Automatic pressure control system and method for hyperbaric oxygen chamber for detecting pressure equilibrium state between outer ear and middle ear

Abstract

In an automatic pressure control system for a hyperbaric oxygen chamber for detecting the pressure equilibrium state between an outer ear and an inner ear, according to an embodiment of the present disclosure, at least one processor may be configured to: calculate an admittance of an eardrum on the basis of the energy level of output waves output from a speaker and the energy level of reflected waves input from a microphone; determine whether a pressure equilibrium state has occurred, on the basis of a change in the calculated admittance; and control an air supply valve on the basis of the determination of whether a pressure equilibrium state has occurred.

Description

Automatic pressure control system and method for a hyperbaric oxygen chamber for detecting pressure equilibrium between the outer ear and the middle ear

[0001] The present disclosure relates to an automatic pressure control system and method of a hyperbaric oxygen chamber that detects a pressure equilibrium state between the outer ear and the middle ear.

[0002] Hyperbaric oxygen therapy is a treatment method that supplies patients with close to 100% oxygen at a pressure more than twice that of atmospheric pressure using a hyperbaric oxygen chamber. It is mainly used for treating decompression sickness, air embolism, gas poisoning, wound treatment, and burn treatment.

[0003] Conventional automatic pressure control systems in hyperbaric oxygen chambers rely on the treatment table to control pressure without considering the patient's condition. However, the pressure difference between the outer and middle ear in the pressurized environment of hyperbaric oxygen therapy can cause middle ear barotrauma. Middle ear barotrauma can cause symptoms ranging from mild pain to congestion and bleeding, and in severe cases, it can even lead to rupture of the eardrum.

[0004] To prevent this type of middle ear barotrauma, methods such as the use of nasal sprays and very slow pressure application have been implemented. However, these methods cannot completely prevent middle ear barotrauma, and their biggest drawback is that during treatment, medical professionals must rely on the patient's subjective impressions through conversation to determine whether middle ear barotrauma has occurred.

[0005] Therefore, a patient-tailored treatment system was needed that could objectively determine whether or not middle ear trauma occurred during hyperbaric oxygen therapy and change the degree of compression according to the patient's condition.

[0006] One purpose of the present disclosure is to objectively determine the pressure difference between the outer and middle ear of a patient receiving hyperbaric oxygen therapy.

[0007] In addition, one purpose of the present disclosure is to automatically control the pressure of a hyperbaric oxygen chamber so that a patient receiving hyperbaric oxygen therapy does not suffer from middle ear trauma.

[0008] However, the technical tasks that this embodiment seeks to accomplish are not limited to the technical tasks described above, and other technical tasks may exist.

[0009] An automatic pressure control system of a hyperbaric oxygen chamber for detecting a pressure equilibrium state between the outer ear and the middle ear according to one embodiment of the present disclosure may include a chamber having a space formed therein in which a patient can be positioned, a probe configured to be mounted on the patient's ear and including a speaker configured to output sound waves and a microphone configured to receive sound waves, an MCU module electrically connected to the probe, an air supply valve configured to open or close an air passage connected to the chamber, an exhaust valve configured to open or close an exhaust passage connected to the chamber, and at least one processor. The MCU module may be configured to output an output wave by the speaker and to receive a reflected wave reflected from the eardrum of the patient by the microphone. The at least one processor may be configured to calculate an admittance of the eardrum based on an energy level of an output wave output from the speaker and an energy level of a reflected wave input from the microphone, determine whether a pressure equilibrium state has occurred based on a change in the calculated admittance, and control the supply valve based on the determined occurrence of the pressure equilibrium state.

[0010] An automatic pressure control method of a hyperbaric oxygen chamber for detecting a pressure equilibrium state between the outer ear and the middle ear according to one embodiment of the present disclosure may include the steps of: outputting an output wave by a speaker, and receiving a reflected wave reflected from the eardrum of the patient by a microphone, wherein the speaker and the microphone are included in a probe configured to be mounted on the ear of the patient; calculating an admittance of the eardrum based on an energy level of the output wave output from the speaker and an energy level of the reflected wave input from the microphone; determining whether the pressure equilibrium state has occurred based on a change in the calculated admittance; and controlling an air supply valve configured to open or block an air supply passage connected to the chamber based on the determined occurrence of the pressure equilibrium state.

[0011] According to one embodiment of the present disclosure, the pressure difference between the outer ear and the middle ear can be objectively determined by detecting the condition of the patient's eardrum.

[0012] In addition, this can prevent middle ear trauma in patients, ensure safety, and improve the efficiency of pressure control in the hyperbaric oxygen chamber.

[0013] FIG. 1 is a block diagram schematically illustrating an automatic pressure control system of a high-pressure oxygen chamber according to one embodiment of the present disclosure.

[0014] FIG. 2 is a signal flow diagram of an automatic pressure control system of a high-pressure oxygen chamber according to one embodiment of the present disclosure.

[0015] FIG. 3 is a drawing showing a probe according to one embodiment of the present disclosure.

[0016] FIG. 4 is a drawing showing a probe according to one embodiment of the present disclosure inserted into a patient's ear.

[0017] FIG. 5 is a block diagram of an MCU module according to one embodiment of the present disclosure.

[0018] Fig. 6 is a circuit diagram of a speaker driving circuit according to one embodiment of the present disclosure.

[0019] Fig. 7 is a circuit diagram of a microphone driving circuit according to one embodiment of the present disclosure.

[0020] FIGS. 8A to 8C illustrate interface screens of an automatic pressure control program according to one embodiment of the present disclosure.

[0021] Figure 9 is a graph showing the results of admittance measurement when the Valsalva maneuver was performed.

[0022] Figure 10 is a graph showing the change pattern of admittance during Valsalva ventilation.

[0023] Figure 11 is a graph showing the results of admittance measurement according to saliva swallowing.

[0024] Figure 12 is a graph showing the change pattern of admittance according to swallowing.

[0025] FIG. 13 is a flowchart of an automatic pressure control method of a hyperbaric oxygen chamber for detecting a pressure equilibrium state between the outer ear and the middle ear according to one embodiment of the present disclosure.

[0026] Below, with reference to the attached drawings, embodiments of the present invention are described in detail to facilitate easy implementation by those skilled in the art. However, the present invention can be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, irrelevant parts have been omitted for clarity, and similar reference numerals have been used throughout the specification to indicate similar elements.

[0027] Throughout this specification, when it is said that an element is "on" another element, this includes not only cases where the element is in contact with the other element, but also cases where another element exists between the two elements.

[0028] Throughout this specification, whenever a part is said to "include" a component, this means that it may include other components, but not to the exclusion of other components, unless otherwise specifically stated.

[0029] The terms "about," "substantially," and the like used throughout this specification are used to mean at or near the numerical values ​​when manufacturing and material tolerances inherent to the meanings stated are presented, and are used to prevent unscrupulous infringers from unfairly exploiting disclosures that state precise or absolute values ​​to aid understanding of this specification. The terms "step of doing" or "step of" used throughout this specification do not mean "step for doing."

[0030] Throughout this specification, the term "combination(s) thereof" included in the expressions in the Makushi format means one or more mixtures or combinations selected from the group consisting of the components described in the expressions in the Makushi format, and means including one or more selected from the group consisting of said components.

[0031] Throughout this specification, references to “A and / or B” mean “A or B, or A and B.”

[0032] Hereinafter, implementation examples and embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention may not be limited to these implementation examples and embodiments and drawings.

[0033] FIG. 1 is a block diagram schematically illustrating an automatic pressure control system for a high-pressure oxygen chamber according to one embodiment of the present disclosure. FIG. 2 is a signal flow diagram of an automatic pressure control system for a high-pressure oxygen chamber according to one embodiment of the present disclosure.

[0034] Referring to FIGS. 1 and 2, an automatic pressure control system of a hyperbaric oxygen chamber according to one embodiment includes a chamber (10), a probe (20), an MCU module (30), a supply valve (50), an exhaust valve (60), and / or a processor (40).

[0035] According to one embodiment, a chamber (10) may be configured to allow a patient to enter and receive hyperbaric oxygen therapy. To this end, the chamber (10) may be formed as a sealed container structure that forms a space within which a patient can be positioned, and may be provided with an entrance / exit.

[0036] According to one embodiment, the chamber (10) may be provided in a cylindrical shape. Accordingly, the internal pressure performance, which can withstand the pressure difference between the exterior and interior of the chamber (10), may be improved. In one embodiment, at least one of a bed or a chair may be provided within the chamber (10).

[0037] A probe (20) according to one embodiment may be configured to generate sound waves and receive reflected sound waves to measure the condition of the eardrum. In one embodiment, the probe (20) is mounted on a patient's ear, generates sound waves toward the patient's eardrum, and receives sound waves reflected from the patient's eardrum to measure the intensity of the sound waves.

[0038] According to one embodiment, the MCU module (30) may be configured to be electrically connected to the probe (20) to control the probe (20) to generate sound waves and to receive sound waves reflected from the probe (20).

[0039] According to one embodiment, the processor (40) can estimate the state of the eardrum based on the intensity of the sound wave input from the MCU module (30). In one embodiment, the processor (40) can generate a control signal for the pressure inside the chamber (10) based on the estimated state of the eardrum.

[0040] A processor (40) according to one embodiment may be implemented using one or more general-purpose computers or special-purpose computers. In one embodiment, the processor (40) may execute an operating system (OS) and one or more software applications running on the operating system. Furthermore, the processor (40) may access, store, manipulate, process, and generate data in response to the execution of software.

[0041] In one embodiment, the air supply valve (50) may be configured to open or close the air supply passage connected to the chamber (10) according to a control signal from the processor (40). In one embodiment, when the air supply valve (50) is opened, air may flow into the chamber (10), thereby increasing the pressure inside the chamber (10).

[0042] An exhaust valve (60) according to one embodiment may be configured to open or close an exhaust passage connected to the chamber (10) according to a control signal from the processor (40). In one embodiment, when the exhaust valve (60) is opened, air inside the chamber (10) may be discharged to the outside, thereby reducing the pressure inside the chamber (10).

[0043] An automatic pressure control system for a hyperbaric oxygen chamber according to one embodiment can control pressure by PID control. In one embodiment, the processor (40) can open the supply solenoid valve (51) and the exhaust solenoid valve (61) when treatment begins.

[0044] According to one embodiment, the processor (40) can present the pressure value of the treatment table as SP (set point), obtain the pressure value inside the chamber (10) through the pressure sensor (70) and present it as PV (process variable), and obtain the MV (manipulated variable) value through PID operation to control the supply proportion valve (53) and / or the exhaust proportion valve (63).

[0045] During the process of pressurizing the hyperbaric oxygen therapy using a chamber (10), barotrauma may occur due to the pressure difference between the inside and outside of the cells of the organs inside the body. Barotrauma is defined as a compound word of baros, meaning pressure, and trauma, meaning damage. Barotrauma that occurs during hyperbaric oxygen therapy includes external auditory canal barotrauma, middle ear barotrauma, inner ear barotrauma, sinus barotrauma, lung barotrauma, and teeth barotrauma. The most frequently occurring of these is middle ear barotrauma, which occurs when pressure equilibrium between the outer and middle ears is not achieved. When middle ear barotrauma occurs, the patient may experience mild pain, hearing loss, bleeding, and in severe cases, eardrum rupture. Middle ear barotrauma can be prevented by opening the Eustachian tube to equalize the pressure between the outer and middle ear. Methods for achieving pressure equalization include the Toynbee breathing method, the Valsalva breathing method, the Frenzel maneuver, the Lowry maneuver, the Edmonds technique, swallowing saliva, and yawning.

[0046] Conventional methods to prevent middle ear barotrauma during hyperbaric oxygen therapy include the use of nasal sprays and the practice of breathing techniques to equalize pressure. However, because assessing middle ear barotrauma during treatment relies on conversations between the patient and the healthcare provider, the risk of middle ear barotrauma still exists even with appropriate precautions. Therefore, a method is needed to objectively assess middle ear barotrauma by directly monitoring the condition of the eardrum in real time during hyperbaric oxygen therapy, rather than relying on the patient's subjective perception.

[0047] The automatic pressure control system and method of a hyperbaric oxygen chamber for detecting the pressure equilibrium state between the outer ear and the middle ear according to one embodiment of the present disclosure can objectively determine barotrauma through a probe (20).

[0048] In one embodiment, the automatic pressure control system and method can determine the condition of the eardrum by measuring the admittance of the eardrum through a probe (20). Here, admittance is the reciprocal of impedance and indicates the degree to which vibration (e.g., sound waves) is easily transmitted. A higher admittance value indicates a property of better vibration transmission, and the unit is mho.

[0049] A probe (20) according to one embodiment may include a speaker (222) capable of presenting a test sound to the eardrum, and a microphone (223) capable of receiving sound waves reflected from the eardrum.

[0050] In one embodiment, the speaker (222) outputs a single sound wave (e.g., 226 [Hz]), which can vibrate air particles in the outer ear. The eardrum resonates with the vibration of the sound wave to receive the sound wave, and the sound wave that is not absorbed is reflected and input to the microphone (223). Depending on the pressure in the outer ear, the eardrum bends toward the outer ear and the middle ear.

[0051] Depending on the degree of curvature of the eardrum, the intensity of the sound wave it absorbs and the intensity of the sound wave it reflects can vary. Here, a single sound wave output from the speaker (222) is sound pressure, and the reflected sound input to the microphone (223) is sound velocity. Using the sound pressure and sound velocity thus obtained, the admittance of the eardrum according to the pressure change can be measured.

[0052] Fig. 3 is a drawing showing a probe (20) according to one embodiment of the present disclosure. Fig. 4 is a drawing showing a probe (20) according to one embodiment of the present disclosure inserted into a patient's ear.

[0053] Referring to FIGS. 3 and 4, the probe (20) according to one embodiment may be provided in the form of a headset. In one embodiment, the probe (20) is provided in the form of a headset including a band (21) and an ear pad (22), and a microphone (223) and a speaker (222) are formed in a protrusion (221) protruding from the surface of the headset that contacts the ear and can be inserted into the patient's outer ear. Accordingly, since the probe (20) is provided in a form familiar to patients, there is an effect of making it easier to provide guidance on how to wear it.

[0054] A probe (20) according to one embodiment may include a speaker (222) and a microphone (223).

[0055] According to one embodiment, a speaker (222) may receive an electrical signal for a test sound from an MCU module (30), convert it into a sound wave, and generate a test sound. In one embodiment, the speaker (222) may be inserted into a patient's external ear and generate a sound wave toward the eardrum.

[0056] In one embodiment, the speaker (222) may have an output sound wave frequency range of 200 [Hz] to 55 [kHz], and may be capable of outputting a single sound wave (e.g., 226 Hz). In one embodiment, the maximum output sound pressure of the speaker (222) is 127 [dB], and may ensure even output capability in all frequency bands.

[0057] In one embodiment, a microphone (223) can convert sound waves reflected from the eardrum into electrical signals. In one embodiment, the microphone (223) can be inserted into the patient's outer ear so that the eardrum is directed toward the sound receiving direction. In one embodiment, the microphone (223) can convert sound waves reflected from the eardrum into electrical signals and transmit them to the MCU module (30).

[0058] In one embodiment, the input frequency range of the microphone (223) may be from 20 [Hz] to 10 [kHz], which may be a frequency range sufficient to receive a single sound wave (e.g., 226 Hz) reflected through the eardrum.

[0059] In one embodiment, the probe (20) may be provided with a passage (224) for equalizing the pressure in the outer ear with the pressure inside the chamber (10). By allowing air to move into the chamber (10) and the outer ear through the passage (224), the pressure in the outer ear can be equalized with the pressure inside the chamber (10).

[0060] In one embodiment, the chamber (10) may be equipped with a pressure sensor (70). In one embodiment, the processor (40) may obtain the pressure of the external ear by measuring the pressure inside the chamber (10) through the pressure sensor (70).

[0061] Fig. 5 is a block diagram of an MCU module (30) according to one embodiment of the present disclosure. Fig. 6 is a circuit diagram of a speaker driving circuit (301) according to one embodiment of the present disclosure. Fig. 7 is a circuit diagram of a microphone driving circuit (302) according to one embodiment of the present disclosure.

[0062] Referring to FIGS. 5 to 7, an MCU module (30) according to one embodiment may be connected to a probe (20) to exchange signals with the probe via a 4-pole Aux cable. In one embodiment, the MCU module (30) may transmit a test sound to a speaker (222) of the probe (20), receive reflected sound waves as electrical signals through a microphone (223), and transmit the acquired microphone signal to a processor (40).

[0063] According to one embodiment, the MCU module (30) may be STM32F103RCT6, which uses an ARM-Cortex M3 core, a 32-bit microprocessor, for control and operation of the entire system.

[0064] An MCU module (30) according to one embodiment may include an LED unit for indicating the status of the system, a UART unit for communicating with the processor (40), a speaker driving circuit (301) for driving a speaker (222) and a microphone (223), and a microphone driving circuit (302). In one embodiment, a 4-pole earphone terminal, FC6818, may be used for signal exchange with the speaker (222) and microphone (223) of the probe (20).

[0065] According to one embodiment, the MCU module (30) can control the speaker (222) using the speaker driving circuit (301) as illustrated in FIG. 6. For example, the speaker driving circuit (301) can apply a sine wave signal having a frequency of 226 Hz and an amplitude of 0-2.5 V to the DAC input terminal of the speaker driving circuit (301) using the DAC (Digital to Analog Converter) of the MCU. Here, the DAC resolution of the STM32F103RCT6 can be 12 bits.

[0066] As an example, since a sine wave with an amplitude of 0 to 2.5 V is a large voltage for driving a speaker (222), the voltage can be lowered from 0 to 100 mV using an OPAMP voltage divider circuit. The sine wave signal with a lowered amplitude can vibrate a capacitor inside the speaker (222) to generate sound pressure.

[0067] According to one embodiment, the MCU module (30) can control the microphone (223) using the microphone driving circuit (302) as illustrated in FIG. 7. In one embodiment, the spatial velocity input to the microphone (223) can be converted into voltage and input to the microphone driving circuit (302). For example, the amplitude of the microphone (223) can be 0-1.3 V, and the maximum amplitude of the 226 Hz signal can be 132 mV. The input range of the ADC (Analog to digital converter) pin of the MCU is 0-3.3 V, and ADC can be performed without any additional amplification or filtering. However, in order to convert the resolution to the maximum, the DC offset of the microphone signal is reset to 1.65 V using the microphone driving circuit (302), and only the 226 Hz signal is amplified 25 times. The amplified signal can be input to the ADC pin of the MCU module (30) and transmitted to the processor (40).

[0068] FIGS. 8A to 8C illustrate interface screens of an automatic pressure control program according to one embodiment of the present disclosure.

[0069] Referring to FIGS. 8A to 8C, the processor (40) can obtain an admittance value of the eardrum from the MCU module (30) and implement an automatic pressure control algorithm using the obtained value. The processor (40) can be configured with a program based on LabView2010 (National Instruments, USA) to implement the automatic pressure control algorithm.

[0070] Specifically, the program description is as follows:

[0071] ①: This is a graph in which the X-axis represents time and the Y-axis represents pressure, and the actual pressure inside the chamber (10) can be displayed as a graph according to the treatment process.

[0072] ②: The actual pressure of the chamber (10) and the Sep Point that the pressure of the chamber (10) must reach by the PID algorithm can be displayed.

[0073] ③: There is a button for starting and ending treatment as a processor (40). In addition, a port can be set for serial communication and the patient's name can be entered.

[0074] ④: The pressure in the middle ear on the left and right can be estimated and displayed in a graph.

[0075] ⑤: The pressure difference between the outer ear and the middle ear can be calculated using the actual pressure inside the current chamber (10) and the estimated middle ear pressure and displayed as a graph.

[0076] ⑥: The measured admittance of the eardrum can be displayed in a graph in real time.

[0077] An automatic pressure control system according to one embodiment can perform an automatic pressure control algorithm based on a middle ear pressure estimation algorithm. In one embodiment, the automatic pressure control algorithm (hereinafter, process 1) operates at 1 Hz depending on the speed of the processor (40), and the middle ear pressure estimation algorithm (hereinafter, process 2) can operate at a speed of 7232 [Hz] (interval 138.274336 [μs])) depending on the speed of transmitting data from the MCU module (30). The two processes operate organically with each other, and the middle ear pressure is the estimated middle ear pressure, and the chamber pressure is the actual pressure of the measured chamber (10), which are used as global variables.

[0078] According to one embodiment, the automatic pressure control system of a hyperbaric oxygen chamber can transmit a start command signal to the MCU module (30) in process 1 when treatment begins. The MCU module (30) that receives the start command signal can perform process 2.

[0079] In one embodiment, the MCU module (30) can take a fixed point digital IIR filter from process 2 and store it in an array. The designed digital filter is a second-order 226 Hz peak filter, and the Q-factor is 50. When all components other than 226 Hz are removed through digital filtering and the array of filtered data reaches 1024, a 1024-point FFT is taken to calculate the power of 226 Hz and the power value can be used to obtain the admittance value of the eardrum.

[0080] Figure 9 is a graph showing the results of admittance measurements when performing the Valsalva maneuver. Figure 10 is a graph showing the change pattern of admittance during the Valsalva maneuver.

[0081] Fig. 9 (a) shows the pressure inside the chamber (10), Fig. 9 (b) shows the pressure difference in the right ear, Fig. 9 (c) shows the admittance in the right ear, Fig. 9 (d) shows the pressure difference in the left ear, and Fig. 9 (e) shows the admittance in the left ear. The horizontal axis of each graph shows time.

[0082] Referring to FIGS. 9 and 10, it can be observed that the pressurization continues from the point where the pressure imbalance begins until the pressure difference between the outer ear and the middle ear becomes 0.04 [ata], and the pressure is maintained when the pressure difference between the outer ear and the middle ear becomes 0.04 [ata].

[0083] When pressure is equalized using the Valsalva maneuver, air from the lungs supplies air to the paranasal sinuses and the Eustachian tube. The air flowing into the Eustachian tube causes the eardrum, which had been deflected toward the middle ear due to external pressure, to deflect toward the outer ear. At this point, the eardrum recovers completely and deflects toward the outer ear, but the admittance value does not increase to its maximum. This is thought to be due to data loss caused by the eardrum changing faster than the data acquisition speed due to the use of admittance value overlap during the admittance calculation process. However, the algorithm can determine that this momentary increase is the point of pressure equalization, and the pressurized state is maintained.

[0084] Immediately after performing the Valsalva maneuver, the admittance value of the eardrum becomes minimum. Since the direction of the eardrum's bending cannot be determined using only the admittance value of the eardrum, the system determines that the eardrum is in a state of pressure imbalance. However, since pressure equalization was achieved immediately before, the pressure in the chamber (10) continues to rise, causing the eardrum, which was bent toward the outer ear, to slowly bend back toward the inner ear, resulting in a pattern as shown in Fig. 10. The pressure in the chamber (10) increases by 0.002 [ata] per second, and since it takes less than 10 seconds from immediately after the Valsalva maneuver to determine the next pressure equalization point, the estimated pressure difference between the outer and middle ear is 0.04 [ata] or less.

[0085] As illustrated in Figure 10, when a state of pressure equilibrium occurs between the outer and inner ear through the Valsalva breathing technique, the admittance shows a change pattern (1010) in which it continuously increases before the point of pressure equilibrium, and the admittance shows a change pattern (1020) in which it continuously decreases after the point of pressure equilibrium.

[0086] Figure 11 is a graph showing the results of admittance measurements according to saliva swallowing. Figure 12 is a graph showing the change pattern of admittance according to saliva swallowing.

[0087] Fig. 11 (a) shows the pressure inside the chamber (10), Fig. 11 (b) shows the pressure difference in the right ear, Fig. 11 (c) shows the admittance in the right ear, Fig. 11 (d) shows the pressure difference in the left ear, and Fig. 11 (e) shows the admittance in the left ear. The horizontal axis of each graph shows time.

[0088] Swallowing causes the Eustachian tube to open briefly due to the momentary muscle movement, allowing outside air to flow into the middle ear. Unlike the Valsalva maneuver, which forcefully forces air into the middle ear through the Eustachian tube, swallowing allows outside air to flow naturally while the Eustachian tube is open momentarily. This prevents 100% recovery of the eardrum, with recovery rates ranging from about 50% to 60% for some individuals. In fact, when admittance is measured in subjects who swallowed saliva, the maximum admittance value is higher.

[0089] As illustrated in Fig. 12, when a pressure equilibrium state occurs between the outer ear and the inner ear by swallowing saliva, the admittance shows a change pattern (1210) in which it continuously increases before the pressure equilibrium point, and the admittance shows a change pattern (1220) in which it continuously decreases after the pressure equilibrium point.

[0090] According to the prior art, if the admittance value is higher than the threshold value set before the start of treatment, it is determined that pressure equilibrium has been achieved, and the Chamber Pressure, which is the pressure value of the current chamber (10), is substituted into the variable Middle ear pressure. If the acquired admittance value is lower than the threshold value, it is determined that pressure equilibrium has not been achieved, and it returns to the beginning of process 2 without any further action, and after obtaining 1024 samples and calculating the first acoustic admittance, the signal acquired from the MCU module (30) is overlapped by 25% and repeated until process 1 is completed.

[0091] According to the conventional technique using a threshold value, the admittance of the patient's eardrum was measured once before hyperbaric oxygen therapy, and the threshold value was set to about 40% of the maximum value, which varies from person to person, and when the threshold value was exceeded, it was judged that pressure equilibrium had been reached.

[0092] However, according to the prior art, the patient's admittance must be measured before entering the chamber (10) and the maximum and minimum values ​​must be input, and if a high value corresponding to noise is output for the admittance, a problem may arise in which the pressure equilibrium is judged to have been reached even though the pressure equilibrium has not actually been reached. In addition, since the overall admittance value also increases when the pressure in the chamber (10) increases, there was a limitation in the prior art using the threshold value.

[0093] An automatic pressure control system according to one embodiment can determine whether pressure equilibrium is achieved based on a change pattern of measured admittance.

[0094] Referring to FIGS. 10 and 12, according to the admittance measurement pattern according to Valsalva maneuver or swallowing, a pattern of continuous upward and / or downward rise or decrease in a certain section can be confirmed when pressure equilibrium is achieved.

[0095] An automatic pressure control system according to one embodiment can set a window in a certain portion of a graph showing a change pattern of admittance, extract points (e.g., 6 points) from an initial value to a final value within the window, and determine whether the admittance has continuously increased or decreased (first condition).

[0096] An automatic pressure control system according to one embodiment can determine whether the last point, which is the largest value within the window, is greater than or equal to a preset multiple of the first point, which is the lowest value (e.g., first point x 1.1 < last point) when the admittance continues to rise (second condition).

[0097] In one embodiment, the automatic pressure control system can determine, on the contrary, if the admittance continues to decrease, whether the first point, which is the largest value within the window, is greater than or equal to a preset multiple of the last point, which is the lowest value (e.g., last point x 1.1 < first point) (second condition).

[0098] An automatic pressure control system according to one embodiment can determine that pressure equilibrium has been achieved when the first condition and the second condition are simultaneously satisfied. By setting the first condition and the second condition to be simultaneously satisfied, the system has a robust effect against noise even when the admittance value jumps high or low due to large noise.

[0099] An automatic pressure control system according to one embodiment can calculate admittance by overlapping a portion of received acoustic data.

[0100] According to the prior art, sound waves are transmitted from a speaker (222) to an eardrum, sound waves reflected from the eardrum are received by a microphone (223), 7232 (7232 [Hz]) data are received per second from the microphone (223), and 1024 of the data are collected to obtain 226 [Hz] data by performing FFT (fast Fourier transform) calculation to convert it into a frequency diagram, thereby obtaining 1 data (admittance) having a frequency of 226 [Hz].

[0101] According to this conventional technology, 7232 pieces of sound wave data were input per second, and 1024 pieces were accumulated for calculation, so about 7 pieces of admittance data could be obtained per second.

[0102] According to one embodiment, an automatic pressure control system can initially calculate using 1024 accumulated sound wave data, and then discard only some of them (e.g., 100), and receive new sound wave data equal to the discarded number (e.g., 100), and obtain admittance data with 1024 sound wave data again. Accordingly, after obtaining the first admittance value by accumulating the first 1024 sound wave data, admittance can be obtained every time 100 sound wave data are obtained, so that more admittance values ​​can be obtained. For example, if 90% of the sound wave data overlaps, approximately 70 admittance data can be obtained per second.

[0103] Therefore, real-time reflection can be improved by maintaining accumulated sound wave data and updating only a portion of it, and accuracy can be improved by increasing the number of admittance values.

[0104] An automatic pressure control system according to one embodiment can obtain sound wave data and admittance values ​​as follows (example) using a microphone (223).

[0105] For the right microphone, it is pushed 2 bits to the left and transmitted to the UART for communication with the processor (40) as 8 bits with the lower 6 bits of the 12 bits and the distinction bit (00), and then it is pushed 6 bits to the right and 2 bits to the left (a total of 4 bits may be pushed to the right) and transmitted to the UART as 8 bits with the upper 6 bits of the 12 bits and the distinction bit (01). Similarly, for the left microphone, it is transmitted to the UART by inserting the distinction bits (10, 11) respectively.

[0106] The data collection section of the UART section can collect Mic Raw data by multiplying the upper and lower 6-bit data by X64 (moving 6 bits to the left) when the distinction bits 00, 01, 10, and 11 are consecutively entered, and adding them to the lower 6-bit data, excluding the distinction bits when it is 00 and 01.

[0107] The UART section can filter data using a Point by Point IIR filter. According to the filter characteristics (2nd order IIR filter, Fs = 7232, Q = 50), the forward coefficient = [0.00195965, 0, -0.00195965], the inverse coefficient = [1, -1.95773, 0.996081], and 1024 pieces of data from the IIR microphone (223) can be collected and FFT performed. If 1024 pieces of data are FFTed, they become 1024, and after FFT, the data at the 32nd index (31st when indexed from 0) of 1024 becomes 226Hz data.

[0108] If 7232 Hz is FFTed with N = 1024, the resolution becomes 7232 / 1024 = 7.0625, and if 7.0625 * 32 is multiplied, it becomes = 226 Hz. Therefore, in order to obtain 226 Hz data from the sound wave data of the microphone (223), the 32nd index of the 1024 arrays of FFT results indicates a 226 Hz signal.

[0109] The window size can be set from 0 to 1024, and for example, if it is set to 100, 100 out of 1024 are discarded and 100 are collected again, and then FFT is performed. Accordingly, since it is 7232 Hz, approximately 72 data can be obtained per second.

[0110] Since acoustic admittance is speaker power / microphone power, we can obtain admittance using speaker power = 261793.72 and the acquired microphone power of 226 Hz.

[0111] An automatic pressure control system according to one embodiment can detect pressure equilibrium based on the acquired admittance value.

[0112] For example, if the admittance is taken in 120 windows and the admittance values ​​of 0, 19, 39, 59, 79, 99, and 119 sequentially increase, the automatic pressure control system can determine that the pressure is in equilibrium if the following conditions 1 and 2 are simultaneously satisfied. In addition, the pressure of the current chamber (10) can be estimated as the pressure of the patient's inner ear.

[0113] Condition 1: ABT_L[0] < ABT_L

[0019] & ABT_L

[0019] < ABT_L

[0039] & ABT_L

[0039] < ABT_L

[0059] & ABT_L

[0059] < ABT_L

[0079] & ABT_L

[0079] < ABT_L

[0099] & ABT_L

[0099] < ABT_L

[0119]

[0114] Condition 2: ABT_L[0] * 1.1 < ABT_L

[0119]

[0115] Conversely, as an example, even if the admittance values ​​of 0, 19, 39, 59, 79, 99, and 119 are sequentially decreased by taking 120 windows of admittance, the automatic pressure control system can determine that pressure equilibrium is reached if conditions 1 and 2 below are simultaneously satisfied. In addition, the pressure of the current chamber (10) can be estimated as the pressure of the patient's inner ear.

[0116] Condition 1: ABT_L[0] > ABT_L

[0019] & ABT_L

[0019] > ABT_L

[0039] & ABT_L

[0039] > ABT_L

[0059] & ABT_L

[0059] > ABT_L

[0079] & ABT_L

[0079] > ABT_L

[0099] & ABT_L

[0099] > ABT_L

[0119]

[0117] Condition 2: ABT_L

[0119] * 1.1 < ABT_L[0]

[0118] An automatic pressure control system according to one embodiment may pause pressurization when the pressure difference between the estimated patient's inner ear pressure and the chamber (10) pressure becomes greater than 0.06 [ata]. In one embodiment, the automatic pressure control system may slowly decompress if the pressure is not relieved within 15 seconds after stopping pressurization.

[0119] An automatic pressure control system according to one embodiment can release the pressurization pause when pressure equilibrium is detected due to decompression, or when the pressure difference between the estimated patient's inner ear pressure and the chamber (10) pressure becomes less than 0.02 [ata], maintain the pressure for 7 seconds, and then resume pressurization according to the table.

[0120] According to one embodiment, the automatic pressure control system obtains the pressure of the chamber (10) through the pressure sensor (70) in the treatment waiting process before starting the treatment, and when the treatment starts and the first process is operated, the treatment waiting process can be terminated. At this time, the measured pressure of the chamber (10) is input as the initial value of SP and generally has a value of 1 [ata]. The Chamber Pressure, which is the current pressure of the chamber (10) during the treatment, is obtained through the pressure sensor (70) and is substituted into the variable PV for use in the processor (40). The difference in pressure between the outer ear and the middle ear, DP (Difference Pressure), can be calculated using the current pressure PV and the Middle ear pressure estimated through the second process operation.

[0121] Hold Flag becomes true when the value of DP exceeds 0.04, which means that the pressure is maintained by not changing SP, and the initial value is false. In an automatic pressure control system according to an embodiment, if the Hold Flag is false, the pressurization is in progress, so the value of DP is compared with 0.04 to determine whether to maintain or pressurize the pressure. In an automatic pressure control system according to an embodiment, if the DP, which is the pressure difference between the outer ear and the middle ear, exceeds 0.04 and the Hold Flag is true, the value of DP is compared with 0.02, and if it is less than 0.02, the pressure imbalance is determined to be resolved, the Hold Flag becomes false, and a value increased by 0.002 can be assigned to the existing SP value to increase the pressure.

[0122] An automatic pressure control system according to one embodiment can control the pressure of a chamber (10) by obtaining and outputting MV by calculating SP and PV determined based on previous calculation results through a PID controller and controlling a proportional control valve.

[0123] According to one embodiment, the automatic pressure control system determines that pressurization is complete when the PV, which is the actual pressure of the chamber (10), becomes higher than the desired pressure to be reached for treatment, and issues a stop command to the MCU module (30), thereby terminating the algorithm. The algorithm is applied to the right and left ears respectively, and is applied even if pressure equalization is not performed in one of the two ears.

[0124] According to one embodiment, an automatic pressure control system can measure admittance by controlling the pressure of the chamber (10) after the patient is positioned inside the chamber (10). The hyperbaric oxygen chamber automatically operates so that the pressure increases at a rate of 0.002 [ata / sec]. At this time, the patient voluntarily and steadily performs pressure equalization. When the pressure of the chamber (10) reaches 1.1 [ata], any action that may achieve pressure equalization is prohibited and the patient is instructed to maintain the pressure imbalance. When the pressure difference between the middle ear and the outer ear becomes 0.04 [ata] or more by maintaining the pressure imbalance, the pressure equalization is instructed after confirming that the pressure of the chamber (10) is maintained. When the pressure of the chamber (10) reaches 1.2 [ata], the above process is repeated, and when it reaches 1.3 [ata], the measurement is terminated and the pressure returns to atmospheric pressure.

[0125] FIG. 13 is a flowchart (1300) of an automatic pressure control method of a hyperbaric oxygen chamber for detecting a pressure equilibrium state between the outer ear and the middle ear according to one embodiment of the present disclosure.

[0126] Referring to FIG. 13, an automatic pressure control system of a hyperbaric oxygen chamber according to one embodiment may control a supply valve (50) to pressurize the internal pressure of the chamber (10) in operation 1310. In one embodiment, the automatic pressure control system of the hyperbaric oxygen chamber may control the supply valve (50) to pressurize the internal pressure of the chamber (10) according to a stored treatment profile based on the initiation of hyperbaric oxygen therapy.

[0127] An automatic pressure control system of a hyperbaric oxygen chamber according to one embodiment comprises, in operation 1320,

[0128] An output wave can be output by a speaker (222), and a reflected wave reflected from the patient's eardrum can be input by a microphone (223).

[0129] An automatic pressure control system of a hyperbaric oxygen chamber according to one embodiment can calculate the admittance of the eardrum based on the energy level of the output wave output from the speaker (222) and the energy level of the reflected wave input from the microphone (223) in operation 1330.

[0130] Here, operations 1320 and 1330 may be continuously performed from the start to the end of hyperbaric oxygen therapy. For example, operations 1320 and 1330 may be performed according to a specified operation cycle.

[0131] In one embodiment, the automatic pressure control system of a hyperbaric oxygen chamber may determine, at operation 1340, whether the difference between the pressure of the inner ear and the pressure of the outer ear is greater than or equal to a preset pressure difference. For example, the preset pressure difference may be 0.06 [ATA].

[0132] An automatic pressure control system of a hyperbaric oxygen chamber according to one embodiment may stop pressurizing the chamber (10) in operation 1350 when the difference between the pressure of the inner ear and the pressure of the outer ear is greater than or equal to a preset pressure difference (operation 1340 - Yes).

[0133] An automatic pressure control system of a hyperbaric oxygen chamber according to one embodiment can continuously pressurize the internal pressure of the chamber (10) according to the stored treatment profile when the difference between the pressure of the inner ear and the pressure of the outer ear is less than a preset pressure difference (operation 1340-No).

[0134] In one embodiment, the automatic pressure control system of a hyperbaric oxygen chamber can determine whether a pressure equilibrium state has occurred based on a change in the calculated admittance in operation 1360. In one embodiment, the automatic pressure control system of a hyperbaric oxygen chamber can determine whether a pressure equilibrium state has occurred based on an accumulated change in the admittance of the eardrum calculated in operations 1320 and 1330 in operation 1360.

[0135] According to one embodiment, the automatic pressure control system of the hyperbaric oxygen chamber may, when it is determined that a pressure equilibrium state has occurred (operation 1360 - Yes), in operation 1370, control the supply valve (50) so that the internal pressure of the chamber (10) is pressurized after maintaining the internal pressure of the chamber (10) for a preset time. Here, the preset time may be 7 seconds, for example. In one embodiment, the automatic pressure control system of the hyperbaric oxygen chamber may continuously pressurize the internal pressure of the chamber (10) according to the stored treatment profile.

[0136] An automatic pressure control system of a hyperbaric oxygen chamber according to one embodiment may determine, in operation 1380, whether a preset pressure difference or more is maintained for a preset time period when it is determined that a pressure equilibrium state has not occurred (operation 1360-No).

[0137] According to one embodiment, the automatic pressure control system of a hyperbaric oxygen chamber can control the exhaust valve (60) to reduce the internal pressure of the chamber (10) in operation 1390 when it is determined that a preset pressure difference or higher is maintained for a preset time (operation 1380 - Yes).

[0138] An automatic pressure control system of a hyperbaric oxygen chamber according to one embodiment can determine whether pressure equilibrium occurs in a state where pressurization of the chamber (10) is stopped in operation 1360 when it is determined that a preset pressure difference is not maintained above a preset pressure difference for a preset time (operation 1380-No).

[0139] In the automatic pressure control system of a hyperbaric oxygen chamber for detecting a pressure equilibrium state between the outer ear and the middle ear described above, the automatic pressure control method of the hyperbaric oxygen chamber for detecting a pressure equilibrium state between the outer ear and the middle ear can also be implemented in the form of a computer program stored in a computer-readable recording medium executed by a computer or a recording medium including commands executable by a computer. In addition, in the automatic pressure control system of a hyperbaric oxygen chamber for detecting a pressure equilibrium state between the outer ear and the middle ear described above, the automatic pressure control method of the hyperbaric oxygen chamber for detecting a pressure equilibrium state between the outer ear and the middle ear can also be implemented in the form of a computer program stored in a computer-readable recording medium executed by a computer.

[0140] A computer-readable recording medium may be any available medium that can be accessed by a computer, and includes both volatile and nonvolatile media, removable and non-removable media. Furthermore, a computer-readable recording medium may include computer storage media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data.

[0141] The functions implemented by the components described in this specification may be implemented in processing circuitry including general-purpose processors, special-purpose processors, integrated circuits, Application Specific Integrated Circuits (ASICs), Central Processing Units (CPUs), circuits, and / or combinations thereof, programmed to implement the described functions. A processor includes transistors or other circuits and is considered a circuit or processing circuit. The processor may be a programmed processor that executes a program stored in memory.

[0142] In this specification, a circuit, part, unit, or means refers to hardware programmed or executing to realize the described function. The hardware may be any hardware disclosed in this specification or any hardware known to be programmed or executing to realize the described function.

[0143] If the hardware is a processor considered to be a circuit type, the circuit, the part, means or unit is a combination of hardware and software used to configure the hardware and / or the processor.

[0144] The above description of the present disclosure is provided for illustrative purposes only, and those skilled in the art will readily appreciate that modifications to other specific forms can be made without altering the technical spirit or essential features of the present disclosure. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, components described as being single may be implemented in a distributed manner, and similarly, components described as being distributed may be implemented in a combined manner.

[0145] The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present disclosure.

Claims

1. In an automatic pressure control system of a hyperbaric oxygen chamber that detects the pressure equilibrium state between the outer ear and the middle ear, A chamber having a space formed inside which a patient can be positioned; A probe configured to be mounted on the ear of the patient, the probe comprising a speaker configured to output sound waves and a microphone configured to receive sound waves; An MCU module electrically connected to the above probe; A supply valve configured to open or close a supply line connected to the chamber; an exhaust valve configured to open or block an exhaust passage connected to the chamber; and Contains at least one processor, The above MCU module is configured to output an output wave by the speaker, and to receive a reflected wave reflected from the patient's eardrum by the microphone. At least one processor of the above: Based on the energy level of the output wave output from the speaker and the energy level of the reflected wave input from the microphone, the admittance of the eardrum is calculated, Based on the change in the above-described admittance, it is determined whether the pressure equilibrium state has occurred, Based on whether the pressure equilibrium state determined above has occurred, the supply valve is set to be controlled. Automatic pressure control system.

2. In paragraph 1, At least one processor of the above: In the configuration for determining whether the above pressure equilibrium state has occurred, it is set to determine that the pressure equilibrium state has occurred when the admittance continuously increases or continuously decreases within a window of a preset size. Automatic pressure control system.

3. In paragraph 2, The above window contains a preset number of values ​​of the admittance, Automatic pressure control system.

4. In paragraph 2, At least one processor of the above: In the configuration for determining whether the above pressure equilibrium state has occurred, if the admittance continuously increases in the window, it is set to determine that the pressure equilibrium state has occurred if the last admittance value of the window is greater than or equal to a preset multiple of the first admittance value. Automatic pressure control system.

5. In paragraph 2, At least one processor of the above: In the configuration for determining whether the above pressure equilibrium state has occurred, if the admittance continuously decreases in the window, it is set to determine that the pressure equilibrium state has occurred if the first admittance value of the window is greater than or equal to a preset multiple of the last admittance value. Automatic pressure control system.

6. In paragraph 1, At least one processor of the above: In the configuration for calculating the admittance, the admittance value is calculated by accumulating time-dependent data for each of the energy level of the output wave and the energy level of the reflected wave by a preset accumulation amount, and the value of the admittance is calculated by overlapping some of the preset accumulation amounts and updating only the remaining part. Automatic pressure control system.

7. In paragraph 1, At least one processor of the above: Control the supply valve so that the internal pressure of the chamber is pressurized, Based on the above-described admittance, the pressure of the chamber is set to be stopped when the difference between the pressure of the inner ear and the pressure of the outer ear is greater than a preset pressure difference. Automatic pressure control system.

8. In paragraph 7, At least one processor of the above: The exhaust valve is set to be controlled so that the internal pressure of the chamber is reduced when the difference between the pressure of the inner ear and the pressure of the outer ear is maintained above the preset pressure difference for a preset time while the pressurization of the chamber is stopped. Automatic pressure control system.

9. In paragraph 1, At least one processor of the above: In the configuration for controlling the above-mentioned supply valve, when it is determined that the pressure equilibrium state has occurred, the internal pressure of the chamber is maintained for a preset time, and then the internal pressure of the chamber is set to be pressurized. Automatic pressure control system.

10. In an automatic pressure control method of a hyperbaric oxygen chamber that detects the pressure equilibrium state between the outer ear and the middle ear, A step of outputting an output wave by a speaker and receiving a reflected wave reflected from the patient's eardrum by a microphone, wherein the speaker and the microphone are included in a probe configured to be mounted on the patient's ear; A step of calculating the admittance of the eardrum based on the energy level of the output wave output from the speaker and the energy level of the reflected wave input from the microphone; A step of determining whether the pressure equilibrium state has occurred based on the change in the above-described admittance; and A step of controlling a supply valve configured to open or block a supply line connected to a chamber based on whether the above-determined pressure equilibrium state has occurred, Automatic pressure control method.

11. In paragraph 10, The step of determining whether the pressure equilibrium state has occurred includes a step of determining that the pressure equilibrium state has occurred when the admittance continuously increases or continuously decreases within a window of a preset size. Automatic pressure control method.

12. In paragraph 11, The step of determining whether the pressure equilibrium state has occurred includes a step of determining that the pressure equilibrium state has occurred when the admittance continuously increases in the window and the last admittance value of the window is greater than or equal to a preset multiple of the first admittance value. Automatic pressure control method.

13. In paragraph 11, The step of determining whether the pressure equilibrium state has occurred includes a step of determining that the pressure equilibrium state has occurred when the admittance continuously increases in the window and the last admittance value of the window is greater than or equal to a preset multiple of the first admittance value. Automatic pressure control method.

14. In paragraph 11, The step of determining whether the pressure equilibrium state has occurred includes a step of determining that the pressure equilibrium state has occurred when the first admittance value of the window is greater than or equal to a preset multiple of the last admittance value, when the admittance continuously decreases in the window. Automatic pressure control method.

15. In paragraph 10, The step of calculating the admittance is to calculate the admittance value by accumulating time-dependent data for each of the energy level of the output wave and the energy level of the reflected wave by a preset accumulation amount, and to calculate the value of the admittance by overlapping a part of the preset accumulation amount and updating only the remaining part. Automatic pressure control method.

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