientation of the torso of the subject. In one embodiment, the sensor assembly is configured and operable to sense the movement and / or the orientation of the head of the subject. In one preferred embodiment, the sensor assembly is configured and operable to sense the movement and / or orientation of the torso and the head of the subject.As noted above, the sensor assembly may be configured and operable to sense the orientation and / or movement of the head of the subject. The head of a person has a range of different movements and orientations, including flexion (bending of the head forwards, typically by up to about 50°), extension (bending of the head backwards, typically by up to about 80°), lateral flexion (tilting of the head to either side, typically by up to about 45°), and rotation (turning the head to either side, typically by up to about 80°). The sensor assembly may be configured and operable to detect movement or an orientation of the head of the subject resulting from one or more of flexion, extension, lateral flexion androtation. In one embodiment, the sensing assembly is configured and operable to detect movement and orientation arising from all of flexion, extension, lateral flexion and rotation.The sensor assembly may be configured and operable to sense movement and the orientation of the torso of the subject. The subject when sleeping may be oriented to be lying on their back (supine), on one side or on their front. Studies have shown that when sleeping a person may spend about 55% of their time on one side, about 38% of their time on their back and about 7% of their time lying on their front (Skarpsno, E. S., et aL, ‘Sleep positions and nocturnal body movements based on free-living accelerometer recordings: Association with demographics, lifestyle, and insomnia symptoms’, Nat. Sci. Sleep, 9, pages 267 to 275 (2017); and Jayaraman, C., et aL, ‘Variables influencing wearable sensor outcome estimates in individuals with stroke and incomplete spinal cord injury: A pilot investigation validating two research grade sensors’, J. Neuroeng. RehabiL, 15, (2018)). The studies showed that participants changed their sleeping position on average about 1 .6 times per hour.As discussed hereinbefore, issues with sleep disorders arise in particular when the person is sleeping in a supine position, that is on their back. This is particularly the case with pregnant women, but is also relevant to other disorders, including Obstructive Sleep Apnoea (OSA), snoring and Bruxism. In one preferred embodiment, the sensor assembly is operable to detect when the subject is in a supine position.The sensor assembly comprises one or more sensors for sensing the orientation and / or movement of the body of the subject. Any suitable sensors may be used. In one preferred embodiment, the sensor assembly comprises one or more accelerometers. Suitable accelerometers are known in the art and are commercially available.In one embodiment, one or more, preferably the or each, accelerometer is a 3-axis accelerometer, that is an accelerometer that is operable to detect motion in three orthogonal directions or three Cartesian coordinates: up / down, left / right and forwards / backwards. In one preferred embodiment, one or more, preferably the or each, accelerometer is a 6-axis accelerometer, that is an accelerometer that is operable to detect motion in the three Cartesian coordinates: up / down, left / right and forwards / backwards, as well as making gyroscopic measurements of rotation about the three Cartesian axes, that is providing a indication of pitch, roll and yaw. A 6-axis accelerometer may be considered to be a combination of a 3-axis accelerometer with a 3-axis gyroscope. In a more preferredembodiment, one or more, preferably the or each, accelerometer is a 9-axis accelerometer, that is an accelerometer that is operable to detect motion in the three Cartesian coordinates: up / down, left / right and forwards / backwards; sense rotation about the three Cartesian axes, that is providing a indication of pitch, roll and yaw; and sense a magnetic field in the three orthogonal directions. A 9-axis accelerometer may be considered to be a combination of a 3-axis accelerometer, a 3-axis gyroscope and a 3-axis magnetometer.Suitable 3-axis, 6-axis and 9 axis accelerometers are known in the art and are commercially available.One particularly preferred class of accelerometer is a micro electro mechanical system (MEMS) accelerometer. Again, suitable MEMS accelerometers are known in the art and are commercially available.The sensor assembly comprises one or more sensors for sensing the orientation and / or movement of part or all of the body of the subject during sleep. The one or more sensors may be located at any suitable position that allows the orientation and / or movement of the body of the subject to be detected and a corresponding signal to be generated and transmitted to the processor. The one or more sensors may be located away from the body of the subject. In one preferred embodiment, the sensor assembly comprises one or more sensors located on the body of the subject. In particular, the sensor assembly comprises one or more sensors located in one or more devices that may be worn by the subject while sleeping.In one preferred embodiment, the sensor assembly comprises one or more sensors that are worn on the head of the subject. The sensor assembly preferably comprises one or more 9-axis accelerometers, as described hereinbefore.More preferably, in one embodiment, the sensor assembly comprises one or more sensors that are located on or in the ear of the subject. In one particularly preferred embodiment, the system comprises an in-ear device to be worn in the ear of the subject, the in-ear device comprising one or more sensors for detecting the orientation and / or movement of the body of the subject. References herein to an ‘in-ear’ device are to a device that has at least a portion that is located in or extends into the ear canal of an ear of the subject. In this embodiment, it is particularly preferred that one or more sensors are located within an ear canal of the user.The one or more sensors located in the ear of the subject may be used to sense the orientation and / or the movement of the head of the subject, as well as other parts of the body of the subject, for example the torso, as described in more detail below. The one or more sensors may be used to detect the position in which the subject is lying, in particular to detect when the subject is lying in a supine position. However, the one or more sensors may detect other movements, for example movements associated with other sleeping disorders. For example, the one or more sensors may be operable to detect movements of the jaw that occur during Bruxism. An in-ear sensor is particularly preferred or detecting jaw movements arising as a result of Bruxism.The system may comprise a single in-ear device to be worn in just one ear of the subject. Alternatively, the system may comprise an in-ear device to be worn in each ear of the subject. In such embodiments, one or both of the in-ear devices may comprise one or more sensors for sensing the orientation and / or movement of all or part of the body of the subject, for example movement of the torso and / or the head of the subject and / or a part of the head of the subject, such as the jaw.In one embodiment, the system comprises a device to be worn on a part of the body of the subject other than the head of the subject. For example, the system may comprise a device for wearing on the torso of the subject during sleep. The device may comprise one or more sensors for sensing movement and / or the orientation of part or all of the body of the subject. The one or more sensors may be any suitable sensor, for example a 3-axis, 6-axis or 9-axis accelerometer, as hereinbefore described. A 6-axis sensor is suitable for many embodiments where the sensor is located on the torso of the subject.In one preferred embodiment, the system comprises a first sensor assembly to be worn on the head of the subject, as hereinbefore described, and a second sensor assembly to be worn on a part of the body other than the head of the subject, also as described above. In one preferred embodiment, the system comprises a first device for wearing on the head of the subject comprising a sensor assembly comprising one or more sensors, as hereinbefore described, and a second device for wearing on the torso of the subject comprising a second sensor assembly comprising one or more sensors, as hereinbefore described. In one preferred embodiment, the first device is an in-ear device.In one preferred embodiment, the first sensor assembly comprises one or more 9- axis accelerometers to sense movement and / or the orientation of the head of the subjectand the second sensor assembly comprises one or more 6-axis accelerometers to sense movement and / or the orientation of the torso of the subject.The sensor assembly generates a signal containing data relating to the position of the subject, which signal is transmitted to a processor. The signal data are processed to determine the position in which the subject is sleeping. The processor determines if the position of the subject is to be changed. If a change in the position or the orientation of the subject is required, the processor transmits a signal to an emitter operable to generate a stimulus to encourage or provoke the subject into changing their orientation or position, as described in more detail below.For example, in the case of a pregnant woman using the system, the processor is operable to determine, on the basis of data received from the sensor assembly, when the woman is in a supine position and to provoke the woman to move to change position out of the supine position. The processor operates in a similar manner in cases where the subject suffers from Obstructive Sleep Apnoea (OSA). In a further example, the processor may determine, on the basis of data received from the sensor assembly, when the subject is in a position that encourages the subject to snore, again for example a supine position, and to provoke the subject to move and change position, thereby reducing or eliminating the tendency to snore. Similarly, the processor may be operable to sense when the subject is in a position that contributes to or increases the likelihood of Bruxism and to provoke the subject to move or change position, thereby reducing or eliminating the tendency for the subject to grind their teeth.Further details of the operation of the processor are described hereinbelow, in relation to the method aspects of the present invention.The processor may be any suitable processor for receiving and analysing the signals received from the sensor assembly. Suitable processors are known in the art and are commercially available.The processor may be comprised in a device with one or more sensors, such as the devices hereinbefore described. For example, the processor may be comprised in an in-ear device as hereinbefore described, together with one or more sensors for sensing movement and / or the orientation of the subject. Alternatively, the processor may becomprised in a device to be worn on the torso of the subject while sleeping, together with one or more sensors for sensing movement and / or the orientation of the subject, again as hereinbefore described.In one embodiment, the system of the present invention comprises an in-ear device for location in the ear canal of the subject, the device comprising a sensor for sensing movement and / or the orientation of the body of the subject or a part thereof and a processor.In one embodiment, the system of the present invention comprises a device for wearing on a part of the body of the subject other than the head, for example the torso, the device comprising a sensor for sensing movement and / or the orientation of the body of the subject or a part thereof and a processor.Alternatively, the processor may be disposed at a location remote from the one or more sensors for sensing movement and / or orientation of the body of the subject. For example, the processor may be comprised in a device for wearing by the subject. Alternatively, the processor may be comprised in a device for location away from the subject.In embodiments where the processor is remote from the one or more sensors, that is the processor is not housed within the same device as one or more sensors, the system further comprises means for transmitting a signal from the one or more sensors to the processor. The signals may be transmitted by wires or cables. More preferably, the system further comprises one or more transmitters for transmitting wireless signals from the one or more sensors and a receiver connected to the processor. Any suitable wireless transmission protocol may be employed and examples include Wi-Fi, Bluetooth, Zigbee, Z- Wave, Bluetooth Low Energy (BLE), Near Field Communication (NFC), and Wireless M- Bus. Bluetooth is a particularly suitable wireless transmission protocol. Suitable transmitters and receivers are known in the art and are commercially available.Depending upon the results of the signal data from the one or more sensors being processed by the processor, the processor sends a signal to an emitter. The emitter generates a stimulus to the subject to prompt the subject to alter their sleeping position, as described in more detail hereinbelow.In addition, having processed the signal received from the sensor assembly, the processor may store the processed signal data. In one embodiment, the system comprises a data storage assembly for storing processed signal data. The data storage assembly may be comprised in the processor. Alternatively, the data storage assembly may be remote from the processor. The data storage assembly may be comprised in one or more devices worn by the subject. Alternatively, the data storage assembly may be remote from the other components of the system, for example remote from the subject.In embodiments where the data storage assembly is remote from the processor, the system further comprises means for transmitting processed data from the processor to the data storage assembly. The data may be transmitted by wires or cables. More preferably, the system further comprises one or more transmitters for transmitting data wirelessly from the processor to the data storage assembly. Any suitable wireless transmission protocol may be employed and examples include Wi-Fi, Bluetooth, Zigbee, Z- Wave, Bluetooth Low Energy (BLE), Near Field Communication (NFC), and Wireless M- Bus. Bluetooth is a particularly suitable wireless transmission protocol. Suitable transmitters and receivers are known in the art and are commercially available.Alternatively or in addition, the system may transmit processed data to a remote storage facility, for example a mobile telecommunications device or remote service (the ‘cloud’). Suitable transmitters and transmission protocols are as described hereinbefore.As noted above, the system further comprises an emitter. The emitter is operable to emit a stimulus to the subject. The stimulus is of a type and intensity to prompt the subject to change their sleeping position. Preferably, the stimulus applied to the subject in response to a signal from the processor is sufficient to alter the stage of sleep of the subject, which in turn encourages or provokes the subject to change position.Sleep is generally considered to occur in five stages: wake; N1 ; N2; N3; and rapid eye movement (REM). Sleep stages N1 to N3 are considered to be non-rapid eye movement (NREM) sleep, with each stage leading to progressively deeper sleep. Approximately 75% of the time a subject is sleeping is spent in the NREM stages, with the majority spent in the N2 stage. In a typical night sleep will consist of 4 to 5 sleep cycles, with the progression of sleep stages in the order as follows: N1 , N2, N3, N2, REM(Feinberg I, et aL, ‘Systematic trends across the night in human sleep cycles’, Psychophysiology,

[1979] May; 16(3), pages 283 to 91). A complete sleep cycle takes about 90 to 110 minutes to conclude. The first REM period of the subject in a given night is typically short, and as the night progresses, longer periods of REM and decreased time in deep sleep (NREM) occur.In a preferred embodiment, the emitter is operable to emit a stimulus to the subject to change their sleep stage. In particular, taking the sleep stages to be in a descending order of from Wake to N1 to N2 to N3 to REM, the stimulus applied to the subject preferably raises their level of sleep to a higher stage.The emitter may generate and emit any stimulus that can be applied to the subject to provoke a change in the sleeping position or orientation of the subject. For example, the emitter may generate a haptic signal, such as a moving contact with the skin of the subject or a vibration, that stimulates the senses of touch and motion of the subject. In one embodiment, the stimulus emitted is light. A preferred stimulus is sound. The system may comprise an emitter for emitting a single type of stimulus. Alternatively, the system may comprise a plurality of emitters for emitting two or more different types of stimulus.Suitable emitters for generating one or more stimuli are known in the art.In one embodiment, the emitter is comprised in a device that is worn by the subject while sleeping. For example, the device may be worn on any suitable part of the body, for example a limb, such as an arm, the torso or the head.In one preferred embodiment, the system comprises an emitter comprised in an in-ear device that generates a sound. The emitter preferably generates a sound within the ear canal of the subject. Suitable in-ear emitters for generating a sound are known in the art and are commercially available.As noted hereinbefore, the stimulus applied to the subject may be one or a combination of various different stimuli. Examples of suitable stimuli include haptic stimuli that stimulate the senses of touch and movement of the subject, such as vibrations or twitching, gripping or rocking movements applied to the subject by devices; and soundsIn one embodiment, the processor is comprised in a device that is separate and remote from the other components of the system, for example a mobile communications device, such as a mobile telephone or a tablet, for example a mobile telephone or tablet programmed to receive and process signals from the one or more sensors, for example a mobile telephone or tablet programmed with a suitable application (‘App’).Accordingly, in a further aspect of the present invention, there is provided a system for managing a sleep disorder of a subject, the system comprising: a sensor assembly for detecting movement and / or the orientation of part or all of the body of the subject and / or movement of the subject during sleep; an emitter for stimulating the subject to change the orientation of their body; and a communication assembly for communicating with a remote processor; wherein the processor is configured to: receive a signal from the sensor assembly, the signal comprising data relating to the orientation and / or movement of the subject; process the data received from the sensor assembly; and transmit a signal to the emitter to apply a stimulus to the subject to alter the orientation of their body.In this embodiment of the present invention, the system employs a processor comprised in a remote device, for example a mobile communications device, such as a mobile telephone or a tablet. The remote device is programmed, for example using an application or ‘App’, to process the signal data received from the sensor assembly and, depending upon the outcome of the processing and the determined position or orientation of the sleeping subject, to transmit a signal to the emitter, as required. The system comprises a communication assembly for communicating with the remote device, preferably comprising a transmitter for transmitting signals to the remote device and a receiver for receiving signals from the remote device. Communication between the systemand the remote device is preferably wireless using a suitable wireless communication protocol, as hereinbefore described.The remote device, for example a remote mobile communications device, may be configured to emit a stimulus to the subject, for example a sound and / or vibration. Details of the stimuli to be provided to the subject are discussed hereinbefore. Typically, mobile communication devices, such as mobile telephones and tablets, comprise the means to generate a stimulus, including a sound and / or a vibration. The present invention may employ the mobile device to perform the function of the emitter.Accordingly, in a further aspect of the present invention, there is provided a system for managing a sleep disorder of a subject, the system comprising: a sensor assembly for detecting movement and / or the orientation of part or all of the body of the subject and / or movement of the subject during sleep; a processor; and a communication assembly for communicating with a remote emitter; wherein the processor is configured to: receive a signal from the sensor assembly, the signal comprising data relating to the orientation and / or movement of the subject; process the data received from the sensor assembly; and transmit a signal to the emitter to apply a stimulus to the subject to provoke the subject to alter the orientation of their body.In one embodiment, the present invention employs a remote device, such as a remote telecommunications device, for example a mobile telephone or a tablet, to perform the functions of both the processor and the emitter. Details of these functions are as set out hereinbefore and below.Accordingly, in a further aspect of the present invention, there is provided a system for managing a sleep disorder of a subject, the system comprising: a sensor assembly for detecting movement and / or the orientation of part or all of the body of the subject and / or movement of the subject during sleep; and a communication assembly for communicating with a remote device, the remote device comprising a processor and an emitter; wherein the processor is configured to: receive a signal from the sensor assembly, the signal comprising data relating to the orientation and / or movement of the subject; process the data received from the sensor assembly; and transmit a signal to the emitter; wherein the emitter is operable to apply a stimulus to the subject to provoke the subject to alter the orientation of their body.As discussed hereinbefore, the system of the present invention functions to detect the movement and / or orientation of the subject while sleeping and to determine whether the subject is sleeping in a position or orientation that causes or promotes a sleeping disorder. If the position or orientation of the subject is related to a sleeping disorder, the system emits a stimulus to provoke or prompt the subject to change their position.Accordingly, in a further aspect, the present invention provides a method for managing a sleep disorder of a subject, the method comprising: i) sensing the position in which the subject is sleeping; ii) determining if the position is related to a sleep disorder; and iii) if the position is related to a sleep disorder, applying a stimulus to the subject to provoke the subject to change their sleeping position.As discussed hereinbefore, the method of the present invention includes sensing the position in which the subject is sleeping. This includes sensing movement or the position or orientation of the whole or part of the body of the subject. As described hereinbefore the method may include sensing the movement and / or orientation of the head of the subject. Alternatively or in addition, the method may include sensing the movement and / or orientation of the torso of the subject.In one preferred embodiment, the position in which the subject is sleeping is determined using one or more sensors located on the head of the subject, more preferably using one or more sensors located on or in the ear of the subject. A preferred embodiment comprises sensing movement and / or the orientation of the subject from within the ear canal of the subject.In this embodiment, the sensor senses movement and / or orientation of the subject while sleeping. For example, an accelerometer measures linear and angular accelerations in 3 orthogonal axes (x, y, z). This can detect a range of movements of the head, such as tilting (angular) or translation (linear). However, when the body of the subject moves, for example rolling to the side, both the head and the torso will experience motion. The accelerometer in the ear will sense both movements and will generate a combined signal containing signal aspects relating to the movement of the head and of the torso. In a preferred embodiment, the method includes differentiating between these aspects of the signal to determine the movement and / or orientation of the head and of the torso.The movements of the torso are typically slower and larger scale compared to the fine and quick movements of the head. For example, a movement by the subject turning their head rapidly left-right is much faster than the subject rolling their torso from lying on their back to lying on their side. As a result, movements of the head will typically manifest as higher-frequency components, that is small but rapid changes in angular acceleration. In contrast, movements of the body, such as rolling, sitting up, or moving side to side, will primarily introduce lower frequency components and consistently affect both linear and angular acceleration.In one preferred embodiment, the signals from the one or more sensors relating to the sensed movement and / or orientation of the subject are analysed to separate the high frequency and low frequency components. Any suitable frequency domain analysis may be applied to the signals and such techniques are known in the art, for example Fourierseries, Fourier Transforms, especially Fast Fourier Transform, Laplace transforms, Z- transforms, or wavelet decomposition.In one embodiment, the signal data from the one or more sensors are filtered to remove the high frequency signals, to isolate the signals corresponding to the movement of the torso of the subject, or to remove low frequency signals in order to isolate the signals corresponding to movement or orientation of the head of the subject. Any suitable filter may be employed, for example a band-pass filter. A low pass filter may be used to isolate lower frequency signals relating to movement of the torso of the subject, while a high pass filter may be used to isolate higher frequency signals relating to the movement of the head of the subject.The initial orientation of the body or the head of the subject may be referenced using a combination of gyroscope data and the linear acceleration signal (gravity vector). From these data, the relative movement of the head may be determined independently of movement of the rest of the body of the subject.When the head of the subject moves independently of the rest of the body of the subject, changes in angular acceleration (rotation) from a sensor on the head of the subject, for example in their ear canal, may not be accompanied by corresponding changes in the position of the rest of the body. When the subject moves parts of their body and their head stays relatively fixed or aligned with the rest of their body, the sensors will detect more uniform acceleration across all axes.In alternative preferred embodiment, the position in which the subject is sleeping is determined using one or more sensors located on the torso of the subject.In a preferred embodiment, the position in which the subject is sleeping is determined using signal data from a first sensor assembly, comprising one or more sensors, disposed on the head of the subject and signal data from a second sensor assembly, comprising one or more sensors, disposed on the torso of the subject. In this embodiment, data from both sensor assemblies is used to better distinguish between movements of the head and movements of the torso of the subject. The first sensor assembly, for example from within the ear canal of the subject, will directly sense movements of the head of the subject, while the second sensor assembly will mainly sense movement of the torso of the subject. The data from both the first and second sensorassemblies may be analysed and compared to distinguish the sources of movement. This may increase the accuracy of the detection of the orientation and position of the subject while sleeping.In one embodiment, further refinement of the detection and determination of the sleeping position of the subject is performed using machine learning algorithms. These algorithms may be applied, for example, to signal data received from one or more sensors located on the head of the subject, after isolating data signals based on their frequency components, or to signal data received from one or more sensors located on the torso of the subject, or to one or more sensors located at both locations on the subject. The machine learning algorithms may be trained to classify movements based on known motions of the head and / or the torso of a subject. In particular, labelled data may be used to train this model. For example, different movements of the subject, such as head-only, body-only, head and body combined, may be collected in controlled experiments by asking the subject to perform a standard set of movements and recording the signals generated by the one or more sensors. In this way, the model can learn to recognise specific patterns in the sensor data corresponding to movements of the head, of the torso, or combined movements. In addition, the machine learning algorithms may be trained using images of the subject while sleeping, in order to enhance the correlation of data generated by the one or more sensors with the actual sleeping position of the subject.The result of the processing of the signal data received from the one or more sensors is a determination of the position or orientation of all or part of the body of the subject while sleeping. The position determined is then assessed with respect to one or more sleeping disorders. If the sleeping position is determined to be one that causes or provokes a sleeping disorder, action is taken to prompt the subject to change their sleeping position. For example, in the case of a pregnant woman, a determination that the subject is sleeping in a supine position is indicating that the sleeping position is one that increases the risk of a stillbirth. Similarly, a determination that a person is sleeping in a supine position may indicate a sleeping position that provokes snoring or Bruxism. A determination may also be made if the subject has their head in a position that is known to provoke snoring or Bruxism. If such a determination is made regarding the sleeping position of the subject, the method includes a further step of applying to the subject astimulus to provoke the subject to change their sleeping position. Suitable stimuli and their generation are as described hereinbefore.Once the stimulus has been applied to the subject, the sensing and monitoring of the position in which the subject is sleeping is continued. There can be a number of outcomes. First, the application of the stimulus to the subject has prompted the subject to change their sleeping position to one that does not result in or provoke a sleeping disorder. For example, the subject has moved from a supine position to lying on one side.Alternatively, the subject has not changed their sleeping position sufficiently or at all in response to the stimulus. In this case, the method preferably includes a further step: iv) if applying the stimulus to the subject does not result in a change in the position of the subject to one that is not relevant to a sleep disorder, applying a second stimulus to the subject.The second stimulus may be same or different to the first stimulus applied, that is the same kind and intensity of stimulus. More preferably, the second stimulus is different to the first stimulus, for example the second stimulus is of a different kind of stimulus and / or the second stimulus is of a greater intensity. For example, if the first stimulus is vibration, the second stimulus applied may be a sound. Alternatively, if the first stimulus is a sound, the second stimulus may be a sound of a different type, such as frequency or pitch, or a different volume. This step is repeated until a sufficient change in the position of the subject has been achieved.In one embodiment, the system and method of the present invention include allowing the subject to adjust the stimuli applied to them by the emitter, so as to personalise the stimuli to those most effective for them. For example, the subject may select the intensity, frequency and type of stimuli. This can improve comfort for the subject and improve compliance.The sensing of the movement and orientation of the subject may be intermittent, that is data signals are processed by the processor intermittently at intervals while the subject is asleep. Alternatively, the processing of the signal data by the processor is continuous, that is the one or more sensors provide continuous data signals to theprocessor and the processor monitors the movement and / or orientation of the subject continuously. In this way, the system may detect as soon as the subject changes their position and moves into a position that causes or provokes a sleeping disorder.The emitter may be operated to apply the stimulus to the subject as soon as it is detected that the subject is in a position that provokes or results in a sleep disorder, such as a supine position. However, it has been found that applying a stimulus to a subject to provoke a change in position immediately upon the subject moving to a new, undesirable position, can lead to significant disruption to the sleep of the subject. Accordingly, in one preferred embodiment, once it has been determined that the subject is lying in a position that causes or provokes a sleeping disorder, the emitter is activated to apply a stimulus to the subject only after a delay period. The delay period may be from 10 seconds, preferably from 20 seconds, more preferably from 30 seconds, still more preferably from 1 minute. The delay period may be up to 10 minutes, more preferably up to 7 minutes, more preferably still up to 5 minutes.The processor may monitor the number of times the emitter is activated and a stimulus applied to the subject during each period of sleep, for example each night. In one embodiment, the number of times that the emitter is activated during each sleep period is restricted to a maximum number, for example 10, 8, 6 or 5 times per sleep period.The processor may monitor the sleep stage of the subject. In this embodiment, the processor may activate the emitter to apply a stimulus to the subject only during some but not all sleep stages. If this regime is employed, it is preferred that stimuli are applied to the subject only when the subject is in sleep stage N1 or N2.However, in cases where the subject is in sleep stage N3 or in REM sleep and the length and / or intensity of the sleeping disorder activity of the subject while sleeping is greater than a threshold length of time and / or threshold intensity, the stimulus may be applied to the subject during these sleep stages.To monitor the sleep stage of the subject, the system may comprise one or more sensors to sense one or more, of the following parameters of the sleeping subject:1 . Respiratory rate;2. Respiratory rate regularity and variability;3. Body movement intensity and duration;4. Body orientation (for example supine, lying on side or lying on front); and5. Head movement frequency and amplitude.It is preferred to sense the minimum number of the above aspects, while still obtaining sufficient data to allow the sleep stage of the subject to be accurately determined In some embodiments, the signal data being provided to the processor by the one or more sensors detecting movement of one or more parts of the body of the subject, such as the head and / or the torso, will allow the sleep stage of the subject to be determined without further aspects being sensed. Alternatively, one or more further parameters of the subject sleeping may be sensed to provide further data to the processor for determining the sleep stage of the subject. In such embodiments, it is preferred that in addition to the movement of the head and / or torso of the subject being sensed by the system, the system also senses the respiration rate of the subject, for example the rate, regularity and variability of the respiration rate.In one embodiment, identifying the sleep stage of the subject is performed using machine learning algorithms. The machine learning algorithms may be trained to identify different sleep stages from a set of input data based on an established set of data generated, for example in a sleep laboratory. In particular, labelled data may be used to train this model.A number of sleep disorders include the subject making or emitting sounds. This is particularly the case with disorders such as snoring and Bruxism. The detection and analysis of these sounds can be used in the management and prevention of such sleep disorders.In a further aspect of the present invention, there is provided as system for managing a sleep disorder of a subject, the system comprising: a sensor assembly for detecting sounds emitted by the subject during sleep; an emitter for stimulating the subject to change the orientation of their body; anda processor configured to: receive a signal from the sensor assembly, the signal comprising data relating to the sounds being emitted by the subject; process the data received from the sensor assembly; and transmit a signal to the emitter to apply a stimulus to the subject to provoke the subject to stir.The system of this aspect of the present invention advantageously allows a range of sleeping disorders to be managed where the subject emits a sound during sleep. For example, the system is operable to manage snoring and Bruxism. These disorders are discussed hereinbefore.The system of this aspect of the present invention is operable to manage sleeping disorders while the subject is asleep, such as, lying in a supine position, snoring and Bruxism. When the occurrence of a sleeping disorder is detected by way of the sounds being emitted by the subject, the system operates to apply a stimulus to the subject to cause the subject to stir. References herein to provoking the subject to ‘stir’ are to the subject being provoked to change their sleeping behaviour, with the intention of having the sleeping disorder cease. This may result in the subject stirring and simply stopping an activity, such as snoring or grinding / clenching their teeth without a change in their position or orientation. Alternatively, the stimulus may result in the subject stirring and changing their sleeping position, which in turn stops the sleeping disorder, such as the subject snoring or grinding / clenching their teeth.The system comprises a sensor assembly for detecting sounds emitted by the subject while sleeping. Any suitable sensors may be used. In one preferred embodiment, the sensor assembly comprises one or more microphones. Suitable microphones are known in the art and are commercially available.The sensor assembly comprises one or more sensors for detecting sound emitted by the subject during sleep. The one or more sensors may be located at any suitable position that allows the sounds to be detected and a corresponding signal to be generatedand transmitted to the processor. The one or more sensors may be located away from the body of the subject. In one preferred embodiment, the sensor assembly comprises one or more sensors located on the body of the subject. In particular, the sensor assembly comprises one or more sensors located in one or more devices that may be worn by the subject while sleeping.In one preferred embodiment, the sensor assembly comprises one or more sensors that are worn on the head of the subject.More preferably, in one embodiment, the sensor assembly comprises one or more sensors that are located on or in the ear of the subject. In one particularly preferred embodiment, the system comprises an in-ear device to be worn in the ear of the subject, the in-ear device comprising one or more sensors for detecting sounds emitted by the subject. References herein to an ‘in-ear’ device are to a device that has at least a portion that is located in or extends into the ear canal of an ear of the subject. In this embodiment, it is particularly preferred that one or more sensors are located within an ear canal of the user. It is especially preferred that the one or more sensors are disposed to detect sounds emitted by the subject and emanating from within and travelling outwards within the ear canal.The system may comprise a single in-ear device to be worn in just one ear of the subject. Alternatively, the system may comprise an in-ear device to be worn in each ear of the subject. In such embodiments, one or both of the in-ear devices may comprise one or more sensors for detecting sounds emitted by the subject.In one embodiment, the system comprises a device to be worn on a part of the body of the subject other than the head of the subject. For example, the system may comprise a device for wearing on the torso of the subject during sleep.In one embodiment, the system comprises a first sensor assembly to be worn on the head of the subject, as hereinbefore described, and a second sensor assembly to be worn on a part of the body other than the head of the subject, also as described above. In one preferred embodiment, the system comprises a first sensor assembly comprising an in-ear device comprising one or more sensors, as hereinbefore described, and a second sensor assembly comprising a second device comprising one or more sensors for wearing on the torso of the subject, as hereinbefore described.The sensor assembly generates a signal containing data relating to the sounds being emitted by the subject while sleeping, which signal is transmitted to a processor. The signal data are processed. The processor determines if the position of the subject is to be changed. If a change in the position or the orientation of the subject is required, the processor transmits a signal to an emitter operable to generate a stimulus to encourage or provoke the subject into changing their orientation or position, as described in more detail below.Further details of the operation of the processor are described hereinbelow, in relation to the method aspects of the present invention.The processor may be any suitable processor for receiving and analysing the signals received from the sensor assembly. Suitable processors are known in the art and are commercially available.The processor may be comprised in a device with one or more sensors, such as the devices hereinbefore described. For example, the processor may be comprised in an in-ear device as hereinbefore described, together with one or more sensors for sounds being emitted by the subject. Alternatively, the processor may be comprised in a device to be worn on the torso of the subject while sleeping, together with one or more sensors for detecting sound from the subject, again as hereinbefore described.In one embodiment, the system of the present invention comprises an in-ear device for location in the ear canal of the subject, the device comprising a sensor for detecting sounds from the subject and a processor.In one embodiment, the system of the present invention comprises a device for wearing on a part of the body of the subject other than the head, for example the torso, the device comprising a sensor for detecting sounds emitted by the subject and a processor.Alternatively, the processor may be disposed at a location remote from the one or more sensors for detecting sounds from the subject. For example, the processor may be comprised in a device for wearing by the subject. Alternatively, the processor may be comprised in a device for location away from the subject.In embodiments where the processor is remote from the one or more sensors, the system further comprises means for transmitting a signal from the one or more sensors to the processor. The signals may be transmitted by wires or cables. More preferably, the system further comprises one or more transmitters for transmitting wireless signals from the one or more sensors and a receiver connected to the processor. Any suitable wireless transmission protocol may be employed and examples include Wi-Fi, Bluetooth, Zigbee, Z- Wave, Bluetooth Low Energy (BLE), Near Field Communication (NFC), and Wireless M- Bus. Bluetooth is a particularly suitable wireless transmission protocol. Suitable transmitters and receivers are known in the art and are commercially available.Depending upon the results of the signal data from the one or more sensors being processed by the processor, the processor sends a signal to an emitter. The emitter generates a stimulus to the subject to prompt the subject to stir, as described in more detail hereinbelow.In addition, having processed the signal received from the sensor assembly, the processor may store the processed signal data. In one embodiment, the system comprises a data storage assembly for storing processed signal data. The data storage assembly may be comprised in the processor. Alternatively, the data storage assembly may be remote from the processor. The data storage assembly may be comprised in one or more devices worn by the subject. Alternatively, the data storage assembly may be remote from the other components of the system, for example remote from the subject.In embodiments where the data storage assembly is remote from the processor, the system further comprises means for transmitting processed data from the processor to the data storage assembly. The data may be transmitted by wires or cables. More preferably, the system further comprises one or more transmitters for transmitting data wirelessly from the processor to the data storage assembly. Any suitable wireless transmission protocol may be employed and examples include Wi-Fi, Bluetooth, Zigbee, Z- Wave, Bluetooth Low Energy (BLE), Near Field Communication (NFC), and Wireless M- Bus. Bluetooth is a particularly suitable wireless transmission protocol. Suitable transmitters and receivers are known in the art and are commercially available.Alternatively or in addition, the system may transmit processed data to a remote storage facility, for example a mobile telecommunications device or remote service (the ‘cloud’). Suitable transmitters and transmission protocols are as described hereinbefore.As noted above, the system further comprises an emitter. The emitter is operable to emit a stimulus to the subject. The stimulus is of a type and intensity to prompt the subject to stir, for example to have the subject stop snoring or grinding / clenching their teeth and / or to have the subject change their sleeping position. Preferably, the stimulus applied to the subject in response to a signal from the processor is sufficient to alter the stage of sleep of the subject, which in turn encourages or provokes the subject to stir sufficiently to change their sleeping behaviour.In a preferred embodiment, the emitter is operable to emit a stimulus to the subject to change their sleep stage. In particular, taking the sleep stages to be in a descending order of from Wake to N1 to N2 to N3 to REM, the stimulus applied to the subject preferably raises their level of sleep to a higher stage.The emitter may generate and emit any stimulus that can be applied to the subject to provoke a change in the sleeping position or orientation of the subject. For example, the emitter may generate a haptic signal, such as a vibration, that stimulates the senses of touch and motion of the subject. One preferred stimulus is sound. Suitable emitters for generating one or more stimuli are known in the art.In one embodiment, the emitter is comprised in a device that is worn by the subject while sleeping. For example, the device may be worn on any suitable part of the body, for example a limb, such as an arm, the torso or the head.In one preferred embodiment, the system comprises an emitter comprised in an in-ear device that generates a sound. The emitter preferably generates a sound within the ear canal of the subject. Suitable in-ear emitters for generating a sound are known in the art and are commercially available.In one embodiment, the processor is comprised in a device that is separate and remote from the other components of the system, for example a mobile communications device, such as a mobile telephone or a tablet, for example a mobile telephone or tablet programmed to receive and process signals from the one or more sensors, for example a mobile telephone or tablet programmed with a suitable application (‘App’).Accordingly, in a further aspect of the present invention, there is provided a system for managing a sleep disorder of a subject, the system comprising: a sensor assembly for detecting sounds emitted by the subject during sleep; an emitter for stimulating the subject to change the orientation of their body; and a communication assembly for communicating with a remote processor; wherein the processor is configured to: receive a signal from the sensor assembly, the signal comprising data relating to the sounds being emitted by the subject; process the data received from the sensor assembly; and transmit a signal to the emitter to apply a stimulus to the subject to provoke the subject to stir.In this embodiment of the present invention, the system employs a processor comprised in a remote device programmed to process the signal data received from the sensor assembly and, depending upon the outcome of the processing and the determined position or orientation of the sleeping subject, to transmit a signal to the emitter, as required. The system comprises a communication assembly for communicating with the remote device, preferably comprising a transmitter for transmitting signals to the remote device and a receiver for receiving signals from the remote device. Communication between the system and the remote device is preferably wireless using a suitable wireless communication protocol, as hereinbefore described.The remote device, for example the remote mobile communications device, may be configured to emit a stimulus to the subject, for example a sound and / or vibration. Details of the stimuli to be provided to the subject are discussed hereinbefore. Typically, mobile communication devices, such as mobile telephones and tablets, comprise themeans to generate a stimulus, including a sound and / or a vibration. The present invention may employ the mobile device to perform the function of the emitter.Accordingly, in a further aspect of the present invention, there is provided a system for managing a sleep disorder of a subject, the system comprising: a sensor assembly for detecting sounds emitted by the subject during sleep; a processor; and a communication assembly for communicating with a remote emitter; wherein the processor is configured to: receive a signal from the sensor assembly, the signal comprising data relating to the sounds emitted by the subject; process the data received from the sensor assembly; and transmit a signal to the emitter to apply a stimulus to the subject to provoke the subject to stir.In one embodiment, the present invention employs a remote device, such as a remote telecommunications device, for example a mobile telephone or a tablet, to perform the functions of both the processor and the emitter. Details of these functions are as set out hereinbefore and below.Accordingly, in a further aspect of the present invention, there is provided a system for managing a sleep disorder of a subject, the system comprising: a sensor assembly for detecting sounds emitted by the subject during sleep; and a communication assembly for communicating with a remote device, the remote device comprising a processor and an emitter; wherein the processor is configured to:receive a signal from the sensor assembly, the signal comprising data relating to the sounds emitted by the subject; process the data received from the sensor assembly; and transmit a signal to the emitter; wherein the emitter is operable to apply a stimulus to the subject to provoke the subject to stir.As discussed hereinbefore, the system of the present invention functions to detect sounds emitted by the subject while sleeping and to identify if the subject is suffering from or experiencing a sleeping disorder. If the sounds being made by the subject are related to a sleeping disorder, the system emits a stimulus to provoke or prompt the subject to change their position.Accordingly, in a further aspect, the present invention provides a method for managing a sleep disorder of a subject, the method comprising: i) sensing the sounds being made by the subject while the subject is sleeping; ii) determining if the sounds are related to a sleep disorder; and iii) if the sounds are related to a sleep disorder, applying a stimulus to the subject to provoke the subject to stir.As discussed hereinbefore, the method of the present invention includes sensing the sounds being made or otherwise emitted by the subject during sleeping.In one preferred embodiment, the sounds of the subject are determined using one or more sensors located on the head of the subject, more preferably using one or more sensors located on or in the ear of the subject. A preferred embodiment comprises sensing sounds being emitted or made by the subject from within the ear canal of the subject.In one preferred embodiment, the sounds emitted or being made by the subject are sensed using one or more sensors located on another part of the body of the subject, for example the torso of the subject.In one embodiment, the sounds emitted or being made by the subject are sensed by a first sensor assembly located on the head of the subject, more preferably using one or more sensors located on or in the ear of the subject, and a second sensor assembly located on another part of the body of the subject, for example the torso of the subject.Snoring sounds are generated by the vibration of soft tissues in the upper airway during sleep, often when airflow through the airway is partially obstructed. The characteristics of snoring can vary based on the specific anatomical structures involved and the position of the body. With regard to sound intensity and volume, snoring sounds typically range between 60 to 80 decibels. However, intense cases of snoring can result in sounds reaching or exceeding 90 decibels. In extreme cases, sounds of snoring have reached levels over 100 dB, which could potentially harm hearing over time.Snoring sounds can be characterised into simple waveform snoring: a quasi- sinusoidal pattern with few internal oscillations, typically associated with soft tissue vibrations, such as the tongue, with frequencies ranging from about 180 Hz to 300 Hz; and complex waveform snoring: involving airway closures, producing repetitive, structured sounds with a "comb-like" spectral pattern, with frequencies ranging from as low as 60 Hz up to 1000 Hz, with peaks indicating different levels of airway involvement.Snoring sounds can be categorised into four types:Type 1 : Low-frequency single-syllable snores.Type 2 and Type 3: Duplex sounds combining low, middle, and sometimes high frequencies.Type 4: Triplex sounds with layered frequencies across low, middle, and high ranges, often involving multiple anatomical structures like the uvula, soft palate, and tongue.The position of the subject and their sleep stage also influence snoring. Snoring often intensifies during deep sleep stages, especially when the subject sleeps in a supine position, as this narrows the airways more than other positions.As noted above, the signal from the one or more sensors detecting sounds emitted by the subject during sleep are processed. The processing includes distinguishing snoring sounds from Bruxism sounds and other ambient sounds.Bruxism, characterised by grinding or clenching the teeth, produces distinct sounds compared to snoring. Unlike snoring, which has a predictable rhythmic pattern associated with breathing, bruxism sounds are often irregular and can vary depending on the specific action, for example grinding the teeth versus clenching the teeth. Grinding sounds are generally lower in volume than snoring but can be loud enough to wake a sleeping partner. Grinding sounds are often continuous or intermittent, involving repetitive jaw movements. In general, clenching sounds are lower volume than grinding sounds, but may still produce noticeable volumes of sounds.Bruxism sounds tend to have lower frequencies compared to snoring due to the mechanical nature of teeth grinding against each other. The frequencies of sounds emitted during Bruxism are typically irregular and may vary widely, reflecting the varied intensity and duration of clenching episodes.Bruxism impacts dental health, leading to worn enamel, fractures, and tooth sensitivity. It also correlates with increased muscle tension, headaches, and potential temporomandibular joint (TMJ) disorders (Lavigne, G. J., et aL, ‘Bruxism physiology and pathology: An overview for clinicians’, Journal of Oral Rehabilitation, Vol. 35, pages 476 to 494 (2008).As noted above, the signal from the one or more sensors detecting sounds emitted by the subject during sleep are processed. The processing includes distinguishing Bruxism sounds from snoring sounds and other ambient sounds.In one preferred embodiment, the signals from the one or more sensors are analysed using Mel-Frequency Cepstral Coefficients (MFCCs), to identify the distinct spectral characteristics of both snoring and bruxism. For instance, the quasi-rhythmic pattern with layered frequencies typical of snoring can be differentiated from the sporadic, lower-frequency sounds of Bruxism.Mel-Frequency Cepstral Coefficients (MFCCs) is an audio feature extraction technique widely used in speech and audio processing to capture the spectral characteristics of sounds. For the analysis of sounds from snoring and Bruxism, MFCCsare particularly advantageous as they model the frequency components in a way that aligns with human auditory perception, allowing for the differentiation of subtle sound variations associated with different conditions.MFCCs are based on the Mel scale, which is a perceptual scale of pitches judged by listeners to be equidistant from one another. This scale approximates how the human ear perceives frequencies, especially at lower frequencies, which makes MFCCs well- suited for analysing sounds found in snoring and Bruxism.The process of calculating MFCCs preferably involves several steps:Pre-emphasis: The audio signal's high-frequency components are amplified to balance the frequency spectrum. This highlights rapid transitions in the waveform, which are important in identifying high-pitched sounds, such as the clicks typically emitted during Bruxism.Framing and Windowing: The audio signal is divided into small frames, typically of 20 to 40 milliseconds in duration, to capture short-term characteristics. Each frame is then windowed, for example with a Hamming window’ to minimise discontinuities at the edges of the frame.Fast Fourier Transform (FFT): The windowed frames are converted from the time domain to the frequency domain, creating a spectrum that reveals the energy distribution across various frequencies.Mel Filter Bank: The resulting spectrum is passed through a bank of filters spaced according to the Mel scale. This step emphasises frequencies that are perceptually more significant to humans, particularly in the lower ranges where snoring sounds are often concentrated.Logarithmic Transformation: The Mel-filtered spectrum is then converted to a logarithmic scale, as humans perceive loudness on a logarithmic scale. This transformation helps accentuate subtle changes in sound energy that differentiate snoring from other sounds.Discrete Cosine Transform (DCT): Finally, a DCT is applied to compress the log Mel spectrum into a smaller set of coefficients, creating the MFCCs. The first fewcoefficients capture the general shape of the sound spectrum, while higher coefficients represent finer details. Focusing on the first 12 to 13 coefficients is generally effective for snoring and Bruxism, as these capture the core characteristics of the spectral envelope of the sound.MFCCs assist with distinguishing snoring from Bruxism due to differences in frequency patterns, intensity, and temporal consistency between the two sound types, as follows:Frequency Distribution:Snoring: Snoring typically consists of low- to mid-frequency sounds. Simple snoring sounds are quasi-sinusoidal, with frequencies ranging from approximately 180 Hz to 300 Hz. Complex snoring, which involves the soft palate and uvula, includes frequencies as low as 60 Hz, with oscillations reaching up to 1000 Hz due to airway obstructions and soft tissue vibrations.Bruxism: Bruxism sounds, especially grinding, often contain higher frequency components due to the mechanical nature of teeth clenching and grinding. Frequencies vary more widely, often appearing as irregular, high-intensity bursts.Temporal Patterns:Snoring: Exhibits a rhythmic pattern aligned with breathing cycles. Each snore sound follows a relatively consistent timing pattern, corresponding to inhalation and exhalation.Bruxism: Bruxism sounds lack the rhythmic structure of snoring. Instead, they manifest as short, irregular bursts without a consistent frequency or amplitude pattern, often occurring in phases rather than continuous sounds.Energy Distribution and Intensity:Snoring usually has consistent energy distribution over time due to its association with steady airflow obstruction. MFCCs for snoring capture a gradual buildup and release in energy, whereas Bruxism involves sudden, sporadic energy bursts, resulting in more variable MFCC coefficients.MFCCs may be used alone to characterise and identify the sounds of snoring and Bruxism. However, in one preferred embodiment, the processing of the signals from the sensors combines MFCCs with additional analyses to improve model accuracy and robustness. Examples of additional analyses that may be applied include:Delta and Delta-Delta Coefficients: measure the dynamic changes in the MFCCs over time, which are useful for tracking the evolving characteristics of snoring and Bruxism sounds.Zero-Crossing Rate (ZCR): measures the rate at which the signal changes sign, providing insights into sound sharpness, which is typically higher in Bruxism events.In one embodiment, the analysis of signal data from the one or more sensors detecting the sounds form the subject is performed using machine learning algorithms. For example, the extracted MFCCs may be fed into machine learning models, such as Convolutional Neural Networks (CNNs) or Recurrent Neural Networks (RNNs), to detect patterns specific to snoring and Bruxism.The result of the processing of the signal data received from the one or more sensors is a determination of the origin of the sounds being emitted by the subject while sleeping. If a determination is made that the subject is snoring or experiencing Bruxism, the method includes a further step of applying to the subject a stimulus to provoke the subject to stir and change their sleeping behaviour, for example to stop snoring or grinding / clenching their teeth or to change their sleeping position. Suitable stimuli and their generation are as described hereinbefore.Once the stimulus has been applied to the subject, the sensing of sounds from the subject while sleeping is continued. There can be a number of outcomes. First, the application of the stimulus to the subject has prompted the subject to change their sleeping behaviour to one that does not result in or provoke a sleeping disorder. For example, thesubject has simply stopped snoring or grinding / clenching their teeth, or moved from a supine position to lying on one side and has stopped snoring.Alternatively, the subject has not changed their sleeping behaviour sufficiently or at all in response to the stimulus. In this case, the method preferably includes a further step: iv) if applying the stimulus to the subject does not result in a change in the sleeping behaviour of the subject to one that is not relevant to a sleep disorder, applying a second stimulus to the subject.The second stimulus may be same or different to the first stimulus applied, that is the same kind and intensity of stimulus. More preferably, the second stimulus is different to the first stimulus, for example the second stimulus is of a different kind of stimulus and / or the second stimulus is of a greater intensity. For example, if the first stimulus is vibration, the second stimulus applied may be a sound. Alternatively, if the first stimulus is a sound, the second stimulus may be a sound of a different type, such as frequency or pitch, or a different volume. This step is repeated until a sufficient change in the position of the subject has been achieved.In one embodiment, the system and method of the present invention include allowing the subject to adjust the stimuli applied to them by the emitter, so as to personalise the stimuli to those most effective for them. For example, the subject may select the intensity, frequency and type of stimuli. This can improve comfort for the subject and improve compliance.The sensing of the sounds being made by the subject may be intermittent, that is data signals are processed by the processor intermittently at intervals while the subject is asleep. Alternatively, the processing of the signal data by the processor is continuous, that is the one or more sensors provide continuous data signals to the processor and the processor monitors the sounds from the subject continuously. In this way, the system may detect as soon as the subject changes their sleeping behaviour to one that causes or provokes a sleeping disorder.The emitter may be operated to apply the stimulus to the subject as soon as it is detected that the subject is emitting sounds that result from a sleep disorder, such as snoring or Bruxism. However, it has been found that applying a stimulus to a subject to provoke a change in position immediately upon the subject moving to a new, undesirable position, can lead to significant disruption to the sleep of the subject. Accordingly, in one preferred embodiment, once it has been determined that the subject is making sounds indicative of a sleeping disorder, the emitter is activated to apply a stimulus to the subject only after a delay period. The delay period may be from 10 seconds, preferably from 20 seconds, more preferably from 30 seconds, still more preferably from 1 minute. The delay period may be up to 10 minutes, more preferably up to 7 minutes, more preferably still up to 5 minutes.The processor may monitor the number of times the emitter is activated and a stimulus applied to the subject during each period of sleep, for example each night. In one embodiment, the number of times that the emitter is activated during each sleep period is restricted to a maximum number, for example 10, 8, 6 or 5 times per sleep period.The processor may monitor the sleep stage of the subject. In this embodiment, the processor may activate the emitter to apply a stimulus to the subject only during some but not all sleep stages. If this regime is employed, it is preferred that stimuli are applied to the subject only when the subject is in sleep stage N1 or N2.However, in cases where the subject is in sleep stage N3 or in REM sleep and the length and / or intensity of the sleeping disorder activity of the subject while sleeping is greater than a threshold length of time and / or threshold intensity, the stimulus may be applied to the subject during these sleep stages.To monitor the sleep stage of the subject, the system may comprise one or more sensors to sense one or more, of the following parameters of the sleeping subject:1 . Respiratory rate;2. Respiratory rate regularity and variability;3. Body movement intensity and duration;4. Body orientation (for example supine, lying on side or lying on front); and5. Head movement frequency and amplitude.It is preferred to sense the minimum number of the above aspects, while still obtaining sufficient data to allow the sleep stage of the subject to be accurately determined In some embodiments, the signal data being provided to the processor by the one or more sensors detecting movement of one or more parts of the body of the subject, such as the head and / or the torso, will allow the sleep stage of the subject to be determined without further aspects being sensed. Alternatively, one or more further parameters of the subject sleeping may be sensed to provide further data to the processor for determining the sleep stage of the subject. In such embodiments, it is preferred that in addition to the movement of the head and / or torso of the subject being sensed by the system, the system also senses the respiration rate of the subject, for example the rate, regularity and variability of the respiration rate.In one embodiment, identifying the sleep stage of the subject is performed using machine learning algorithms. The machine learning algorithms may be trained to identify different sleep stages from a set of input data based on an established set of data generated, for example in a sleep laboratory. In particular, labelled data may be used to train this model.A system and method have described above for each of two aspects of the present invention: a first in which one or more sensors are employed to sense movement and / or the orientation of the subject while sleeping; and a second in which one or more sensors are employed to detect the sounds being made by the subject while sleeping. In one embodiment, both aspects are combined in a single system.According to a further aspect of the present invention, there is provided a system for managing a sleep disorder of a subject, the system comprising: a first sensor for detecting sounds emitted by the subject during sleep; a second sensor for detecting the orientation of a part or all of the body of the subject and / or movement of the subject during sleep;an emitter for stimulating the subject to change the orientation of a part or all of their body during sleep; and a processor configured to: receive a signal from the first sensor with data relating to the sounds emitted by the subject during sleep; receive a signal from the second sensor with data relating to the orientation and / or movement of the subject; process the data received from the first and second sensors; and transmit a signal to the emitter to apply a stimulus to the subject to provoke the subject to stir.In an analogous manner, the present invention also provides in a further aspect a method of managing a sleep disorder of a subject, the method comprising: i) sensing the position in which the subject is sleeping; ii) sensing sounds being emitted by the subject while sleeping; iii) determining if the position and / or the sounds are related to a sleep disorder; and iv) if one or both of the sounds or position is related to a sleep disorder, applying a stimulus to the subject to provoke the subject to stir.Details of the components of the system and their function and manner of operation are as hereinbefore described.As also described above, preferred embodiments of the present invention employ an in-ear device having at least a portion disposed within an ear canal of the subject.According to the present invention there is also provided an in-ear device for location in the ear of a subject, the in-ear device comprising:a sensor for detecting sound emitted by the subject; and / or a sensor for detecting movement and / or the orientation of part or all of the body of the subject.In one embodiment, the in-ear device further comprises, an emitter for emitting a stimulus to the subject, preferably an emitter for emitting a sound into the ear of the subject.In one embodiment, the in-ear device further comprises a transmitter for transmitting signal data from the or each sensor. In embodiments in which the in-ear device comprises an emitter, the device preferably further comprises a receiver for receiving signals from a processor for operating the emitter.Embodiments of the present invention will now be described, by way of example only, having regard to the accompanying drawings, in which:Figure 1 is a diagram of an in-ear device according to one embodiment of the present invention located in the ear canal of an ear of a subject;Figure 2 is a perspective side view of an in-ear device according to one embodiment of the present invention;Figure 3 is a view of the in-ear device of Figure 2 showing the internal components;Figure 4 is schematic diagram of one embodiment of a system according to one embodiment of the present invention;Figure 5 is a schematic diagram showing a decision tree for one embodiment of the system of the present invention for managing when a sleeping subject is in a supine position;Figure 6 is a schematic diagram showing a decision tree for one embodiment of the system of the present invention for managing Bruxism in a sleeping subject;Figure 7 is a schematic diagram showing the components of a system for sensing the orientation and / or movement of a subject during sleep according to one embodiment of the present invention;Figure 8 is a schematic diagram showing the components of a stand-alone processor device for receiving signal data and managing a sleep disorder of a subject during sleep according to one embodiment of the present invention; andFigure 9 is a schematic diagram showing the components of a system for managing a sleep disorder of one embodiment of the present invention.Turning to Figure 1 , there is shown an in-ear device according to one embodiment of the present invention. The in-ear device, generally indicated as 2, is shown located in the ear canal 4 of one ear 6 of a subject. The in-ear device 2 is shown in perspective view in Figure 2 and comprises a housing 10 having an outer housing portion 10a and an inner housing portion 10b. In use, with the in-ear device located in the ear canal of the subject, the outer housing portion 10a extends outwards, while the inner housing portion 10b extends inwards within the ear canal towards the ear drum. The inner housing portion 10b is provided with a soft cover 12, formed from silicone or foam for example, to securely and comfortably locate the device 2 in the ear canal of the subject, as is known in the art.Turning to Figure 3, there is shown a diagram of the in-ear device 2 of Figure 2, showing the internal components of the device. The outer housing portion 10a houses a battery 20. The battery 20 is preferably rechargeable, with the outer housing portion 10a further containing a charging system for the battery, for example by induction. A circuit board 22 contains components for the operation of the in-ear device 2, including a processor 22a comprising one or more chips, a wireless transmitter 22b for transmitting wireless signals, an accelerometer 22c and, optionally, a receiver for receiving wireless signals. Other components that may be contained on the circuit board 22 include an oscillator.The in-ear device 2 further comprises an acoustic chamber 24, within which are located components for detecting sounds and for emitting sounds. In particular, the acoustic chamber 24 contains a microphone 24a for sensing sounds and a sound emitter 24b for emitting sounds.The inner housing portion 10b comprises an acoustic bore 26 therethrough, the acoustic bore having a distal opening 26a at the distal end of the inner housing portion. At its proximal end 26b the acoustic bore 26 opens into the acoustic chamber 24. In use, the distal opening 26a of the acoustic bore 26 is innermost within the ear canal of the ear of the subject. Sound emitted by the subject while sleeping, for example as a result of snoring or grinding / clenching of teeth, passes along the ear canal and enters the acoustic bore 26 at its distal opening 26a, passes along the acoustic bore and enters the acoustic chamber 24. Similarly, sound generated by the emitter 24b leaves the acoustic chamber 24, passes along the acoustic bore 26 and enters the ear canal of the ear of the subject.The outer housing 10a is provided with openings 28 to allow for pressure equalisation between the interior of the housing 10 and the exterior.Turning to Figure 4, there is shown a schematic diagram of a system according to one embodiment of the present invention. The system, generally indicated as 102, generally operates to sense sound emitted by a subject while sleeping, detect movement of a part or all of the subject while sleeping, process signal data relating to the sound and movement, and emitter a sound stimulus to the subject. Details of the system of this embodiment are as follows:The system 102 comprises:A microphone 104 for detecting sounds emitted by the subject during sleep, for example the sounds of the subject snoring or grinding / clenching their teeth. In the embodiment shown, a commercially available microphone in the form of a MEMS microphone MP23ABS1TR available from STMICROELECTRONICS.A movement sensor 106 for sensing movement of a part or all of the body of the subject while sleeping. In the embodiment shown, the movement sensor is an accelerometer, ADXL367BCCZ-RL7 available from Analog Devices, Inc. (ADI).A communications assembly 108 comprising a transmitter and a receiver for wireless communication with a remote processor. The communications assembly is configured to communicate using the Bluetooth wireless protocol. In the embodimentshown, the communications assembly is the wireless transmitter / transceiver nRF52840- CKAA-R available from Nordic Semiconductor ASA.An oscillator 110 to provide is a precise and stable clock signal for control of the processor functions, recording the timestamps of events for later analysis and tracking sleep patterns over time, and create precise wake-up timers for the processor and other components, enabling the device to enter low-power sleep modes between sensor readings and Bluetooth transmissions, significantly extending battery life. In the embodiment shown, the oscillator is the standard clock oscillator SIT1533AI-H4-D26- 32.768E available from SiTime.A sound emitter 112 to generate and emit a sound as a stimulus to the subject to stir the subject from sleep. In the embodiment shown, the sound emitter is the AB0818B piezo buzzer and audio indicator available from PUI Audio.A battery 114.The above components are shown in Figure 4 to be comprised in a single device. Such a device may be a in-ear device of the kind shown in Figures 1 to 3. However, it is to be understood that the components may be distributed between two or more different devices.In the embodiment shown in Figure 4, the signal data from the microphone 104 and the accelerometer 106 are transmitted wirelessly to a remote device for processing by a processor. Signals from the processor are transmitted in return to the sound emitter 112, as required to activate the sound emitter to generate a stimulus for the subject. In the embodiment shown, it is indicated that the remove device is a mobile telecommunications device programmed with an appropriate application (App) running TensorFlow Lite software for data processing.Turning to Figure 5, there is shown a decision tree for an embodiment of the system of the present invention for managing the sleeping position of a subject. As shown, when the processor 202 receives signal data indicating the movement and / or orientation of the sleeping subject, it makes an analysis to determine the position in which the subject is sleeping. If the processor determines that the subject is in a non-supine position, nofurther action is taken. If the processor determines that the subject is in a supine position, the processor acts to have a stimulus (a vibration as shown in Figure 5) applied to the subject. If further signal data indicate that the subject has changed their position to a nonsupine position, the processor takes no further action. In the event the subject remains in a supine position, the processor repeats the procedure until the subject moves into a nonsupine position.Turning to Figure 6, there is shown a schematic diagram showing a decision tree for one embodiment of the system of the present invention for managing Bruxism in a sleeping subject.References in Figure 6 to a ‘Bud’ are to an in-ear device, for example the device shown in Figures 1 to 3, which is located in the ear canal of an ear of the subject for the detection of the sounds emitted by the subject while sleeping and for emitting a sound as a stimulus to the subject. The in-ear device may be replaced by another device, for example a device worn by the subject on their torso while sleeping, and operate in an analogous manner.References in Figure 6 to ‘Case’ are to the processor for analysing and processing data relating to detected sounds and issuing appropriate command signals to a sound emitter for stimulating the subject in the event that the sounds of Bruxism are identified. The processor may be located within the in-ear device or may be a separate device communicating with the in-ear device, for example wirelessly.The method illustrated in Figure 6 is for the detection and management of Bruxism. It is to be understood that an analogous method may be used for the detection and management of snoring. In this case, the algorithms run by the processor analyse the signals received from the sensors to identify the sounds of the subject snoring. Similarly, an analogous method to that shown in Figure 6 may be used in the management of the position in which the subject is sleeping, for example in the case of a pregnant woman to detect when the subject is lying in a supine position and to stimulate the subject to prompt movement to a different, safer position.Referring now to Figure 7, there is shown a schematic diagram showing the components of a system for sensing the orientation and / or movement of a subject during sleep according to one embodiment of the present invention. The system of Figure 7 may be comprised in a single device to be worn on the torso of the subject while they are sleeping.The system, generally indicated as 202, comprises: a 9-axis accelerometer 204 for sensing the movement of the subject; a printed circuit board (PCB) controller 206 comprising a processor for processing signal data and issuing command signals; a MEMS vibrator 208 for emitting a stimulus in the form of vibrations to the subject; an oscillator 210 for providing a stable clock signal; a data storage module 212 for storing data; a communication module 214 for communicating with a remote device using the Bluetooth protocol, for example a mobile telecommunications device 216; and power supply assembly 218 comprising a battery 218a, a USB power supply 218b and a power connection 218c.The system 202 has the facility for a manual input 220, allowing a subject to input operating parameters and retrieve data from the processor or the data storage module, for example. Data may be displayed by the subject on a display device 222.Figure 7 shows the interconnections between the components of the system 202, as well as the type and transfer of data during the operation of the system.Referring to Figure 8, there is shown a schematic diagram showing the components of a stand-alone processor device for receiving signal data and managing a sleep disorder of a subject during sleep according to one embodiment of the present invention. The device shown in Figure 8 may be used in conjunction with one or more wearable devices for wearing by the subject during sleep, which wearable devices comprise one or more sensors for sensing the movement and / or orientation of the subject and / or for sensing sounds being emitted by the subject.The device of Figure 8, generally indicated as 302, comprises a printed circuit board (PCB) controller 304 comprising a processor for processing signal data and issuing command signals; an oscillator 306 for providing a stable clock signal; a data storage module 308 for storing data; a communication module 310 for communicating with aremote device using the Bluetooth protocol, for example a mobile telecommunications device or a remote server (Cloud) 312; and a power supply assembly 314.The system 302 may display data on a display device 316.Figure 8 shows the interconnections between the components of the system 302, as well as the type and transfer of data during the operation of the system. In operation, wireless signal data 320 from one or more sensors detecting movement and / or the orientation of the subject and / or sounds emitted by the subject during sleep are received by the communication module 310. Similarly, wireless command signals 322 are transmitted by the communication module 310 to an emitter to generate and emit a stimulus, such as sound, light and / or a haptic stimulus, to the subject to cause the subject to stir.In the embodiment shown in Figure 8, the processor is programmed with the commercially available TensorFlow software for processing the received signal data 320 and generate command signals 322.Finally, referring to Figure 9, there is shown a schematic diagram showing the components of a system for managing a sleep disorder of one embodiment of the present invention. The components shown in Figure 9 may be incorporated into a single device, in particular a device to be worn on the head of the subject while sleeping, especially an in- ear device. The system shown in Figure 9 may be used to manage a range of sleeping disorders by detecting the movement and / or orientation of the subject while sleeping and sounds emitted by the subject during sleep.The system, generally indicated as 402, comprises: a 9-axis accelerometer 404 for sensing the movement of the subject; a printed circuit board (PCB) controller 406 comprising a processor for processing signal data and issuing command signals; a MEMS microphone 408 for sensing sounds emitted by the subject; an oscillator 410 for providing a stable clock signal; a data storage module 412 for storing data; a communication module 414 for communicating with a remote device using the Bluetooth protocol, for example a mobile telecommunications device or a remote server (Cloud) 416; a sound emitter (Sound Bender) 418 for emitting a sound to stimulate the subject to stir; and a power supply assembly 420 comprising a battery 420a, a power supply 420b and a power connection 420c.The system 402 has the facility for a manual input from a mobile device 422, such as a mobile telecommunications device programmed with a suitable application (App), allowing a subject to input operating parameters and / or retrieve data from the processor or the data storage module, for example. Figure 9 shows the interconnections between the components of the system 402, as well as the type and transfer of data during the operation of the system.

Claims

CLAIMS1 . A system for managing a sleep disorder of a subject, the system comprising: a sensor assembly for detecting movement and / or the orientation of part or all of the body of the subject and / or movement of the subject during sleep; an emitter for stimulating the subject to change the orientation of their body; and a processor configured to: receive a signal from the sensor assembly, the signal comprising data relating to the orientation and / or movement of the subject; process the data received from the sensor assembly; and transmit a signal to the emitter to apply a stimulus to the subject to provoke the subject to alter the orientation of part or all of their body.

2. The system according to claim 1 , wherein the sensor assembly is operable to detect the movement and / or orientation of the torso and / or the head of the subject.

3. The system according to either of claims 1 or 2, wherein the sensor assembly is operable to detect when the subject is in a supine position.

4. The system according to any preceding claim, wherein the sensor assembly comprises one or more 3-axis accelerometers, one or more 6-axis accelerometers, one or more 9-axis accelerometers, or a combination thereof.

5. The system according to any preceding claim, wherein the sensor assembly comprises one or more sensors for wearing on the head of the subject.

6. The system according to claim 5, wherein the system comprises an in-ear device, the in-ear device comprising one or more sensors of the sensor assembly.

7. The system according to any preceding claim, wherein the sensor assembly comprises one or more sensors for wearing on the torso of the subject.

8. The system according to any preceding claim, wherein the system comprises a first device for wearing on the head of the subject comprising a sensor assembly comprising one or more sensors and a second device for wearing on the torso of the subject comprising a sensor assembly comprising one or more sensors for wearing on the torso of the subject.

9. The system according to any preceding claim, wherein the system comprises an in- ear device for location in the ear canal of the subject, the device comprising a sensor for sensing movement and / or the orientation of the body of the subject or a part thereof and the processor; and / or wherein the system comprises a device for wearing on a part of the body of the subject other than the head, the device comprising a sensor for sensing movement and / or the orientation of the body of the subject or a part thereof and the processor.

10. The system according to any preceding claim, wherein the emitter is operable to emit a stimulus to the subject to change their sleep stage.11 . The system according to any preceding claim, wherein the emitter emits a stimulus comprising light, sound, a haptic signal or a combination of two or more thereof.

12. The system according to any preceding claim, wherein the system comprises an in- ear device comprising the emitter.

13. The system according to any preceding claim, wherein the system further comprises a sensor assembly for detecting sounds emitted by the subject during sleep.

14. The system according to claim 13, wherein the system comprises an in-ear device comprising a sensor for detecting sounds.

15. The system according to claim 14, wherein the sensor for detecting sounds is disposed to detect sounds emitted by the subject and emanating from within and travelling outwards within the ear canal when the in-ear device is in use.

16. A method for managing a sleep disorder of a subject, the method comprising: i) sensing the position in which the subject is sleeping; ii) determining if the position is related to a sleep disorder; andiii) if the position is related to a sleep disorder, applying a stimulus to the subject to provoke the subject to change their sleeping position.

17. The method according to claim 16, wherein the position of the subject is sensed using one or more sensors, each sensor generating a signal, wherein the signals from the one or more sensors relating to the sensed movement and / or orientation of the subject are analysed to separate the high frequency and low frequency components.

18. The method according to either of claims 16 or 17, wherein the signals from the one or more sensors are filtered to remove the high frequency signals, to isolate the signals corresponding to the movement of the torso of the subject, or to remove low frequency signals in order to isolate the signals corresponding to movement or orientation of the head of the subject.

19. The method according to any of claims 16 to 18, wherein the position in which the subject is sleeping is determined using signal data from a first sensor assembly, comprising one or more sensors, disposed on the head of the subject and signal data from a second sensor assembly, comprising one or more sensors, disposed on the torso of the subject.

20. The method according to any of claims 16 to 18, further comprising: iv) if applying the stimulus to the subject does not result in a change in the position of the subject to one that is not relevant to a sleep disorder, applying a second stimulus to the subject.21 . The method according to any of claims 16 to 20, wherein once it has been determined that the subject is lying in a position that causes or provokes a sleeping disorder, the emitter is activated to apply a stimulus to the subject only after a delay period.

22. The method according to any of claims 16 to 21 , further comprising monitoring the sleep stage of the subject, wherein the stimulus is applied to the subject in some but not all sleep stages.

23. The method according to any of claims 16 to 22, further comprising the steps of: i) sensing the sounds being made by the subject while the subject is sleeping; ii) determining if the sounds are related to a sleep disorder; andiii) if the sounds are related to a sleep disorder, applying a stimulus to the subject to provoke the subject to stir.

24. The method according to claim 23, further comprising distinguishing snoring sounds from Bruxism sounds and other ambient sounds.

25. An in-ear device for location in the ear of a subject, the in-ear device comprising: a sensor for detecting sound emitted by the subject; and / or a sensor for detecting movement and / or the orientation of part or all of the body of the subject.

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