A respiratory muscle function testing device and method based on a ventilator

Abstract

The present invention provides a respiratory muscle function test device based on a ventilator, which is used to be connected to the ventilator, including: a test head; a host; a computer; the ventilator includes an exhalation duct and an intake duct, which are connected to the test head through a Y-type connector; one end of the test head is connected to the Y-type connector, and the other end is connected to a tracheal tube, and at the same time, the test head is connected to the host through a pipeline and / or a cable; the host and the computer are connected through a cable or wireless communication. Based on the above-mentioned test device, the present invention provides a respiratory muscle function test method. Based on the principle of cardiopulmonary exercise test, the present invention changes the respiratory muscle work of intubated mechanically ventilated patients with autonomous ventilation ability by adjusting ventilator parameters, obtains the change in oxygen uptake after the change in respiratory muscle work, and thus directly reflects the working capacity of the respiratory muscles.

Description

Technical Field

[0001] The invention belongs to the field of medical technology, and in particular relates to a respiratory muscle function testing device and method based on a ventilator. Background Art

[0002] Respiratory movement is the rhythmic expansion and contraction of the thorax caused by the contraction and relaxation of respiratory muscles, thereby achieving the purpose of inhaling oxygen and exhaling carbon dioxide. The inspiratory muscles mainly include the diaphragm, external intercostal muscles, and auxiliary inspiratory muscles, such as the scalene muscles and sternocleidomastoid muscles. As the main inspiratory muscle, the diaphragm plays a 70% role in the quiet inspiration process. Decreased diaphragm strength can cause shortness of breath and difficulty breathing, and even respiratory failure. Objective and effective evaluation of respiratory muscle function, including the diaphragm, will help with diagnosis.

[0003] In the prior art, there are limited methods for measuring diaphragm function. Currently, the commonly used detection technologies are:

[0004] 1) Chest X-ray or DR: The normal diaphragm projection position can be seen on the chest X-ray, and the diaphragm function can be evaluated by imaging characteristics. However, due to the positional limitations of mechanically ventilated patients, the evaluation effect of this method is not ideal.

[0005] 2) Pulmonary function: It is usually assessed by supine and upright lung function tests. The supine vital capacity of patients with diaphragmatic paralysis is about 50% lower than that of patients in the upright position. In addition, maximum inspiratory pressure and expiratory pressure can also be used as a means of assessment, but the use of this method is limited in patients on mechanical ventilation.

[0006] 3) Diaphragm ultrasound: The diaphragm thickness after quiet breathing and forced inspiration, as well as the diaphragm displacement after forced inspiration, are evaluated. However, the diaphragm morphology cannot fully reflect the diaphragm strength of a specific individual; the diaphragm movement amplitude under the action of the ventilator cannot reflect the patient's true diaphragm movement ability.

[0007] 4) Diaphragm electromyography: Although it is more complicated, it can better distinguish whether the diaphragm is neurogenic or myogenic, but it cannot evaluate its function.

[0008] 5) Transdiaphragmatic pressure (Pdi): It is the gold standard for diaphragmatic paralysis and requires a special catheter to be inserted into the esophagus for measurement. Pdi = abdominal pressure (Pga) - thoracic pressure (Ppl). When the inspiratory tidal volume is at its peak, the Pdi of a normal patient is positive, while the Pdi of a patient with diaphragmatic paralysis is negative.

[0009] There is currently no effective method to detect the function of respiratory muscles other than the diaphragm.

[0010] In view of the current limitations of respiratory muscle function testing and the serious impact of respiratory muscle dysfunction on the recovery of patients undergoing mechanical ventilation, how to detect the functional capacity of respiratory muscles during mechanical ventilation has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0011] In order to solve the above technical problems, the purpose of the present invention is to propose a technical method for evaluating the respiratory muscle function status of a patient under invasive mechanical ventilation (i.e., intubation ventilator) treatment.

[0012] In view of this, the present invention first provides a respiratory muscle function testing device based on a ventilator, which is used to be connected to the ventilator, comprising:

[0013] Test head; host; computer;

[0014] The test head is connected to the exhalation pipe and the intake pipe of the ventilator respectively through a Y-type connector;

[0015] One end of the test head is connected to the Y-type connector, and the other end is connected to the endotracheal tube. At the same time, the test head is connected to the host through a pipeline and / or a cable;

[0016] The host is connected to the computer via a cable or wireless communication.

[0017] Further, the test head includes a flow sensor, a gas sampling port, a pressure detection port and a disposable ultrasonic pipeline;

[0018] The host includes a flow / volume signal collector, a fast gas analyzer, and a pressure signal collector;

[0019] The flow sensor is connected to the flow / volume signal collector via a cable;

[0020] The fast gas analyzer is connected to the gas sampling port;

[0021] The pressure signal collector is connected to the pressure detection port.

[0022] Furthermore, the fast gas analyzer includes a fast CO2 gas analyzer, a fast O2 gas analyzer and a vacuum pump.

[0023] Furthermore, the computer is configured to have data processing, analysis and display functions.

[0024] Based on the above respiratory muscle function testing device, the present invention also provides a respiratory muscle function testing method, comprising the following steps:

[0025] S1. Connect the respiratory muscle function test device to a testee with autonomous ventilation ability, keep all components in normal working state, and perform mechanical ventilation on the testee;

[0026] S2, obtaining the oxygen uptake data and corresponding ventilator parameter data of the subject under current mechanical ventilation through the host and the computer;

[0027] S3, lowering the ventilator support pressure parameter, and obtaining oxygen uptake data under the current mechanical ventilation again;

[0028] S4. Analyze and compare the oxygen uptake data before and after adjusting the ventilator support pressure parameters.

[0029] Further, in step S2, the computer receives the data uploaded by the host, calculates the ventilation volume VE and oxygen uptake VO2 per breath, then calculates the data per minute, averages the data during this period, and obtains the average oxygen uptake and ventilation volume under the current ventilator support level.

[0030] Furthermore, in step S3, after adjusting the ventilator parameters, it is necessary to re-analyze and calculate to calculate the ventilation volume VE and oxygen uptake VO2 for each breath, and then calculate the data for each minute, average the data within this period of time, and obtain the average oxygen uptake and ventilation volume after adjusting the ventilator parameters. The respiratory muscle function of the subject is converted and calculated through the change data of ventilation volume VE and oxygen uptake VO2 before and after the ventilator parameter adjustment.

[0031] Furthermore, according to the analysis and comparison results, if the oxygen uptake and ventilation data both increase after lowering the ventilator support level, the ventilator support parameters should be gradually lowered.

[0032] The diaphragm is the most important respiratory muscle in the human body. A large number of studies have shown that the diaphragm of patients receiving invasive mechanical ventilation (intubation ventilator) may become significantly thinner, the muscle fibers may atrophy, and the contraction may become weak. Severe diaphragmatic function declines, which is one of the most important reasons for the failure of ventilator weaning. The basic scheme of the present invention is to borrow the idea of ​​​​exercise muscle oxygen consumption test, adjust the ventilator parameters, change the respiratory muscle movement work, measure and compare the changes in oxygen uptake (VO2) data before and after parameter adjustment, accurately obtain the respiratory muscle work capacity, and then evaluate the patient's autonomous breathing ability, and according to the oxygen uptake VO2 test results, by changing the ventilator parameters, train the respiratory muscle strength, and finally achieve the purpose of significantly improving the success rate of weaning.

[0033] Specifically, the technical solution disclosed in the present invention has the following technical features:

[0034] 1) Based on the principle of cardiopulmonary exercise test, by adjusting the pressure level of the ventilator, the respiratory muscle work of patients with spontaneous ventilation ability is changed, and the change in oxygen uptake after the change in respiratory muscle work is obtained, thereby directly reflecting the functional capacity of the respiratory muscles.

[0035] 2) Apply oxygen metabolism testing to mechanical ventilation (ventilator) therapy to monitor the tidal volume, respiratory rate, inspired oxygen concentration and expired oxygen concentration, expired carbon dioxide concentration, end-tidal oxygen partial pressure and carbon dioxide partial pressure of mechanical ventilation, so as to understand the nutritional and metabolic conditions under breathing.

[0036] 3) Use a pressure sensor to detect the pressure data at the endotracheal tube under mechanical ventilation, and then compare the oxygen uptake change information before and after the ventilator support pressure is adjusted.

[0037] 4) Since patients under mechanical ventilation have a lot of airway secretions, flow sensors in many original devices are reused, so cross infection is inevitable. The present invention uses an ultrasonic flow sensor and an internal disposable breathing tube.

[0038] 5) There are currently methods for testing diaphragmatic function, but there are no methods for testing respiratory muscle function, especially under mechanical ventilation. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of a specific implementation of a respiratory muscle function testing device based on a ventilator disclosed in the present invention;

[0040] Among them, the part numbers in the figure are represented as follows:

[0041] 1. Ventilator, 2. Y-type connector, 3. Flow sensor, 4. Endotracheal tube, 5. Ultrasonic flow sensor cable, 6. Gas sampling pipeline, 7. Pressure detection pipeline, 8. Host, 9. Computer, 11. Exhalation pipeline, 12. Intake pipeline, 81. Flow / volume signal collector, 82. Fast CO2 gas analyzer 82, 83. Fast O2 gas analyzer 83, 84. Vacuum pump, 85. Pressure sensor. DETAILED DESCRIPTION

[0042] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. The principles and features of the present invention are described below in combination with the accompanying drawings. It should be noted that the accompanying drawings are only schematic diagrams for illustrating the present invention, rather than real physical projection diagrams; in addition, the embodiments and features in the embodiments of the present application can be combined with each other without conflict. The examples cited are only used to explain the present invention and are not used to limit the scope of the present invention.

[0043] Several glossaries involved in this invention are explained as follows:

[0044] Mechanical ventilation: Mechanical ventilation is with the help of a ventilator to maintain airway patency, improve ventilation and oxygenation, prevent hypoxia and carbon dioxide accumulation in the body, so that the body can survive respiratory failure caused by the underlying disease and create conditions for the treatment of the underlying disease. Mechanical ventilation is a ventilation method that uses mechanical devices to replace, control or change spontaneous breathing movements. Mechanical ventilation allows the respiratory muscles to rest and reduces oxygen consumption, but if the respiratory muscles rest for too long, disuse atrophy may occur, leading to respiratory muscle weakness; and when the ventilator is used improperly and there is a conflict between spontaneous breathing and the ventilator, the work of the respiratory muscles will increase, and the oxygen consumption of the respiratory muscles will increase significantly, which can eventually lead to fatigue and weakness of the respiratory muscles.

[0045] Oxygen uptake: Oxygen uptake (VO2) refers to the amount of oxygen that the body ingests and actually uses per unit time, in ml / min. Oxygen uptake is obtained by a metabolic tester, i.e., a cardiopulmonary function tester. The principle is to measure the gas volume of breathing and the concentration of inhaled / exhaled gas, and then calculate it using the following formula. Under normal resting conditions, oxygen uptake is equal to the actual oxygen demand, and the body is in an aerobic metabolic state; when the actual oxygen demand is higher than the actual oxygen supply, the body enters an anaerobic metabolic state. Anaerobic metabolism is unsustainable and can only be used for short-term emergencies.

[0046] VO2=VI*F I O2-VE*F E O2

[0047] Here VI and VE are the volumes of inhaled and expired gases, respectively, and F I O2 and F E O2 is the concentration of oxygen inhaled and exhaled respectively.

[0048] In the background technology of the present invention, five methods of diaphragm function testing are listed, each of which is an indirect way to understand the functional status of the diaphragm. For example, diaphragm ultrasound, which is the most commonly used method in ICUs, can measure the thickness of the diaphragm, but the diaphragm thickness cannot accurately represent the diaphragm function; transdiaphragmatic pressure measurement is an invasive detection method; and other detection methods are not suitable for patients on mechanical ventilation.

[0049] The present invention provides a respiratory muscle function test device based on a ventilator, which is connected to a ventilator 1, and the ventilator 1 has a supporting pressure regulation function;

[0050] In a specific embodiment, the device comprises:

[0051] Test head;

[0052] Host 8;

[0053] Computer 9;

[0054] The ventilator 1 includes an exhalation pipe 11 and an intake pipe 12, which are connected to the test head via a Y-type connector 2;

[0055] One end of the test head is connected to the Y-type connector 2, and the other end is connected to the endotracheal tube 4. At the same time, the test head is connected to the host 8 through a pipeline and / or a cable;

[0056] The host 8 is connected to the computer 9 via a cable or wireless communication, for example, via an RS232 communication cable.

[0057] Specifically, the test head includes a flow sensor 3, a gas sampling port, a pressure detection port and a disposable ultrasonic pipeline; the flow sensor 3 is used to measure the respiratory flow signal of the patient's endotracheal intubation 4. The flow sensor 3 is preferably an ultrasonic flow sensor. There are no obstacles inside the sensor. The ultrasonic probe is located outside the pipeline and does not contact the patient, which is conducive to preventing cross infection. After the test is completed, the internal disposable ultrasonic pipeline can be quickly replaced to prevent the occurrence of cross infection (intubated patients have more secretions). The end of the internal pipeline of the ultrasonic flow sensor is connected to the Y-type connector 2, and the front end of the disposable ultrasonic pipeline located inside the ultrasonic flow sensor is connected to the endotracheal intubation 4.

[0058] The host 8 includes a flow / volume signal collector 81, a fast gas analyzer, and a pressure signal collector; the flow sensor 3 is connected to the flow / volume signal collector 81 through an ultrasonic flow sensor cable 5; the fast gas analyzer is connected to the gas sampling port; the pressure signal collector can use a pressure sensor 85, which is connected to the pressure detection port through a pressure detection pipeline 7. The fast gas analyzer is connected to the gas sampling port through a gas sampling pipeline 6, and the fast gas analyzer includes a fast CO2 gas analyzer 82, a fast O2 gas analyzer 83, and a vacuum pump 84.

[0059] After the signals are collected by the signal collector in the host 8, the data is sent to the computer 9 through the RS232 communication cable for analysis and processing. The sampling frequency is 100 sample points per second, and a fast gas analyzer is required, namely a fast CO2 gas analyzer 82 and a fast O2 gas analyzer 83, so that the gas volume and the corresponding gas concentration at each moment can be restored.

[0060] The pressure sensor can measure the changes in the subject's tracheal pressure, and thus calculate:

[0061] 1) Peak inspiratory pressure (PIP);

[0062] 2) Maximum inspiratory negative pressure (MIP);

[0063] 3) Maximum expiratory pressure (PEP);

[0064] 4) PEEP (end-expiratory pressure);

[0065] 5) end-inspiratory airway pressure Pplat;

[0066] 6) Mean airway pressure Pmean;

[0067] 7) Minimum airway pressure Pmin;

[0068] Computer 9, as a control unit, performs functions such as data processing, analysis, display, storage and printing. Computer 9 receives data uploaded by host 8, and can calculate the ventilation volume VE and oxygen uptake VO2 per breath according to the formula of oxygen uptake, and then calculates the data per minute, averages the data during this period, and obtains the average oxygen uptake and ventilation volume under the current ventilator support level. When the pressure support level is adjusted, it is necessary to re-analyze and calculate to obtain the adjusted average oxygen uptake and ventilation volume, and then compare the data before and after.

[0069] Based on the above respiratory muscle function testing device, the present invention discloses a respiratory muscle function testing method, comprising the following steps:

[0070] S1. Connect the respiratory muscle function test device to a testee with autonomous ventilation ability, keep all components in normal working state, and perform mechanical ventilation on the testee;

[0071] S2, obtaining the oxygen uptake data of the subject under current mechanical ventilation and the corresponding support pressure data of the ventilator 1 through the host 8 and the computer 9;

[0072] S3, lowering the support pressure of the ventilator 1, and obtaining the oxygen uptake data under the current mechanical ventilation and the corresponding support pressure data of the ventilator 1 again;

[0073] S4. Analyze and compare the oxygen uptake data before and after the ventilator 1 supports pressure adjustment.

[0074] Specifically, in step S2, the computer 9 receives the data uploaded by the host 8, calculates the ventilation volume VE and oxygen uptake VO2 per breath, and then calculates the data per minute, averages the data during this period, and obtains the average oxygen uptake and ventilation volume under the current ventilator support level.

[0075] In step S3, after adjusting the support pressure level of the ventilator 1, it is necessary to re-analyze and calculate to calculate the ventilation volume VE and oxygen uptake VO2 for each breath, and then calculate the data per minute, average the data during this period, and obtain the average oxygen uptake and ventilation volume after adjusting the support pressure level of the ventilator 1.

[0076] According to the analysis and comparison results, if the oxygen uptake and ventilation data both increase after lowering the ventilator 1 support pressure, the ventilator 1 support pressure level will be gradually lowered.

[0077] according to Figure 1 After the structures are connected, we can obtain the oxygen uptake data of the subject under the current mechanical ventilation and the corresponding ventilator 1 support pressure, and then we can appropriately lower the support pressure level of ventilator 1. That is to say, ventilator 1 originally led the patient to breathe, and the patient's own respiratory muscles did not participate in the respiratory movement, and the patient was passively breathing with ventilator 1. Now the patient must use his own respiratory muscles to participate in breathing, just like a cardiopulmonary exercise test, with increasing power doses, and the leg muscles have to work. Now the pressure support level is lowered, and the main muscle responsible for breathing - the diaphragm must work, and the size of the diaphragm's work capacity is mainly reflected in the change in oxygen uptake.

[0078] For patients with good respiratory muscle function, after lowering the support pressure, the respiratory muscles (mainly the diaphragm) will participate in the work, and the oxygen uptake and ventilation will increase. For such patients, the pressure level of ventilator 1 can be gradually lowered to allow the patient's diaphragm to participate more in the respiratory movement, which is conducive to rapid extubation and weaning. For patients with severely reduced respiratory muscle function, who are completely dependent on ventilator 1, after lowering the pressure level, the oxygen uptake and ventilation will also decrease, and the oxygen saturation will soon decrease. Such patients are definitely not suitable for weaning.

[0079] According to the respiratory muscle testing device and method disclosed in the present invention, actual tests were carried out in combination with actual clinical practice:

[0080] Patient A, Tao, 89 years old, was tested twice, each time for 3 minutes. The pressure support level of the ventilator was lowered by 5 cm of water column. The data before and after the lowering were as follows:

[0081] VO2 VE Before Downgrade 591 6.57 After downgrade 539 5.68

[0082] According to the data comparison before and after the pressure level was lowered, the patient's oxygen uptake VO2 and ventilation volume VE both decreased after the ventilator support pressure was lowered, so it was not suitable for weaning.

[0083] Patient B, Li, 32 years old, was tested twice, each test lasted about 1 minute, and the pressure was lowered by 2cm of water column. Since the patient was awake, he was a little nervous after the pressure was lowered, but it did not affect the test results. The test data is as follows:

[0084] VO2 VE Before Downgrade 223 3.55 After downgrade 234 3.69

[0085] According to the data comparison before and after the pressure level was lowered, the patient's oxygen uptake VO2 increased compensatorily and the ventilation volume VE also increased after the ventilator support pressure was lowered. Therefore, the ventilator pressure level can be gradually lowered for this patient to allow the respiratory muscles (diaphragm) to participate more in the respiratory movement, which will help to extubate and wean the patient as soon as possible.

[0086] The technical solution disclosed in the present invention is to use a metabolic tester in a mechanical ventilator (respirator). Based on the principle of cardiopulmonary exercise test, by adjusting the support pressure level of the ventilator, the respiratory muscles (mainly the diaphragm) are allowed to participate in the respiratory exercise, and the changes in oxygen uptake after the respiratory muscles participate in the spontaneous breathing exercise are obtained, thereby directly reflecting the respiratory function of the diaphragm. This method is simpler than several traditional methods, has high feasibility, is a non-invasive test, and the data is relatively direct. Specifically, the technical solution provided by the present invention has the following advantages over the existing diaphragm detection method:

[0087] 1) Although the oxygen uptake data reflects the oxygen uptake of the whole body, after adjusting the support pressure parameters of the ventilator, the respiratory muscle work of patients with spontaneous breathing will change. At this time, the change in oxygen uptake is the data of the change in respiratory muscle work, which can directly reflect the respiratory muscle function; while the results of imaging examinations (X-rays and diaphragm ultrasound) are only changes in imaging significance and cannot truly reflect the actual changes in diaphragm function;

[0088] 2) The present invention does not require the patient's subjective cooperation, and the test results can truly reflect the patient's physiological state;

[0089] 3) The present invention is a non-invasive test that does not require intubation (such as transdiaphragmatic pressure testing) or acupuncture (diaphragmatic electromyography);

[0090] 4) The present invention is a radiation-free test that measures the patient's respiratory gas volume and gas concentration. The test can be performed at any time without radiation protection requirements;

[0091] 5) The metabolic data changes obtained by the present invention, namely the energy metabolism and the consumption ratio of the three major nutrients, can provide more valuable information for clinicians. Mechanical ventilation itself is to solve the patient's breathing problem, but the settings on the ventilator are all related to ventilation information, and the oxygen uptake data is not only related to ventilation, but also to the gas exchange function.

[0092] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not limited to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0093] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A respiratory muscle function test device based on a ventilator, used to be connected to a ventilator, characterized in that: include: Test head; Host; computer; The test head is connected to the exhalation pipe and the intake pipe of the ventilator respectively through a Y-type connector; One end of the test head is connected to the Y-type connector, and the other end is connected to the endotracheal tube. At the same time, the test head is connected to the host through a pipeline and / or a cable; The host is connected to the computer via a cable or wireless communication; and The test head includes a flow sensor, a gas sampling port, a pressure detection port and a disposable ultrasonic pipeline; The host includes a flow / volume signal collector, a fast gas analyzer, and a pressure signal collector; The flow sensor is connected to the flow / volume signal collector via a cable; The fast gas analyzer is connected to the gas sampling port; The pressure signal collector is connected to the pressure detection port; and The fast gas analyzer includes a fast CO2 gas analyzer, a fast O2 gas analyzer and a vacuum pump; wherein The respiratory muscle function testing device based on a ventilator performs the following steps: S1. Connect the respiratory muscle function test device based on a ventilator to a testee with autonomous ventilation ability, keep all components in normal working state, and perform mechanical ventilation on the testee; S2, obtaining the oxygen uptake data and corresponding ventilator parameter data of the subject under current mechanical ventilation through the host and the computer; S3, lowering the ventilator support pressure parameter, and obtaining oxygen uptake data under the current mechanical ventilation again; S4. Analyze and compare the oxygen uptake data before and after adjusting the ventilator support pressure parameters; in In step S2, the computer receives the data uploaded by the host, calculates the ventilation volume VE and oxygen uptake VO2 per breath, then calculates the data per minute, averages the data during this period, and obtains the average oxygen uptake and ventilation volume under the current ventilator support level; and In step S3, after adjusting the ventilator parameters, it is necessary to re-analyze and calculate to calculate the ventilation volume VE and oxygen uptake VO2 for each breath, and then calculate the data for each minute, average the data during this period, and obtain the average oxygen uptake and ventilation volume after adjusting the ventilator parameters. The respiratory muscle function of the subject is converted and calculated through the change data of ventilation volume VE and oxygen uptake VO2 before and after the ventilator parameter adjustment.

2. A respiratory muscle function testing device based on a ventilator according to claim 1, characterized in that: The computer is configured to have data processing, analysis and display functions.

3. A respiratory muscle function testing device based on a ventilator according to claim 1, characterized in that: According to the analysis and comparison results, if the oxygen uptake and ventilation data both increase after lowering the ventilator support level, the ventilator support pressure parameters can be gradually lowered.

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