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Title:
IN-EAR MICROPHONES FOR AR/VR APPLICATIONS AND DEVICES
Document Type and Number:
WIPO Patent Application WO/2023/150213
Kind Code:
A1
Abstract:
A device for in-ear use is provided. The device includes an in-ear fixture configured to seal an ear canal of a user, an internal microphone coupled to receive an internal acoustic signal, propagating through the ear canal of the user, an external microphone coupled to receive an external acoustic signal, propagating through an environment of the user, and a processor that is coupled to an augmented reality headset, the processor configured to identify a vital sign of the user based on at least one of the internal acoustic signal and the external acoustic signal. A memory storing instructions which, when executed by a processor, cause a method for use of the above device to identify a vital sign of a user, the memory, the processor, and the method are also provided.

Inventors:
LUNNER NILS THOMAS FRITIOF (US)
WEINER JOSHUA (US)
KHALEGHIMEYBODI MORTEZA (US)
OUDERKIRK ANDREW JOHN (US)
SILVERSTEIN BARRY DAVID (US)
RUMSFELD JOHN (US)
Application Number:
PCT/US2023/012198
Publication Date:
August 10, 2023
Filing Date:
February 02, 2023
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
META PLATFORMS TECH LLC (US)
International Classes:
A61B5/01; A61B5/0205; H04R1/10; A61B5/00
Foreign References:
US20170112671A12017-04-27
US20200261027A12020-08-20
US20140094663A12014-04-03
US20180235540A12018-08-23
Attorney, Agent or Firm:
COLBY, Steven et al. (US)
Download PDF:
Claims:
CLAIMS

WHAT IS CLAIMED IS:

1. A device, comprising: an in-ear fixture configured to seal an ear canal of a user; an internal microphone coupled to receive an internal acoustic signal, propagating through the ear canal of the user; and a processor that is coupled to an augmented reality headset, the processor configured to identify a vital sign of the user based on the internal acoustic signal.

2. The device of claim 1, further comprising a first electrode mounted on the in- ear fixture and configured to receive an electronic signal from a skin in the ear canal of the user, and the processor is configured to: identify the vital sign of the user based on at least one of the internal acoustic signal and the electronic signal; and/or to determine a blood pressure value based on a time delay between the electronic signal and the internal acoustic signal.

3. The device of claim 1 or 2, wherein the internal microphone is a contact microphone and the internal acoustic signal is indicative of a movement of an internal organ of the user.

4. The device of any one of the preceding claims, further comprising: an external microphone coupled to receive an external acoustic signal, propagating trough an environment of the user; and a speaker on the in-ear fixture and facing the ear canal of the user, wherein the processor is configured to filter the external acoustic signal with the internal acoustic signal to form an acoustic waveform, and to provide the acoustic waveform to the speaker.

5. The device of any one of the preceding claims, wherein the processor is configured to form a waveform with the internal acoustic signal and generate a spectrogram of the waveform, and wherein to identify the vital sign of the user, the processor is configured to: extract a heart rate from the spectrogram; and/or extract a blood pressure value from the spectrogram.

6. The device of any one of the preceding claims, wherein the processor is configured to form a waveform with the internal acoustic signal, to identify a systolic portion and a diastolic portion of the waveform, and wherein the vital sign of the user is a blood pressure derived from the systolic portion and the diastolic portion of the waveform.

7. The device of any one of the preceding claims, wherein to identify a vital sign for the user, the processor is configured to form a waveform with the internal acoustic signal and to: determine a blood pressure for the user based on a ratio of a systolic portion and a diastolic portion of the waveform; and/or select a spectral component from the waveform in a sub-Hertz acoustic range.

8. A computer-implemented method, comprising: receiving, from a first microphone, a first acoustic signal from a first ear canal of a user of an in-ear monitor; forming a first waveform with the first acoustic signal; and identifying a vital sign of the user based on the first waveform.

9. The computer-implemented method of claim 8, wherein the first acoustic signal is an internal signal from a body of the user and identifying a vital sign of the user comprises determining a heart rate of the user based on the first waveform.

10. The computer-implemented method of claim 8 or 9, further comprising receiving, from a second microphone, a second acoustic signal from the first ear canal of the user of the in-ear monitor; forming a second waveform with the first acoustic signal filtered from the second acoustic signal; and providing the second waveform to the user via a speaker, wherein the second acoustic signal is an audio signal from an external environment of the user.

11. The computer-implemented method of any one of claims 8 to 10, further comprising receiving an electronic signal from an electrode in the in-ear monitor; and wherein identifying the vital sign of the user comprises: determining a heart rate of the user based on a correlation of the electronic signal with the first waveform; and/or identifying a systolic portion and a diastolic portion of the first waveform based on a correlation of the electronic signal with the first acoustic signal; and determining a blood pressure value with the systolic portion and the diastolic portion of the first waveform.

12. The computer-implemented method of any one of claims 8 to 11, further comprising identifying a systolic portion and a diastolic portion of the first waveform, wherein identifying a vital sign of the user comprises: determining a blood pressure value based on the systolic portion and the diastolic portion of the first waveform; and/or determining a blood pressure value based on an amplitude of the diastolic portion compared to an amplitude of the systolic portion of the first waveform.

13. The computer-implemented method of any one of claims 8 to 12, wherein identifying a vital sign for the user comprises generating a spectrogram of the first waveform; and identifying at least one of a heart rate value or a blood pressure value from the spectrogram of the first waveform.

14. The computer-implemented method of any one of claims 8 to 13, further comprising providing, with a speaker, a sound signal into the first ear canal, for the user, wherein the first acoustic signal comprises a back reflection of the sound signal, from an inner ear, and wherein identifying a vital sign of the user comprises determining a hearing condition of the user based on a delay and amplitude of the back reflection of the sound signal.

15. The computer-implemented method of any one of claims 8 to 14, wherein the first acoustic signal includes a sound gesture generated by the user as an input command, further comprising identifying the input command from the first waveform, and having a processor in a smart glass to execute the input command.

Description:
IN-EAR MICROPHONES FOR AR/VR APPLICATIONS AND DEVICES

Field

[0001] The present disclosure is related to in-ear microphones for use in virtual reality and augmented reality environments and devices. More specifically, the present disclosure is related to microphones configured to receive acoustic input inside and outside the ear for health monitoring with in-ear devices for immersive reality applications.

Background

[0002] Current in-ear devices (e.g., hearing aids, hearables, headphones, earbuds, and the like) for mobile and immersive applications are typically bulky and uncomfortable for the user. Adding health sensing capabilities to in-ear devices is hindered by the small form factors desirable in such devices and the complex data processing and analysis involved.

[0003] The present disclosure seeks to address, at least in part, any or all of the drawbacks and disadvantages described above.

SUMMARY

[0004] According to a first aspect of the present disclosure there is provided a device includes an in-ear fixture configured to seal an ear canal of a user, an internal microphone coupled to receive an internal acoustic signal, propagating through the ear canal of the user, and a processor that is coupled to an augmented reality headset, the processor configured to identify a vital sign of the user based on at least one of the internal acoustic signal.

[0005] In some embodiments, the device may further comprise an external microphone coupled to receive an external acoustic signal, propagating through an environment of the user, and the processor is further configured to identify a vital sign of the user based on the external acoustic signal.

[0006] In some embodiments, the device may further comprise a first electrode mounted on the in-ear fixture and configured to receive an electronic signal from a skin in the ear canal of the user, and the processor may be configured to identify the vital sign of the user based on at least one of the internal acoustic signal and the electronic signal.

[0007] In some embodiments, the device may further comprise a first electrode mounted on the in-ear fixture and configured to receive an electronic signal from a skin in the ear canal of the user, and to identify the vital sign of the user the processor may be configured to determine a blood pressure value based on a time delay between the electronic signal and the internal acoustic signal.

[0008] In some embodiments, the internal microphone may be a contact microphone and the internal acoustic signal may be indicative of a movement of an internal organ of the user. [0009] In some embodiments, the device may further comprise: an external microphone coupled to receive an external acoustic signal, propagating trough an environment of the user; and a speaker on the in-ear fixture and facing the ear canal of the user, wherein the processor may be configured to filter the external acoustic signal with the internal acoustic signal to form an acoustic waveform, and to provide the acoustic waveform to the speaker.

[0010] In some embodiments, the processor may be configured to form a waveform with the internal acoustic signal and generate a spectrogram of the waveform, and wherein to identify the vital sign of the user, the processor may be configured to extract a heart rate from the spectrogram.

[0011] In some embodiments, the processor may be configured to form a waveform with the internal acoustic signal and generate a spectrogram of the waveform, and wherein to identify the vital sign of the user, the processor may be configured to extract a blood pressure value from the spectrogram.

[0012] In some embodiments, the processor may be configured to form a waveform with the internal acoustic signal, to identify a systolic portion and a diastolic portion of the waveform, and wherein the vital sign of the user may be a blood pressure derived from the systolic portion and the diastolic portion of the waveform.

[0013] In some embodiments, to identify a vital sign for the user, the processor may be configured to form a waveform with the internal acoustic signal and to determine a blood pressure for the user based on a ratio of a systolic portion and a diastolic portion of the waveform.

[0014] In some embodiments, to identify a vital sign for the user the processor may be configured to form a waveform with the internal acoustic signal and to select a spectral component from the waveform in a sub-Hertz acoustic range.

[0015] According to a second aspect of the present disclosure there is provided a computer- implemented method comprising: receiving, from a first microphone, a first acoustic signal from a first ear canal of a user of an in-ear monitor, forming a first waveform with the first acoustic signal, and identifying a vital sign of the user based on the first waveform.

[0016] In some embodiments, the first acoustic signal may be an internal signal from a body of the user and identifying a vital sign of the user may comprise determining a heart rate of the user based on the first waveform.

[0017] In some embodiments, the computer-implemented method may further comprise receiving, from a second microphone, a second acoustic signal from the first ear canal of the user of the in-ear monitor; forming a second waveform with the first acoustic signal filtered from the second acoustic signal; and providing the second waveform to the user via a speaker, wherein the second acoustic signal may be an audio signal from an external environment of the user.

[0018] In some embodiments, the computer-implemented method may further comprise receiving an electronic signal from an electrode in the in-ear monitor; and wherein identifying the vital sign of the user may comprise determining a heart rate of the user based on a correlation of the electronic signal with the first waveform.

[0019] In some embodiments, the computer-implemented method may further comprise receiving an electronic signal from an electrode; and wherein identifying the vital sign of the user may comprise identifying a systolic portion and a diastolic portion of the first waveform based on a correlation of the electronic signal with the first acoustic signal; and determining a blood pressure value with the systolic portion and the diastolic portion of the first waveform.

[0020] In some embodiments, the computer-implemented method may further comprise identifying a systolic portion and a diastolic portion of the first waveform, wherein identifying a vital sign of the user may comprise determining a blood pressure value based on the systolic portion and the diastolic portion of the first waveform.

[0021] In some embodiments, identifying a vital sign for the user may comprise generating a spectrogram of the first waveform; and identifying at least one of a heart rate value or a blood pressure value from the spectrogram of the first waveform.

[0022] In some embodiments, identifying the vital sign of the user may comprise identifying a systolic portion and a diastolic portion of the first waveform, and determining a blood pressure value based on an amplitude of the diastolic portion compared to an amplitude of the systolic portion of the first waveform.

[0023] In some embodiments, the computer-implemented method may further comprise providing, with a speaker, a sound signal into the first ear canal, for the user, wherein the first acoustic signal may comprise a back reflection of the sound signal, from an inner ear, and wherein identifying a vital sign of the user may comprise determining a hearing condition of the user based on a delay and amplitude of the back reflection of the sound signal.

[0024] In some embodiments, the first acoustic signal may include a sound gesture generated by the user as an input command, and may further comprise identifying the input command from the first waveform, and having a processor in a smart glass to execute the input command. [0025] According to a third aspect of the present disclosure there is provided a non-transitory , computer-readable medium stores instructions which, when executed by a processor, cause a computer to perform a method. The method includes receiving, from a first microphone, a first acoustic signal from a first ear canal of a user of an in-ear monitor, forming a first waveform with the first acoustic signal, and identifying a vital sign of the user based on the first waveform. [0026] In yet other embodiments and aspects of the present disclosure, a system includes a first means to store instructions, and a second means to execute the instructions to cause the system to perform a method. The method includes receiving, from a first microphone, a first acoustic signal from a first ear canal of a user of an in-ear monitor, forming a first waveform with the first acoustic signal, and identifying a vital sign of the user based on the first waveform. [0027] These and other embodiments will become apparent to one of ordinary skill, in view of the following.

[0028] It will be appreciated that any features described herein as being suitable for incorporation into one or more aspects or embodiments of the present disclosure are intended to be generalizable across any and all aspects and embodiments of the present disclosure. Other aspects of the present disclosure can be understood by those skilled in the art in light of the description, the claims, and the drawings of the present disclosure. The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the claims.

BRIEF DESCRIPTION OF THE FIGURES

[0029] FIG. 1 illustrates an AR headset and an in-ear monitor (IEM) in an architecture configured to assess a user’s health, according to one or more embodiments of the present disclosure.

[0030] FIG. 2 illustrates an augmented reality ecosystem including wearable devices in the ear and wrist to assess a user’s health, according to one or more embodiments of the present disclosure.

[0031] FIGS. 3A-3D illustrate different embodiments of an in-ear monitor (IEM), according to one or more embodiments of the present disclosure.

[0032] FIG. 4 illustrates a frequency-domain analysis of acoustic signals collected by an internal microphone in an IEM, according to one or more embodiments of the present disclosure.

[0033] FIGS. 5A-5C illustrate a user wearing an in-ear microphone (IEM) and an outer-ear microphone (OEM) as well as a spectrogram of an acoustic waveform from an IEM signal, an IEM signal combined with an ECG signal, and a blood pressure regression chart, according to one or more embodiments of the present disclosure.

[0034] FIG. 6 illustrates a waveform obtained with a contact microphone in an IEM to determine a heart rate of a user, according to one or more embodiments of the present disclosure.

[0035] FIG. 7 is a flow chart illustrating steps in a method 700 for using microphones in an in-ear monitor for assessing the health of a user of a headset or smart glasses, according to one or more embodiments of the present disclosure.

[0036] FIG. 8 is a block diagram illustrating an exemplary computer system with which headsets and other client devices, and the method in FIG. 7 can be implemented, according to one or more embodiments of the present disclosure.

[0037] In the figures, elements having the same or similar reference numeral are associated with the same or similar features and attributes, unless expressly stated otherwise.

DETAILED DESCRIPTION

[0038] In the following detailed description, numerous specific details are set forth to provide a full understanding of the present disclosure. It will be apparent, however, to one ordinarily skilled in the art, that the embodiments of the present disclosure may be practiced without some of these specific details. In other instances, well-known structures and techniques have not been shown in detail so as not to obscure the disclosure.

General Overview

[0039] Head- worn devices (e.g. , devices worn on head including but not limited to hearables, smart glasses, AR/VR headsets and smart glasses, etc.) offer opportunities to access valuable health information.

[0040] The ear (e.g., the ear canal and ear concha) has close proximity to the brain, to body chemistry, and blood vessels indicative of brain activity and cardio-respiratory activity, and inner body temperature. More specifically, sensors including electrodes, inertial motion units (IMUs), accelerometers, and microphones can be placed inside the ear canal or around the ear (in the case of AR/VR headsets or smart glasses) to sense brain, heart, and ocular electrophysiological activities (e.g, electro-encephalography, EEG, electro-cardiography, ECG, electro-oculography, EOG, electrodermal activity, EDA, and the like); or to sense vital signs (heart rate, breathing rates, blood pressure, body temperature, and the like); or to sense the body chemistry (e.g., blood alcohol level, blood glucose estimation, and the like).

[0041] Microphones as disclosed herein may include contact microphones to detect motion, internal microphones and external microphones, acoustic microphones, and the like. In addition to microphones, in-ear devices as disclosed herein may also include speakers to generate and provide sound signals to the user of the in-ear device.

[0042] Electrodes in embodiments as disclosed herein may be used in EOG, ECG, and EEG measurements, e.g., for determining auditory attention; heart rate estimation, breathing rate, and the like, Auditory Steady State Response -ASSR-, auditory brainstem response -ABR-. In some embodiments, in-ear electrodes as disclosed herein may be useful to measure resting state electric oscillations (alpha waves in an EEG) that can track relaxation/activity. With the combination of other measurements (e.g, photoplethysmography, PPG), a new branch of diagnostic possibilities is open. In-ear EEG measurements can be applied to track user attention (e.g, distinguishing between attention focus from eye gaze direction).

[0043] Methods and devices disclosed herein include optical, acoustical, motion sensors, chemical sensors, and temperature sensors, in and around the ears of AR/VR headset users, in combination with software correlation of the signals provided by the above sensors to generate comprehensive diagnostics and health evaluation of the user.

[0044] Some of the features disclosed herein include in-ear or head-wom body temperature sensing using infrared sensing and spectroscopy techniques. In some embodiments, the contact area for sensors as disclosed herein include the in-ear canal (like an in-ear earbud) and within the conchal bowl (in human pinna), areas on top of the human ear (where the glasses sit), and areas in the nose-pad of a headset or smart glasses (where glasses sit on the nose). Some measurements may include in-ear or around the ear sensing of glucose level, alcohol sensing, body temperature, blood pressure, and the like. Some embodiments include pulse transit time (PTT) methodology to estimate blood pressure for a glasses/headset device using a combination of optical and electrical signals (e.g, PPG + ECG sensors respectively) or using a combination of electrical and acoustical or motion-based information (e.g, ECG + acoustic or motion sensors respectively). Some embodiments include optical-based pulse transit time (PTT) methodology to estimate blood pressure for a glasses/headset device using a combination of optical signals collected from multiple different wavelength (e.g., using a PPG sensor with more than one distinct wavelength). Some embodiments obtain user’s blood pressure using an optical sensing technique (PPG) in combination with a deep neural network to train a network based using both PPG information and a corresponding ground-truth blood pressure information. Some embodiments include motion-based pulse transit time (PTT) methodology to estimate blood pressure for a glass/headset device using a combination of motion sensor and electrical signals (e.g, IMU + ECG sensors respectively). Once fully trained, the neural network can then quantify and predict the user’s blood pressure using just the PPG information and leveraging this pre-trained network. To further improve the accuracy, some subjective calibrations may be desirable. In some embodiments, PPG signals collected in IEM devices as disclosed herein may be able to estimate the cognitive load on the user with analysis of oxygenated and deoxygenated blood flow (oxy- and deoxy -hemoglobin) to the brain. Some embodiments include sensing alcohol levels through emissions around the ear. Some embodiments incorporate chemical sensing intake around the contact points of the ear. In some embodiments, IEM devices may perform alcohol monitoring and fat burning during user exercise.

Example System Architecture

[0045] FIG. 1 illustrates an AR headset 110-1 and an in-ear monitor (IEM) 100 in an architecture 10 configured to assess the health of a user 101, according to some embodiments. IEM 100 is inserted in the ear 170 of user 101, reaching the ear canal 161. AR headset 110-1 may include smart glasses having a memory circuit 120 storing instructions and a processor circuit 112 configured to execute the instructions to perform steps as in methods disclosed herein. AR headset 110-1 (or smart glasses) may also include a communications module 118 configured to wirelessly transmit information (e.g., Dataset 103-1) between AR headset 110-1 (and/or in-ear device 100, and/or a smart watch, or combination of the above) and a mobile device 110-2 with the user (AR headset 110-1 and mobile device 110-2 will be collectively referred to, hereinafter, as “client devices 110”). Communications module 118 may be configured to interface with a network 150 to send and receive information, such as dataset 103-1, dataset 103-2, and dataset 103-3, requests, responses, and commands to other devices on network 150. In some embodiments, communications module 118 can include, for example, modems or Ethernet cards. Client devices 110 may in turn be communicatively coupled with a remote server 130 and a database 152, through network 150, and transmi t/share information, files, and the like with one another (e.g., dataset 103-2 and dataset 103-3). Datasets 103-1, 103-2, and 103-3 will be collectively referred to, hereinafter, as “datasets 103.” Network 150 may include, for example, any one or more of a local area network (LAN), a wide area network (WAN), the Internet, and the like. Further, the network can include, but is not limited to, any one or more of the following network topologies, including a bus network, a star network, a ring network, a mesh network, a star-bus network, tree or hierarchical network, and the like.

[0046] In some embodiments, at least one of the steps in methods as disclosed herein are performed by processor 112, providing dataset 103-1 to mobile device 110-2. Mobile device 110-2 may further process the signals and provide dataset 103-2 to database 152 via network 150. Remote server 130 may collect dataset 103-2 from multiple AR headsets 110-1 and mobile devices 110-2 in the form and perform further calculations. In addition, having aggregated data from a population of individuals, the remote server may perform meaningful statistics. This data cycle may be established provided each of the users involved have consented for the use of de-personalized, or anonymized data. In some embodiments, remote server 130 and database 152 may be hosted by a healthcare network, or a healthcare facility or institution (e.g., hospital, university, government institution, clinic, health insurance network, and the like). Mobile device 110-2, AR headset 110-1, in-ear device 100, and applications therein may be hosted by a different service provider (e.g, a network carrier, an application developer, and the like). Moreover, AR headset 110-1 and mobile devices 110-2 may proceed from different manufacturers. User 101 is ultimately the sole owner of dataset 103-1 and all data derived therefrom (e.g., datasets 103), and so all the data flows (e.g, datasets 103), while provided, handled, or regulated by different entities, are authorized by user 101, and protected by network 150, server 130, database 152, and mobile device 110-2 for privacy and security. [0047] FIG. 2 illustrates an augmented reality ecosystem 200 including wearable devices in the ear 205-1 (e.g, an IEM), wrist 205-2, chest 205-3, and smart glass sensors 205-4 to assess the health of user 201, according to some embodiments. In some embodiments, IEM 205-1 further includes an optical sensor configured to provide an optical signal 220-1 to a processor in a computer 240 via a data acquisition module (DAQ) 230. IEM 205-1 may further include one or more contact electrodes configured to provide an electrical signal to a processor in a computer 240 via a data acquisition module (DAQ) 230. Computer 240 is configured to identify a cardiovascular condition of user 201 based on a first electronic signal from IEM 205- 1 and optical signal 220-1. In some embodiments, IEM 205-1 further includes a motion sensor (e.g, an accelerometer, a contact microphone, or an IMU) configured to provide a motionbased signal to computer 240 via DAQ 230. In some embodiments, a pair of IEMS 205 will be placed in both ears and different optical, electrical (electrode), acoustic (microphone), or motion sensors (accelerometer, IMU, contact microphone, etc.) may be placed in either both sides; or in some cases, some sensors may be placed on one side (e.g, the Right side) and some other sensors may be placed on the other side (e.g, Left side). Computer 240 is configured to identify a cardiovascular condition of the user based on a first electronic signal from IEM 205- 1 and the motion signal. The optical sensor may be a photo-plethysmography (PPG) sensor and optical signal 220-1 may include a digital or analog signal indicative of a vascular activity inside the ear of user 201. Chest sensors 205-3 and smart glass sensors 205-4 may include ECG sensors to provide a distributed signals 220-3 and 220-4 from one or more areas around the chest and face (e.g, the outside of the ear, the chin, and the nose) of user 201, respectively (or alternatively an ECG can be collected from some electrodes placed on areas on the head or from electrodes placed in IEM 205-1, or electrodes placed on the wrist device 205-2), and a wrist PPG sensor in device 205-2 may provide a separate signal 220-2 for vascular activity around the wrist of user 201. IEM 205-1, wrist sensor 205-2, chest sensors 205-3, and smart glass sensors 205-4 will be collectively referred to, hereinafter, as “wearable devices (and sensors) 205.” Blood pressure (BP) measurements may be obtained with a cuff or cuff-less BP monitor 210 and may also be determined by comparing PPG signals 220-1 and 220-2. Signals 220-1, 220-2, 220-3 and 220-4 (hereinafter, collectively referred to, hereinafter, as “signals 220”) may be collected and digitized by DAQ 230 in computer 240, for processing. In some embodiments, signals 220 and others may be wired, or wireless. In some embodiments, it may be preferable to have wireless signal communication between the different wearable devices 205 with user 201. In some embodiments, wearable devices and sensors 205 may include one or more motion sensors, and the motion-based information collected from the smart glass, the IEM, chest or wrist can be combined to create a more meaningful information.

[0048] FIGS. 3A-3D illustrate different embodiments of an in-ear monitor (IEM) 300A, 300B, 300C, and 300D (hereinafter, collectively referred to as “IEMS 300”), according to some embodiments. IEMs 300 may include a front end 301-1 including sensors and open to ear canal 361 and ear drum 362, and aback end 301-2 including a processor 312. IEMs 300 may include sensors such as: an electrode 305 to sense electrical signals, acoustic sensors 325-1 and 325-2 (e.g, collectively referred hereinafter, as “microphones 325”), motion sensors 327 (e.g, accelerometers, contact microphones, inertial motion units -IMUs, and the like), temperature sensors 329, and optical sensors including an emitter 321 and a detector 323 (e.g., LEDs and PDs in PPG sensors, functional near-infrared Spectroscopy fNIRS sensors -Fourier transform based, spectroscopic based-). Electrodes 305 may include bio-potential electrodes for applications such as EEG, ECG, EOG, and EDA). In some embodiments, in-ear fixture 340 (also known as eartip) may be entirely made out of soft conductive materials; so, the entire eartip will be conductive and will act as a soft electrode. In addition, processor 312 may handle at least some of the operations for signal acquisition and control of components and sensors 321, 323, 324 (a speaker), 325-1 (internal microphone), 325-2 (external microphone, hereinafter, collectively referred to as “microphones 325”), 327, and 329 via a digital-to-analog and/or analog-to-digital converter (D AC/ ADC) 330. Processor 312 may include a feedforward stage 31 Iff and a feedback stage 31 Ifb that cooperate to process the signal from the sensors: noise reduction, balancing, filtering, and amplification.

[0049] In some embodiments, electrodes 305 include a contact electrode configured to transmit a current from the skin in the ear canal of the user. In some embodiments, an electrode 305 is coated with at least one of a gold layer, a silver layer, a silver chloride layer, or a combination thereof. In some embodiments, electrodes 305 include a capacitive coupling electrode disposed sufficiently close, but not in contact, with the user’s skin. In some embodiments, IEMS 300 further include at least a second electrode 305 mounted on in-ear fixture 340, the second electrode 305 configured to receive a second electronic signal from the skin in ear canal 361. In some embodiments, the in-ear fixture 340 may be entirely made out of soft conductive materials (e.g, conductive polymers, conductive adhesives, conductive paints, etc.); so, the entire eartip will be conductive and will act as a soft electrode to collect electrical signals from the skin of the ear-canal. In some embodiments, processor 312 is configured to select the first electronic signal when a quality of the first electronic signal is higher than a pre-selected threshold. In some embodiments, processor 312 is configured to reduce a noise background from the first electronic signal with the second electronic signal. In some embodiments, processor 312 is configured to determine a heart rate of the user from the first electronic signal. In some embodiments, processor 312 is configured to determine a brain activity from the first electronic signal that corresponds to an acoustic stimulus received in the external microphone.

[0050] IEMs 300 in the AR headset or smart glasses may include an in-ear fixture 340 configured to hermetically seal an ear canal of a user, a first electrode 305 mounted on in-ear fixture 340 and configured to receive a first electronic signal from a skin in ear canal 361, and an internal microphone 325-1 coupled to receive an internal acoustic signal, propagating through ear canal 361. An acoustic front end includes internal microphone 325-1 configured to detect acoustic waves (xBc(t)) propagated through ear canal 361 and generated by the inner body (e.g, heart rate at about <100Hz, breathing rate at about 50-1000Hz, and other sounds in the laryngeal cavity). An external microphone 325-2 is coupled to receive an external acoustic signal x(t), propagating through an environment of the user. In some embodiments, the internal signal XBc(t) in conjunction with the external signal x(t) may be used in acoustic procedures such as audio streaming, hear-through, active noise cancelation (ANC), hearing corrections, virtual presence and spatial audio, call services, and the like. In some embodiments, at least some of the above processes are performed in conjunction between left-ear and right-ear IEM monitors 300.

[0051] In some embodiments, speaker 324 and internal microphone 325-1 may be part of a self-mixing interferometer (SMI). An SMI is a compact, low power, inexpensive and sensitive acoustic interferometry device configured to measure displacement of the skin based on acoustic interference patterns between a portion of an emitted acoustic wave and the acoustic wave reflected from the skin. In some embodiments, a displacement of the skin obtained with an SMI is combined with heart rate measurements (e.g, from PPG sensors, motion sensors or ECG electrodes) to measure blood pressure and heart rate, or even vibration of the eardrum to also act as an internal microphone.

[0052] IEM 300B includes a sealing gasket 341 that separates the inner portion of ear canal 361 from the environment, leaving a back-volume vent including an acoustically resistive mesh 344 for a pressure equalizer (PEQ) tube 342 to vent into resistive mesh 344 (also shown in IEM 300C). The sealed cavity may enable breathing and heart rate monitoring (e.g., isolating the signal from internal acoustic microphone 325-1) at low power usage and with a small form factor.

[0053] IEM 300C illustrates processor circuit 312 to identify a cardiovascular condition or a neurologic condition of the user, based on at least one of a first electronic signal, an internal acoustic signal, and an external acoustic signal (e.g., from microphones 325). Some embodiments may include a down cable 345 to electrically couple the IEM with the VR headset or smart glasses, including a strain relief 343.

[0054] IEM 300D illustrates a flexible, printed circuit board (FPCB) 342 that provides internal electrical connectivity to the different components and sensors 321, 323, 324, 325, 327, and 329.

[0055] FIG. 4 is a chart 400 illustrating a frequency-domain graph 410 of acoustic signals collected by an internal microphone in an IEM, according to some embodiments. The abscissae 401 indicates time (e.g, seconds), and an ordinate 402a indicates frequency (e.g, Hertz). A grayscale 402b indicates a power spectral density (in decibels per Hertz, dB/Hz). The higher power density areas (in bright yellow) indicate spectral contents of the user’s heartbeat 417.

[0056] FIGS. 5A-5C illustrate a user 501 wearing an in-ear microphone (IEM) 500 and an outer-ear microphone (OEM) as well as a spectrogram 530 of an acoustic waveform 510 from a signal collected by IEM 500. Acoustic waveform 510 is combined with an ECG signal 515, and a blood pressure 501c regression chart 520 (e.g, a correlation 502c), according to some embodiments. The captured audio signal (IEM) is processed by the processor to classify portions of the audio signal as corresponding to different heart sounds indicative of different stages of the user’s heartbeat. The processor is further configured to analyze properties of the identified heart sounds to estimate a blood pressure level of the user, e.g., based on an intensity ratio of a first heart sound to a second heart sound, a time delay between an onset of the first heart sound and an onset of the second heart sound, spectral content of the second heart sound, or some combination thereof.

[0057] Spectrogram 530 displays a spectral decomposition (e.g. , amplitude 503b) of acoustic waveform 510 as a function of time 502b and frequency 501b. By analyzing the time evolution of different spectral components of acoustic waveform 510, vital signs for the patient may be determined, such as blood pressure 501c and the like.

[0058] In some embodiments, an in-ear microphone signal (cf. in-ear microphone 325-1) forms acoustic waveform 510 that may be overlapped with ECG signal 515 provided by an in- ear electrode (cf. electrode 305), or any electrode disposed on a wearable device (e.g, a smart watch, or wristband 205, and the like). ECG signal 515 provides a reference time for the start of a heart pulse, from which a systolic portion 505 and a diastolic portion 507 of acoustic waveform 510 may be identified. Accordingly, a time lapse 517 between the initial electronic pulse and diastolic portion 507 may be indicative or have a direct correlation with the user’s blood pressure 501c. Other correlation factors to determine user’s blood pressure 501c may include a ratio 502c between an amplitude of systolic portion 505 to diastolic portion 507.

[0059] In some embodiments, the captured audio signal (IEM) is processed by the processor to classify portions of the audio signal as corresponding to different heart sounds indicative of different stages of the user’s heartbeat. The processor is further configured to analyze properties of the identified heart sounds to estimate a blood pressure level of the user, e.g., based on an intensity ratio of a first heart sound to a second heart sound, a time delay between an onset of the first heart sound and an onset of the second heart sound, spectral content of the second heart sound, or some combination thereof.

[0060] In some embodiments, the spectral signature of systolic portion 505 and diastolic portion 507 may also be indicative of user’s vital signs. It is generally observed that systolic portion 505 includes a narrower frequency bandwidth, while diastolic portion 507 has a broader bandwidth.

[0061] FIG. 6 illustrates a chart 600 including a waveform 610 obtained with a contact microphone in an IEM to determine a heart rate of a user, according to some embodiments. Chart 600 includes an abscissa 601 indicative of time, and ordinates 602a and 602b (signal amplitude), hereinafter, collectively referred to as “ordinates 602.” Waveform 610 is obtained from a contact microphone inside the ear-canal of an IEM user. In some embodiments, a similar waveform may be obtained with an IMU, accelerometer, and the like. A ground-truth ECG 615 includes the locations of the R-peak 617 (e.g., the heartbeat).

[0062] Other measurements available from waveform 610 (from a contact microphone) may include, in addition to heart rate and breathing rate, and without limitation: step count, pose estimation, and fall detection. Moreover, some embodiments enable blood pressure estimation using a pulse transit time (PTT) technique combining a contact microphone/motion sensor and an ECG sensor.

[0063] In some embodiments, in-ear microphones and contact microphones may retrieve body-bome infrasound and low frequency sounds associated with a user’s vital signs. Signal processing techniques, in conjunction with artificial intelligence (Al) processing can be used to extract user’s vital signs from these acoustic waveforms (e.g, heart rate, heart rate variability, breathing rate, and blood pressure).

[0064] FIG. 7 is a flow chart illustrating steps in a method 700 for using microphones in an in-ear monitor for assessing the health of a user of a headset or smart glasses, according to some embodiments. In some embodiments, at least one or more of the steps in method 700 may be performed by a processor executing instructions stored in a memory in either one of smart glasses or other wearable device on a user’s body part (e.g, head, arm, wrist, leg, ankle, finger, toe, knee, shoulder, chest, back, and the like). In some embodiments, at least one or more of the steps in method 700 may be performed by a processor executing instructions stored in a memory, wherein either the processor or the memory, or both, are part of a mobile device for the user, a remote server or a database, communicatively coupled with each other via a network (cf., processors 112, 312, and memory 120, client devices 110, server 130, database 152, and network 150). Moreover, the mobile device, the smart glasses, and the wearable devices may be communicatively coupled with each other via a wireless communication system and protocol (e.g, communications module 118, radio, Wi-Fi, Bluetooth, near-field communication -NFC- and the like). In some embodiments, a method consistent with the present disclosure may include one or more steps from method 700 performed in any order, simultaneously, quasi-simultaneously, or overlapping in time.

[0065] Step 702 includes receiving, from a first microphone, a first acoustic signal from a first ear canal of a user of an in-ear monitor.

[0066] Step 704 includes forming a first waveform with the first acoustic signal. In some embodiments, step 704 includes receiving, from a second microphone, a second acoustic signal from the first ear canal of the user of the in-ear monitor, forming a second waveform with the first acoustic signal filtered from the second acoustic signal, and providing the second waveform to the user via a speaker, wherein the second acoustic signal is an audio signal from an external environment of the user.

[0067] Step 706 includes identifying a vital sign of the user based on the first waveform. In some embodiments, the first acoustic signal is an internal signal from a body of the user and step 706 includes determining a heart rate of the user based on the first waveform. In some embodiments, step 706 includes identifying and classifying the SI and S2 sections of the heart sound from the acoustic signals collected by the first acoustic signal and forming a ration of (S1/S2) to enable real-time blood pressure monitoring for the user. [0068] In some embodiments, step 706 includes receiving an electronic signal from an electrode in the in-ear monitor; and wherein identifying the vital sign of the user comprises determining a heart rate of the user based on a correlation of the electronic signal with the first waveform. In some embodiments, step 706 includes receiving an electronic signal from an electrode; and wherein identifying the vital sign of the user comprises identifying a systolic portion and a diastolic portion of the first waveform based on a correlation of the electronic signal with the first acoustic signal, and determining a blood pressure value with the systolic portion and the diastolic portion of the first waveform. In some embodiments, step 706 includes identifying a systolic portion and a diastolic portion of the first waveform, wherein identifying a vital sign of the user comprises determining a blood pressure value based on the systolic portion and the diastolic portion of the first waveform. In some embodiments, step 706 includes generating a spectrogram of the first waveform; and identifying at least one of a heart rate value or a blood pressure value from the spectrogram of the first waveform. In some embodiments, step 706 includes identifying a systolic portion and a diastolic portion of the first waveform, and determining a blood pressure value based on an amplitude of the systolic portion compared to an amplitude of the diastolic portion of the first waveform. In some embodiments, step 706 includes providing, with a speaker, a sound signal into the first ear canal, for the user, wherein the first acoustic signal comprises a back reflection of the sound signal, from an inner ear, and wherein identifying a vital sign of the user comprises determining a hearing condition of the user based on a delay and amplitude of the back reflection of the sound signal. In some embodiments, the first acoustic signal includes a sound gesture generated by the user as an input command, and step 706 includes identifying the input command from the first waveform, and having a processor in smart glasses to execute the input command.

Hardware Overview

[0069] FIG. 8 is a block diagram illustrating an exemplary computer system 800 with which headsets and other client devices 110, and method 700 can be implemented, according to some embodiments. In certain aspects, computer system 800 may be implemented using hardware or a combination of software and hardware, either in a dedicated server, or integrated into another entity, or distributed across multiple entities. Computer system 800 may include a desktop computer, a laptop computer, a tablet, a phablet, a smartphone, a feature phone, a server computer, or otherwise. A server computer may be located remotely in a data center or be stored locally.

[0070] Computer system 800 includes a bus 808 or other communication mechanism for communicating information, and a processor 802 (e.g., processors 112) coupled with bus 808 for processing information. By way of example, the computer system 800 may be implemented with one or more processors 802. Processor 802 may be a general-purpose microprocessor, a microcontroller, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a controller, a state machine, gated logic, discrete hardware components, or any other suitable entity that can perform calculations or other manipulations of information.

[0071] Computer system 800 can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them stored in an included memory 804 (e.g., memory 120), such as a Random Access Memory (RAM), a flash memory, a Read-Only Memory (ROM), a Programmable Read-Only Memory (PROM), an Erasable PROM (EPROM), registers, a hard disk, a removable disk, a CD-ROM, a DVD, or any other suitable storage device, coupled with bus 808 for storing information and instructions to be executed by processor 802. The processor 802 and the memory 804 can be supplemented by, or incorporated in, special purpose logic circuitry.

[0072] The instructions may be stored in the memory 804 and implemented in one or more computer program products, e.g, one or more modules of computer program instructions encoded on a computer-readable medium for execution by, or to control the operation of, the computer system 800, and according to any method well known to those of skill in the art, including, but not limited to, computer languages such as data-oriented languages (e.g, SQL, dBase), system languages (e.g., C, Objective-C, C++, Assembly), architectural languages (e.g, Java, .NET), and application languages (e.g., PHP, Ruby, Perl, Python). Instructions may also be implemented in computer languages such as array languages, aspect-oriented languages, assembly languages, authoring languages, command line interface languages, compiled languages, concurrent languages, curly-bracket languages, dataflow languages, data-structured languages, declarative languages, esoteric languages, extension languages, fourth-generation languages, functional languages, interactive mode languages, interpreted languages, iterative languages, list-based languages, little languages, logic-based languages, machine languages, macro languages, metaprogramming languages, multiparadigm languages, numerical analysis, non-English-based languages, object-oriented class-based languages, object-oriented prototype-based languages, off-side rule languages, procedural languages, reflective languages, rule-based languages, scripting languages, stack-based languages, synchronous languages, syntax handling languages, visual languages, wirth languages, and xml-based languages. Memory 804 may also be used for storing temporary variable or other intermediate information during execution of instructions to be executed by processor 802.

[0073] A computer program as discussed herein does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g, one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g, files that store one or more modules, subprograms, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network. The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output.

[0074] Computer system 800 further includes a data storage device 806 such as a magnetic disk or optical disk, coupled with bus 808 for storing information and instructions. Computer system 800 may be coupled via input/output module 810 to various devices. Input/output module 810 can be any input/output module. Exemplary input/output modules 810 include data ports such as USB ports. The input/output module 810 is configured to connect to a communications module 812. Exemplary communications modules 812 include networking interface cards, such as Ethernet cards and modems. In certain aspects, input/output module 810 is configured to connect to a plurality of devices, such as an input device 814 and/or an output device 816. Exemplary input devices 814 include a keyboard and a pointing device, e.g, a mouse or a trackball, by which a consumer can provide input to the computer system 800. Other kinds of input devices 814 can be used to provide for interaction with a consumer as well, such as a tactile input device, visual input device, audio input device, or brain-computer interface device. For example, feedback provided to the consumer can be any form of sensory feedback, e.g, visual feedback, auditory feedback, or tactile feedback; and input from the consumer can be received in any form, including acoustic, speech, tactile, or brain wave input. Exemplary output devices 816 include display devices, such as an LCD (liquid crystal display) monitor, for displaying information to the consumer.

[0075] According to one aspect of the present disclosure, headsets and client devices 110 can be implemented, at least partially, using a computer system 800 in response to processor 802 executing one or more sequences of one or more instructions contained in memory 804. Such instructions may be read into memory 804 from another machine-readable medium, such as data storage device 806. Execution of the sequences of instructions contained in main memory 804 causes processor 802 to perform the process steps described herein. One or more processors in a multi-processing arrangement may also be employed to execute the sequences of instructions contained in memory 804. In alternative aspects, hard-wired circuitry may be used in place of or in combination with software instructions to implement various aspects of the present disclosure. Thus, aspects of the present disclosure are not limited to any specific combination of hardware circuitry and software.

[0076] Various aspects of the subject matter described in this specification can be implemented in a computing system that includes a back end component, e.g., a data server, or that includes a middleware component, e.g, an application server, or that includes a front end component, e.g., a client computer having a graphical consumer interface or a Web browser through which a consumer can interact with an implementation of the subject matter described in this specification, or any combination of one or more such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. The communication network can include, for example, any one or more of a LAN, a WAN, the Internet, and the like. Further, the communication network can include, but is not limited to, for example, any one or more of the following network topologies, including a bus network, a star network, a ring network, a mesh network, a star-bus network, tree or hierarchical network, or the like. The communications modules can be, for example, modems or Ethernet cards.

[0077] Computer system 800 can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. Computer system 800 can be, for example, and without limitation, a desktop computer, laptop computer, or tablet computer. Computer system 800 can also be embedded in another device, for example, and without limitation, a mobile telephone, a PDA, a mobile audio player, a Global Positioning System (GPS) receiver, a video game console, and/or a television set top box.

[0078] The term “machine-readable storage medium” or “computer-readable medium” as used herein refers to any medium or media that participates in providing instructions to processor 802 for execution. Such a medium may take many forms, including, but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical or magnetic disks, such as data storage device 806. Volatile media include dynamic memory, such as memory 804. Transmission media include coaxial cables, copper wire, and fiber optics, including the wires forming bus 808. Common forms of machine- readable media include, for example, floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, an EPROM, a FLASH EPROM, any other memory chip or cartridge, or any other medium from which a computer can read. The machine-readable storage medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter affecting a machine-readable propagated signal, or a combination of one or more of them.

[0079] As used herein, the phrase “at least one of’ preceding a series of items, with the terms “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list (e.g, each item). The phrase “at least one of’ does not require selection of at least one item; rather, the phrase allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C.

[0080] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Phrases such as an aspect, the aspect, another aspect, some aspects, one or more aspects, an implementation, the implementation, another implementation, some implementations, one or more implementations, an embodiment, the embodiment, another embodiment, some embodiments, one or more embodiments, a configuration, the configuration, another configuration, some configurations, one or more configurations, the subject technology, the disclosure, the present disclosure, other variations thereof and alike are for convenience and do not imply that a disclosure relating to such phrase(s) is essential to the subject technology or that such disclosure applies to all configurations of the subject technology. A disclosure relating to such phrase(s) may apply to all configurations, or one or more configurations. A disclosure relating to such phrase(s) may provide one or more examples. A phrase such as an aspect or some aspects may refer to one or more aspects and vice versa, and this applies similarly to other foregoing phrases.

[0081] A reference to an element in the singular is not intended to mean “one and only one” unless specifically stated, but rather “one or more.” Pronouns in the masculine (e.g, his) include the feminine and neuter gender (e.g, her and its) and vice versa. The term “some” refers to one or more. Underlined and/or italicized headings and subheadings are used for convenience only, do not limit the subject technology, and are not referred to in connection with the interpretation of the description of the subject technology. Relational terms such as first and second and the like may be used to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. All structural and functional equivalents to the elements of the various configurations described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and intended to be encompassed by the subject technology. Moreover, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly recited in the above description.

[0082] While this specification contains many specifics, these should not be construed as limitations on the scope of what may be described, but rather as descriptions of particular implementations of the subject matter. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially described as such, one or more features from a described combination can in some cases be excised from the combination, and the described combination may be directed to a subcombination or variation of a subcombination.

[0083] The subject matter of this specification has been described in terms of particular aspects, but other aspects can be implemented and are within the scope of the following claims. For example, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. The actions recited in the claims can be performed in a different order and still achieve desirable results. As one example, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the aspects described above should not be understood as requiring such separation in all aspects, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. [0084] The title, background, brief description of the drawings, abstract, and drawings are hereby incorporated into the disclosure and are provided as illustrative examples of the disclosure, not as restrictive descriptions. It is submitted with the understanding that they will not be used to limit the scope or meaning of the claims. In addition, in the detailed description, it can be seen that the description provides illustrative examples, and the various features are grouped together in various implementations for the purpose of streamlining the disclosure. The method of disclosure is not to be interpreted as reflecting an intention that the described subject matter requires more features than are expressly recited in each claim. Rather, as the claims reflect, inventive subject matter lies in less than all features of a single disclosed configuration or operation. The claims are hereby incorporated into the detailed description, with each claim standing on its own as a separately described subject matter.

[0085] The claims are not intended to be limited to the aspects described herein but are to be accorded the full scope consistent with the language claims and to encompass all legal equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirements of the applicable patent law, nor should they be interpreted in such a way.