Patent Application
20230240546
This invention relates to a wearable fitness tracking and/or monitoring device for monitoring fitness and other physiological metrics, such as heart rate (and/or other cardio-respiratory signals) of a user, for use in, for example, sports and other activities.
Fitness tracking devices are well known and can be used to monitor a user's fitness-related metrics to provide feedback regarding their fitness and/or performance. Indeed, there is an ongoing desire to enable, for example, an athlete's fitness, fatigue and effort to be monitored during training and matches in order to provide key performance insights and reduce the risk of injury.
For example, heart rate monitors are known for use in measuring heart rate (and/or other cardio-respiratory signals) for applications such as health monitoring, sports training and fitness. Conventional devices capable of constantly monitoring a user's heart rate (and/or other cardio-respiratory signals) have, until recently, been rather cumbersome. For example, heart rate monitors often use electrocardiogram (EKG) signals, which require electrodes or a strap placed around the user's chest.
A less cumbersome technique for monitoring heart rate is based on pulse oximetry using a photoplethysmograph sensor. A photoplethysmograph sensor nonOinvasively measures the absorption of light passing through a user's tissue, e.g. a finger or ear lobe, to determine the oxygen saturation level of arterial blood and heart rate. The resulting signal is referred to as a photoplethysmograph (PPG), and the PPG signal can be analysed to determine, among other things, the heart rate (and/or other cardio-respiratory signals) of the person to which the PPG sensor is attached.
Conventionally, pulse oximetry has required the user to remain relatively motionless to ensure that a good PPG signal is obtained. When a PPG sensor is used with a person that is in motion, displacement of the sensor and motion artifacts or noise in the PPG signal can result in inaccuracies in the estimated heart rate (and/or other cardio-respiratory signals) of the user.
U.S. Pat. No. 10,456,053 describes a wrist worn heart rate monitor including a PPG sensor and an inertial sensor, wherein signals from the inertial sensor are used to identify and remove noise from the PPG signals. An initial heart rate value is selected from a number of heart rate candidates that remain in the resulting PPG spectrum and is used to track the heart rate of the user. The PPG spectrum is monitored while tracking the heart rate (and/or other cardio-respiratory signals) to determine if the selected initial heart rate value is in error. The PPG spectrum is monitored and the heart rate value reset as required.
Wrist worn PPG sensors of this type are becoming increasingly prevalent within fitness tracking watches and the like. However, watches or other wrist-worn devices are often not practical (or permitted) when playing contact sports such as rugby, as they can cause injuries to the wearer or other players. Furthermore, wrist-worn fitness trackers may not necessarily be sufficiently accurate for highly effective fitness tracking, at least in some applications, even with software to remove noise from the monitoring signals.
Performance tracking in professional sport is currently achieved with wearables such as GPS trackers and chest-worn heart-rate monitors, and/or video analysis. However, such wearables are known to restrict movement, and they all measure what is happening to the athlete, rather than how their body is reacting, and all such wearables are located within clothing or on the skin (e.g. chest strap) which allows them to move around during use, leading to inaccurate sensor measurements.
Thus, it would be desirable to provide an accurate, user-worn fitness and/or performance tracking device, that is convenient and safe to wear during contact sports and/or over long periods of time, and which provides accurate physiological signals that can be used to monitor the user's fitness, performance and/or health, and aspects of the present invention seek to address at least one or more of these issues.
In accordance with a first aspect of the present invention, there is provided a mouthpiece for a fitness tracking and/or monitoring system, the mouthpiece comprising a retainer member shaped and configured to be worn, in use, within a user's mouth, the retainer member being formed of at least two layers of elastomeric material having a physiological sensor therebetween.
In a preferred embodiment, the sensor may be configured to generate signals representative of the heart rate (and/or other cardio-respiratory signals) of a user. The sensor may, beneficially, comprise a photoplesythmograph sensor comprising a light source for, in use, shining a light on a region of the inside of a user's mouth and a sensor for receiving light reflected from said region of the inside of the user's mouth and generating electrical signals representative thereof.
At least one of the at least two layers of elastomeric material nearest the inner surface of the user's mouth, when in use, may be substantially transparent. At least one of the two layers of elastomeric material furthest from the inner surface of the user's mouth, when in use, may be substantially opaque. Thus, if the sensor is a photoplethysmograph (PPG) sensor, the inner layer allows light to pass through to the user's skin and light reflected back from the blood vessel(s) to pass back to the sensor, and the outer layer prevents ambient light entering the user's mouth from interfering with the accuracy of the sensor.
The elastomeric material is, beneficially, an elastomeric polymer such as Ethylene-Vinyl Acetate (EVA).
The sensor is beneficially located within said retainer member such that, in use, it is located adjacent the user's palate. The inventors have, surprisingly, discovered that the PPG signal that can be obtained from the user's palate is clearer and more stable than that which could be obtained from other regions of the user's mouth.
The sensor may beneficially be incorporated on a substrate, said substrate further incorporating a control module, a power supply unit and a memory module. The substrate (e.g. printed circuit board or PCB) may further incorporate a wireless communication module and antenna configured to wirelessly transmit data representative of signals generated by said sensor to a remote receiver. Thus, physiological data generated by the sensor can be collected in substantially real time whilst the mouthpiece is being worn.
In an exemplary embodiment, the sensor may be incorporated at one end of a first elongate flexible connector. A second elongate flexible connector may be provided or integrally formed at the other end of the first elongate flexible connector (substantially at right angles thereto), said second elongate flexible connector having incorporated at one end thereof at least one or more of a control module, a power supply unit, a memory module, a wireless communication module and a wireless communication antenna. The first and second elongate flexible connectors, together, may form a substantially T-shaped flexible connector. Thus, in an exemplary embodiment, a PPG sensor can be located the free end of the central ‘leg’ of the T-shaped flexible connector (so that it is located adjacent the user's palate, in use), and other sensors and electronic components can be located at the free ends of the ‘arms’ of the T-shaped flexible connector. Other sensors may include an accelerometer for measuring impact.
The retainer member may, in some embodiments, be formed of at least three layers of elastomeric material, with said sensor being located between first and second layers, nearest the inner surface of the user's mouth when in use, and a third layer formed over said second layer. Again, the sensor beneficially comprises a photoplethysmograph sensor, and said first and third layers are substantially transparent and said second layer is substantially opaque. Once again, the photoplethysmograph sensor may be provided on a flexible connector and located within the retainer member such that, in use, it is positioned adjacent the user's palate.
In accordance with a second aspect of the invention, there is provided a mouthpiece assembly comprising a mouthpiece substantially as described above, and a storage case for receiving said mouthpiece, when not in use, the mouthpiece comprising a receiving element of a wireless charging system and said storage case comprising a transmitting element of a wireless charging system and, wherein said transmitting element is positioned adjacent said receiving element when the mouthpiece is located within the storage case.
The receiving element may comprise a conductive coil printed or otherwise provided on a flexible printed circuit board located between said at least two layers of elastomeric material, and said transmitting element may comprise a plurality of overlapping conductive coils.
In accordance with a third aspect of the present invention, there is provided a fitness tracking and/or monitoring system comprising at least one mouthpiece substantially as described above, a receiver for receiving physiological data from the sensor of said at least one mouthpiece and an analytics platform for analysing said physiological data and providing an output indicative of fitness and/or performance of the or each user.
In accordance with a fourth aspect of the present invention, there is provided a method of manufacturing a mouthpiece for a fitness tracking and/or monitoring system, the method comprising forming a positive mould of or representative of a user's teeth and gum, forming a first layer of elastomeric material over said mould, securing a physiological sensor circuit to said first layer of elastomeric material, and forming a second layer of elastomeric material over said physiological sensor circuit.
As before, the first layer may be substantially transparent, said second layer may be substantially opaque, and said sensor circuit may comprise a light source, a photoplethysmograph sensor, and a wireless communications module for wirelessly transmitting data representative of signals generated by said sensor to a remote receiver, in use.
These and other aspects of the invention will become apparent from the following detailed description.
Embodiments of the present invention will now be described, by way of examples only, and with reference to the accompanying drawings, in which:
Referring to
The or each health tracking device 10 comprises a printed circuit board (PCB), incorporating one or more sensors, embedded in a mouthpiece such as a sports mouthguard, gum shield, orthodontic appliance, such as those used to alleviate or treat snoring or sleep apnoeia, retainer, etc. Such mouthpieces may be generic or they may be custom fitted to the user's mouth. The sensor(s) on the PCB generate physiological signals obtained whilst the mouthpiece is worn and wirelessly transmit the signals (or data representative thereof) to the edge device 12, which is essentially a receiver (or multiple receivers) configured to receive the data transmitted from the mouthpiece PCB. The primary purpose of the edge device 12 is to receive data from the mouthpiece, in use, and save the data locally and/or upload it to the cloud 14. Thus, it acts as a ‘gateway’ between the mouthpiece 10 and the analytics platform. The user's mouthpiece data is processed and analysed by a cloud (or local) computing platform 14, and a web-based dashboard 16 allows users to view their data and analytics in substantially real time on a personal computer, tablet, phone or any web browser.
Referring to
The IMU 34 may comprise a 3-axis magnetometer, a 3-axis accelerometer and a 3-axis gyroscope which, together in use, can be used to generate data representative of impacts on a player's head in terms of force, rotation and direction. The HIA 36 can be used to detect much greater impacts than the IMU. The pulse oximeter and heart rate sensor 38 is used to obtain a PPG which represents blood volume changes in the user's microvascular bed of tissue. The PPG sensor 38 works by shining a light source (from the LED 32) onto a region inside the user's mouth, e.g. the palate, and measuring the amplitude of green, red and infrared light reflected back to the sensor to obtain the PPG, in the ranges of 537 nm, 660 nm and 88 nm respectively. This allows for parameters to be collected that cannot typically be obtained in real time by prior art devices during sports, as set out in the table below.
Referring to
The PSU 28 comprises, for example, a 38 mAh Lithium polymer battery which can be charged, for example, by a wireless charging arrangement using cooperative oscillating coils, with the transfer of energy occurring by means of magnetic induction between the coils.
A conventional mouthguard is formed of multiple layers of Ethylene-Vinyl Acetate (EVA) plastic, heated and vacuum formed, a layer at a time, over a positive mould of a user's teeth and gum. The layers of EVA are subsequently trimmed and polished (between formation of each layer) to achieve a smooth surface finish. A mouth guard or mouthpiece according to an embodiment of the invention may be manufactured as follows. In a first step, a positive mould of a user's teeth and gum is produced in any known manner. Next, a first, transparent layer 44 of EVA is heated and vacuum formed over the mould, and then trimmed and polished in a known manner. The PCB 20 is then stuck to the first layer 44, positioning the PPG sensor 38 under the ‘teeth’ onto the palate region. In this exemplary embodiment, the PPG signals are obtained from the user's palate, as it has surprisingly been discovered by the inventors to yield sufficiently clear and stable results. However, it will be appreciated that the PCB 20 could, in theory, be positioned in the mouthpiece such that PPG signals can be obtained from another part of the user's mouth. Next, a black layer 42 of EVA is heated and vacuum formed over the first layer 44 and
PCB 20, and then trimmed and polished. Labels/logos may be stuck to the black layer 42 if required. Finally, a third, transparent layer 40 of EVA is heated and vacuum formed over the black layer 42 and labels/logos (if present), and then trimmed and polished, as before, to form the finished device.
In an alternative exemplary method of manufacture, the second and third layers 40, 42 may be formed by, first, heating the black EVA layer 42 to its melting point, then applying any labels/logos thereto, and then finally slowly applying the third layer 40.
The PCB 20 may be configured to be ‘split’ into three separate sections, connected together by a flexible connector in the form of, for example, polyimide flexible PCB material. As shown in
Charging of the PSU 28 may be achieved by means of wireless charging using two sets of conducting coils: one incorporated on the PCB 20 within the mouthpiece 10 and electrically connected to the Lithium polymer battery, and the other in a storage case (for example) and electrically connectable to a power source (e.g. by means of a USB (or other) charging cable (not shown). Referring to
The MCU 21 of the or each mouthpiece 10 runs embedded firmware configured to sample the sensors (PPG, IMU, HIA), save the data to the onboard flash memory module 30 and send that data to the edge device 12. Each mouthpiece (e.g. sports mouthguard) have at least a “game” (or data collection) mode/state, for sampling and logging data during use, and an “idle” mode/state, where nothing is done and power saving is optimised. Referring to
In an alternative exemplary embodiment, the PCB 20 may be mounted in or on a retainer, such as those commonly used for teeth whitening, teeth straightening or protection. The much thinner form factor of such mouthpieces means that the breathing and speech of a user is not significantly impaired, at they can be worn during any activity, whether contact sport or otherwise. The PCB could, in this case, be sandwiched between two layers of material, such as EVA plastic, in a similar manner to that described above. Both layers could be transparent, although the outer layer could, in theory, be formed of a darker material if desired. The retainer thus provides a more streamlined mouthguard, whilst still providing the functionality of the sensor(s) as described above. In this case, a mouthguard which is overmolded to fit over the retainer and the user's teeth can be worn over the retainer when the user participates in contact sports.
It will be apparent to a person skilled in the art, from the foregoing description, that modifications and variations can be made to the described embodiments without departing from the scope of the invention as defined by the appended claims, In the above detailed description, a sports mouthguard is specifically referenced and described. However, it will be appreciated that the invention can be adapted to provide the PPG measurement capability in other types of mouth-worn devices, including dental or orthodontic retainers used for various purposes, and the present invention is not necessarily intended to be limited in this regard.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008477.8 | Jun 2020 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2021/051317 | 5/28/2021 | WO |
