Hearing device comprising an optical sensor

Abstract

The present invention relates to a hearing device including an optical sensor. A hearing device such as an in-ear receiver assembly (100) includes: a housing (104) including a cavity (102a) extending through the housing (104); an optical transducer (201) mounted in the cavity (102a) within the thickness of the housing (104), the optical transducer (201) being mounted on a circuit board layer (208) such that there is a gap (207) between one side of the optical transducer (201) and the side wall (216) of the cavity (102a); the circuit board layer (208) extending under the housing (104) and contacting the housing (104) such that the optical transducer (201) is held within the cavity (102a) without contacting the housing (100); and a protective substance (210) forming a shield over the optical transducer (201) and the cavity (102a), the protective substance (210) being configured to affect the field of view of the optical transducer (201).

Description

Technical Field

[0001] The present disclosure relates to a hearing device for positioning within or at the user's ear canal, such as an in-ear receiver assembly or earbud. The in-ear receiver assembly includes a housing having at least one cavity and at least one optical transducer mounted within the at least one cavity (e.g., within the thickness of the housing). The transducer may also be located exactly below (or above) the housing thickness. All embodiments will also apply to this position of the transducer. Background Art

[0002] An in-ear receiver hearing aid is a hearing aid that fits at least partially within the user's ear canal. It includes a speaker or receiver that can generate sound within the ear canal of a hearing-impaired user. An in-ear receiver assembly for positioning within or at the user's ear canal typically does not include an optical sensor within its housing, as miniaturizing these sensors to fit the harsh environment within the ear is a manufacturing challenge. The present disclosure provides solutions for improving the efficacy of optical sensors / systems embedded within in-ear receiver assemblies and other hearing devices.

[0003] An in-ear receiver assembly typically does not include an optical sensor for measuring a user's physiological parameters related to health or other conditions. Additionally, even if an optical sensor is provided on the in-ear receiver assembly, its efficacy is reduced because the light beam from the emitter within the optical sensor cannot be properly directed or amplified to the region of interest within the user's ear. This is because combining a light-emitting diode (LED) or detector with an optical amplifier (e.g., a reflector) within the in-ear receiver assembly is a challenge. First, an LED or detector with an optical amplifier has a larger form factor compared to an LED without an optical amplifier. Embodiments of the present disclosure provide solutions for at least solving this problem and other problems related to embedding an optical sensor within an in-ear receiver assembly. Summary of the Invention

[0004] A first aspect of the present disclosure provides a hearing device, such as an in-ear receiver assembly or earbud, comprising:

[0005] A housing including one or more wall portions defining an interior space and including a cavity extending through the wall portions of the housing;

[0006] A receiver disposed within the interior space;

[0007] A circuit board layer;

[0008] An optical transducer, which is installed in a cavity. The optical transducer is installed on a circuit board layer such that there is a gap between the side surface of the optical transducer and the side wall of the cavity. The circuit board layer extends under the wall portion and contacts the wall portion, so as to hold the optical sensor

[0009] in the cavity; and

[0010] A protective substance, which forms a shielding cover on the optical sensor and the cavity. The protective substance is configured to affect the field of view of the optical sensor.

[0011] The protective element or substance can be a protective substance configured to hermetically seal the assembly and / or affect the field of view of the emitter.

[0012] On the other hand, there is provided a hearing device for positioning in or partially or completely located in the ear canal. The device includes:

[0013] A housing, which includes a cavity extending through the housing;

[0014] A transducer such as an optical emitter or detector or sensor, which is at least partially installed within the thickness of the housing where the cavity is located. The transducer is installed such that there is a gap between the side surface of the emitter and the side wall of the cavity; and

[0015] A protective element, which forms a shielding cover on the transducer and the cavity.

[0016] The protective element or substance can be a protective substance configured to hermetically seal the assembly or the cavity and / or affect the performance of the transducer.

[0017] In this case, the housing can be formed by one or more wall portions. The wall portion defines an internal space, which is at least partially defined by the wall portion. The outer surface of the wall portion can form a part of the outer surface of the housing, while the inner surface of the wall portion can participate in the definition of the internal space.

[0018] A receiver is provided in the internal space. Therefore, preferably, a sound output is provided in the housing, and the sound output also extends from the internal space to the periphery of the housing. The receiver is a sound emitter, usually very small in size, and can be used for hearing aids and RICs. Usually, the maximum size of the receiver is 8 mm or less. The receiver can include an electrical conductor for transmitting an electrical signal to the receiver, etc. Such a conductor can extend from the internal space to the periphery of the housing.

[0019] The housing can have walls or wall portions of a predetermined thickness. Since the cavity extends, for example, from the internal space through the wall portion of the housing to the surroundings of the housing at least before the transducer and the protection element are provided, it is not a problem to incorporate the emitter in the thin-walled housing of the in-ear receiver assembly, because the emitter can be located in the cavity and thus does not occupy space in the internal space of the housing. If the wall portion is straight, its outer and inner surfaces define parallel planes between which the transducer can be provided. In this context, "within the thickness of the housing" means that the receiver is located inside the cavity and does not extend from the cavity to any side of the cavity to extend beyond the thickness of the housing, for example, at the edge of the cavity.

[0020] The circuit board layer can be a so-called PCB and can be rigid or flexible. The circuit board layer typically has conductors of one or more conductors or connectors electrically connected to the transducer. The circuit board layer extends under the wall portion and contacts the wall portion, for example, is attached to the wall portion or biased towards the wall portion. Then, the optical sensor is held in the cavity and fixed in the cavity, for example, by the engagement between the optical sensor and the circuit board and the engagement between the circuit board and the wall portion. The circuit board can have a surface on which the optical sensor is provided and which engages with the wall portion.

[0021] The transducer can be an emitter such as an LED for emitting photoplethysmography (PPG) light of a selected wavelength or wavelengths. The emitter can be mounted such that the top of the emitter is in line with the outer surface of the housing. Alternatively, the transducer can be a light receiver. In fact, the transducer can include an emitter and a detector / receiver.

[0022] Alternatively, multiple transducers can be provided separately in separate cavities, where one or more transducers are emitters and one or more transducers are receivers.

[0023] In one embodiment, the side wall of the cavity includes one or more stepped portions, one or more straight portions, one or more inclined portions, or any combination thereof. The side wall can have: a generally vertical straight portion for mounting the emitter in a closely fitting manner (with the adjacent LED surface); and an inclined portion that is generally inclined such that the desired emission angle does not exceed 180 degrees, depending on the field of view of the emitter. The cross-sectional profile of the side wall can be piecewise linear, having straight portions, inclined portions, etc.

[0024] In one embodiment, the side wall is curved or parabolic. The segmented construction of the side wall can also include not only the straight portions as described above, but also curved portions.

[0025] In one embodiment, the sidewall of the cavity includes one or more reflective surfaces. The reflective surfaces can reflect, for example, at least 30% of the light emitted by the emitter at selected light wavelengths such as red, green, and / or near-infrared light and / or a wavelength of 850 nm.

[0026] In one embodiment, the one or more reflective surfaces include suitable materials such as plastics that reflect color, plastics with reflective particles, metals, coated surfaces, or any combination thereof. The composition and surface structure of the one or more reflective surfaces and / or the angles of the one or more reflective surfaces can cause the one or more reflective surfaces to reflect light of different wavelengths at different reflection angles and with different direct or diffused beam shapes.

[0027] In one embodiment, the one or more reflective surfaces can extend below the housing. In some embodiments, all of the reflective surfaces are below the housing, thereby allowing (at least) a portion of the housing to be made of a translucent or transparent material (such as transparent plastic, glass, transparent ceramic, etc.). Then, the one or more reflective surfaces can be extended along the inner surface of the wall portion. In some embodiments, when using a transparent material and reflective surfaces located below the housing, reflective surfaces on the sidewall or on the outer surface of the sidewall are not included in the in-ear receiver assembly.

[0028] In some embodiments, the one or more reflective surfaces are disposed below the emitter. In some embodiments, the one or more reflective surfaces are located on the outer surface of the housing, such as on the outer surface of one or more wall portions. The reflective surfaces according to the embodiments of the present disclosure can be made of a separate reflective component. The reflective surfaces according to the embodiments of the present disclosure can be made of a reflective coating or layer deposited or laminated on the surface of the housing, sidewall, etc.

[0029] In one embodiment, the protective substance includes one or more sealants. At least one of the one or more sealants can fill the cavity and form the shielding cover into an outwardly curved shielding cover. The curvature of the outwardly curved shielding cover affects the field of view of the emitter. The one or more sealants can have different functions, for example, sealing the interior of the cavity, protecting the electronic devices and the emitter, setting optical lenses, etc. The one or more sealants can include potting materials, overmolding, epoxy resin / resin / polyurethane, etc.

[0030] Alternatively or additionally, the protective substance can include a lens. The lens can be a plastic lens or a glass lens. The protective substance includes a Fresnel lens, and the Fresnel lens forms the shielding cover into a flat surface.

[0031] In one embodiment, the radiation element of the emitter is positioned at a distance from the circuit board layer such that increasing this distance increases the field of view of the emitter.

[0032] Another aspect of the present disclosure provides a hearing device such as an in-ear receiver assembly or earbud, comprising:

[0033] A housing including a cavity extending through the housing;

[0034] A transmitter or detector at least partially mounted within the thickness of the housing located within the cavity, the transmitter being mounted on a circuit board layer such that there is a gap between the side of the transmitter and the sidewall of the cavity;

[0035] The circuit board layer extends beneath the housing and contacts the housing such that the transmitter or detector is held within the cavity without contacting the housing; and

[0036] A protective element forming a shield over the transmitter and the cavity.

[0037] Obviously, all of the above considerations, embodiments, and circumstances are equally important in this context.

[0038] Another aspect of the present disclosure provides an in-ear receiver assembly, comprising:

[0039] A housing including a cavity extending through the housing, the housing being made of a transparent material, the housing may include one or more wall portions defining an internal space in which a receiver may be disposed;

[0040] A transmitter mounted within the thickness of the housing located within or in the cavity, the transmitter being mounted on a circuit board layer such that there is a gap between the side of the transmitter and the sidewall of the cavity;

[0041] The circuit board layer extends beneath the housing or the wall portion of the housing at the internal space and includes a reflective surface that contacts the housing or the wall portion such that the transmitter is held within the cavity without contacting the housing; and

[0042] A protective substance forming a shield over the transmitter and the cavity.

[0043] Again, all of the above considerations, embodiments, and circumstances are equally important in this context.

[0044] The protective substance may be configured to affect the field of view of the transmitter.

[0045] The last aspect of the present disclosure provides a component for a device to be worn at or in the ear canal, the component comprising:

[0046] A housing (904) which may include one or more wall portions defining an internal space, including a cavity extending through the housing (904), such as a cavity through a wall portion of the housing (904), the housing (904) or the wall portion being at least partially made of a transparent material;

[0047] An optical transducer (901) is mounted inside or within a cavity, and the optical transducer (901) is mounted on a circuit board layer (908) such that there is a gap between the side of the optical transducer (901) and the side wall (916) of the cavity;

[0048] - A reflective surface (953) that extends below the housing (904) or wall portion, for example, on one side of the internal space, and the reflective surface (953) contacts the housing (904) or wall portion; and

[0049] A protective substance (910) that forms a shielding cover over the optical transducer (901) and the cavity, and the protective substance (910) can be configured to affect the field of view of the optical transducer (901).

[0050] The foregoing and other aspects and embodiments of the present disclosure will be apparent to those skilled in the art from the detailed description of various embodiments and / or implementations with reference to the accompanying drawings and the following summary. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The foregoing and other advantages of the present disclosure will become apparent by reading the following detailed description and referring to the accompanying drawings.

[0052] Figure 1A 、 Figure 1B and Figure 1C Illustrate an in-ear receiver assembly according to an embodiment of the present disclosure from different perspectives;

[0053] FIGS. 1D, 1E, and 1F illustrate an in-ear receiver assembly with size labels Figure 1A ;

[0054] FIG. 1G is a table providing an example range of the size labels of FIGS. 1D, 1E, and 1F;

[0055] Figure 2A Illustrates a perspective view of a transmitter in a cavity in a housing of an in-ear receiver assembly without a protective substance Figure 1A ;

[0056] Figure 2B Illustrates Figure 2A a top view of the transmitter in

[0057] Figure 2C Illustrates Figure 2A a side cross-sectional view of the transmitter in

[0058] Figure 2D Illustrates Figure 2A a cross-sectional view of the transmitter in

[0059] Figure 2E and2F Views of the transmitters with dimensional labels are shown separately Figure 2B and Figure 2D in

[0060] Figure 2G is a table providing an example range of dimensional labels for Figure 2E and 2F ;

[0061] Figure 3 illustrates the position of a transmitter within a cavity of a housing of an in-ear receiver assembly according to an embodiment of the present disclosure;

[0062] Figure 4 illustrates the position of a transmitter within a cavity of a housing of an in-ear receiver assembly according to an embodiment of the present disclosure;

[0063] Figure 5A illustrates a transmitter-detector system embedded within an in-ear receiver assembly and the optical path from the transmitter unit to the detector unit according to an embodiment of the present disclosure;

[0064] Figure 5B and Figure 5C illustrate the concept of narrowing the field of view according to an embodiment of the present disclosure;

[0065] Figure 6 illustrates a cavity located within a housing of an in-ear receiver assembly having inclined sidewalls according to an embodiment of the present disclosure;

[0066] Figure 7 illustrates a cavity located within a housing of an in-ear receiver assembly having parabolic sidewalls according to an embodiment of the present disclosure;

[0067] Figure 8 illustrates an example of a Fresnel lens for beam shaping according to an embodiment of the present disclosure;

[0068] Figure 9A , 9B and 9C illustrate example regions having reflective surfaces according to an embodiment of the present disclosure;

[0069] Figure 9D illustrates an example of adding a reflective surface to improve detector efficiency according to an embodiment of the present disclosure;

[0070] Figure 10 illustrates a reflective surface mounted within a housing according to an embodiment of the present disclosure;

[0071] FIG. 11A, FIG. 11B, and FIG. 11C illustrate examples of using a reflector to reduce the spacing between a transmitter and a detector according to some embodiments of the present disclosure;

[0072] Figure 12A Illustrates shielding a cavity with a preformed window according to an embodiment of the present disclosure;

[0073] Figure 12B and 12C Illustrates a ray trace according to some embodiments of the present disclosure;

[0074] Figure 12D Compares the sizes of two cavities including two different emitters according to some embodiments of the present disclosure;

[0075] Figure 12E Illustrates two types of emitters according to an embodiment of the present disclosure;

[0076] Figure 13A Illustrates the concept of a critical angle according to an embodiment of the present disclosure;

[0077] Figure 13B and Figure 13C Illustrates a ray trace according to some embodiments of the present disclosure;

[0078] Figure 13D Illustrates a ray trace for a housing without a reflective surface according to some embodiments of the present disclosure;

[0079] Figure 13E Illustrates a ray trace for a housing having a reflective surface according to some embodiments of the present disclosure;

[0080] Figure 14A Illustrates a perspective view of an earbud having an optical sensor according to some embodiments of the present disclosure;

[0081] Figure 14B Illustrates Figure 14A a cross-sectional view of the earbud in

[0082] Figure 15A Illustrates a perspective view of an earbud mouthpiece having an optical sensor according to some embodiments of the present disclosure;

[0083] Figure 15B Illustrates Figure 15A a cross-sectional view of the earbud mouthpiece in

[0084] Figure 16A Illustrates a cross-sectional view of an earbud having an optical sensor according to some embodiments of the present disclosure;

[0085] Figure 16B Illustrates Figure 16A a cross-sectional view of the electronic components of the earbud in

[0086] Figure 16C Illustrates Figure 16AEmbodiment of the separation between the emitter and the window in the earplug;

[0087] Figure 16D Illustrated in Figure 16A The mouthpiece used in the earplug and the electronic components of the mouthpiece;

[0088] Figure 17A Perspective view of an earplug with an optical sensor according to some embodiments of the present disclosure;

[0089] Figure 17B Illustrated Figure 17A Cross-sectional view of the earplug in

[0090] Figure 18A Perspective view of an earplug with an optical sensor according to some embodiments of the present disclosure; and

[0091] Figure 18B Illustrated Figure 18A Cross-sectional view of the earplug in Detailed Description

[0092] Although the present disclosure is susceptible to various modifications and alternative forms, specific embodiments have been illustrated by way of example in the drawings and will be described in detail herein. However, it should be understood that the present disclosure is not intended to be limited to the particular forms disclosed. On the contrary, the present disclosure will cover all modifications, equivalents, and alternative forms falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0093] Hearing aids and similar devices are designed to improve hearing by enabling hearing-impaired individuals to hear sounds. In some cases, if the hearing aid devices and systems are not properly calibrated, the hearing-impaired individuals may deteriorate continuously during the use of the hearing aid devices and systems. Thus, there should be methods and systems that can monitor at least a part of a person's auditory system when using a hearing aid. An in-ear receiver hearing aid device is a hearing aid device designed to place a receiver (speaker) inside a patient's ear canal. The receiver is configured to generate amplified sounds captured from the external ear environment through a microphone or some wireless device.

[0094] Introducing electronic devices into a patient's ear canal can be challenging for both the designers of the electronic devices and the patients. Patients may be concerned about the comfort, efficacy, fashionability and aesthetics, discretion, and whether the electronic devices interfere with routine procedures of the electronic devices. Designers may be concerned about the energy requirements of the electronic devices, protecting the electronic devices from moisture and earwax, and the overall efficacy of the electronic products.

[0095] Although there may be other overlaps between the patient and the designer, the efficacy of the hearing aid device is important to both parties. The efficacy of the hearing aid device may depend on the electronic components used and the patient's biological condition. The electronic components wear out over time, and the patient may adapt to the stimuli over time, so higher intensities are required to obtain similar results. There are also other sources of change in the patient's body. For example, due to problems with oxygen entering the tissue, the patient may develop complications, the patient's body may develop resistance to continuous stimulation in the same area, and so on. There should be a way to monitor changes in the tissue around the ear canal or monitor life within the ear canal to determine how the patient's body responds to hearing aid stimuli over time. Embodiments of the present disclosure provide a system and method for monitoring a patient using a transmitter-detector system integrated with an in-ear receiver hearing aid assembly. The transmitter-detector system can provide biological information such as heart rate and blood pressure.

[0096] An example transmitter-detector system for monitoring tissue includes a photoplethysmography (PPG) sensor. The PPG sensor can be a pulse oximeter, which can illuminate the skin and measure changes in light absorption. For example, a light-emitting diode (LED) can be used to illuminate the skin, and a photodetector or photodiode can be used to measure changes in light absorption after the light from the LED interacts with the skin. The PPG sensor has numerous applications. The PPG sensor can monitor changes in the blood volume of the microvascular bed of the tissue. The PPG sensor can be used to monitor blood pressure, monitor the patient's heart rate and cardiac cycle, monitor the patient's respiration, and so on. Embodiments of the present disclosure provide a transmitter-detector system that is small enough to be incorporated into an in-ear or in-the-ear canal wearable device, including means for continuously monitoring an in-ear receiver hearing aid assembly of a patient, and can also be installed in any device (such as a RIC, ITE, ITC, earbud), and also does not require a receiver / micro speaker. Although an in-the-ear canal hearing aid assembly is used as an example in the embodiments of the present disclosure, some embodiments can be applied to in-the-ear canal (ITC) and in-ear (ITE) hearing aids or to situations where there is no receiver.

[0097] Figure 1A 、 1B and 1C illustrate the in-ear receiver assembly 100 according to embodiments of the present disclosure from different perspectives. Refer to Figure 1A, a top view of the in-ear receiver assembly 100 is provided. The in-ear receiver assembly 100 includes a housing 104 of a certain thickness. The housing 104 is a protective cover for electronic devices and a receiver (not shown) disposed within the in-ear receiver assembly 100. The in-ear receiver assembly 100 may include a cable 106 for connecting the electronic devices within the in-ear receiver assembly 100 to other electronic components outside the in-ear receiver assembly 100. The in-ear receiver assembly 100 includes a nozzle member 108. The nozzle member 108 includes a hollow nozzle channel 110 for guiding sound from the receiver disposed within the in-ear receiver assembly 100 to the ear canal. The in-ear receiver assembly 100 further includes one or more emitter positions 102a, 102b, 102c,... for placing one or more emitters. The one or more emitter positions 102a, 102b, 102c,... are cavities in the housing 104.

[0098] Reference Figure 1B , a side view of the in-ear receiver assembly 100 is provided. The side view illustrates one detector position for placing a detector 112 on the in-ear receiver assembly 100. Reference Figure 1C , a front view of the in-ear receiver assembly 100 is provided. The front view is from the perspective of observing the hollow nozzle channel 110. Although Figure 1A - 1C provides three emitter positions and one detector position, it can be understood that any number of emitter positions and any number of detector positions can be provided around the in-ear receiver assembly 100. The three emitter positions and one detector position are provided only as examples. Additionally, the emitter and the detector can be on the same side or the same surface of the in-ear receiver assembly. The emitter and the detector can be located on opposite sides or surfaces of the in-ear receiver assembly. The emitter and the detector can be located on adjacent sides or surfaces of the in-ear receiver assembly. The emitter and the detector can be placed on the front (near the eardrum) or the back of the in-ear receiver assembly. Compared with the housing surface of the in-ear receiver assembly, the emitter and the detector can be oriented to have a field of view at any angle in any direction (up / down / front / back / left / right).

[0099] Figures 1D, 1E, and 1F illustrate the Figure 1A in-ear receiver assembly with dimensional labels. Figure 1D illustrates a cross-section from the rear view of the in-ear receiver assembly 100. Figure 1D identifies the receiver height 103H and the receiver width 103W. Figure 1E illustrates the housing portion length 104L of the in-ear receiver assembly 100. Figure 1F illustrates the housing portion width 104W, the housing portion height 104H1, and the housing portion height 104H2 with a protrusion.

[0100] Figure 1G is a table providing an example range of the size labels of FIGS. 1D, 1E, and 1F. The length 104L of the housing part can be in the range of 6 to 15 mm. The width 104W of the housing part can be in the range of 2 to 8 mm. The height 104H1 of the housing part and the height 104H2 of the housing part with a protrusion can be in the range of 2 to 8 mm. An example value of the length 104L of the housing part multiplied by the width 104W of the housing part multiplied by the height 104H1 of the housing part is 11.0 mm × 3.5 mm × 4.6 mm. For the previous example, the height 104H2 of the housing part with a protrusion can be 5.0 mm.

[0101] The range of the receiver height 103W and the receiver width 103H can be from 2 to 5 mm. In some embodiments, the dimensions of the receiver height 103W multiplied by the receiver width 103H include 2.7 mm × 0.98 mm, 2.7 mm × 1.96 mm, 3.1 mm × 2.55 mm, 2.8 mm × 4.09 mm, etc. The length range of the receiver can be 5 mm to 8 mm.

[0102] Figure 2A A perspective view of the transmitter 201 positioned in the cavity of the housing 104 of the in-ear receiver assembly 100 is illustrated. The protective cover for the cavity is not shown in this perspective view. The cavity can have a stepped design 202. Refer to Figure 2B , a top view of the transmitter 201 is provided. In addition to the stepped design 202, the cavity can include gaps between the housing 104 and the transmitter 201, such as gap 206 and gap 207. The gaps 206 and 207 can be, for example, 0.15 mm. The gaps 206 and 207 can be used as the positioning tolerances of the transmitter 201. In addition, the gaps 206 and 207 can be used as the capillary distance / gap for a protective filler (such as glue) for holding the transmitter 201 in place. The cavity in the housing 104 exposes the circuit board layer 208. The circuit board layer 208 can be a flexible circuit board including a flexible polymer.

[0103] Refer to Figure 2C , a side cross-sectional view of the transmitter 201 in Figure 2A is provided. Examples of the transmitter 201 include a transmitter for emitting electromagnetic waves, an LED, an outlet of an optical fiber / light guide (emitting light generated at different positions), etc. In an example where the transmitter 201 is an LED, from Figure 2CIn a side cross-sectional view, the emitter 201 may have an active or radiating element 214 and wires 212 for connecting the radiating element 214 to a power source. The emitter 201 may have a ceramic base 218 for providing structure to the radiating element 214. The height of the ceramic base 218 may be used to adjust the height of the radiating element 214 relative to the height or thickness of the housing 104. The emitter 201 may have a transparent LED coating 220 to protect the radiating element 214 and the wires 212 from environmental and physical effects. The transparent LED coating 220 may be a transparent glue or overmolded.

[0104] In Figure 2C the emitter 201 is covered by a protective substance 210. The protective substance 210 fills the space within the cavity in the housing 104. The protective substance 210 may be a glue that conforms to the space within the cavity. In some embodiments, the protective substance 210 is a glue that forms a lens for guiding the light beam from the emitter 201. The protective substance 210 is applied to cover all corners and surfaces of the emitter 201.

[0105] Figure 2C The cavity in

[0106] is shown to have side walls 216. The side walls 216 are inclined. The cavity also includes a stepped design 202. Although two steps are illustrated in the stepped design 202, more than two steps may be provided in the cavity. The stepped design 202 enables the protective substance 210 to remain within the cavity during manufacturing, thus facilitating the formation of a dome of the protective substance 210 around the cavity.

[0106] Referring Figure 2D to Figure 2D a cross-sectional view of the emitter 201 without the radiating element 214 and the wires 212 is provided. As Figure 2D shown, the cavity completely penetrates the housing 104 such that within the cavity, the emitter 201 is placed on the circuit board layer 208 rather than on the housing 104. The inner surface of the housing 104 abuts the circuit board layer 208. Also as Figure 2D shown, the ceramic base 218 of the emitter 201 is shown to have an electrical channel 217 that connects to the circuit board layer 208.

[0107] Figure 2E is Figure 2B a replicated view of Figure 2F with size labels, while Figure 2D is Figure 2D a replicated view of Figure 2G with size labels. Figure 2E and 2FExample ranges for the size labels. The emitter width 201W can be in the range of 0.25 mm to 1 mm. The ranges for the emitter length 201L and the emitter height 201H can be from 0.5 mm to 2 mm. The ceramic substrate height 201SH of the emitter can be in the range of 0.1 mm to 0.3 mm. The range of the effective height 201AH including the ceramic substrate and the radiation element can be from 0.2 mm to 0.5 mm. The raised protrusion height 203H1 of the protective substance can be in the range of 0.05 mm to 0.3 mm, while the height 203H2 of the protruding substance starting from the top of the emitter can be between 0 mm and 1.8 mm.

[0108] Figure 2E and 2F shows a cavity having side walls. The bottom width 205W1 and the top width 205W2 of the cavity can be greater than 0.25 mm. The bottom length 205L1 of the cavity can be in the range of 0.5 mm to 2 mm, while the top length 205L2 of the cavity can be in the range of 1 mm to 4 mm. The flat side wall height 205H1 of the flat portion of the side wall of the cavity can be in the range of 0.05 mm to 0.1 mm. The inclined side wall height 205H2 of the inclined portion of the side wall of the cavity also includes the flat side wall height 205H1, and its range can be from 0.1 mm to 0.5 mm.

[0109] For the example device, the dimensions of the emitter width 201W multiplied by the emitter length 201L multiplied by the emitter height 201H are 0.5 mm × 1 mm × 0.45 mm. The dimension of the ceramic base height 201SH is also 0.18 mm, and the dimension of the effective height 201AH is 0.33 mm. The raised protrusion height 203H1 can be 0.33 mm, and the height 203H2 of the protruding substance can be 0.4 mm. The bottom width 205W1 and the top width 205W2 of the cavity can be 0.8 mm and 1.7 mm respectively. The bottom length 205L1 and the top length 205L2 of the cavity can be 1.3 mm and 2.3 mm respectively. The flat side wall height 205H1 and the inclined side wall height 205H2 can be 0.1 mm and 0.5 mm respectively.

[0110] Figure 3 illustrates the emitter position 300 within the cavity of the housing 304 of an in - ear receiver assembly according to an embodiment of the present disclosure. The cavity is shown to have straight side walls 316. Inside the cavity is an emitter having a radiation element 314 on a ceramic base 318. The radiation element 314 is connected to the circuit board layer 308 by a wire 312. A protective cover 310 is provided according to an embodiment of the present disclosure. Figure 3The configured positioned radiation element 314 is shown to have a field of view (FoV) controlled by an angle α. The angle α can be designed based on the thickness of the housing 304, the position of the radiation element 314 relative to the housing 304, and the shape formed by the protective element 310. The higher the position of the radiation element 314 relative to the housing 304, the larger the angle α, indicating a larger FoV.

[0111] Figure 4 The emitter position 400 within the cavity of the housing 404 of the in-ear receiver assembly according to an embodiment of the present disclosure is illustrated. The cavity is shown to have an inclined sidewall 416 with a step 402. Although one step is shown in Figure 4 , one or more steps as shown above with respect to Figure 2A may be present. Inside the cavity is an emitter having a radiation element 414 on a ceramic base 418. The radiation element 414 is connected to the circuit board layer 408 by wires 412. A protective cover 410 is provided according to an embodiment of the present disclosure. The radiation element 414 positioned in Figure 4 's configuration is shown to have a field of view (FoV) controlled by an angle β. The angle β can be designed based on the thickness of the housing 404, the position of the radiation element 414 relative to the housing 404, the shape formed by the protective element 410, the inclination angle of the inclined sidewall 416, and the size of the step 402.

[0112] Compare Figure 4 with Figure 3 . The addition of the inclined sidewall 416 and the step 402 indicates that the angle β can be designed to be greater than the angle α. Thus, the radiation element 414 will have a larger FoV compared to the radiation element 314. Additionally, compared to the angle α, the larger angle β ensures that the design in Figure 4 has a larger radius of the protective substance compared to Figure 3 . A larger radius indicates a smaller curvature of the protective substance surface. The advantage is that less light is reflected from the radiation element 414 at the boundary of the protective substance 410 compared to the light reflected from the radiation element 314 at the boundary of the protective substance 310.

[0113] The angles α and β can be further adjusted based on the relative positions of the radiation elements 314 and 414 respectively with respect to the Figure 3 and Figure 4 respective outer edges of the cavities. For example, in Figure 3 , the radiation element 314 is located below the outer surface of the housing 304 such that the sidewall 316 limits the FoV to the angle α. On the other hand, in Figure 4Among them, the radiation element 414, which is also located below the surface of the housing 404, has an inclined side wall 416 and a step 402, such that the angle β is greater than α. If the radiation elements 314 and 414 are respectively positioned relatively high with respect to the housings 304 and 404, the angles α and β will increase. The positioning of the radiation elements 314 and 414 is limited by the maximum size of their respective in-ear receiver assemblies. That is, the in-ear receiver assembly should fit the smallest ear canal, so the in-ear receiver assembly has a maximum width and a maximum height. In some embodiments, the transmitter is designed to sink into the cavity as shown in Figure 3 and Figure 4 so as not to violate the maximum size of the in-ear receiver assembly.

[0114] Having a wider FoV may have some disadvantages. For example, Figure 5A FIG. shows a cross-sectional view of an in-ear receiver assembly having a transmitter unit 530a and detector units 530b and 530c within its housing 504. Figure 5A Also shown are the optical paths from the transmitter unit 530a to the detector units 530b and 530c. Examples of the transmitter unit 530a include those components that have been described for any one of Figure 2A - 2D shown in FIGS. 3 and 4. The detector units 530b and 530c may take a form and shape similar to that of the transmitter unit 530a, except that an absorption element (DET) replaces the radiation element (EMT) as the active element. The absorption element may be a photodetector, an electromagnetic receiver, etc. The detector units 530b and 530c may also look different from the transmitter unit 530a. For example, the detector units 530b and 530c may have a flat window, may or may not include glue, may or may not include a reflector, etc.

[0115] The desired operation of the transmitter-detector system includes causing the transmitter to emit a signal that interacts with the test object, and then causing the detector to detect the signal after it has interacted with the test object. Signals that do not interact with the test object will distort the accuracy and introduce errors into the results obtained from the transmitter-detector system. In Figure 5AIn [description], the transmitter unit 530a radiates signals according to the FoV. The desired signals that should reach the detector units 530b and 530c should interact with the tissue in the ear (such as the ear canal wall 532). That is, the optical signal 544 from the transmitter unit 530a that reaches the ear canal wall 532 and then interacts with the ear canal wall 532 before reaching the detector 530c is the desired signal. The signals generated by the transmitter unit 530a can distort the measurement results in various ways. For example, the optical signal 540 can pass through the housing 504 to reach the detector unit 530b. Similarly, the optical signal 546 can be guided through the housing 504 to reach the detector unit 530c. In another example, the optical signal 542 can propagate directly from the transmitter unit 530a to the detector unit 530b.

[0116] There are various ways to mitigate the issues regarding Figure 5A discussed. A reflective layer can be built into the flexible PCB. In another example, the housing 504 can be made of an opaque material to prevent the optical signals 540 and 546 from reaching the detector units 530b and 530c respectively. The FoV of the transmitter unit 530a and / or the detector units 530b and 530c can be redesigned. Figure 5B and Figure 5C illustrate the concept of narrowing the FoV according to an embodiment of the present disclosure. The overlapping FoV between the transmitter unit and the detector unit introduces measurement errors. In Figure 5B the in-ear receiver block diagram 564 includes a transmitter unit 562 that generates a wide beam 560a. The transmitter unit 562 can be designed to narrow the wide beam 560a into a narrow beam 560b that does not overlap with the FoV of another transmitter unit or detector unit. In Figure 5C the in-ear receiver block diagram 566 includes a transmitter unit and a detector unit on the same side. The transmitter unit and the detector unit have wide FoVs indicated by the wide beams 568a and 570a. Using some embodiments of the present disclosure, the FoVs of the transmitter unit and the detector unit can be adjusted to 568b and 570b respectively.

[0117] Figure 6 and Figure 7 illustrate the design of a cavity for reducing the FoV according to some embodiments of the present disclosure. In Figure 6 the cavity in the housing 604 includes an inclined sidewall 616. The sidewall can be inclined at an angle 630 with respect to the circuit board layer 608. The angle 630 can be at least 90 degrees such that the signal reflected from the inclined sidewall 616 points towards the central axis of the cavity. In an embodiment where the radiation element 614 is the active region of an LED, having the inclined sidewall 616 increases the luminous intensity around the central axis of the cavity. The inclined sidewall 616 can include a deposit of a reflective material to increase the amount of reflected light.

[0118] Figure 6 In comparison with Figure 2C it also incorporates a new design for the emitter. The emitter 201 in FIG. 2 includes a ceramic base 218 and a transparent LED coating 202. In Figure 6 it, the emitter can be made smaller by not including a ceramic base, and the active substance (radiating element 614) can be directly bonded to the circuit board layer 608. An example size of the radiating element 614 is 0.22 mm in length by 0.22 mm in width by 0.15 mm in height. By filling the cavity with a protective substance instead of having a transparent LED coating under the protective substance, manufacturing can be simplified. The advantage of removing the ceramic substrate from the emitter is that since the height of the radiating element 614 is lower than the combined height of the radiating element and the ceramic substrate, the housing 604 can be made thinner.

[0119] Referring to Figure 7 a cavity with a parabolic wall 716 is provided in the housing 704. Figure 7 It includes an emitter 701 for emitting a signal propagating within the FoV indicated by reference numeral 730. Similar to Figure 2C the emitter 701 can be located on the circuit board layer 708. Due to the parabolic wall 716, the signal beam from the emitter 701 is narrower.

[0120] A narrower beam can also be obtained by shaping the top boundary of the protective substance (e.g., the protective substance 210). For example, the top boundary can be shaped by adding a layer of glue of the protective substance on the top (or inside), or by pressing a lens shape into the glue when the glue solidifies. The protective substance 210 is in a dome shape. For example, the glue can be deposited as the protective substance 210 and it retains the dome shape once it solidifies. In some embodiments, a Fresnel lens according to Figure 8 can be used for a flat surface instead of the dome-shaped top boundary. Figure 8 A dome-shaped lens 802 with a top surface 806 is illustrated according to an embodiment of the present disclosure. The dome-shaped lens 802 can be used to replace or in addition to the protective substance 210. Alternatively, a transparent window (e.g., in the form of a plano lens or a Fresnel lens 804) can be used to cover the cavity in the housing of an in-ear receiver assembly containing an emitter or a detector. The outer surface 808 of the Fresnel lens can be shaped to be parallel to the plane of the emitter (e.g., the emitter 201). The inner surface 810 in contact with the protective substance can be patterned to encourage a narrower signal beam.

[0121] In some embodiments, a lens covers or obscures a cavity in a housing of an in-ear receiver assembly that includes an optical transducer. The obscured cavity can be filled with a sealant to environmentally protect the interior of the cavity. Preferably, the obscured cavity is filled with a transparent glue, epoxy resin, or adhesive to optically couple the lens to the optical transducer optimally. Also preferably, the space between the side surface of the optical transducer (e.g., the transparent LED coating 220) and the housing is filled with a transparent glue, epoxy resin, or adhesive that contacts the side surface of the optical transducer without air bubbles to achieve optimal optical coupling of the lens to the side surface of the optical transducer. In the case where there is a lens not only on the top but also the coupling of the transducer to the outside of the device is optimized, filling the volume of the side of the transducer may be a preferred design.

[0122] To further prevent the emitted signal from penetrating the housing, one or more reflective surfaces or reflectors can be provided as Figure 9A and 9B such. A reflective surface is a surface that reflects incident light reaching the surface. For example, if it reflects more than 50% of the incident light, more than 75% of the incident light, more than 90% of the incident light, or more than 99% of the incident light, the surface can be classified as a reflective surface. Figure 9A Illustrated is the position of a transmitter within a cavity of a housing 904 of an in-ear receiver assembly according to an embodiment of the present disclosure. The cavity is shown as having inclined sidewalls 916. Within the cavity is a transmitter 901 that has a radiation element 914 on a ceramic base 918. The radiation element 914 is connected to a circuit board layer 908 via a wire 912. According to an embodiment of the present invention, a protective cover 910 is provided.

[0123] A reflective surface 952 can be provided in the cavity. The reflective surface 952 may not extend below the housing 904. In some embodiments, a reflective surface 953 that extends below the housing 904 can be provided (as Figure 9B shown). The inclined sidewalls 916 can have a reflective surface 950. The area of the housing 904 covered by the protective substance 910 can have a reflective substance 954 between the housing 904 and the protective substance 910. The area of the housing not covered by the protective substance 910 can have a reflective substance 956 that covers the housing 904.

[0124] In some embodiments, a small amount of the reflective substance 956 is used, whereby the reflective substance 956 is positioned in areas of the housing near the transmitter 901 and / or areas of the housing near the detector. In some embodiments, the reflective substance 956 can be used anywhere on the housing and is not limited to areas near the transmitter or detector.

[0125] Using a reflective substance according to an embodiment of the present disclosure allows Figure 9A and9B The housing 904 therein is at least partially made of a transparent material. The remaining part of the housing 904 that is not made of a transparent material may be made of an opaque material to obtain a relatively high bifurcation between the emitter and the detector, so as to reduce the light (e.g., see Figure 5A the optical signals 540 and 546) that passes through the housing from the emitter and reaches the detector without disturbing the user's ear canal tissue, and / or to obtain shielding of the detector from ambient light or other interfering light sources. In some embodiments, the reflective substance is a metal deposit, such as a copper deposit. By using a conductive material as the reflective surface and connecting the conductive material to a circuit or electrical ground, the conductive material can be used as an electromagnetic interference (EMI) shield or a capacitive sensing element. In some embodiments, the metal layer of the circuit board layer 908 serves both as the reflective surface and as the EMI shield.

[0126] A reflective surface according to some embodiments can be formed by coating the surface with a reflective coating. The reflective surface can be plastic having a reflective color for each light wavelength, plastic having reflective particles, metal, etc. Using the reflective surface and substance according to the embodiments of the present disclosure provides multiple advantages. The reflective surface can prevent light from entering the housing of the in-ear receiver hearing aid. Therefore, there is no loss associated with the absorption of light inside the housing or no loss that causes measurement errors as described for Figure 5A the optical signal 546 in. When added to the sidewall, the reflective surface can increase the light intensity by 10% to 20%. Therefore, the reflective surface can be used to facilitate a focused beam and / or converging light. The converged light may be beneficial for obtaining biometric data from a specific location in the patient's ear. The converged light improves the bifurcation by ensuring that the light does not directly propagate from the emitter to the detector without interacting with the tissue in the ear.

[0127] In an emitter that supports multiple wavelengths, a reflective surface can be used to direct light of different wavelengths in different directions. This is beneficial because different wavelengths can be aligned to different regions within the ear canal to simultaneously measure signals at specific locations. In some embodiments, the reflective surface used inside the housing of the in-ear receiver assembly can achieve a higher measurement efficiency compared to the case without a reflective surface. The LED with a reflector is too large to fit in a small in-ear receiver assembly. Thus, the embodiments of the present disclosure provide a design that can be adapted to be placed on a small in-ear receiver assembly. Embedded and used in transparent and / or translucent materials such as, for example, transparent housings, adhesives, sealants, lenses, windows, etc., may have other optical properties. For example, these materials can form a filter to filter out certain wavelengths. In an example, the transparent and / or translucent material can filter out ambient light so that the ambient light does not reach the detector.

[0128] Because detectors cannot be provided on every square millimeter of the in-ear receiver component, a reflective surface of the housing covering the in-ear receiver component can direct an optical signal from the ear canal to a detector provided on the housing of the in-ear receiver component. The optical signal can bounce back and forth between the reflective surface and the ear canal until it reaches the detector.

[0129] Figure 9C An example of adding a reflective surface 951 to a stepped sidewall 915 is illustrated. The stepped sidewall 915 is shown as including only one step, but in other embodiments, the sidewall can include more than one step, and the present disclosure does not limit the number of sidewall steps. Although the reflective surface 951 is added to the stepped sidewall 915, other embodiments that do not include the reflective surface 951 can be shown.

[0130] Figure 9D An example of adding a reflective surface 972 to a cavity 970 including a detector 971 according to an embodiment of the present disclosure is illustrated. The cavity 970 is formed in a housing 974 of the in-ear receiver component. The detector 971 can be covered by a window 980 and can be coupled to a circuit board layer 978. The detector can include an active sensing element 984. The window 980 can be a daylight filtering window that filters ambient light. The window 980 can have rounded corners 976 for improving the FoV of the detector 971. The void in the cavity 970 can be filled with glue 982 to hold the window 980 and the detector 971 in place. In some embodiments, a reflective surface 972 can be added to improve the efficiency of the light sensed by the detector 971.

[0131] Figure 10 An example of a reflective surface 1053 installed in a transparent housing 1004 of an in-ear receiver component according to an embodiment of the present disclosure is illustrated. The reflective surface 1053 can be obtained by folding or wrapping a reflective foil or reflective layer inside the transparent housing 1004. The reflective layer can be omitted at locations where other reflective components are present (e.g., the receiver housing).

[0132] Figures 11A, 11B, and 11C illustrate examples of using a reflector to reduce the separation between a transmitter and a detector according to some embodiments of the present disclosure. Referring to Figure 11A, a transmitter unit 1130a is separated from a detector unit 1130b by a thin wall 1104, with reflectors 1134a and 1134b on each side of the thin wall 1104.

[0133] Referring to FIG. 11B, the emitter unit 1130c is separated from the detector unit 1130d by the reflector 1136. Since the reflector 1136 is only a reflector, the emitter unit 1130c can be placed closer to the detector unit 1130d compared to the emitter and detector units of FIG. 11A. The gap between the emitter unit 1130c and the detector unit 1130d can be filled with the transparent adhesive 1137. Referring to FIG. 11C, the emitter unit 1130f and the detector unit 1130e can be placed very close to each other and are separated only by the reflector 1138. The emitter units and detector units of FIGS. 11A - 11C can be built on the edge of the in-ear receiver assembly. Compared with Figure 5A In comparison, the use of reflectors in FIGS. 11A and 11B eliminates the noise effect on the optical signal 546, thus allowing the emitter and detector units to be arranged more compactly. Compared with Figure 5A In comparison, the reflector 1138 eliminates the noise effect on the optical signal 540, thus allowing the emitter and detector units to be arranged more compactly.

[0134] It should be noted that the transducer in FIG. 11A can be covered only by the transparent adhesive as a protective layer, while the transducer in FIG. 11B can be covered at least by the molded window and preferably by the adhesive between the window and the emitter.

[0135] Figure 12A Illustrated is a cavity 1200 shielding an emitter including a preformed window 1210 according to an embodiment of the present disclosure. The preformed window 1210 can be a lens as described above. The emitter is mounted on a circuit board layer 1208 within the cavity 1200 formed in the housing 1204 of the in-ear receiver assembly. The preformed window 1210 can include one or more pieces of adhesive 1203a, 1203b,.... The adhesive 1203b can be an environmental sealant, and the adhesive 1203a can provide the optical properties for guiding the light from the emitter through the preformed window 1210. The gap within the cavity can be filled with the transparent adhesive 1207 so that no air flows from the cavity to the external environment, and / or so that there is an optimal optical coupling between the transducer and the outside.

[0136] Figure 12B and 12C Illustrated are the light traces of different emitter units according to some embodiments of the present disclosure. Referring to Figure 12B , the emitter emits light propagating in the directions indicated by rays 1217 and 1211. The light can be reflected when it reaches the boundary or flows from one medium to another. Thus, some of the light from ray 1211 can be reflected at reference numeral 1213, while some can pass through at reference numeral 1215. The light intensity lost due to reflection can be approximately two percent to six percent. In contrast, Figure 12CNo reflection is shown because rays 1219 and 1221 follow the same trajectory as the emission trajectory from the emitter. As Figure 12A Arranging the glue 1207 as in

[0137] Figure 12D will minimize the reflection 1213. The dimensions of two cavities including two different emitters according to some embodiments of the present disclosure are compared. The first emitter has a ceramic base 1218 and a transparent LED coating 1220 and is located between the housings 1204a. A protective substance 1210 covers the first emitter. The second emitter does not have a ceramic base or a transparent LED coating (similar to the emitter in Figure 6 ), and is located between the housings 1204b. As a result, the housing 1204b can be made thinner than the housing 1204a, and less material can be used as the protective substance for the second emitter compared to the protective substance 1210. In Figure 12D , the length 1205L2a is greater than the length 1205L2b, and the height 1205H2a is greater than the height 1205H2b.

[0138] Figure 12E Two types of emitters according to embodiments of the present disclosure are illustrated. The first type of emitter may only have an active element 1214 and a wire 1212. The second type of emitter may also have a transparent coating 1209 in addition to the active element 1214 and the wire 1212. When the second type of emitter is installed in the housing of an in-ear receiver assembly, the second type of emitter pre-covered with the transparent coating 1209 is more resilient to damage to the wire 1212.

[0139] Figure 13A The concept of the critical angle according to an embodiment of the present disclosure is illustrated. When light travels from a first medium to a second medium and the angle of incidence at the boundary between the two media is greater than the critical angle θ, the refracted ray will not emerge in the second medium. For example, the ray 1350 has an angle of incidence less than the critical angle θ, so the refracted ray 1352 emerges. The angle of incidence of the ray 1351 is greater than the critical angle θ, so it is reflected as a reflected ray 1353 at the boundary.

[0140] Figure 13B and Figure 13C illustrate the ray traces according to some embodiments of the present disclosure. Referring to Figure 13B , the curvature of the protective layer affects the light escaping from the emitter. In Figure 13B , the emitter on the left is under a protective layer with a greater curvature compared to the protective layer covering the emitter on the right. Thus, more light rays 1315 escape from the protective layer of the emitter on the right compared to the emitter on the left. Therefore, more light rays 1313 are reflected at the protective layer of the emitter on the left compared to the emitter on the right.

[0141] Reference Figure 13B One way to change the radius of curvature can be to select the appropriate material.

[0142] Reference Figure 13C The light efficiency of the light escaping from the emitter can be improved by using a reflector. Three designs are provided. The first design has no protective layer, the second design has a protective layer 1310, and the third design has a protective layer 1310 and a reflector 1340. In the first design, the light ray 1313a is reflected and will ultimately be absorbed by the housing, while the light ray 1315a escapes. In the second design, the light ray 1313b is reflected and will ultimately be absorbed by the housing, while the light ray 1315b escapes. In the third design, the light ray 1317c is reflected by the protective layer and then captured and reflected as the light ray 1319c by the reflector 1340. In this way, the light rays 1315c and 1319c escape while the light ray 1313c is captured. Comparing the brightness of the three designs, the brightness of the second design is 5% higher than that of the first design, and the brightness of the third design is 23% higher than that of the first design.

[0143] Figure 13D Illustrated is a light ray trace for a housing 1304 according to some embodiments of the present disclosure. Light from an emitter in a cavity of the housing 1304 impinges on the ear canal wall 1370 and can bounce in the ear canal wall 1370, thereby picking up a biometric signal. The light ray can then leave the ear canal wall 1370 as light rays 1375 and 1377. The light ray 1375 misses the detector and is absorbed by the housing 1304, while the detector detects the light ray 1377.

[0144] Figure 13E Illustrated is a light ray trajectory for a housing 1304 having a reflective surface 1342 according to some embodiments of the present disclosure. Figure 13E In addition to the reflective surface 1342 preventing the light beam 1373 from being absorbed by the housing 1304, similar to the above Figure 13D case, instead of reflecting the light ray 1373 as the light ray 1371, a biometric signal is further picked up in the ear canal wall 1370 as part of the light ray 1377 before returning to the detector.

[0145] In some embodiments, the goal is to reflect light at the wavelengths used by the PPG sensor (e.g., wavelengths at near-infrared 850 nm, green, or red). The minimum reflectivity is about 30% to 40%, an acceptable reflectivity is about 75%, a good reflectivity can be about 90%, and an excellent reflectivity can be higher than 97%. The thickness of any layer or housing material can be determined by the amount of light reflected from that layer, so the minimum thickness of any layer can be set based on the light reflected from that material. For example, a reflectivity of 50% can be set as the minimum value, and a reflectivity of 90% can be set as the desired value. Then the material thickness of the housing can be designed to obtain the desired reflectivity. The maximum thickness of the material can be determined according to design, production limitations, and cost limitations. Examples of these limitations may include the fitting rate of the hearing aid in the ear canal, the ability to bend the metal part, the cost of evaporating gold, etc.

[0146] For example, the layer thickness can be:

[0147] Metal (e.g., gold): approximately 50 nm;

[0148] Paint / ink: approximately 10 - 50 μm;

[0149] For plastics, the thickness may depend on the material and fillers. Generally, the plastic thickness depends on the largest structural dimension, and for our common wall thicknesses of 0.2 mm or 0.35 mm (for small and large sizes respectively), the plastic is usually partially transparent.

[0150] Embodiments of the present disclosure can be used not only in hearing aid devices but also incorporated in earbuds. Figure 14A A perspective view of an earbud 1400 with an optical sensor according to some embodiments of the present disclosure is illustrated. The earbud 1400 may include a transparent dome 1408, a housing 1406, and one or more emitters positioned along the mouth of the earbud 1400. Reference numerals 1402a, 1402b, 1402c denote transparent windows through which the emitters emit light, and reference numeral 1404 denotes a transparent window for the detector to collect light. Figure 14B Illustrated is Figure 14A a cross-sectional view of the earbud 1400 in

[0151] Figure 15A A perspective view of the mouth of an earbud with an optical sensor according to some embodiments of the present disclosure is illustrated. The mouth of this earbud can replace Figure 14A the mouth of Figure 15B Illustrated is Figure 15A a cross-sectional view of the mouth of the earbud in Figure 15AThe earplug tip has a thick housing, which includes a transparent window 1502, a transmitter 1504, a detector 1508, and a window 1510 for the detector 1508. A speaker 1506 may be disposed in the earplug tip for providing sound that propagates through the sound channel 1512.

[0152] Figure 16A FIG. illustrates a cross-sectional view of an earplug 1600 with an optical sensor according to some embodiments of the present disclosure. The earplug 1600 includes a tip 1614 that holds a flexible circuit board 1620 and a speaker / receiver 1606. Figure 16B illustrates Figure 16A a cross-sectional view of the electronic components of the earplug 1600 of. A transmitter 1604 is disposed on the flexible circuit board 1620. A detector 1608 is disposed on the flexible circuit board 1620. There may be a gap between the transmitter 1604 and the housing of the tip 1614. Figure 16C illustrates Figure 16B an embodiment of the separation between the transmitter 1604 and the window 1602 of. The gap may be filled with an optical waveguide 1605. The optical waveguide 1605 may be, for example, glue, plastic, air, etc. Figure 16D illustrates Figure 16A - 16B the tip 1614 and the electronic components of the tip 1614 of. The tip 1614 may have guides that allow the flexible circuit board 1620 to slide into the tip 1614.

[0153] Figure 17A FIG. illustrates a perspective view of an earplug 1700 with an optical sensor according to some embodiments of the present disclosure. Figure 17B illustrates Figure 17A a cross-sectional view of the earplug 1700 of. The earplug 1700 includes a single dome, and the transmitter may be placed at position 1701.

[0154] Figure 18A FIG. illustrates a perspective view of an earplug 1800 with an optical sensor according to some embodiments of the present disclosure. Figure 18B illustrates Figure 18A a cross-sectional view of the earplug 1800 of. The earplug 1800 includes two domes with dome flanges 1816. The transmitter may be placed at position 1801 below the dome flanges 1816. One or both of the dome flanges 1816 may be transparent to the wavelengths used by the sensor.

[0155] Embodiments of the present disclosure have been described with respect to positioning a transmitter within an in-ear receiver assembly. There are similar issues with positioning a detector within an in-ear receiver assembly as there are with positioning a transmitter within an in-ear receiver assembly. Thus, the various techniques and embodiments described may be combined to design or implement a desired field of view for the transmitter and / or detector.

[0156] All embodiments described in this patent application can also operate where there is direct (physical) contact between the optical transducer and human tissue.

Claims

1. A hearing device, comprising: a housing including one or more wall portions defining an internal space and including a cavity extending through the wall portions of the housing; a loudspeaker disposed in the internal space; a circuit board layer; an optical transducer mounted in the cavity, the optical transducer being mounted on the circuit board layer such that there is a gap between a side surface of the optical transducer and a side wall of the cavity; the circuit board layer extends under the wall portion and contacts the wall portion such that the optical transducer is held within the cavity; and a protective substance forming a shielding cover over the optical transducer and the cavity, the protective substance being configured to affect a field of view of the optical transducer, characterized in that the protective substance includes one or more sealants, the one or more sealants filling the cavity and forming the shielding cover into an outwardly curved shielding cover.

2. The hearing device according to claim 1, wherein the side wall of the cavity includes one or more stepped portions, one or more straight portions, one or more inclined portions, or any combination thereof.

3. The hearing device according to claim 1 or 2, wherein the side wall is curved.

4. The hearing device according to claim 1 or 2, further comprising one or more reflective surfaces configured to reflect at least 30% of red, green, and / or near-infrared wavelengths.

5. The hearing device according to claim 4, wherein the one or more reflective surfaces extend on an inner surface of the wall portion.

6. The hearing device according to claim 4, wherein the one or more reflective surfaces extend along a surface of the optical transducer opposite to a surface of the optical transducer configured to transmit light.

7. The hearing device according to claim 4, wherein the one or more reflective surfaces are located on an outer surface of the wall portion or on the side wall.

8. The hearing device according to claim 4, wherein the one or more reflective surfaces include a material reflecting a color, a plastic having reflective particles, a metal, or any combination thereof.

9. The hearing device according to claim 1 or 2, wherein the protective substance fills the cavity and contacts all sides of an optical transducer coating included in the optical transducer.

10. The hearing device according to claim 1 or 2, wherein the protective substance includes a lens or a transparent material.

11. The hearing device according to claim 1 or 2, wherein the protective substance includes a Fresnel lens, the Fresnel lens forming the shielding cover into a flat surface.

12. The hearing device according to claim 1 or 2, wherein the optical transducer includes a radiation element spaced a predetermined distance from the circuit board layer.

13. The hearing device according to claim 1 or 2, wherein the optical transducer comprises: a radiation element, a ceramic base, and glue.

14. The hearing device according to claim 1 or 2, wherein the field of view of the optical transducer is further affected by a shape of the side wall, a thickness of the housing, a curvature of the protective substance, a reflective layer, or any combination thereof.

15. The hearing device according to claim 1 or 2 further comprises one or more reflective surfaces configured to reflect at least 30% of the wavelength of 850 nm.

16. The hearing device according to claim 1 or 2, wherein the sidewall is parabolic.

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