Patent ID: 12257100

DETAILED DESCRIPTION OF EMBODIMENTS

Definition: As exemplified inFIG.1, a “thermometer-shaped device”1comprises a handle section2and a mouthpiece comprising a neck3and a tip4. The tip4is configured for placement under the tongue and the neck3is configured for being wrapped around and sealed by the lips.

Reference is now made toFIG.2, showing a preferred embodiment of the device5of the present invention. The device5comprises a handle section19and a mouthpiece20. The mouthpiece20contains an assembly for the detection and recording of respiratory and lung sounds when it is placed in the patient's mouth. When the tip10of the mouthpiece20is placed under the patient's tongue, the patient's lips close around a neck11of the mouthpiece20, creating a sound box reaching from the lungs to the oronasal cavity, via the trachea. Thus, the action of placing the device in the mouth enables the detection of respiratory and lung sounds to take place. In some embodiments, the tip10contains a thermistor for taking of the patient's temperature. Suitable thermistors for the oral temperature-sensing include the MF51E2252F3950C bead type thermistor from Cantherm (Montreal, Canada).

In some embodiments, the oral device5further comprises an ECG circuit and/or pulse oximetry sensor, wherein the handle section19comprises two grasping points12,13for holding the device, a display14, an activation button15, two electrode contacts16,17and a pulse oximetry sensor18. Located within the device is an internal electronics board (PCB) containing a control circuit50whose block diagram is shown inFIG.5. The control circuit50processes the signals measured from the various sensors and optionally transmits all or part of the signals data to an external device such as a smartphone (not shown).

Reference is now made toFIGS.3A and3B, showing external exploded and assembled views, respectively, of the mouthpiece20, according to some embodiments of the invention; as well asFIGS.4A and4B, showing internal exploded and assembled views, respectively, of the mouthpiece20, according to some embodiments of the invention. The mouthpiece10contains one or more in-mouth microphones33and34, for listening to respiratory sounds. When the mouthpiece20is inserted into the mouth, the tip10is placed under the tongue and the lips rest against the neck11. When the lips are thus sealed around the mouthpiece20of the oral device5, acoustic access holes21and22are located within the mouth and thus exposed to the sounds detectable therein.

Acoustic access holes21,22can be slightly recessed, such that there is a place to insert a disc of an air/liquid filter material30and31, where the microphones33,34are mounted inside the mouthpiece on the other side of the holes21,22. This arrangement prevents the entry of liquid into the microphones, while ensuring that the microphones are able to pick up the sounds detectable within the oral cavity. It is possible to use a plurality of microphones for this purpose, with the sounds analyzed potentially representing the sum (or some other function) of the sounds detected by the microphones. One advantage of using two microphones is that, in the event that one gives a clear signal and the other seems blocked—for example by the tongue—then the stronger signal can be used. Suitable potential microphones for this purpose include digital microphones like the MP34DT06J PDM-type microphone from STMicroelectronics NV (Eindhoven, Holland); and sensitive analog microphones such as the CMC-4015-25L 100 electret condenser microphone from CUI Devices (Lake Oswego, OR, USA). An example of a suitable material for the air/liquid filters30,31are hydrophobic membranes from W. L. Gore & Associates, Inc. (Newark, DE, USA).

Reference is now made toFIG.5, showing a functional block diagram of the control circuit50of the oral device5, according to some embodiments of the invention. In preferred embodiments, the microphones33,34are digital, such that they can be interfaced directly into the bus of the processor52. For this preferred embodiment, an example processor52is the Cypress BLUETOOTH® Low Energy microprocessor module CYBLE-416045-02 from Cypress Semiconductor Corp. (San Jose, CA, USA) may be used. Advantageously, the Cypress processor contains an integrated BLUETOOTH® Low-Energy (BLE) module, thereby obviating the need to incorporate a separate communications chip58in the control circuit50. Advantageously, the thermistor(s)62described above can also be connected directly to the Cypress processor, using its internal A/D conversion channels.

The ECG electrodes16,17on the body19of the device are interfaced to an ECG chip54, which is interfaced digitally into the microprocessor52. In a preferred embodiment of the circuit, a single chip contains both the ECG module54and the pulse oximetry module56, of which the sensor18is a part. An example integrated sensor chip of this type is the MAX86150 chip from Maxim Integrated (San Jose, CA, USA). Advantageously, by building the circuit around just two main chips—an integrated microprocessor plus BLUETOOTH® Low Energy module and an integrated sensor chip—the complexity is reduced while the costs are minimized. Suitable displays for the device of the present invention include liquid crystal displays (LCDs) and light emitting diodes (LEDs), for example the 1.44″ graphical TFT-type LCD display model KSF128128A0-1.44, from KSF Ltd. (Hong Kong).

Operation of the device of the present invention to detect and record respiratory and lung sounds, in preferred embodiments, proceeds as follows. After activating the device using its switch, the patient grasps the device, preferably using the grasping positions12and13, and places the mouthpiece in his mouth such that the oral-temperature tip is under his/her tongue and his/her lips are closed around the neck11. It is recommended to use the grasping positions such that a finger rests in the recess while the opposable thumb presses against the underside of the device at that place. After approximately 20-30 seconds, the device issues a beep and/or an indication on the display14, to signal that the “temperature reading” is complete. Note that, due to the thermometer-type design of the device, the measurements taken during this time include (as a minimum) both oral temperature and a recording of the sounds detected within the mouth by the microphone during this period. A digital recording of these sounds, at the resolution and sampling rate chosen (for example 12 bits at 4 kHz), is stored in the memory66of the control circuit50and/or transmitted via the communications module to a computer or smartphone (not shown), or uploaded to the internet (for example over the personal area network protocol Wi-Fix (IEEE 802.11x standards)). In preferred embodiments, the data is transmitted over the wireless network protocol BLUETOOTH® Low Energy to a smartphone for recording and uploading to a remote computer system. This configuration enables a remote physician to listen to the sounds recorded and analyze them. As physicians typically perform auscultation for only a few seconds at any given body location, it will typically be sufficient to record and forward between 5 and 10 seconds of the sound recording taken by the device of the present invention.

Reference is now made toFIG.6. The respiratory system extends from the oronasal cavity70, down through the trachea72to the lungs74. Also shown is the internal structure76of the lungs. Advantageously, as the microphones33,34are located within the respiratory system, it is possible to detect the respiratory sounds within the entire respiratory system. Additionally, and synergistically with the standard use of a thermometer, the mouth is kept closed by the patient for the duration of the temperature reading, thereby increasing the degree to which the respiratory and lung sounds are trapped within a mostly closed space and external interference is reduced. A key advantage of the present invention is that this sound detection is performed internally within the body, as opposed to requiring an external membrane interface external to the body (as is the case when a stethoscope is used). In this manner, the present invention serves to enable the functional equivalent of lung auscultation to be performed, but without the use of a stethoscope.

Reference is now made toFIG.7, showing a typical waveform77of lung sounds detected by chest auscultation of a single respiratory cycle, taken by a conventional digital stethoscope. (In the Experimental section below, the digital stethoscope waveform77shall be compared with waveforms from the oral device5.) The waveform is overlaid by an air flow plot78(inspirium/experium) detected at the mouth. It is noted that there is a low-frequency periodicity associated with the breathing action (typically 10-15 breaths/min in an adult), and higher-frequency lung sounds are detectable during both the inhalation and expiration phases of each breath.

The low-frequency wave shown is isolated in order to calculate the patient's respiratory rate and I:E ratio. Respiratory rate is an important vital sign, and so, in a preferred embodiment, this rate is calculated within the control circuit50of the device and displayed on its internal display14.

The oral device5shown inFIG.1, measures and displays the respiratory rate and the oral-temperature. In some embodiments, additional sensors detect and enable display of further medical parameters. A pulse oximetry sensor18can be located along a finger grasping location (either12or13). In this configuration, when the patient grasps the oral device5as instructed, his/her pulse rate and peripheral oxygen saturation (SpO2) parameters will be measured by the pulse oximeter while the temperature reading is underway. In a preferred embodiment, these data are also be shown on the display14of the device; such that it is possible to display the four vital signs: temperature, respiratory rate, pulse rate and SpO2on the display. The vital signs may either be displayed simultaneously or, for example, by using a switch15to toggle between showing the different parameters.

Similarly, during the time that the patient is holding the device in his/her mouth to perform the temperature measurement, if the patient is holding the device as instructed, with a finger of each hand in the grasping places12,13, then the electrodes16,17, located in the grasping areas12,13enable an ECG reading to be taken at the same time. The electrodes16,17are connected to the ECG chip54described in conjunction with the block diagram shown inFIG.4. In some embodiments, an additional third electrode is applied at the mouth, either via a metallic section23on the mouthpiece20, or by using the metallic tip10which houses the temperature sensor. Where a three-electrode configuration is used—one on each finger and one in the mouth—the ECG trace generated may be calculated according to the description given in co-pending patent PCT/IL2020/050874.

Thus, by proper use of an oral device5of the present invention, a large number of medical parameters may be measured simultaneously. Any or all of this information may be transmitted via the communications module to a remote computer, via a smartphone or any other suitable means.

The lung sounds detected by an oral device5of the present invention can serve to diagnose respiratory conditions and enable the progression of respiratory disease to be monitored. As described above, typical lung sounds associated with specific respiratory conditions include different types of wheezes, crackles, or combinations thereof which can serve to characterize asthma, COPD, bronchiolitis, cystic fibrosis and PAH. For example, asthma is typically identified by the combination of early inspiratory crackles and late inspiratory fine crackles, whereas bronchiectasis can be identified by wet crackles. Similarly, the combination of a mid-inspiratory wheeze and a mid-expiratory wheeze suggests bronchiolar disease.

In a similar manner, specific heart sounds detected via the device can also be indicative of cardiac conditions, and their worsening can indicate deterioration.

Reference is now made toFIG.8, showing a functional block diagram of a system80for remote measurement of lung auscultation and/or other vital signs. The oral device5digitally samples the lung sounds and transmits the sampled data wirelessly to a cloud server90. For example, the data may be transmitted from the oral device5by a SIM module or 5G modem82; or, for example, by BLUETOOTH®/BLUETOOTH® Low Energy84to a smartphone86and then via Wi-Fix or cellular88from the smartphone86to the cloud server90. The cloud server90uploads and stores the sampled data, for transmission to a physician or computer analysis, as further described herein. Alternatively, some or all analysis may be performed within the control circuit50and/or the smartphone86. The control circuit50, smartphone86, or cloud server90may timestamp the sampled data.

A display device92, connected to the cloud server90, of medical personnel94can display the auscultation waveform to the medical personnel94for remotely monitoring a patient. Alternatively, or in addition, a healthcare bot can monitor and analyze changes in the sounds over time. For example, a healthcare bot within or accessible to the cloud server90may analyze an auscultation waveform of a patient over time for indications of disease progression. In particular, numerical indices of wheezes and crackles can be generated by isolating these sounds from the sound recording, and the trends of these indices can be observed. For example, an index of Twheeze/Ttotalshowing the ratio of time that the breathing also includes a wheeze component can be recorded and followed, where a rise in this ratio shows a trend towards a worsening condition. Similarly, “crackles” can be detected and a count of “crackles” maintained, preferably organized according to the breathing phase, such that the number of crackles during the early/late inspiratory phase and during the early/late expiratory phase of the breathing is known, in addition to the total number of crackles. All three of these indices can be monitored for trends, where an increase in the crackle count signifies a deterioration in the condition of the lungs. Early inspiratory and expiratory crackles are the hallmark of chronic bronchitis, whereas late inspiratory crackles may mean pneumonia, CHF, or atelectasis.

These potential problems can then be signaled as alerts to medical personnel94, caretakers, and/or patients. Such a remote analytics system and method can also factor in additional physiological data (such as ECG and vital signs) and their trends, whether this additional data is collected by the device5or other devices.

Experimental Data

On placement of the device into the mouth and sealing of the lips around it, the microphone was located within the oronasal cavity. The raw sound waveform for several respiratory cycles is shown inFIG.9A. The high frequency whistling and noise present within the oronasal cavity serve to obscure the underlying sound pattern. However, by applying a high-pass filter set at 1000 Hz to this data, with a roll-off of 6 dB/octave, the received data shown inFIG.9Bclearly shows a typical inspirium and experium pattern as would be heard by applying a stethoscope to the chest.

In order to determine the relative importance of the noise reduction, we applied a 16 dB noise reduction with a sensitivity of 6.0, using 3 frequency smoothing bands, with the results being shown inFIG.9C. We then applied the high-pass filter used above (i.e. 1000 Hz, with a roll-off of 6 dB/octave) to the noise-reduced data, in order to yield the sound wave shown inFIG.9D.

As is readily appreciated, the signal processing enables the production of an auscultation-type sound wave which is significantly equivalent to that yielded by the use of a stethoscope against the chest in traditional auscultation.

Comparing the experimentally-derived waveforms inFIGS.9B and9Dto a standard “textbook” illustration of the components of a chest auscultation, as shown inFIG.7, it is clear that the major components—inspirium, experium, and lung sounds—are all present in the sound wave data, as detected and then processed by an oral device5of the current invention.

The oral device5enables a physician to perform remote auscultation, by receiving and listening to the sound data file at a remote location. Advantageously, this system enables the performance of remote auscultation to be performed without the traditional requirement for the patient to place an electronic stethoscope on his chest. Essentially, the patient just needs to “take his temperature” and the process of recording, signal-processing and transmission of the data is performed automatically.