Device and method for simulating breathing depth and frequency of thoracico-abdominal breathing bandage of polysleep monitor

Abstract

The invention relates to the technical field of medical equipment, and discloses a breathing depth and frequency simulation device and method for a thoracico-abdominal breathing bandage of a polysleep monitor, and the device comprises a standard simulation person which simulates the sleep posture of a human body and the fluctuation change of the chest in the breathing process; the active respiration simulator is connected with the inflatable lung, comprises a control device, an air pump assembly and a feedback control unit, and is used for setting respiration frequency, amplitude and mode through the control device, generating mechanical ventilation pressure to drive expansion and contraction of the inflatable lung and simulating chest movement in deep and shallow sleep, irregular respiration and apnea states; and the breathing displacement waveform monitoring module comprises a sensing circuit, a signal conversion unit and a data processing unit and is used for monitoring the displacement change of the chest of the standard simulation human, converting a capacitance signal into a voltage signal and calculating the breathing depth, frequency and mode through the data processing unit. According to the invention, the sleep posture of the human body is simulated, and the fluctuation change of the chest in the sleep breathing process of the human body is simulated.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a simulation device and method for respiratory depth and frequency of a thoracic and abdominal respiration band of a polysomnograph. Background Art

[0002] A polysomnograph is a medical device used for diagnosing sleep disorders, which records various physiological signals, including respiratory depth, respiratory frequency, electroencephalogram, electrooculogram, electromyogram, electrocardiogram, and respiratory activity, for evaluating the respiratory pattern of a person during sleep. In polysomnography, respiratory depth and respiratory frequency are generally measured by the method of thoracic and abdominal belts. The thoracic and abdominal belts are elastic bands that surround the chest and abdomen, and are internally configured with sensors that can detect the pressure changes or deformations generated with respiratory movements, thereby reflecting the depth of respiration.

[0003] However, there is currently no corresponding measurement standard in China for measuring the accuracy of the sensors of the thoracic and abdominal belts of polysomnographs, and respiratory depth and respiratory frequency play a crucial role in the diagnosis of sleep disorders.

[0004] Therefore, it is necessary to provide a simulation device and method for respiratory depth and frequency of a thoracic and abdominal respiration band of a polysomnograph. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the present invention provides a simulation device and method for respiratory depth and frequency of a thoracic and abdominal respiration band of a polysomnograph to solve the above technical problems.

[0006] In a first aspect, a simulation device for respiratory depth and frequency of a thoracic and abdominal respiration band of a polysomnograph is provided, including:

[0007] A standard simulation human for simulating the undulation changes of the chest during the human body's sleeping posture and breathing process, the standard simulation human including an inflatable lung and an adjustable chest outline;

[0008] An active breathing simulator connected to the inflatable lung, including an embedded control device, an air pump assembly, and a feedback control unit, for setting the breathing frequency, amplitude, and mode through the embedded control device, generating mechanical ventilation pressure to drive the expansion and contraction of the inflatable lung, and simulating the chest movements in light and deep sleep, irregular breathing, and apnea states;

[0009] A respiratory displacement waveform monitoring module, including a sensing circuit, a signal conversion unit, and a data processing unit, for real-time monitoring of the displacement changes of the chest of the standard simulation human, converting capacitance signals into voltage signals, and calculating the respiratory depth, frequency, and mode through the data processing unit.

[0010] Furthermore, the standard human simulator includes:

[0011] A plurality of simulated human bodies with different height lengths for simulating different body type differences;

[0012] A plurality of lung sacs with different hardnesses for simulating the differences in lung compliance of people of different age groups. Among them, the hardness of the lung sac is associated with the expansion and contraction characteristics when gas is filled / extracted.

[0013] Furthermore, the air pump assembly is connected to the inflatable lung through a gas conduit.

[0014] Furthermore, the feedback control unit is connected to the respiratory displacement waveform monitoring module, configured to receive the chest displacement feedback signal, and dynamically adjust the drive signal through the PID control algorithm.

[0015] Furthermore, the sensing circuit includes:

[0016] A moving electrode plate fixed to the chest of the human simulator;

[0017] A fixed electrode plate fixed to the chest of the human simulator and arranged in parallel with the moving electrode plate, with the distance changing with the chest undulation;

[0018] An operational amplifier circuit for converting the capacitance change into a linear voltage signal;

[0019] An oscilloscope device for displaying the voltage waveform and converting it into a respiratory displacement value.

[0020] Furthermore, the data processing unit is configured to:

[0021] Perform high-pass filtering on the voltage signal to eliminate low-frequency noise;

[0022] Extract the instantaneous respiratory rate through discrete wavelet transform;

[0023] Based on the amplitude standard deviation, apnea duration, and baseline displacement parameters, determine the respiratory pattern through a decision tree classifier.

[0024] In a second aspect, there is provided a method for simulating the respiratory depth and frequency of the thoracic and abdominal respiratory band of a polysomnography monitor. Based on the simulation device for the respiratory depth and frequency of the thoracic and abdominal respiratory band of the polysomnography monitor described in any one of the foregoing, it includes:

[0025] Simulate the chest undulation under different body types and lung compliance conditions through a standard human simulator;

[0026] Generate a target respiratory waveform through an active breathing simulator, and dynamically adjust the mechanical ventilation pressure based on the PID algorithm to match the target respiratory waveform;

[0027] The thoracic displacement is measured in real time by the respiratory displacement waveform monitoring module, converted into respiratory depth and frequency parameters, and the respiratory pattern is classified and identified.

[0028] Further, the generation of the target respiratory waveform includes:

[0029] Select the corresponding mathematical expression according to the preset mode;

[0030] Set waveform parameters by combining the actual data of the population and clinical standards.

[0031] Further, the classification and identification of the respiratory pattern include:

[0032] Calculate the standard deviation of the instantaneous frequency, the standard deviation of the amplitude, and the duration of apnea;

[0033] Judge the current respiratory pattern as deep sleep, light sleep, apnea, or irregular breathing through the decision rule.

[0034] The invention adopting the above technical solution has the following advantages:

[0035] The present invention is used to simulate the posture of the human body during sleep and the undulation of the chest during the sleep breathing process of the human body; the active breathing simulation module is used to simulate the active breathing process of the human body, generate external mechanical ventilation pressure through the feedback control unit, and simulate the chest undulation in different situations of deep sleep, light sleep, irregular breathing, and apnea of the human body; the respiratory displacement waveform monitoring module is used to measure and display the displacement of the simulated human chest and calculate the respiratory depth. Description of the Drawings

[0036] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the specific embodiments will be briefly introduced below. In all the drawings, the components or parts do not necessarily draw according to the actual proportion.

[0037] Figure 1 It is a flowchart of the simulation device and method for the respiratory depth and frequency of the thoracic and abdominal respiration strap of the polysomnograph of the present invention;

[0038] Figure 2 It is a structural schematic diagram of the simulation device and method for the respiratory depth and frequency of the thoracic and abdominal respiration strap of the polysomnograph of the present invention;

[0039] Figure 3 It is a schematic diagram of the sensing circuit in the simulation device and method for the respiratory depth and frequency of the thoracic and abdominal respiration strap of the polysomnograph of the present invention;

[0040] Reference Signs:

[0041] Standard simulation man 1, inflatable lungs 2, active breathing simulator 3, sensing circuit 4, gas conduit 5, oscilloscope device 6, operational amplifier circuit 7

[0042] Moving electrode plate 41, fixed electrode plate 42 Specific implementation mode

[0043] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application

[0044] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices

[0045] Referring to "embodiment" in the present application means that the specific features, structures or characteristics described in connection with the embodiment may be included in at least one embodiment of the present application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described in the present application can be combined with other embodiments

[0046] As Figures 1 to 3 shown, the simulation device for the breathing depth and frequency of the chest and abdomen breathing band of the polysomnography monitor of the present invention includes

[0047] A standard simulation man 1, used to simulate the undulation changes of the chest during the human sleep posture and breathing process. The standard simulation man 1 includes an inflatable lung 2 and an adjustable chest outline

[0048] An active breathing simulator 3, connected to the inflatable lungs 2, includes an embedded control device (STM32), an air pump assembly and a feedback control unit, and is used to set the breathing frequency, amplitude and mode through the embedded control device, generate mechanical ventilation pressure to drive the expansion and contraction of the inflatable lungs 2, and simulate the chest movements in light and deep sleep, irregular breathing and apnea states

[0049] The breathing displacement waveform monitoring module includes a sensing circuit 4, a signal conversion unit, and a data processing unit, and is used to monitor the displacement change of the chest of the standard manikin 1 in real time, convert the capacitance signal into a voltage signal, and calculate the breathing depth, frequency, and pattern through the data processing unit.

[0050] Specifically, the present invention is used to simulate the posture of the human body during sleep and the undulation change of the chest during the sleep breathing process of the human body; the active breathing simulation module is used to simulate the active breathing process of the human body, generate an external mechanical ventilation pressure through the feedback control unit, and simulate the chest undulation in different situations such as deep sleep, irregular breathing, and apnea of the human body; the breathing displacement waveform monitoring module is used to measure and display the displacement of the chest of the manikin and calculate the breathing depth.

[0051] In this embodiment, the air pump assembly is connected to the inflatable lungs 2 through the gas conduit 5.

[0052] In this embodiment, the feedback control unit is connected to the breathing displacement waveform monitoring module, and is used to receive the chest displacement feedback signal and dynamically adjust the driving signal through the PID control algorithm.

[0053] Specifically, the active breathing simulator 3 further includes a valve assembly. Among them, the embedded control device is used to set the sleep breathing frequency, amplitude, and pattern, control the air pump assembly to generate air pressure, and compensate for errors through the PID control algorithm to make the breathing amplitude of the manikin reach the set waveform;

[0054] The PID control algorithm is an algorithm program running on the embedded control device, and is used to control the expansion and contraction of the chest of the manikin, calculate the error according to the preset breathing waveform frequency, amplitude, and pattern, and adjust the driving pressure according to the error, and adopt different proportional parameters, integral parameters, and differential parameters in different situations such as deep sleep, irregular breathing, and apnea of the human body to make the manikin respond quickly. The specific steps of the algorithm are as follows:

[0055] S1: Set the frequency, amplitude, and pattern of the breathing movement of the manikin. Among them, the patterns include deep sleep breathing pattern, shallow sleep breathing pattern, apnea pattern, and irregular breathing pattern;

[0056] S2: Generate a breathing pattern waveform. The deep sleep and shallow sleep breathing patterns of the manikin are expressed as:

[0057] D(t) = Asin(2πft) + D0

[0058] In the formula, f represents the frequency, A represents the amplitude, t represents the time, and D0 is the baseline displacement of the chest of the manikin.

[0059] Among them, the deep sleep breathing pattern has a larger amplitude and a slower frequency compared to the shallow sleep. The specific numerical settings should refer to the actual values of the local population and relevant norms and standards.

[0060] The apnea pattern of the simulated human is expressed as:

[0061]

[0062] In the formula, T1 is the normal breathing time period, and T2 is the set apnea time period.

[0063] The irregular breathing pattern of the simulated human can be expressed as:

[0064] D(t) = Ae -αt sin(2πft) + D0

[0065] S3: Set the initial value of the air pump pressure and apply air pressure to the simulated human.

[0066] S4: The simulated human's chest generates displacement, and the breathing displacement waveform monitoring module measures and feeds back the actual value of the chest displacement of the simulated human to obtain the actual displacement.

[0067] S5: Calculate the error between the actual value and the set value of the simulated human's chest displacement, expressed as:

[0068] e(t) = r(t) - y(t)

[0069] In the formula, r(t) represents the target displacement, and y(t) represents the actual displacement.

[0070] S6: Calculate the feedback correction air pump output pressure and return to S4, expressed as:

[0071]

[0072] In the formula, u(t) is the air pump output air pressure, e(t) is the feedback error, K p is the proportionality coefficient, K i is the integral coefficient, K d is the differential coefficient;

[0073] The air pump assembly and the valve assembly receive signals from the embedded control device and generate air pressure to drive the expansion and contraction of the simulated human lung sac.

[0074] The gas conduit 5 is used to connect the inflatable lung 2 and conduct gas into or out of the inflatable lung 2.

[0075] In another embodiment, the active breathing simulator 3 can also be a ventilator.

[0076] In this embodiment, the standard simulated human 1 includes:

[0077] Multiple simulated human bodies with different heights and lengths, used to simulate different body shape differences;

[0078] Multiple lung sacs with different hardnesses, used to simulate the differences in lung compliance among people of different age groups. Among them, the hardness of the lung sac is associated with the expansion and contraction characteristics when gas is filled / extracted.

[0079] Specifically, a series of simulated human bodies with different heights and lengths are used to simulate the chest contour of the human body. As the inflatable lungs 2 expand and contract, the breathing straps of the wearable polysomnography monitor on the outer chest can simulate different body shape differences of the human body;

[0080] A series of lung sacs with different hardnesses are used to simulate the expansion process of inhaling gas and the contraction process of exhaling gas in the human lungs. When gas is filled into the lungs, the two lung lobes expand accordingly. When gas is extracted from the lungs, the two lung lobes contract accordingly, and the differences in lung compliance among people of different age groups can be simulated.

[0081] In this embodiment, the sensing circuit 4 includes:

[0082] A moving electrode plate 41, fixed to the chest of the simulated human body;

[0083] A fixed electrode plate 42, fixed to the chest of the simulated human body and arranged in parallel with the moving electrode plate, and the distance between them changes with the ups and downs of the chest;

[0084] An operational amplifier circuit 7, used to convert the capacitance change into a linear voltage signal;

[0085] An oscilloscope device 6, used to display the voltage waveform and convert it into a respiratory displacement value.

[0086] In this embodiment, the data processing unit is configured to:

[0087] Perform high-pass filtering on the voltage signal to eliminate low-frequency noise;

[0088] Extract the instantaneous respiratory rate through discrete wavelet transform;

[0089] Based on the amplitude standard deviation, apnea duration, and baseline displacement parameters, determine the respiratory pattern through a decision tree classifier.

[0090] Specifically, the respiratory displacement waveform monitoring module can measure and display the displacement of the chest of the simulated human body, and monitor the respiratory state of the simulated human body. Among them, the sensing circuit 4 is a circuit that measures distance through capacitance change. This circuit sets a moving electrode plate at the position of the chest of the simulated human body, and sets a fixed electrode plate 42 at a certain distance directly above the moving electrode plate 41. The up and down movement of the chest of the simulated human body will cause a change in the capacitance between the moving electrode plate 41 and the fixed electrode plate 42. Let the plate spacing be d, and the capacitance between the variable pole distance plates be C x , Therefore, the depth of the simulated human ventilator is expressed as:

[0091]

[0092] Wherein, d is the measurement result of the breathing depth, A is the relative coverage area of the electrode plates, ε0 is the vacuum permittivity, and ε r is the relative permittivity of the medium between the plates, ε is the permittivity of the medium between the electrode plates, and ε = ε0ε r .

[0093] The operational amplifier circuit 7 further converts the capacitance signal into a voltage signal. The relationship between the output voltage and the input voltage of the operational amplifier circuit 7 is:

[0094]

[0095] Wherein, C0 is a capacitor with a fixed capacitance value, and C x is the variable capacitance between the pole plates, and the amplification factor of the connected amplifier is K.

[0096] The oscilloscope device 6 displays and measures the voltage waveform and converts the value of the voltage waveform into a displacement value simulating the breathing movement of the human chest. By combining the above two formulas, we can obtain:

[0097]

[0098] Wherein, u0 is the output voltage of the operational amplifier circuit, u i is the input voltage of the operational amplifier circuit, C0 is a capacitor with a fixed capacitance value, ε is the permittivity of the medium between the electrode plates, A is the relative coverage area of the electrode plates, and then the breathing depth after being amplified by the operational circuit becomes a voltage value, and the voltage value and the breathing depth are linearly related:

[0099] The algorithm for simulating human breathing monitoring mainly calculates the current breathing mode, breathing frequency and breathing depth of the simulated human according to the voltage value signal waveform. The specific process is as follows:

[0100] S1: Eliminate low-frequency interference from the voltage value signal through a high-pass filter (cutoff frequency 0.1 Hz);

[0101] S2: Set the sampling frequency of the digital signal, decompose the digital signal using the Morlet wavelet, and define the Morlet mother wavelet, which is expressed as:

[0102]

[0103] Wherein, ψ(t) represents the Morlet mother wavelet at a time point, ω0 is the center frequency of the mother wavelet, and the discrete wavelet transform of the digital signal is performed to obtain the transform coefficient, which is expressed as:

[0104]

[0105] Where W T (s,n) is the coefficient of variation of discrete wavelet transform, s is the scale parameter, n is the displacement parameter, x(k) is the discrete digital signal of voltage wave, ψ * is the complex conjugate of the wavelet, and the estimation of respiratory frequency is expressed as:

[0106] f resp (t)=argmax(W T (s,n))

[0107] Where, f resp (t) is the estimated homeopathic frequency;

[0108] S3: Display and measure the output voltage on the oscilloscope to obtain a curve that changes with time, and take the maximum value u of this digital signal max and minimum value u min , then the accuracy of the measurement of breathing depth is:

[0109]

[0110] Where d is the measurement of breathing depth, ε is the dielectric constant of the medium between the plates, C0 is a capacitor with a fixed capacitance value, and A is the relative area covered by the plates.

[0111] S4: Set the pattern discrimination rule and use the decision tree classifier to classify the voltage waveform digital signal. The pattern discrimination rule is expressed as:

[0112]

[0113] In the formula, δ f represents the instantaneous frequency standard deviation, δ d represents the standard deviation of deep sleep amplitude, δ A represents the standard deviation of light sleep amplitude, f resp represents the estimated instantaneous frequency, d mean represents the average respiratory amplitude, T apnea Indicates the duration of apnea, d base represents the baseline breathing depth, d peak Indicates the peak of apnea.

[0114] In other embodiments, a method for simulating the breathing depth and frequency of a polysomnographic chest-abdominal breathing strap is provided. The device for simulating the breathing depth and frequency of a polysomnographic chest-abdominal breathing strap based on any of the above items includes:

[0115] The standard simulator 1 is used to simulate chest rise and fall under different body shapes and lung compliance conditions;

[0116] Generate a target breathing waveform through the active breathing simulator 3, and dynamically adjust the mechanical ventilation pressure based on the PID algorithm to match the target breathing waveform;

[0117] Measure the chest displacement in real time through the breathing displacement waveform monitoring module, convert it into breathing depth and frequency parameters, and classify and identify the breathing mode.

[0118] In this embodiment, the generation of the target breathing waveform includes:

[0119] Select the corresponding mathematical expression according to the preset mode;

[0120] Set the waveform parameters by combining the actual data of the population and clinical standards.

[0121] In this embodiment, the classification and identification of the breathing mode include:

[0122] Calculate the standard deviation of the instantaneous frequency, the standard deviation of the amplitude, and the apnea duration;

[0123] Judge the current breathing mode as deep sleep, light sleep, apnea, or irregular breathing through the decision tree rule.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. Simulation device for respiratory depth and frequency of thoracic and abdominal respiration straps of polysomnography monitor, characterized in that, Comprising: A standard mannequin, used to simulate the sleeping posture of the human body and the chest undulation during the breathing process. The standard mannequin includes an inflatable lung and an adjustable chest contour; An active breathing simulator, connected to the inflatable lung, including an embedded control device, a gas pump assembly and a feedback control unit, used to set the breathing frequency, amplitude and mode through the embedded control device, generate mechanical ventilation pressure to drive the expansion and contraction of the inflatable lung, and simulate the chest movement under light sleep, irregular breathing and apnea states; A respiratory displacement waveform monitoring module, including a sensing circuit, a signal conversion unit and a data processing unit, used to monitor the displacement change of the chest of the standard mannequin in real time, convert the capacitance signal into a voltage signal, and calculate the breathing depth, frequency and mode through the data processing unit.

2. The simulation device for respiratory depth and frequency of the chest and abdomen breathing strap of the polysomnography monitor according to claim 1, characterized in that, The standard mannequin includes: Multiple simulated human bodies with different height lengths, used to simulate different body type differences; Multiple lung sacs with different hardnesses, used to simulate the differences in lung compliance of people in different age groups. Among them, the hardness of the lung sac is associated with the expansion and contraction characteristics when gas is filled / extracted.

3. The simulation device for respiratory depth and frequency of the chest and abdomen respiration strap of the polysomnography monitor according to claim 1, characterized in that The gas pump assembly is connected to the inflatable lung through a gas conduit.

4. The simulation device for respiratory depth and frequency of the chest and abdomen breathing strap of the polysomnography monitor according to claim 1, wherein, The feedback control unit is connected to the respiratory displacement waveform monitoring module, used to receive the chest displacement feedback signal, and dynamically adjust the driving signal through the PID control algorithm.

5. The simulation device for respiratory depth and frequency of the chest and abdomen breathing strap of the polysomnography monitor according to claim 1, characterized in that, The sensing circuit includes: A moving electrode plate, fixed to the chest of the mannequin; A fixed electrode plate, fixed to the chest of the mannequin and arranged parallel to the moving electrode plate, with the distance changing with the chest undulation; An operational amplifier circuit, used to convert the capacitance change into a linear voltage signal; An oscilloscope device, used to display the voltage waveform and convert it into a respiratory displacement value.

6. The simulation device for respiratory depth and frequency of the chest and abdomen breathing strap of the polysomnography monitor according to claim 5, wherein The data processing unit is configured to: Perform high-pass filtering on the voltage signal to eliminate low-frequency noise; Extract the instantaneous value of the respiratory rate through discrete wavelet transform; Based on the amplitude standard deviation, apnea duration and baseline displacement parameters, determine the breathing mode through a decision tree classifier.

7. A method for simulating the breathing depth and frequency of a chest and abdomen breathing strap of a polysomnography monitor, characterized in that, An analog device for the breathing depth and frequency of the polysomnography chest and abdomen breathing strap according to any one of claims 1 to 6, including: Simulating the chest undulation under different body types and lung compliance conditions through a standard mannequin; Generating a target breathing waveform through an active breathing simulator, and dynamically adjusting the mechanical ventilation pressure based on the PID algorithm to match the target breathing waveform; Measuring the chest displacement in real time through a respiratory displacement waveform monitoring module, converting it into breathing depth and frequency parameters, and classifying and identifying the breathing mode.

8. The method for simulating the breathing depth and frequency of the chest and abdomen breathing strap of the polysomnography monitor according to claim 7, characterized in that, The generation of the target breathing waveform includes: Selecting the corresponding mathematical expression according to the preset mode; Setting the waveform parameters in combination with the actual data of the population and clinical standards.

9. The method for simulating the breathing depth and frequency of the chest and abdomen breathing strap of the polysomnography monitor according to claim 7, characterized in that, The classification and identification of the breathing mode includes: Calculating the instantaneous frequency standard deviation, amplitude standard deviation and apnea duration; Judging the current breathing mode as deep sleep, light sleep, apnea or irregular breathing through the decision tree rule.

Images