US20220401256A1

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Publication number: US20220401256A1
Application number: US17/897,278
Authority: US
Inventors: Dominique M. Durand
Original assignee: Case Western Reserve University
Current assignee: Case Western Reserve University
Priority date: 2017-02-28
Filing date: 2022-08-29
Publication date: 2022-12-22
Also published as: WO2018160670A1; US20190380864A1; US11426305B2

Abstract

One aspect of the present disclosure relates to a system that monitors and detects obstructive sleep apnea (OSA). The system includes an oropharynx protection appliance, which includes a passive tongue retention structure having an end portion adapted to prevent a pharyngeal portion of a tongue of a subject from collapsing and at least one anchoring structure that is connected to the passive tongue retention structure and adapted to secure the passive tongue retention structure within the subject's mouth in a removable fashion. The system also includes a sensing system attached to a portion of the oropharynx apparatus. The sensing system includes a sensor to measure a position of the pharyngeal portion of the tongue to detect an obstruction of the oropharynx; and a wireless transceiver to transmit data related to the obstruction of the oropharynx to a remote diagnostic device.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/567,358, filed Oct. 3, 2017, entitled “SYSTEMS AND METHODS FOR OBSTRUCTIVE SLEEP APNEA DETECTION AND MONITORING”. This application also claims the benefit of U.S. Provisional Application No. 62/464,702, filed Feb. 28, 2017, entitled “TONGUE RETENTION PROSTHESIS FOR OBSTRUCTIVE SLEEP APNEA” and U.S. Provisional Application No. 62/516,863, filed Jun. 8, 2017, entitled “OROPHARYNX PROTECTION APPLIANCE.” These provisional applications are hereby incorporated by reference in their entirety for all purposes.

TECHNICAL FIELD

The present disclosure relates generally to obstructive sleep apnea (OSA) and, more specifically, to systems and methods for OSA detection and monitoring.

BACKGROUND

Sleep apnea is a sleep disorder in which a sufferer has trouble breathing during sleep. This trouble breathing during sleep can lead to nocturnal hypoxemia and sleep fragmentation, which can lead to co-morbidities, like daytime sleepiness, as well as cardiac and neural complications. The most common type of sleep apnea is obstructive sleep apnea (OSA), affecting 27 million patients in the US alone. OSA is characterized by the recurrent collapse of soft tissue obstructing the upper airway during sleep. Such airway obstructions have been attributed, in part, to a collapse of the soft tissue structures surrounding the upper airway into the airway when the throat and tongue muscles relax during sleep. These airway obstructions are dangerous, leading to pauses in breathing or instances of shallow or infrequent breathing.

The frequent airway obstructions experienced by individuals suffering from OSA can negatively impact such individuals' health and quality of life. While no drug therapies exist to treat sleep apnea, several mechanical therapies exist, such as continuous positive airway pressure (CPAP) therapy or a mandibular advancement device (MAD) treatment. However, individuals with OSA are rarely aware of their difficulty breathing, even upon awakening, leading to the associated poor diagnosis and treatment. Even when an individual suspects OSA, current techniques for diagnosis, like polysomnography, are expensive and require an overnight stay in a sleep lab. Furthermore, while polysomnography measures various symptoms of OSA, like oxygen saturation, respiration, chest movements during sleep, and sleep patterns, polysomnography does not provide a direct measure of airway obstruction.

SUMMARY

The present disclosure relates generally to obstructive sleep apnea (OSA) and, more specifically, to systems and methods for OSA detection and monitoring. For example, the systems and methods can track movement of a subject's tongue during sleep to determine the amount and duration of airway obstruction that are indicative of OSA. As another example, the systems and methods can also monitor additional properties associated with OSA, including air flow, force, oxygen saturation (SaO₂), electrocardiogram (ECG), temperature, and/or sound.

In one aspect, the present disclosure includes a system that tracks obstruction of the oropharynx. The system includes an oropharynx protection appliance, which is made of a passive tongue retention structure having an end portion adapted to prevent a pharyngeal portion of a tongue of a subject from collapsing and at least one anchoring structure that is connected to the passive tongue retention structure and adapted to secure the passive tongue retention structure within the subject's mouth in a removable fashion. The system also includes a sensing system attached to a portion of the oropharynx apparatus. The sensing system includes a sensor to measure a position of the pharyngeal portion of the tongue to detect an obstruction of the oropharynx; and a wireless transceiver to transmit data related to the obstruction of the oropharynx to a remote diagnostic device.

In another aspect, the present disclosure includes a method for tracking obstruction of the oropharynx. The method can include measuring, by a sensor of a sensing system attached to a portion of an oropharynx apparatus, a position of the pharyngeal portion of a tongue of a subject during sleep. Data related to the position of the pharyngeal portion of the tongue can be transmitted, by a wireless transceiver, to an external diagnostic device. The method can also include determining, by the external diagnostic device, a degree of obstruction of the oropharynx at one or more times during sleep based on the transmitted data.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present disclosure will become apparent to those skilled in the art to which the present disclosure relates upon reading the following description with reference to the accompanying drawings, in which:

FIG.1 is an illustration of a system that detects and monitors obstructive sleep apnea (OSA), in accordance with an aspect of the present disclosure;

FIG.2 is an illustration of an example of the system ofFIG.1 in communication with a remote diagnostic device;

FIG.3 is a photograph of another example of the system ofFIG.1;

FIGS.4-14 are illustrations of various examples of the oropharynx appliance ofFIG.1;

FIG.15 is a side view illustration showing an example of the system ofFIG.1 being used in a subject's mouth during sleep to detect OSA;

FIG.16 an illustration of an example of the system ofFIG.1 as a closed loop;

FIG.17 is a process flow diagram showing an example of a method for OSA detection and monitoring, in accordance with another aspect of the present disclosure; and

FIG.18 is a process flow diagram showing an example of a method for constructing an OSA prevention device, in accordance with yet another aspect of the present disclosure.

DETAILED DESCRIPTIONI. Definitions

Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure pertains.

As used herein, the singular forms “a,” “an” and “the” can also include the plural forms, unless the context clearly indicates otherwise.

As used herein, the terms “comprises” and/or “comprising” can specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups.

As used herein, the term “and/or” can include any and all combinations of one or more of the associated listed items.

It will be understood that when an element is referred to as being “on,” “attached” to, “connected” to, “coupled” with, “contacting,” etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, “directly on,” “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

Spatially relative terms, such as “under,” “below,” “lower,” “over,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms can encompass different orientations of the apparatus in use or operation in addition to the orientation depicted in the figures. For example, if the apparatus in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features.

As used herein, the terms “first,” “second,” etc. are not meant to be limiting, instead, these terms are only used to distinguish one element from another. Thus, a “first” element discussed below could also be termed a “second” element without departing from the teachings of the present disclosure. The sequence of operations (or acts/steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise.

As used herein, the terms “obstructive sleep apnea” and “OSA” can refer to a sleep disorder that is caused by complete or partial obstruction of a subject's airway, leading to repetitive episodes of shallow or paused breathing during sleep, despite the subject's effort to breathe.

As used herein, the term “obstruction” can refer to something that impedes or prevents passage. For example, an obstruction in the oropharynx can prevent the passage of air through the oropharynx. The obstruction of the oropharynx can be due to a collapse of soft tissue of the subject's upper airway into the oropharynx.

As used herein, the term “sleep” can refer to a period of rest of a patient's body and mind during which consciousness is partially or completely suspended and bodily functions are partially suspended.

As used herein, the term “detection” can refer to the action or process of identifying or revealing the presence of something that is normally concealed. For example, symptoms related to the presence of OSA can be detected in a patient, including airway obstruction, air flow, force, oxygen saturation (SaO₂), electrocardiogram (ECG), sound, and the like. In some instances, the detection can be performed by one or more sensors.

As used herein, the term “sensor” can refer to a device that detects or measures a physical property and records, indicates, or otherwise responds to the physical property.

As used herein, the term “diagnosis” can refer to an identification of the nature of an illness or other problem through examination of the symptoms.

As used herein, the term “diagnostic” can refer to one or more devices that can examine physical properties of symptoms and create data related to a diagnosis of an illness or other problem.

As used herein, the term “oral cavity” can refer to the cavity of the mouth, bounded by the upper and lower jawbones and the cheeks.

As used herein, the term “mouth” can refer to the structures enclosing or being within the oral cavity. The mouth can include a plurality of teeth and a tongue. The mouth can also include gums and tissue surrounding the upper and lower jawbones.

As used herein, the term “mandible” can refer to a subject's lower jawbone. In some instances, the mandible can also refer to at least a portion of the tissue within the mouth surrounding the lower jawbone. Notably, the lower jawbone is the only moveable bone in the skull.

As used herein, the term “tongue” can refer to the fleshy muscular organ in a subject's mouth. The tongue can be composed of an anterior oral part and a posterior pharyngeal part. The posterior pharyngeal part can be the posterior third of the tongue that is part of the oropharynx.

As used herein, the term “pharynx” can refer to a membrane-lined cavity behind the nose and mouth, connecting the nose and mouth to the esophagus.

As used herein, the term “oropharynx” can refer to a part of pharynx generally lying behind the mouth between the soft palate and the hyoid bone. The oropharynx begins where the oral cavity stops and includes the posterior pharyngeal part of the tongue.

As used herein, the term “wire” can refer to a metal, polymer, composite, or other material structure. In some instances, the diameter of the material structure can be constant. In other instances, the diameter of the material structure can be variable in at least a portion of the wire. The cross section of the wire can be circular, rectangular, flat, star, or any other shape.

As used herein, the term “arcuate” can refer to a generally curved shape. Examples of arcuate shapes include an arc or a bow. However, in some instances, the arcuate shape can include one or more bent portions as long as the general curvature exists.

As used herein, the term “spring” can refer to a resilient device that can be pressed or pulled but returns to its former shape when released. In some instances, a spring can be shaped in an at least partially helical manner Exemplary uses of a spring include exerting constant tension or absorbing movement.

As used herein, the term “appliance” can refer to a device designed to perform a specific task. For example, the specific task can be a dental task related where example apparatuses can include mouthguards, retainers, crowns, or the like. The term “apparatus” may be used interchangeably with the term “appliance”.

As used herein, the term “wireless” can refer to the use of radio waves, microwaves, or the like (as opposed to wires or cables) to exchange (e.g., transmit and/or receive) signals.

As used herein, the term “wireless transceiver” can refer to a hardware element that can facilitate the exchange (e.g., transmission and/or reception) of signal embodied within radio waves, microwaves, or the like.

As used herein, the term “non-invasive” can refer to a medical procedure or medical device that does not require the opening of a subject's body and/or the introduction of medical instruments into the body.

As used herein, the terms “subject” and “patient” can be used interchangeably and refer to any warm-blooded organism including, but not limited to, a human being, a pig, a rat, a mouse, a dog, a cat, a goat, a sheep, a horse, a monkey, an ape, a rabbit, a cow, etc.

II. Overview

The present disclosure relates generally to obstructive sleep apnea (OSA) and, more specifically, to systems and methods for OSA detection and monitoring. OSA can be characterized by recurrent airway obstructions during sleep. The airway obstructions can be due to soft tissue collapsing into the oropharynx, such as sleep-induced relaxation of throat and/or tongue muscles. OSA can be detected and monitored by tracking movement of a subject's tongue during sleep to determine the amount and duration of airway obstructions that are indicative of OSA.

A non-invasive oropharynx appliance can be coupled to a sensing system. The oropharynx appliance can be adapted to prevent the pharyngeal portion of the tongue from collapsing. The oropharynx appliance can include a passive tongue retention structure having an end portion adapted to prevent the pharyngeal portion of the tongue from collapsing and at least one anchoring structure adapted to secure the passive tongue retention structure within the subject's mouth in a removable fashion. The oropharynx appliance can also be coupled to one or more sensors of the sensing system to detect properties indicative of OSA. The one or more sensors can be arranged at various positions on the oropharynx appliance. For example, the one or more sensors can include a sensor to detect movement of a portion of the tongue into the oropharynx, an air flow sensor, a force sensor, an oxygen saturation (SaO₂) sensor, an electrocardiogram (ECG) sensor, a temperature sensor, and/or a sound sensor. The oropharynx appliance can also be coupled to a wireless transceiver (e.g., including a wireless transmitter and/or a wireless receiver) to transmit data recorded by the one or more sensors to a remote diagnostic device.

III. Systems

One aspect of the present disclosure, as shown inFIG.1, can include asystem10 that detects and monitors obstructive sleep apnea (OSA). OSA can be characterized by recurrent airway obstructions during sleep due to soft tissue collapsing into the oropharynx. Thesystem10 can include asensing system14 that can track movement of a subject's tongue during sleep to determine the amount and duration of airway obstructions that are indicative of OSA. Thesensing system14 can also detect additional parameters indicative of OSA, such as air flow, force, oxygen saturation (SaO₂), electrocardiogram (ECG), temperature, and/or sound/vibration.

At least a portion of thesensing system14 can be attached to or integrated within theoropharynx appliance12. Theoropharynx appliance12 and at least a portion of thesensing system14 can be adapted for insertion into a subject's mouth. Theoropharynx appliance12 can be an at least partially non-invasive solution to maintain airway patency during sleep. In other words, thesystem10 can be configured for placement into a subject's mouth during sleep—at night and/or during the day. For example, thesystem10 can be placed in the subject's mouth at a sleep lab or at home. At least a portion of theoropharynx appliance12 can be fitted to or constructed for at least a portion of the subject's mouth. In some instances, theoropharynx appliance12 can be fitted tightly within the subject's mouth (e.g., to the subject's lower teeth) so that theoropharynx appliance12 does not dislodge when placed into the subject's mouth before, during, or after sleep.

Theoropharynx appliance12 can employ a mechanical design that is configured to prevent airway occlusion during sleep. The mechanical design prevents the undesired collapse of soft tissue into the oropharynx, thereby maintaining airway patency. In some instances, the soft tissue can be the tongue. Muscles of the tongue relax during sleep, causing tissue of the tongue to be pulled into the oropharynx by negative pressure generated during inspiration and obstruct the airway. The mechanical device can prevent the tongue from moving backwards into the oropharynx during inspiration and obstructing the airway. Although an oropharynx appliance that can be situated behind the tongue in the oropharynx will be described throughout, it will be noted that other placements for theoropharynx appliance12 can be used, such as behind the soft palate in the nasopharynx. Theoropharynx appliance12 need not be behind the tongue and, instead may be in any position that is adapted to prevent the pharyngeal portion of the tongue from collapsing. Thesensing system14 can detect and monitor instances of the collapse of the pharyngeal portion of the tongue indicative of OSA that are restrained by theoropharynx appliance12.

FIG.2 illustrates asystem20 that includes theoropharynx appliance12 attached to and/or integrated with thesensing system14. Theoropharynx appliance12 and thesensing system14 can be integrated as a standalone device, in some instances. Thesensing system14 can include one ormore sensors16 that can record data and send the data to awireless transceiver17. Thewireless transceiver17 can send the data to an externaldiagnostic device18. The externaldiagnostic device18, in some instances, can be remote from thesensing system14. The externaldiagnostic device18 can be associated with the subject (e.g., a mobile phone, tablet computer, PDA, laptop computer, desktop computer, or the like). The externaldiagnostic device18 associated with the patient can send the data to a device associated with a physician for diagnosis and/or monitoring. Thesystem20 can be used for long term monitoring of OSA. In other instances, thesystem20 can be used for compliance monitoring to determine whether the subject is using a prescribed OSA prevention device.

Thesensing system14 can include one ormore sensors16. For example, one of the sensors can track movement of a subject's tongue during sleep to facilitate the determination of the amount and duration of airway obstructions that are indicative of OSA. Data related to the tracking of the movement of the tongue can be transmitted to thediagnostic device18, which can analyze the data, which may lead to the detection, diagnosis, and/or monitoring of obstructive sleep apnea (OSA). Thesensors16 can also include one or more of an air flow sensor, a force sensor, an oxygen saturation (SaO₂) sensor (e.g., a plethysmograph, a light emitting diode, a photoresistor, etc.), an electrocardiogram (ECG) sensor (e.g., sensing electrodes, a reference electrode, and an amplifier), a temperature sensor, and/or a sound/vibration sensor (e.g., a passive microphone, a piezoelectric sensor, a vibration sensor, etc.). Thesensors16 can be located at different parts of theoropharynx appliance12. For example, thesensors16 can be located at specific parts of the passivetongue retention structure13 and/or the anchoringstructure15.

In some instances, thesensors16 can include a force sensor. For example, the force sensor can be configured to measure a force associated with movement of the passivetongue retention structure13. The force can be used to measure a position of the pharyngeal portion of the tongue to detect an obstruction of the oropharynx. In some instances, the force sensor can include a force transducer to directly measure the force associated with movement of the passivetongue retention structure13. In other instances, the force sensor can include a displacement sensor to measure the force indirectly without a force transducer. The displacement sensor can be, for example, a capacitive sensor, a resistive sensor, or an inductive sensor. One type of displacement sensor that may be especially useful is a linear variable displacement transducer (LVDT). When thesensor16 is a displacement sensor and the at least oneanchoring structure15 includes at least one spring portion, the force, F, associated with the passive tongue retention structure can be determined by the equation F=kx, where k is a spring constant of the at least one spring portion and x is the position (or displacement) of the posterior portion of the tongue. In some instance, thesensing system14 can include one of moreadditional sensors16 to measure other properties related to the detection, diagnosis, and/or monitoring of OSA. One example additional sensor can be an air flow sensor that can measure air flow through the oropharynx. The air flow sensor can be located on an end portion of the passivetongue retention structure13. For example, the air flow sensor can be included with the engagement device, when the engagement device is present. The additional sensors can include other sensors to detect SaO₂, EKG, temperature, or other properties that can contribute to the diagnosis of OSA. In other instances, thesensing system14 can include a stimulation means that can be used to retrain muscles contributing to the obstruction to behave properly. The stimulation means can include at least one electrode located between 0 and 20 degrees from the end of the passivetongue retention structure13. Through stimulation with an electrical waveform, the tongue can be activated to reflexively move forward and out of the obstructing position. The waveform can be configured to activate the tongue to move, but not to activate the oropharynx and not to cause pain.

Thewireless transceiver17 of thesensing system14 can be configured to transmit data recorded by thesensor16 to an externaldiagnostic device18. In some instances, thewireless transceiver17 can also be configured to receive signals from an external device. For example, portions of thesystem10 can be powered externally and thewireless transceiver17 can receive the power signal. Thewireless transceiver17 can be configured for short range and/or long-range transmission. For example, when the externaldiagnostic device18 is located in the same room as thewireless transceiver17, thewireless transceiver17 can transmit the data from thesensor16 to the externaldiagnostic device18 according to a short-range wireless protocol (e.g., Bluetooth, Zigbee, or the like). However, when the externaldiagnostic device18 is located outside of the same room as thewireless transceiver17, thewireless transceiver17 can transmit the data from thesensor16 to the externaldiagnostic device18 according to a long range wireless protocol (e.g., Wi-Fi, cellular, or the like). In either situation, the externaldiagnostic device18 can be a smartphone, a tablet computing device, a laptop computer, a desktop computer, one or more servers, or the like.

The externaldiagnostic device18 can receive the data from thesensor16 and analyze the data to determine whether the subject exhibits characteristics of OSA, which can lead to the diagnosis of OSA. Information garnered from the data can be used to generate an OSA prevention device. The weight of the tongue can be estimated and a force required to prevent the tongue from falling into the throat can be estimated or calculated based on the displacement measurement and the k-constant of the spring. An OSA appliance can be fabricated that provides the force required to prevent the tongue from falling into the throat. The analysis performed by the externaldiagnostic device18 can include a calibration procedure in which the data is normalized relative to a location of a reference point (e.g., the top of an incisor tooth). It is then possible to determine the distance between the back of the tongue (or the position of the portion of the passive tongue retention structure13) and a known position of the dorsal wall of the oropharynx. If this distance is near zero, then a complete occlusion has occurred. The amount of time for which the occlusion occurs can also be calculated. In some instances, at least a portion of this determination can occur in thesensing system14. In other instances, the externaldiagnostic device18 can receive sensed data from thesensing system14 and determine that theoropharynx appliance12 is no longer working (e.g., positioned correctly). Thediagnostic device18 can display a warning indicating that theoropharynx appliance12 is no longer working correctly as a visual message on a display, as an audio message from a speaker, as a tactile message through vibration, or the like.

FIG.3 is a photograph showing another example 30 implementation of the

system

10 or20 with a passivetongue retention structure13 attached to amouthguard15 configured for the lower jaw with springs and loops. It should be noted thatFIG.3 presents just one possible implementation to detect, monitor, and/or diagnose sleep apnea in a patient, to detect compliance for insurance purposes, and/or to detect effective use when no obstruction is present. Themouthguard16 can be a different type of dental device that can be used to anchor the passivetongue retention structure13, such as a hook, a mouth guard, a retainer, a crown, or the like. However, in some instances, the dental appliance is not needed at all and, instead, the passivetongue retention structure13 can be anchored by a device that is at least partially within the oropharynx appliance, such as a spring, a loop, or a hook. Theoropharynx appliance12 can also include other anchoring means, such as one or more magnets, hydraulics, electrostatics, or the like.

Additional features can include a tube that holds the spring and/or the wire placed inside the mandible, further components to allow for better engagement of the tongue, and/or a spring-loaded telescoping system to eliminate the spring. In use, the system can be placed in the subject's mouth at night like a regular mouth guard. The system is fitted to the subject's mouth and fits tightly onto the lower teeth. The system can prevent any obstruction during sleep while the tongue muscles are relaxed from the lack of muscle tone. The natural movement of the tongue into the oropharynx can be prevented by the springs that resist the tongue's weight. Thus, in some instances, the spring specifications can be adjusted to the subject's tongue mass so that the subject can swallow any saliva generated at any time. The system can be removed in the morning and cleaned with methods similar to those used for false teeth. Thesystem10 allows a preset clearance of about 5-10% of the maximum distance between the wire and the teeth.

As shown inFIG.3, thesensors16 can include a permanent magnet that is attached to the wire and a proximity sensor (reed switch) that closes when the magnet indicates an obstruction. Upon closure of the reed switch, signals are transmitted by telemetry to an externaldiagnostic device18. Additionally, the circuit elements of thesystem10 are also powered externally. Alternatively, a linear variable displacement transducer (LVDT) can be substituted for thesensor16 to record the displacement. A microprocessor samples the displacement (x) and calculates the force (F) based on the spring constant (k).

As shown inFIG.2, theoropharynx appliance12 can include a passivetongue retention structure13 and at least oneanchoring structure15. In one aspect, the passivetongue retention structure13 can be primarily constructed of a thin wire (made of metal, polymer, organic material, or the like) that is stiff enough to prevent bending by the tongue. For example, the thickness of the wire can be nonconstant. Additionally, the wire can have a circular, curved, rectangular, linear, curvilinear, star, flat, or any other shaped cross section. The wire can be biocompatible to minimize irritation in the patient's mouth. Additionally, the wire can be durable and/or robust so that portions of the wire do not dislodge while the subject is sleeping. For example, the wire can be constructed of a metal, organic material, and/or polymer that is itself biocompatible or coated with a biocompatible material. The end portion of the passivetongue retention structure13 can be constructed of the same wire or a different biocompatible material.

For example, as an alternative toFIG.2, theoropharynx appliance12 can be configured identically or similarly to any one of the configurations shown inFIGS.4-14. Any one of theoropharynx appliances12 shown inFIGS.4-14 can interface with a removable and/or permanent dental device (like a hook, a mouth guard, a retainer, a crown, or the like) to anchor to a subject's mouth. However, the oropharynx appliance does not need the dental devices and can instead be anchored by a device that is at least partially within the oropharynx appliance, such as a spring, a loop, or a hook. The oropharynx can also include other anchoring means, such as one or more magnets, hydraulics, electrostatics, or the like. Thesensing system14 can be located at any part of the oropharynx appliances2 shown inFIGS.4-14 and/or in the accompanying dental device.

FIG.4 shows an example of a mechanical device, shown and described herein as anoropharynx appliance12, including a passivetongue retention structure13 and an anchoringstructure15 that holds the passivetongue retention structure13 in the subject's mouth. Theoropharynx appliance12 can extend from an anchor point (a tooth, as shown, or another area such as a portion of the gum, the tongue, or any other desired anchor point), along a lingual surface of the mandible and/or over the top surface of the tongue, and ultimately, behind at least a portion of the pharyngeal portion of the subject's tongue to prevent the portion of the tongue from collapsing into the throat.

In some instances, the passivetongue retention structure13 can be maintained within a plane that is parallel with the mandible. In still other instances, the passivetongue retention structure13 can extend over the surface of the tongue. In still other instances, the tongue retention structure can extend over, under, or around the tongue in any configuration as long as at least a portion of the passivetongue retention structure13 extends behind at least a portion of the pharyngeal portion of the subject's tongue to prevent the pharyngeal portion of the tongue from collapsing into the throat. However, the passivetongue retention structure13 need not be behind the tongue and, instead may be in any position that is adapted to prevent the pharyngeal portion of the tongue from collapsing.

Theoropharynx appliance12 subject to several design considerations. The passivetongue retention structure13 must prevent the tongue from moving backwards into the oropharynx, while also allowing movement of the tongue for swallowing. However, at least a portion of the passivetongue retention structure13 must allow movement of the tongue, but prevent the passivetongue retention structure13 from moving upwards or downwards into the oral cavity or oropharynx. Additionally, the portion of the passivetongue retention structure13 must not generate a gag reflex and must not generate a significant amount of saliva (e.g., more than normally generated without the oropharynx appliance12).

In one aspect, the passivetongue retention structure13 can be primarily constructed of a thin wire (made of metal, polymer, an organic material, or the like) that is stiff enough to prevent bending by the tongue. For example, the thickness and/or cross-sectional area of the wire can be nonconstant. Additionally, the wire can have a circular, curved, rectangular, linear, flat, curvilinear, or any other shaped cross section. The wire can be biocompatible to minimize irritation in the patient's mouth. Additionally, the wire can be durable and/or robust so that portions of the wire do not dislodge while the subject is sleeping. The wire can, in some instances, be constructed of a metal and/or polymer that is itself biocompatible or coated with a biocompatible material. As an example, the wire can have a ribbon-like form with a flat direction facing the tongue and the cheeks with at least one wiggle through the length (this eliminates the need for the spring shown inFIG.5). The passivetongue retention structure13 can include anend portion22 that can be constructed of the same wire or a different biocompatible material. For example, the end portion can be arcuate.

In another aspect, theend portion22 can be adapted to restrain all or at least a portion of the subject's tongue. The passivetongue retention structure13 can be sized and dimensioned so that theend portion22 prevents the posterior pharyngeal portion of the tongue from obstructing the subject's oropharynx during sleep, without triggering the gag reflex, while still permitting the tongue to move during swallowing. In some instances, theend portion22 can include at least a rounded portion. In other instances, theend portion22 can include one or more bends.

As shown inFIG.6, theend portion22 can include anengagement structure42 that is configured to establish contact with the posterior pharyngeal portion of the tongue. In some instances, theengagement structure42 can be larger than the rest of the passivetongue retention structure13 to prevent the tongue from obstructing the oropharynx. For example, theengagement structure42 can be in the form of: one or more wire coils of the same or different biocompatible material as the wire of the passivetongue retention structure13; an additional portion of the same or different wire attached to the passivetongue retention structure13; and/or a piece of material either the same as the wire or different from the wire. Theengagement structure42 can provide an additional portion to prevent the tongue from moving backwards into the oropharynx during inspiration and obstructing the airway, while not generating the gag reflex and not generating an excess amount of saliva.

The anchoringstructure15 can be adapted to secure the passivetongue retention structure13 to at least one of the subject's teeth or a portion of the subject's mandible in a removable fashion. For example, the anchoringstructure15 can include one or more loops to secure theoropharynx appliance12 to one or more teeth and/or portions of the mandible. In another example, the anchoringstructure15 can include a magnet configured to attach to a reciprocal magnetic member that is connected to a portion of the subject's mouth. In some instances, as shown in theoropharynx appliance12 ofFIG.5, the anchoringstructure15 can include one or more springs32. The one ormore springs32 can be configured to allow movement of the tongue for swallowing. Although illustrated separately, it will be appreciated that, in some instances, the one ormore springs32 and theengagement structure42 can be used together in another example of the oropharynx apparatus of the present disclosure.

FIG.7 shows an alternative configuration of anoropharynx appliance12, in which the passivetongue retention structure13 loops or bends back to the anchoringstructure15, increasing the strength of the passive tongue retention structure. In other words, theoropharynx appliance12 can extend from an anchor point, along a lingual surface of the mandible, behind at least a portion of the posterior pharyngeal portion of the subject's tongue to contact the posterior pharyngeal portion of the subject's tongue, and then extend back along the lingual surface of the mandible, to again contact the anchor point. In some instances, the passivetongue retention structure13 can stay within a plane that is parallel with the mandible. In other instances, the portion of the passivetongue retention structure13 can run over an upper surface of the tongue.

Theoropharynx appliance12 ofFIG.7-9, is subject to several design considerations. The passivetongue retention structure13 must prevent the tongue from moving backwards into the oropharynx, while also allowing movement of the tongue for swallowing. However, at least a portion of the passivetongue retention structure13 must be attached so that movement of the tongue does not bring the passivetongue retention structure13 upwards or downwards into the oral cavity or oropharynx. For example, the portion of the passivetongue retention structure13 can remain in line with one or more of the subject's lower incisive teeth. Additionally, the portion of the passivetongue retention structure13 must not generate a gag reflex and must not generate a significant amount of saliva (e.g., more than normally generated without the oropharynx appliance12).

In theoropharynx appliance12 ofFIG.7, the thickness, cross-sectional shape, and/or stiffness of the passivetongue retention structure13 must be well controlled to hold the tongue so that the tongue does not block the oropharynx while preventing a gag reflex, preventing the formation of excess saliva, and allowing movement of the tongue for swallowing.

FIG.8 shows a further example of anoropharynx appliance12 that can include two or

more springs

32aand32b. The two or

more springs

32aand32bcan allow greater movement of the tongue for swallowing and stronger attachment of the passivetongue retention structure13 to the anchoringstructure15.FIG.9 shows a further example of anoropharynx appliance12 that can include anengagement structure42. Although the two or

more springs

32aand32band theengagement structure42 are illustrated as being used separately, it will be appreciated that the two or

more springs

32aand32band theengagement structure42 can be used together in the same oropharynx protection appliance. However, as an example, to eliminate the need for the

springs

32a,32b, the passivetongue retention structure13 can have a ribbon-like form with a flat direction facing the tongue and the cheeks with at least one wiggle through the length.

FIG.10 shows an alternative configuration of anoropharynx appliance12 in which the passivetongue retention structure13 includes a portion (end portion22) adapted to prevent the pharyngeal portion of the tongue from collapsing. The passivetongue retention structure13 extends between

bilateral anchoring structures

15aand15b. The anchoring

structures

15aand15bcan attach the passivetongue retention structure13 to one or more teeth located bilaterally on the subject's lower jaw. However, at least one of the anchoring

structures

15aand15bcan attach to a portion of the subject's lower jaw itself. Alternatively, at least one of the anchoring

structures

15aand15bcan attach to a portion of the subject's tongue.

In some instances, the passivetongue retention structure13 can stay within a plane that is parallel with the mandible. In other instances, a portion of the passivetongue retention structure13 can extend over the top of the tongue. In further instances, the tongue retention structure can extend over, under, or around the tongue in any configuration as long as a portion of the passivetongue retention structure13 prevents a pharyngeal portion of a tongue of a subject from collapsing.

Theoropharynx appliance12 ofFIGS.10-14 is subject to several design considerations. The passivetongue retention structure13 must prevent the tongue from moving backwards into the oropharynx, while also allowing movement of the tongue for swallowing. However, at least a portion of the passivetongue retention structure13 must prevent movement of the tongue from bringing the passivetongue retention structure13 upwards or downwards into the oral cavity or oropharynx. For example, the portion of the passivetongue retention structure13 can remain in line with one or more of the subject's lower incisive teeth. However, the passivetongue retention structure13 is not required to be in line with the subject's lower incisive teeth. Additionally, the portion of the passivetongue retention structure13 must not generate a gag reflex and must not generate a significant amount of saliva (e.g., more than normally generated without the oropharynx appliance12) when preventing the portion of the pharyngeal portion of the tongue from collapsing into the oropharynx. For example, the passivetongue retention structure13 can be of a thin, stiff wire with examples similar to that described with respect toFIG.4.

In one aspect, each anchoring

structure

15aand15b(FIG.10) can be adapted to secure the passivetongue retention structure13 to at least two of the subject's teeth and/or portions of the subject's mandible in a removable fashion. For example, the anchoring

structure

15aand15bcan each include one or more loops to secure theoropharynx appliance12 to the two or more teeth, portions of the gum, portions of the tongue, and/or portions of the mandible. In another example, the anchoring

structure

15aand15bcan include magnets configured to attach to a reciprocal magnetic member that is connected to a portion of the subject's mouth. In some instances, theoropharynx appliance12, as shown inFIG.11, can include one or

more springs

32aand32bextending from the anchoring

structures

15aand15b. Although one

spring

32aor32bis shown as part of one

anchoring structure

15aand15b, two or more springs can be attached to each anchoring

structure

15aand15bto allow for greater movement of the tongue for swallowing and a stronger attachment of the passivetongue retention structure13 to the anchoring

structures

15aand15b.

In another aspect, theend portion22 can be adapted to contact a posterior pharyngeal portion of the subject's tongue. The passivetongue retention structure13 can be sized and dimensioned so that theend portion22 prevents the posterior pharyngeal portion of the tongue from obstructing the subject's oropharynx during sleep, without triggering the gag reflex, while still permitting the tongue to move during swallowing. As shown in theoropharynx appliance12 ofFIG.12, theend portion22 can include anengagement structure42 that is configured to establish contact with the posterior pharyngeal portion of the tongue. In some instances, theengagement structure42 can have a cross-sectional area larger than the rest of the passivetongue retention structure13 to prevent the tongue from obstructing the oropharynx. For example, theengagement structure42 can be in the form of one or more wire coils62, as shown inFIG.13. Theengagement structure42 can be of the same or different biocompatible material as the wire of the passivetongue retention structure13. As a further example, theengagement structure42 can be an additional portion of the same or different wire attached to the passivetongue retention structure13. In another example, theengagement structure42 can include a piece ofmaterial72,FIG.14, either the same as the wire or different from the wire. Theengagement structure42 can provide an additional surface area to prevent the tongue from moving backwards into the oropharynx during inspiration and obstructing the airway, while not generating the gag reflex and not generating an excess amount of saliva. Theengagement structure42, in some instances, can be used in combination with the

springs

32aand32bin an oropharynx appliance.

As an example, the passivetongue retention structure13 need not be straight, as illustrated. Instead, the passivetongue retention structure13 can be bent caudally by a small amount. Additionally, use of one or

more springs

32a,32bcan be replaced by two earth magnets sliding into a groove. Moreover, the device need not contact the back of the tongue if one or more magnets are implanted in the tongue.

.FIG.15 is a side view illustration showing an example of the system of10 or20 being used in a subject's mouth during sleep to detect, diagnose, and/or monitor OSA. In this example, the passivetongue retention structure13 is made of a thin, stiff wire (made of an organic material, a polymer material, a metal, or the like) and the anchoringstructure15 includes a mouthguard or other dental appliance. In some examples, the mouthguard can be 3D-printed from a cone beam computer tomography (CBCT) obtained for the patient from a dentist's office. The design of theoropharynx appliance12 can then be determined from the CBCT.

In constructing theoropharynx appliance12, the wire is chosen to be very stiff in order to prevent bending by the tongue movement during swallowing. The wire is very thin to minimize the amount of saliva production and to minimize the gag reflex. The wire is attached to the mouthguard by aspring32 and adisplacement sensor16. The wire is designed to wrap around the tongue, following the mandible, into the oropharynx. The spring allows movement of the tongue forward for swallowing. Thedisplacement sensor16 measures movement of the tongue. For example, as the tongue is falling into the oropharynx during an obstruction event, thedisplacement sensor16 detects the displacement of the tongue (x). Once the obstruction event is terminated, the tongue will move back to its normal resting place.

FIG.16 shows an exampleclosed loop system40, which includes theoropharynx appliance12, thesensing system14, and the external diagnostic device, which can be aneffector system142 that communicates with thesensing system14 and theoropharynx appliance12. Theeffector system142 can deliver a signal to theoropharynx appliance12 in response to the data from thesensing system14. For example, theeffector system142 can deliver a pulse of electricity (or other signal that causes reflexive tightening of upper airway muscles) to theoropharynx appliance12 for delivery to the tongue when a collapse is detected. This reflexive tightening can be used to train the tongue not to collapse into the oropharynx.

IV. Methods

Another aspect of the present disclosure can relate to methods for non-invasive direct monitoring, diagnosis, and treatment of obstructive sleep apnea (OSA).FIG.17 shows an example of amethod1600 for OSA detection and monitoring.FIG.18 shows an example of amethod1700 constructing an OSA prevention device.

The

methods

1600 and1700 are illustrated as process flow diagrams with flowchart illustrations. For purposes of simplicity, the

methods

1600 and1700 are shown and described as being executed serially; however, it is to be understood and appreciated that the present disclosure is not limited by the illustrated order as some steps could occur in different orders and/or concurrently with other steps shown and described herein. Moreover, not all illustrated aspects may be required to implement the

methods

1600 and1700.

FIG.17 shows amethod1600 for OSA detection and monitoring. As an example, themethod1600 can be accomplished using thesystem10 ofFIG.1 or the examples shown inFIGS.2-16. At least a portion of theoropharynx appliance12 can be fitted to or constructed for at least a portion of the subject's mouth. In some instances, theoropharynx appliance12 can be fitted tightly within the subject's mouth (e.g., to the subject's lower teeth) so that theoropharynx appliance12 does not move when placed into the subject's mouth before, during, or after sleep.

At1602, a property related to OSA can be measured (e.g., by one ormore sensors16 on an oropharynx appliance12). The property can include one or more of movement of a portion of the tongue into the oropharynx, air flow, force, oxygen saturation (SaO₂), electrocardiogram (ECG), and/or sound. At1604, data related to the property can be transmitted (e.g., by wireless transceiver17) to an external device (e.g., diagnostic device18). At1606, a signal can be received from the external device (e.g., diagnostic device18) based on the data.

FIG.18 shows amethod1700 for constructing an oropharynx appliance to prevent or treat sleep apnea in the subject based on tracking data that tracks the position of the pharyngeal portion of a subject's tongue during sleep. The measurement can be made of the position of the posterior pharyngeal portion of the tongue relative to the oropharynx (e.g., a known position of the dorsal wall of the oropharynx). The measurement can include one or more recorded data related to the distance, spread apart by a known time interval. For example, when motion of the tongue is detected, a plurality of measurements can occur separated by a known time interval for a specified amount of time. The data related to the position of the posterior pharyngeal portion of the tongue can be transmitted (e.g., bywireless transceiver17 of sensing system14) to an external diagnostic device (e.g., diagnostic device18). A degree of obstruction of the oropharynx can be determined (e.g., by diagnostic device18) at one or more times during sleep based on the transmitted data. For example, the sensor can determine a displacement of the posterior pharyngeal portion of the tongue during sleep. To increase accuracy of the measurement, a calibration procedure can be performed based on a distance between a reference point in a mouth of the subject (e.g., the tip of a lower incisor tooth) and a normal (resting) position of the posterior pharyngeal portion of the tongue.

At1702 a weight of the tongue can be estimated (e.g., by the diagnostic device18) based on data related to the position of the posterior pharyngeal portion of the tongue. At1704, a force required to prevent the tongue from falling into the oropharynx can be determined (e.g., by the diagnostic device18). When the sensor (e.g., sensor16) and the oropharynx appliance (e.g., oropharynx appliance12) are coupled by a spring, a force, F, associated with the passive tongue retention structure can be determined by the equation F=kx, where k is a spring constant of the spring and x is the position of the posterior pharyngeal portion of the tongue. At1706, a device (e.g., oropharynx appliance12) can be constructed based on the force required to prevent the tongue from falling into the oropharynx.

From the above description, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications are within the skill of one in the art and are intended to be covered by the appended claims.

Claims

1-21. (canceled)

22. A system comprising:

an oropharynx appliance configured to be placed within a mouth of a subject in a removable fashion, the oropharynx appliance comprising:

a passive tongue retention structure configured to extend along a lingual surface between a first end point and a second end point, the passive tongue retention structure having an arcuate portion that is sized and dimensioned to extend across and contact an entire width of a pharyngeal portion of a tongue of the subject to prevent the pharyngeal portion of the tongue of the subject from collapsing when the oropharynx appliance is placed in the mouth of the subject; and

at least one anchoring structure that is connected to the passive tongue retention structure and adapted to secure the passive tongue retention structure within the subject's mouth; and

a sensing system attached to a portion of the oropharynx appliance, the sensing system comprising:

at least one sensor for detecting at least one property associated with obstructive sleep apnea (OSA) in the subject during sleep; and

a wireless transceiver to transmit data related to the at least one property associated with OSA to a remote diagnostic device.

23. The system ofclaim 22, wherein the first end point and the second end point are configured to be positioned on opposing sides of a mandible of the subject.

24. The system ofclaim 23, wherein a portion of the passive tongue retention structure extends in a plane parallel to the mandible.

25. The system ofclaim 22, wherein the at least one anchoring structure comprises a first anchoring structure and a second anchoring structure, wherein the first end point connects to the first anchoring structure at a first anchor point and the second end point connects to the second anchoring structure at a second anchor point, wherein the first and second anchor points are proximal to the mandible.

26. The system ofclaim 25, wherein each of the first and second anchoring structures comprises a resilient device that returns to its former shape when released after being pressed or pulled, a hydraulic portion, a magnetic portion, and/or an electrostatic portion.

27. The system ofclaim 25, wherein each of the first and second anchoring structures is configured to prevent movement of the passive tongue retention structure under a weight of the tongue but allows movement of the passive tongue retention structure during swallowing.

28. The system ofclaim 25, wherein each of the bilateral anchoring structures anchors free ends of the oropharynx appliance at the first and second end points of the passive tongue retention structure and extends away from the free ends.

29. The system ofclaim 22, further comprising an engagement structure that is connected to, or integrally formed with, the arcuate portion of the passive tongue retention structure.

30. The system ofclaim 29, wherein the engagement structure has a cross-sectional area greater than a cross-sectional area of the passive tongue retention structure.

31. The system ofclaim 22, wherein the at least one anchoring structure further comprises a dental appliance mated to the passive tongue retention structure, the dental appliance being one of a mouthguard, a retainer, or a crown, and at least a portion of the sensing system being attached to the dental appliance.

32. The system ofclaim 22, wherein the at least one property associated with OSA is air flow through the oropharynx, oxygen saturation of the subject, temperature, cardiac electrical signals, sound, and/or a position of the pharyngeal portion of the tongue.

33. The system ofclaim 22, wherein the at least one property associated with OSA is oxygen saturation of the subject.

34. A method comprising:

placing, in a removable fashion, an oropharynx appliance in a mouth of a subject, the oropharynx appliance comprising:

a passive tongue retention structure configured to extend along a lingual surface between a first end point and a second end point, the passive tongue retention structure having an arcuate portion that extends across and contacts an entire width of a pharyngeal portion of a tongue of the subject to prevent the pharyngeal portion of the tongue of the subject from collapsing;

at least one anchoring structure that is connected to the passive tongue retention structure secures the passive tongue retention structure within the subject's mouth; and

a sensing system that is attached to a portion of the oropharynx appliance;

measuring, by a sensor of a sensing system, at least one property associated with obstructive sleep apnea (OSA) in a subject during sleep,

transmitting, by a wireless transceiver of the sensing system, data related to the at least one property to an external diagnostic device; and

determining, by the external diagnostic device, a degree of obstruction of an oropharynx of the subject at one or more times during sleep based on the transmitted data.

35. The method ofclaim 34, wherein the placing further comprises placing the oropharynx appliance into the mouth of the subject before sleep such that the oropharynx appliance is fitted tightly within the mouth.

36. The method ofclaim 34, further comprising constructing the oropharynx appliance to prevent or treat OSA based on the transmitted data.

37. The method ofclaim 34, wherein the at least one property associated with OSA is air flow through the oropharynx, oxygen saturation of the subject, temperature, cardiac electrical signals, sound, and/or a position of the pharyngeal portion of the tongue.

38. The method ofclaim 37, wherein the transmitted data corresponds to oxygen saturation of the subject.

39. The method ofclaim 34, further comprising treating the subject for OSA based on the determined degree of obstruction.

40. A system comprising:

an oropharynx appliance comprising:

a passive tongue retention structure that is sized and dimensioned to extend across and contact an entire width of a pharyngeal portion of a tongue of a subject to prevent the pharyngeal portion of the tongue of the subject from collapsing when the oropharynx appliance is placed in a mouth of the subject, wherein the passive tongue retention structure is configured to extend from a first end point on a side of a mandible of the subject along a lingual surface to a second end point on an opposing side of the mandible in a plane parallel to the mandible;

bilateral anchoring structures that are connected to the first end point and the second end point of the passive tongue retention structure and are configured to secure the passive tongue retention structure to first and second anchor points, respectively, proximal to the mandible, wherein each of the bilateral anchoring structures comprises at least one resilient device that returns to its former shape when released after being pressed or pulled, wherein the bilateral anchoring structures anchor free ends of the oropharynx appliance at the first and second end points of the passive tongue retention structure and extend away from the free ends, and wherein the bilateral anchoring structures are configured to be proximal to one or more of the subject's lower incisive teeth when the oropharynx appliance is placed in the mouth of the subject; and

a mouthguard attached to the passive tongue retention structure;

an oxygen sensor for detecting oxygen saturation in an oropharynx of the subject; and

a wireless transceiver to transmit data related to the oxygen saturation in the oropharynx to a remote diagnostic device.