An integrated optical fiber acoustic sensing ventilation therapy mask monitoring system and method

Abstract

The application provides a ventilation treatment mask monitoring system and method integrated with optical fiber acoustic sensing. The system comprises: a ventilation treatment mask configured to be in contact with a user's face and form a ventilation cavity; an optical fiber acoustic sensing assembly arranged in the ventilation cavity; a reference sensing unit arranged outside the ventilation cavity, used to collect a reference signal including airflow noise and / or environmental noise; an acoustic coupling channel, which is communicated between the ventilation cavity and the acoustic transduction unit, used to facilitate the transmission of acoustic vibration to the acoustic transduction unit; a buffer structure arranged in the ventilation cavity, used to weaken the impact of the airflow input into the ventilation cavity on the acoustic transduction unit; and a signal processing module connected with the optical fiber acoustic sensing assembly and the reference sensing unit respectively, used to perform adaptive noise suppression and feature extraction on the optical signal change and the reference signal, and obtain the real breathing sound of the user. The continuous and real-time collection and effective extraction of the real breathing sound of the user under the condition of strong continuous airflow input are realized.

Description

Technical Field

[0001] This application relates to the field of ventilation therapy equipment technology, and in particular to a ventilation therapy mask monitoring system and method integrating fiber optic acoustic sensing. Background Technology

[0002] Ventilation therapy masks are widely used in operating room anesthesia management, intensive care, emergency transport, and home oxygen therapy. Taking anesthesia masks as an example, during anesthesia induction, pre-intubation oxygenation and denitrification, and anesthetic ventilation, the patient's respiratory status may change rapidly, such as respiratory depression, upper airway obstruction, and laryngospasm. In oxygen therapy scenarios, the oxygen flow rate of ordinary oxygen masks is typically 5 L / min to 15 L / min. The turbulence noise generated by the oxygen jet, the mask's internal structure, and the exhaust vents can reach 60 dB to 80 dB, easily masking respiratory sounds and making it difficult for traditional acoustic acquisition methods to work stably in clinical settings.

[0003] Current ventilation status monitoring mainly relies on indirect indicators such as pulse oximetry, end-tidal carbon dioxide, and thoracic impedance. However, this approach suffers from issues such as delayed response, inability to directly reflect the acoustic characteristics of breath sounds, and insufficient stability in environments with movement, vibration, or electromagnetic interference. In the multi-device electromagnetic environment of an operating room, electrical microphones for collecting breath sounds are susceptible to electromagnetic interference from equipment such as radiofrequency electrosurgical units and monitors. Furthermore, wiring, insulation, and sterilization increase structural complexity.

[0004] Fiber optic sensors possess characteristics such as being passive, resistant to electromagnetic interference, small in size, and highly sensitive. Existing technologies propose integrating fiber optic acoustic sensors into airway devices such as catheters to acquire patients' respiratory sound signals. However, traditional airway devices do not address the continuous high-flow-rate airflow impact environment unique to therapeutic masks. For example, anesthesia masks experience combined interference from loop airflow and mechanical vibration during loop ventilation and denitrification oxygenation. Ordinary oxygen masks face direct impact noise from the open jet. Therefore, traditional solutions are ill-suited to the strong airflow noise environment of masks, resulting in a severely insufficient signal-to-noise ratio in therapeutic mask usage scenarios. Summary of the Invention

[0005] To address the aforementioned issues, one or more embodiments of this application aim to provide a ventilation therapy mask monitoring system and method integrating fiber optic acoustic sensing, so as to achieve continuous, real-time acquisition and effective extraction of the user's real breathing sounds under strong continuous airflow input conditions.

[0006] In a first aspect, this application provides a ventilation therapy mask monitoring system integrating fiber optic acoustic sensing, the system comprising: The system includes: The ventilation therapy mask is configured to contact the user's face and form an air cavity; An optical fiber acoustic sensing component is disposed within the ventilation cavity; wherein, the optical fiber acoustic sensing component includes an optical fiber and an acoustic transducer unit disposed on the optical fiber, the acoustic transducer unit being used to convert the acoustic vibration caused by the airflow within the ventilation cavity into changes in optical signals for transmission through the optical fiber. An acoustic coupling channel connects the ventilation cavity and the acoustic transducer unit to facilitate the conduction of acoustic vibrations to the acoustic transducer unit. A buffer structure is provided inside the ventilation cavity to reduce the impact of airflow input into the ventilation cavity on the acoustic transducer unit. A reference sensing unit is disposed outside the ventilation cavity and is used to collect reference signals including airflow noise and / or ambient noise. The signal processing module is communicatively connected to the fiber optic acoustic sensing component and the reference sensing unit, respectively, and is used to perform adaptive noise suppression and feature extraction on the changes in the optical signal and the reference signal to obtain the user's real breathing sound. The acoustic coupling channel and the buffer structure together form a structural suppression path for airflow noise, and the reference sensing unit and the fiber optic acoustic sensing component together form an electrical suppression path for airflow noise, thereby enabling the acquisition of realistic breathing sounds under strong airflow noise.

[0007] Optionally, the ventilation therapy mask includes a mask body, a sealing gasket, and a gas interface for receiving the airflow; wherein, Both the fiber optic acoustic sensing component and the acoustic coupling channel are disposed within the sealing gasket or the enclosure; and the acoustic coupling channel is located on the side of the fiber optic acoustic sensing component facing the ventilation cavity. The buffer structure is embedded in the acoustic coupling channel and / or the gas interface; wherein the buffer structure includes at least one of a microporous plate and a baffle plate; The reference sensing unit is located anywhere on the gas interface, outside the mask, or in the ventilation pipeline connected to the ventilation therapy mask.

[0008] Optionally, the system further includes a vibration isolation layer, which is in close contact with the side of the acoustic transducer unit away from the ventilation cavity, to reduce the transmission of external vibrations to the acoustic transducer unit.

[0009] Optionally, the gas interface is a closed-loop interface or an open oxygen flow interface; the ventilation line includes an anesthesia gas supply circuit or an oxygen supply circuit. The ventilation therapy mask is connected to the anesthesia gas supply circuit via the sealed circuit interface and is used for spontaneous breathing before anesthesia induction, denitrification oxygenation, or anesthesia ventilation. The open oxygen flow interface includes an oxygen inlet connector and an exhaust port. The ventilation therapy mask is connected to the oxygen supply pipeline via the oxygen inlet connector and the exhaled gas is discharged through the exhaust port for monitoring spontaneous breathing in oxygen therapy scenarios.

[0010] Optionally, the acoustic transducer unit includes a sensitive diaphragm and a cavity located between the sensitive diaphragm and the end face of the optical fiber; wherein, when the sensitive diaphragm is subjected to acoustic vibration, it flexes, causing a change in the cavity length of the cavity, thereby triggering a change in the optical signal.

[0011] Optionally, the acoustic transducer unit includes a fiber Bragg grating; wherein, when the fiber Bragg grating is subjected to acoustic vibration, strain occurs, causing a shift in the center reflection wavelength of the fiber Bragg grating, thereby triggering a change in the optical signal.

[0012] Optionally, the acoustic transducer unit is a multi-segment fiber grating, wherein the multiple fiber gratings are spaced apart and have different center reflection wavelengths to achieve wavelength division multiplexing; Multiple fiber optic gratings are distributed circumferentially along the sealing gasket to acquire acoustic signals at different locations.

[0013] Optionally, the system further includes an optical fiber demodulator connected to the optical fiber acoustic sensing component and the reference sensing unit respectively, for converting the optical signal change and the reference signal into a respiratory electrical signal and a reference electrical signal respectively; the optical fiber demodulator is also communicatively connected to the signal processing module for transmitting the respiratory electrical signal and the reference electrical signal to the signal processing module.

[0014] Optionally, the sealing gasket is snapped into the periphery of the cover, and an embedding groove is formed in the sealing gasket. The fiber optic acoustic sensing component is embedded in the embedding groove and encapsulated with encapsulation material.

[0015] Secondly, this application provides a method for monitoring a ventilation therapy mask integrating fiber optic acoustic sensing, applied to the system provided in the first aspect of this application, the method comprising: The ventilation therapy mask is worn on the user's face and forms a ventilation cavity, allowing the fiber optic acoustic sensing component to sense the acoustic vibration caused by the airflow in the ventilation cavity and generate changes in the optical signal. The optical signal changes transmitted by the fiber optic acoustic sensing component are acquired by the optical demodulator and converted into a respiratory electrical signal. At the same time, the reference signal transmitted by the reference sensing unit is acquired and converted into a reference electrical signal. The signal processing module performs adaptive noise suppression based on the respiratory electrical signal and the reference electrical signal, and extracts features from the noise-reduced signal to obtain the user's true breathing sound.

[0016] Compared with the prior art, this application has the following advantages: The system provided in this application embodiment places the fiber optic acoustic sensing component inside the ventilation cavity of the ventilation therapy mask and connects the ventilation cavity with the acoustic transducer unit through an acoustic coupling channel, thereby realizing near-field conduction of the sound pressure of the user's breathing sounds; at the same time, the fiber optic sensing can work passively and is resistant to electromagnetic interference, making it suitable for complex electromagnetic environments such as operating rooms and intensive care units.

[0017] A structural noise suppression path for airflow is constructed by employing a buffer structure in conjunction with an acoustic coupling channel. The buffer structure reduces the impact of the gas jet on the acoustic transducer unit, while the acoustic coupling channel transmits the sound pressure to the acoustic transducer unit, avoiding impact noise caused by the jet directly hitting the sensitive diaphragm or grating. Reliable breathing sound signals can still be obtained under high flow conditions.

[0018] An adaptive noise suppression path for airflow noise is constructed by employing a collaborative approach involving a reference sensing unit, fiber optic acoustic sensing components, and a signal processing module. The reference sensing unit acquires a reference signal related to airflow noise and / or ambient noise. Based on this reference signal, the signal processing module performs adaptive noise cancellation on the breath sound signal, further improving the signal-to-noise ratio without significantly weakening the effective components of the breath sound.

[0019] The method described above has the same advantages over existing technologies as the system described above, and will not be repeated here. Attached Figure Description

[0020] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a three-dimensional structural diagram of the ventilation therapy mask provided in Embodiment 1 of this application from an inner perspective; Figure 2 This is a three-dimensional structural diagram of the ventilation therapy mask provided in Embodiment 1 of this application from an external perspective; Figure 3 This is a front view of the ventilation therapy mask provided in Embodiment 1 of this application; Figure 4 yes Figure 3 Cross-sectional view along the AA direction; Figure 5 This is a perspective view of the sealing gasket provided in Embodiment 1 of this application; Figure 6 yes Figure 4 A magnified view of a section at point A in the middle; Figure 7 This is a three-dimensional structural diagram of the ventilation therapy mask provided in Embodiment 2 of this application from an inner perspective; Figure 8 This is a partial cross-sectional view of the ventilation therapy mask provided in Embodiment 2 of this application; Figure 9 This is an electrical connection diagram of the ventilation therapy mask monitoring system with integrated fiber optic acoustic sensing provided in Embodiment 3 of this application; Figure 10 This is a flowchart of the steps of a ventilation therapy mask monitoring method with integrated fiber optic acoustic sensing provided in an embodiment of this application.

[0022] Explanation of reference numerals in the attached figures: 1. Cover; 2. Sealing gasket; 3. Microporous plate; 4. Fiber optic acoustic sensing assembly; 41. First optical fiber; 42. First acoustic transducer unit; 421. Sensitive diaphragm; 422. Cavity; 423. Fiber grating; 5. Reference sensing unit; 51. Second optical fiber; 52. Second acoustic transducer unit; 6. Gas interface; 7. Acoustic coupling channel. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] It should be noted that before describing the technical solution of this application in detail, the current state of the prior art and its limitations will be further explained in order to facilitate understanding of the improvements made by the technical solution of this application compared with the prior art.

[0025] It should be noted that in the field of ventilation therapy, ventilation therapy masks can be of various types, including anesthesia masks (closed or semi-closed circuit type), ordinary oxygen masks (open or semi-open type), oxygen reservoir masks, or Venturi masks. Their common feature is that they form a ventilation cavity in contact with the user's face and continuously deliver airflow into the ventilation cavity. The "ventilation therapy mask" mentioned in this application includes, but is not limited to, the aforementioned types of masks.

[0026] In existing technologies, fiber optic acoustic sensors are integrated into airway devices. These devices are inserted into or near the user's airway opening, and the acoustic environment they face is primarily composed of sound waves generated by the user's own breathing airflow, without the impact of the high-flow-rate airflow continuously input from the gas interface 6, which is unique to ventilation therapy masks. In mask usage scenarios, the airflow input from the gas interface 6 (e.g., gas supplied to the anesthesia circuit or the jet from the oxygen bag / oxygen machine's input tube) generates strong turbulent noise and impact vibrations. If the fiber optic acoustic sensor is directly exposed to this airflow environment, the noise component in the acoustic transducer's response signal will severely mask the respiratory sound component, leading to a sharp decrease in the signal-to-noise ratio.

[0027] Therefore, the technical problem to be solved in this application is how to deeply integrate fiber optic acoustic sensing with a ventilation therapy mask, and design a dual-path synergy of structural noise reduction and electrical noise reduction for continuous airflow input conditions to obtain usable respiratory sound signals.

[0028] In order to overcome or at least partially solve the above problems, one or more embodiments of this application will be further described below with reference to specific embodiments.

[0029] like Figures 1-9 As shown, the system in this embodiment includes a ventilation therapy mask, a fiber optic acoustic sensing component 4, an acoustic coupling channel 7, a buffer structure, a reference sensing unit 5, and a signal processing module. The ventilation therapy mask is configured to contact the user's face and form a ventilation cavity. In clinical use, the ventilation therapy mask is worn on the user's face via a headband. The mask body 1 and the user's face are sealed or semi-sealed by a sealing gasket 2. Airflow (e.g., anesthesia circuit gas supply or oxygen supply line) is connected through the gas interface 6 on the mask, creating a continuous high-flow-rate airflow environment within the ventilation cavity. The fiber optic acoustic sensing component 4 is disposed within this ventilation cavity. The fiber optic acoustic sensing component 4 includes an optical fiber and an acoustic transducer unit disposed on the optical fiber. The acoustic transducer unit is used to convert the acoustic vibrations caused by the respiratory airflow within the ventilation cavity into changes in optical signals for transmission via the optical fiber. The acoustic vibrations include the sound frequency pressure fluctuations generated within the ventilation cavity due to the user's spontaneous breathing, i.e., respiratory sound waves; and the micro-amplitude mechanical vibrations caused by the vibration of the mask structure due to the airflow impacting the mask. Acoustic vibration acts on the acoustic transducer and causes changes in the optical signal. These changes in the optical signal are processed by the signal processing module and become the user's breath sound signal. In some embodiments, if the ventilation therapy mask is an anesthesia mask and there is no spontaneous breathing (mechanical ventilation), the acoustic vibration is generated by the interaction between the airflow input by the anesthesia machine / ventilator periodically supplying air and the user's airway.

[0030] In this embodiment, the acoustic coupling channel 7 is disposed on the ventilation therapy mask, with one end connected to the ventilation cavity and the other end connected to the acoustic transducer unit, for transmitting respiratory sound waves to the acoustic transducer unit. The diameter of the acoustic coupling channel 7 is much smaller than the ventilation cavity and the wavelength of the respiratory sound waves. Wall viscosity loss is minimal in such a narrow channel, and the respiratory sound waves are transmitted with low attenuation in the form of plane waves within the acoustic coupling channel 7, thereby increasing the effective sound pressure at the acoustic transducer unit. This achieves a near-field sound pressure transmission effect, resulting in low-loss and low-distortion transmission of respiratory sound waves, making the respiratory sound signal collected by the acoustic transducer unit closer to real respiratory sounds. In some embodiments, the diameter of the acoustic coupling channel 7 ranges from 1 to 10 mm.

[0031] Furthermore, since the acoustic transducer also responds to minute mechanical vibrations, interference introduced by external vibrations, if not suppressed, will directly mix into the vibration signal generated by the breathing airflow. External vibrations can include mechanical vibrations of the mask structure itself caused by factors such as friction from the user's facial movements, external contact, vibrations from bedside equipment, or during transport. For non-target mechanical vibrations not caused by breathing airflow, a vibration isolation layer is designed at the acoustic transducer. This layer is in close contact with the side of the acoustic transducer away from the ventilation cavity, reducing the transmission of external vibrations to the acoustic transducer. Specifically, the vibration isolation layer is located on the back side of the acoustic transducer, i.e., the side of the mask closest to the external environment, directly reducing the transmission of external mechanical disturbance energy to the acoustic transducer. In addition, the vibration isolation layer can be made of flexible damping materials such as foam, silicone or elastomer. Utilizing its viscoelastic properties of low elastic modulus and high loss factor, the solid-conducted energy (mask vibration caused by external factors) is converted into heat energy dissipation in the vibration isolation layer, so that the structural vibration amplitude reaching the acoustic transducer unit is greatly reduced to a significantly lower level than the original amplitude, thereby achieving physical blocking of external mechanical crosstalk and avoiding external disturbances from interfering with changes in optical signals.

[0032] Among them, the acoustic coupling channel 7 is set on the front side of the acoustic transducer unit, that is, the side of the mask close to the ventilation cavity, forming a noise reduction structure path of front sound guidance and rear vibration isolation, so that the acoustic transducer unit mainly receives the breathing sound waves caused by breathing airflow and structural micro-vibrations, thereby achieving the noise reduction effect.

[0033] In some embodiments, a buffer structure is disposed within the ventilation cavity to reduce the impact of airflow entering the ventilation cavity on the acoustic transducer unit. Exemplarily, the buffer structure includes at least one of a microporous plate 3 and a baffle plate. The microporous plate 3 has a plurality of micropores that can break up and homogenize the flow field pressure of the incoming airflow. The baffle plate has a deflection angle and is inclined relative to the direction of airflow, forcing the airflow to change direction when passing through the baffle plate, converting the kinetic energy of the airflow into static pressure dissipation. Exemplarily, the buffer structure may be disposed inside the acoustic coupling channel 7, forming a structural suppression path for airflow noise together with the acoustic coupling channel 7, so that the high-frequency airflow undergoes pressure equalization and / or kinetic energy dissipation before reaching the acoustic transducer unit, effectively reducing impact noise and protecting the acoustic transducer unit from direct impact interference.

[0034] The breathing sound signal received by the signal processing module typically includes the breathing sound signal generated by the user's breathing airflow, as well as noise signals caused by airflow noise and / or environmental noise. A reference sensing unit 5 is positioned outside the ventilation cavity to collect a reference signal primarily composed of airflow noise and / or environmental noise. For example, the reference sensing unit 5 is arranged near the gas interface 6, in the air supply line, or on the outside of the mask. The reference sensing unit 5 and the fiber optic acoustic sensing component 4 can employ the same type of fiber optic acoustic sensing structure to ensure consistency in frequency response characteristics between the reference signal and the breathing sound signal. The signal processing module is communicatively connected to both the fiber optic acoustic sensing component 4 and the reference sensing unit 5 to perform adaptive noise suppression and feature extraction based on changes in the optical signal and the reference signal, thereby obtaining the user's true breathing sound.

[0035] For example, firstly, the acoustic-optical changes acquired by the fiber optic acoustic sensing component 4 and the reference sensing unit 5 are converted into electrical signals usable by the signal processing module using a fiber optic demodulator. It is understood that the demodulation principle employed by the fiber optic demodulation module depends on the type of fiber optic sensing structure used in the fiber optic acoustic sensing component 4 and the reference sensing unit 5, and this application does not limit this. Then, the signal processing module uses the reference electrical signal corresponding to the reference signal as the reference input of the adaptive filter and the respiratory electrical signal corresponding to the changes in the breath sound signal / optical signal as the main input. It performs differential noise reduction processing on the reference electrical signal and the respiratory electrical signal, including but not limited to adaptive filtering, phase compensation, amplitude normalization, spectral difference, short-time Fourier transform, and time-frequency domain feature extraction, to remove the reference electrical signal containing noise and thus extract the true breath sound. Among them, adaptive filtering algorithm, phase compensation processing, amplitude normalization processing, spectrum subtraction processing and short-time Fourier transform processing are all mature technologies in the field of digital signal processing. Those skilled in the art can select appropriate algorithms or combinations thereof according to actual application scenarios to implement the noise reduction function of this application. Therefore, this application will not elaborate on the specific principles of each known technology.

[0036] Therefore, the adaptive noise suppression of the fiber optic acoustic sensing component 4, the reference sensing unit 5, and the signal processing module constitutes an electrical suppression path for airflow noise, maintaining a stable noise reduction effect under different airflow rates, different facial fit degrees, and different ventilation treatment environments. Through the coordinated operation of the structural and electrical suppression paths, the structural path physically reduces jet impact and external vibration interference, improving the signal-to-noise ratio of the breath sound signal; then, the electrical path further suppresses external noise interference at the signal processing level, achieving more refined noise removal on top of the structural noise reduction results. Together, they ensure the authenticity of the breath sound signal under high flow conditions.

[0037] In one embodiment of this application, the ventilation therapy mask includes a mask body 1, a sealing gasket 2, and a gas interface 6 for receiving airflow. The sealing gasket 2 is a flexible sealing gasket 2. Both the fiber optic acoustic sensing component 4 and the acoustic coupling channel 7 are disposed within the sealing gasket 2 or the mask body 1, and the acoustic coupling channel 7 is located on the side of the fiber optic acoustic sensing component 4 facing the ventilation cavity, ensuring that the inlet of the acoustic coupling channel 7 is inside the ventilation cavity and the outlet faces the receiving surface of the acoustic transducer unit, achieving efficient directional transmission of sound pressure. A buffer structure is disposed within the acoustic coupling channel 7 and / or the gas interface 6, located on the gas flow surface, which can fully equalize the airflow pressure. For example, a microporous plate 3 or a baffle plate is inserted into the gas interface 6 to equalize the pressure of the oncoming airflow, transforming the high-speed jet into a uniform low-speed flow field, reducing the overall impact intensity of the airflow entering the ventilation cavity from the source. For example, a microporous plate 3 or a baffle plate can be embedded within the acoustic coupling channel 7 to specifically force the airflow to reach the surface of the acoustic transducer unit at an extremely low velocity, avoiding direct impact noise from the airflow on the sensitive diaphragm 421 or fiber optic grating 423. The reference sensing unit 5 is located on the gas interface 6, outside the cover 1, or in the ventilation pipeline connected to the ventilation therapy mask. These locations are all areas with strong airflow noise and environmental noise, and the high correlation between the reference signal and the noise component in the breath sound signal is beneficial for the convergence of adaptive noise suppression.

[0038] In one embodiment of this application, the gas interface 6 is either a closed-loop interface or an open oxygen flow interface. In the closed-loop interface configuration, the ventilation therapy mask is connected to the anesthesia supply gas circuit via this interface to form a closed ventilation cavity 422, suitable for spontaneous breathing before anesthesia induction, denitrification oxygenation, or the anesthesia ventilation phase. In this scenario, the gas interface 6 interfaces with the gas supply circuit of the anesthesia machine / ventilator, enabling fully machine-controlled ventilation or assisted spontaneous breathing. Oxygen or mixed gases, such as one or more of O2, N2O, and volatile anesthetics, can be input into the anesthesia supply gas circuit. In the open oxygen flow interface configuration, the interface includes an oxygen inlet connector and an exhaust port. The ventilation therapy mask is connected to the oxygen supply line via the oxygen inlet connector and exhausts exhaled gas through the exhaust port, suitable for monitoring spontaneous breathing in oxygen therapy scenarios. Pure oxygen or high-concentration oxygen can be input into the oxygen supply line. Therefore, this embodiment can employ both types of interfaces to allow the same system to be adapted to different clinical ventilation therapy mask application scenarios.

[0039] In one embodiment of this application, the acoustic transducer includes a sensitive diaphragm 421 and a cavity 422 located between the sensitive diaphragm 421 and the end face of the optical fiber. Under no-pressure conditions, a spectrometer records the initial reflected interference spectrum (reference spectrum) of the acoustic transducer. When acoustic vibration acts on the sensitive diaphragm 421, the diaphragm 421 undergoes a slight elastic bending deformation, bending towards the end face of the optical fiber, causing the cavity length of the cavity 422 to decrease from its initial value. At this time, the reflected interference spectrum shifts relative to the reference spectrum. By accurately measuring the wavelength shift using the spectrometer, a precise breath sound signal is obtained using a pre-stored mechanical model of the sensitive diaphragm 421 in the system. This structure allows for higher displacement resolution under low-frequency and weak sound pressure conditions.

[0040] In another embodiment of this application, the acoustic transducer unit includes a fiber Bragg grating 423. When subjected to sound pressure and structural micro-vibrations, the fiber Bragg grating 423 experiences axial strain, causing a shift in its central reflection wavelength, which in turn induces a change in the optical signal. The wavelength shift of the fiber Bragg grating 423 is linearly related to its axial strain. The fiber optic demodulator reconstructs the breath sound signal by detecting the shift in the central wavelength of the reflection spectrum. Furthermore, multiple grating segments with different central reflection wavelengths can share the same optical fiber and demodulation channel, which is beneficial for achieving multi-point distributed monitoring.

[0041] Furthermore, the acoustic transducer unit is a multi-segment fiber Bragg grating 423, which is spaced apart and has different center reflection wavelengths to achieve wavelength division multiplexing. The multi-segment fiber Bragg gratings 423 are distributed circumferentially along the sealing gasket 2 to acquire and fuse respiratory acoustic signals from different locations. For example, four segments of fiber Bragg gratings 423 are arranged circumferentially at intervals within the annular periphery of the sealing gasket 2, with center reflection wavelengths of 1530 nm, 1540 nm, 1550 nm, and 1560 nm, respectively. The four segments share a single optical fiber and are coupled to a fiber demodulator via an optical circulator. The fiber demodulator synchronously acquires the four wavelength signals, and the signal processing module performs fusion analysis or multi-channel independent analysis on the multi-channel respiratory sound signals from different locations. For example, weighted averaging can be performed by adaptively allocating weights based on the real-time signal-to-noise ratio of each channel, or coherent accumulation of in-phase breath sound components in each channel can be performed to suppress incoherent noise, thereby improving the overall signal-to-noise ratio. When the signal amplitude or phase at a certain location deviates significantly from the other channels, the area where abnormal breath sounds occur can be located. By adopting a wavelength division multiplexing multi-point fusion scheme, the difference information of breath sounds at different spatial locations can be obtained, improving the robustness of monitoring changes in the location of the sound source under different breathing postures of the user.

[0042] Preferably, there are multiple acoustic coupling channels 7 distributed circumferentially along the sealing gasket 2. Each acoustic coupling channel 7 connects a corresponding fiber Bragg grating 423 to the ventilation cavity. The inlet of each acoustic coupling channel 7 connects to the ventilation cavity, and the outlet faces the corresponding fiber Bragg grating 423, so that the breathing sound waves at each position are conducted to the corresponding fiber Bragg grating 423 through the acoustic coupling channel 7, thereby ensuring that the fiber Bragg grating 423 at each position can be efficiently coupled to the acoustic signal.

[0043] In one embodiment of this application, the sealing gasket 2 is snapped into the periphery of the cover 1, and an embedding groove is formed within the sealing gasket 2. The fiber optic acoustic sensing component 4 is embedded within the embedding groove and encapsulated with an encapsulation material. For example, during the molding process of the sealing gasket 2, an embedding groove extending radially is reserved. After the fiber optic acoustic sensing component 4 is positioned within the groove, it is encapsulated with medical-grade silicone of the same material as the sealing gasket 2 or biocompatible material. This structure, where the fiber optic acoustic sensing component 4 is embedded within the sealing gasket 2, provides structural protection for the fiber optic acoustic sensing component 4, preventing sensor damage caused by facial pressure or friction. Simultaneously, it allows the sealing gasket 2 and the fiber optic acoustic sensing component 4 to form an integrated, replaceable module. The main body of the mask is reusable, while the sealing gasket 2 module is disposable, thus balancing infection control and cost control.

[0044] It should also be noted that the function of the "signal processing module" in this application can be implemented by an independent embedded controller or a software module running on the monitor or central monitoring station. This application does not limit the specific hardware implementation of the above modules.

[0045] The present application will be illustrated below with reference to specific embodiments.

[0046] Example 1: Please refer to it again. Figures 1-6 A ventilation therapy mask monitoring system integrating fiber optic acoustic sensing is disclosed. The system includes a ventilation therapy mask worn on the face via a headband (not shown). The ventilation therapy mask includes a mask body 1, a sealing gasket 2, and a gas interface 6. The gas interface 6 can be connected to an anesthesia supply circuit to an anesthesia machine as an anesthesia mask for patient use; or connected to an oxygen supply line to an oxygen generator as an oxygen mask for patient or user use. An exemplary case is shown in the figure when used as an anesthesia mask. The sealing gasket 2 is a flexible annular sealing gasket 2, located at the opening edge of the mask body 1, so that the mask body 1 forms a seal on the facial area when worn on the patient's face. A fiber optic acoustic sensing component 4 and a reference sensing unit 5 are provided. The fiber optic acoustic sensing component 4 includes a first optical fiber 41 and a first acoustic transducer unit 42; the reference sensing unit 5 includes a second optical fiber 51 and a second acoustic transducer unit 52. A groove is formed within the sealing gasket 2, into which a first acoustic transducer unit 42 is embedded. A first optical fiber 41 extends outward from the sealing gasket 2 from the first acoustic transducer unit 42 to connect with the fiber optic demodulator. A channel is further formed on the front side of the groove within the sealing gasket 2, extending from the first acoustic transducer unit 42 into the housing 1 to form an acoustic coupling channel 7. One end of the acoustic coupling channel 7 connects to the first acoustic transducer unit 42, and the other end connects to the ventilation cavity formed in the housing 1 when worn. A small hole is formed within the groove wall of the gas interface 6, into which a second acoustic transducer unit 52 is embedded. A second optical fiber 51 extends outward from the second acoustic transducer unit 52 to connect with the fiber optic demodulator. Both the first acoustic transducer unit 42 and the second acoustic transducer unit 52 include a sensitive diaphragm 421 and a cavity 422 located between the sensitive diaphragm 421 and the end face of the optical fiber. Continue to install a microporous plate 3 inside the gas interface 6. The periphery of the microporous plate 3 is in contact with the inner wall of the gas interface 6, so that the airflow introduced through the anesthesia gas supply circuit / oxygen supply pipeline enters the ventilation chamber after being evenly pressurized by the microporous plate 3.

[0047] Example 2: Please refer to it again. Figures 7-8Unlike the previous embodiment, both the first acoustic transducer unit 42 and the second acoustic transducer unit 52 are multi-segment fiber Bragg gratings 423, and these multi-segment fiber Bragg gratings 423 are integrated into one unit via optical fibers. An annular groove is formed circumferentially along the contour line within the sealing gasket 2, and the first acoustic transducer unit 42 is embedded within the annular groove. The first optical fiber 41 extends from the tail end of the first acoustic transducer unit 42 out of the sealing gasket 2. Similarly, an annular groove is formed circumferentially along the contour line on the outer surface of the tubular gas interface 6, and the second acoustic transducer unit 52 is embedded within the annular groove. The second optical fiber 51 extends from the tail end of the second acoustic transducer unit 52 out of the sealing gasket 2. A channel is formed within the sealing gasket 2 corresponding to the position of each fiber Bragg grating 423. Each channel extends from the fiber Bragg grating 423 into the housing 1 to form an acoustic coupling channel 7, such that one end of the acoustic coupling channel 7 connects to the fiber Bragg grating 423, and the other end connects to the ventilation cavity formed by the housing 1 when worn.

[0048] Example 3: Please refer to it again. Figure 9 The fiber optic demodulator includes a light source module, a fiber optic circulator, and a spectrometer. The output of the light source module is connected to the input of the fiber optic circulator, the output of the fiber optic circulator is connected to the acoustic transducer unit via optical fiber, and the return end of the fiber optic circulator is connected to the spectrometer. The first fiber 41 of the fiber optic acoustic sensing component 4 and the second fiber 51 of the reference sensing unit 5 are both optically connected to the fiber optic demodulator. The two fibers are responsible for transmitting the incident light from the light source module to the corresponding acoustic transducer unit, and transmitting the reflected interference light signal containing cavity length information back to the spectrometer for demodulation and digital output, realizing bidirectional transmission of optical signals.

[0049] The fiber optic demodulator transmits two signals to a signal processing module, which includes an adaptive noise suppression module. This module uses a reference electrical signal corresponding to the reference signal as the reference input to an adaptive filter and a respiratory electrical signal corresponding to the respiratory sound signal as the main input. It employs either the least mean square (LMS) or recursive least squares (RLS) algorithm to denoise the respiratory sound signal. The signal processing module further performs feature extraction on the denoised respiratory sound signal. Feature extraction may include at least one of the following: temporal envelope extraction, spectral energy distribution calculation, zero-crossing rate statistics, bandwidth estimation, and respiratory phase segmentation. Based on the extracted features, respiratory parameters are calculated. These respiratory parameters include at least one of the following: respiratory rate, inspiratory-to-expiratory ratio, ventilation intensity index, apnea events, hypoventilation events, and abnormal respiratory sound events. These respiratory parameters characterize the user's true respiratory sounds. The signal processing module compares the calculated respiratory parameters with preset thresholds. When alarm conditions are met, it generates an alarm command and transmits it to the alarm module. Alarm conditions include at least one of the following: apnea duration exceeding a preset time threshold, ventilation intensity index falling below a preset minimum ventilation threshold, inspiratory-to-expiratory ratio deviating from a preset normal range, and abnormal breathing sound event being identified. The alarm module can be an audible and visual alarm device, or it can send alarm information to a remote terminal via a communication module.

[0050] Correspondingly, regarding the second aspect, please refer to Figure 10 As shown, Figure 10 This application provides a flowchart illustrating the steps of a method for monitoring a ventilation therapy mask using integrated fiber optic acoustic sensing. The method, applied to any of the above-mentioned system embodiments, includes the following steps: S1. The ventilation therapy mask is worn on the user's face to form a ventilation cavity, so that the fiber optic acoustic sensing component 4 can sense the acoustic vibration caused by the airflow in the ventilation cavity and generate changes in the optical signal. S2. The optical signal change transmitted by the fiber optic acoustic sensing component 4 is obtained by the optical demodulator and converted into a respiratory electrical signal. At the same time, the reference signal transmitted by the reference sensing unit 5 is obtained and converted into a reference electrical signal. S3. The signal processing module performs adaptive noise suppression based on the respiratory electrical signal and the reference electrical signal, and extracts features from the noise-reduced signal to obtain the user's real breathing sound.

[0051] It should be noted that, for the method embodiments, the embodiments of this application are not limited to the described order of actions, because according to the embodiments of this application, some steps may be performed in other orders or simultaneously.

[0052] The above method embodiments are basically similar to the system embodiments, so the description is relatively simple. For relevant details, please refer to the description of the system embodiments.

[0053] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0054] It should also be noted that, in this document, the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor should they be construed as indicating or implying relative importance. Moreover, the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device.

[0055] The above provides a detailed description of the ventilation therapy mask monitoring system and method integrating fiber optic acoustic sensing provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand this application, and the content of this specification should not be construed as limiting this application. Furthermore, those skilled in the art will recognize that various modifications may be made to the specific implementation methods and application scope based on this application. It is neither necessary nor possible to exhaustively list all implementation methods here, but obvious variations or modifications derived therefrom are still within the protection scope of this application.

Claims

1. A ventilation therapy mask monitoring system integrating fiber optic acoustic sensing, characterized in that, The system includes: The ventilation therapy mask is configured to contact the user's face and form an air cavity; An optical fiber acoustic sensing component is disposed within the ventilation cavity; wherein, the optical fiber acoustic sensing component includes an optical fiber and an acoustic transducer unit disposed on the optical fiber, the acoustic transducer unit being used to convert the acoustic vibration caused by the airflow within the ventilation cavity into changes in optical signals for transmission through the optical fiber. A reference sensing unit is disposed outside the ventilation cavity and is used to collect reference signals including airflow noise and / or ambient noise. At least one acoustic coupling channel is provided between the ventilation cavity and the acoustic transducer unit to facilitate the conduction of the acoustic vibration to the acoustic transducer unit. A buffer structure is provided inside the ventilation cavity to reduce the impact of airflow input into the ventilation cavity on the acoustic transducer unit. The signal processing module is communicatively connected to the fiber optic acoustic sensing component and the reference sensing unit, respectively, and is used to perform adaptive noise suppression and feature extraction on the changes in the optical signal and the reference signal to obtain the user's real breathing sound.

2. The ventilation therapy mask monitoring system integrating fiber optic acoustic sensing according to claim 1, characterized in that, The ventilation therapy mask includes a mask body, a sealing gasket, and a gas interface for receiving the airflow; wherein, Both the fiber optic acoustic sensing component and the acoustic coupling channel are disposed within the sealing gasket or the enclosure; and the acoustic coupling channel is located on the side of the fiber optic acoustic sensing component facing the ventilation cavity. The buffer structure is disposed within the acoustic coupling channel and / or the gas interface; wherein the buffer structure includes at least one of a microporous plate and a baffle plate; The reference sensing unit is located anywhere on the gas interface, outside the mask, or in the ventilation pipeline connected to the ventilation therapy mask.

3. The ventilation therapy mask monitoring system integrating fiber optic acoustic sensing according to claim 1, characterized in that, The system also includes a vibration isolation layer, which is in close contact with the side of the acoustic transducer unit away from the ventilation cavity, to reduce the transmission of external vibrations to the acoustic transducer unit.

4. The ventilation therapy mask monitoring system integrating fiber optic acoustic sensing according to claim 2, characterized in that, The gas interface is a closed-loop interface or an open oxygen flow interface; the ventilation pipeline includes an anesthesia gas supply circuit or an oxygen supply pipeline. The ventilation therapy mask is connected to the anesthesia gas supply circuit via the sealed circuit interface and is used for spontaneous breathing before anesthesia induction, denitrification oxygenation, or anesthesia ventilation. The open oxygen flow interface includes an oxygen inlet connector and an exhaust port. The ventilation therapy mask is connected to the oxygen supply pipeline via the oxygen inlet connector and the exhaled gas is discharged through the exhaust port for monitoring spontaneous breathing in oxygen therapy scenarios.

5. The ventilation therapy mask monitoring system integrating fiber optic acoustic sensing according to claim 1, characterized in that, The acoustic transducer unit includes a sensitive diaphragm and a cavity located between the sensitive diaphragm and the end face of the optical fiber; wherein, when the sensitive diaphragm is subjected to acoustic vibration, it flexes, causing the cavity length of the cavity to change, thereby triggering a change in the optical signal.

6. The ventilation therapy mask monitoring system integrating fiber optic acoustic sensing according to claim 1, characterized in that, The acoustic transducer unit includes a fiber Bragg grating; wherein, when the fiber Bragg grating is subjected to acoustic vibration, it undergoes strain, causing the center reflection wavelength of the fiber Bragg grating to drift, thereby triggering a change in the optical signal.

7. A ventilation therapy mask monitoring system integrating fiber optic acoustic sensing according to claim 6, characterized in that, The acoustic transducer unit is a multi-segment fiber grating, and the multiple fiber gratings are spaced apart and have different center reflection wavelengths to achieve wavelength division multiplexing. Among them, multiple fiber optic gratings are distributed circumferentially along the sealing pad of the ventilation therapy mask to acquire acoustic signals at different locations; The acoustic coupling channels are multiple and distributed circumferentially along the sealing gasket, and each acoustic coupling channel connects a corresponding section of the fiber optic grating to the ventilation cavity.

8. The ventilation therapy mask monitoring system integrating fiber optic acoustic sensing according to claim 1, characterized in that, The system also includes an optical fiber demodulator connected to the optical fiber acoustic sensing component and the reference sensing unit respectively, for converting the optical signal change and the reference signal into a respiratory electrical signal and a reference electrical signal respectively. The fiber optic demodulator is also communicatively connected to the signal processing module, and is used to transmit the respiratory electrical signal and the reference electrical signal to the signal processing module.

9. A ventilation therapy mask monitoring system integrating fiber optic acoustic sensing according to claim 2, characterized in that, The sealing gasket is snapped into the periphery of the cover, and an embedding groove is formed in the sealing gasket. The fiber optic acoustic sensing component is embedded in the embedding groove and encapsulated with encapsulation material.

10. A method for monitoring a ventilation therapy mask integrating fiber optic acoustic sensing, characterized in that, The method, applied to the system as described in any one of claims 1 to 9, comprises: The ventilation therapy mask is worn on the user's face and forms a ventilation cavity, allowing the fiber optic acoustic sensing component to sense the acoustic vibration caused by the airflow in the ventilation cavity and generate changes in the optical signal. The optical signal changes transmitted by the fiber optic acoustic sensing component are acquired by the optical demodulator and converted into a respiratory electrical signal. At the same time, the reference signal transmitted by the reference sensing unit is acquired and converted into a reference electrical signal. The signal processing module performs adaptive noise suppression based on the respiratory electrical signal and the reference electrical signal, and extracts features from the noise-reduced signal to obtain the user's true breathing sound.

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