Method, device, system and medium for calculating tidal volume of a ventilator

Abstract

The present invention discloses a method, device, system, and medium for calculating ventilator tidal volume, comprising: real-time acquisition of ventilator flow rate; integration of the ventilator flow rate, stopping integration when the ventilator flow rate meets a stop-integration rule; and outputting the ventilator tidal volume based on the integration result. This application integrates the ventilator flow rate and, when the stop-integration rule is met, calculates the ventilator tidal volume based on the integration result, thereby resolving the flow rate inaccuracy caused by AD zero drift, while also preventing jumps in the ventilator tidal volume and improving the accuracy of ventilator tidal volume calculation.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to a method, device, system and medium for calculating the tidal volume of a ventilator. Background Art

[0002] An emergency transport ventilator is a medical device that provides emergency ventilation for patients with respiratory failure. It is commonly used for long-distance and short-distance ambulance transport, intra-hospital transport, and field emergency treatment. The ventilator can be placed in the ambulance for emergency treatment. The flow rate of the emergency transport ventilator is monitored by a differential pressure flow sensor. The pressure difference is collected through a fixed aperture. The sensor then converts the pressure difference into a voltage signal, and finally converts it into an AD value. However, the AD value of the flow collected by the hardware will experience zero-point AD fluctuation and zero-point AD drift. Zero-point AD fluctuation can be effectively improved by filtering, but zero-point AD value offset cannot be solved by filtering.

[0003] Since AD ​​drift causes the flow rate baseline to shift, this flow rate drift will seriously affect the calculation of tidal volume, especially the calculation of tidal volume in the expiratory phase. There are cases where the exhalation time is long, and the actual expiratory flow rate is close to zero. However, due to the existence of AD zero drift, the AD resolution of the smaller flow rate is low (i.e., the AD value with less change corresponds to the larger change in flow rate). This will result in a larger end-expiratory flow rate due to AD zero drift. At this time, the cumulative calculation of the expiratory flow rate to calculate the expiratory tidal volume is not accurate.

[0004] To effectively address the issue of end-tidal flow velocity not returning to zero due to zero drift, thus affecting expiratory tidal volume calculation, we propose raising the starting flow velocity threshold for tidal volume calculation to 3 L / min. (Generally, the flow velocity baseline will have some offset, and the zero-point AD offset of the EV5 machine is generally within ±3 L / min.) However, when the baseline offset is around 3 L / min, it can fluctuate between positive and negative. This indicates that flow rates less than 3 L / min will be directly recorded as zero, while those greater than 3 L / min will be calculated as the actual value. This can cause sudden jumps in tidal volume. For example, if the end-tidal flow velocity in the previous cycle was less than 3 L / min and below the flow velocity integration threshold, tidal volume calculation will be omitted, resulting in a smaller tidal volume in the previous cycle. However, if the end-tidal flow velocity in the current cycle is greater than 3 L / min and above the integration threshold, it will still be integrated, resulting in a larger tidal volume in the current cycle. Even though the flow velocity only slightly changes between the two states, it can still cause a sudden jump in tidal volume.

[0005] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a method for calculating the tidal volume of a ventilator, aiming to solve the problem of inaccurate flow rate caused by AD zero drift, while avoiding jump changes in the tidal volume of the ventilator, thereby improving the accuracy of the tidal volume calculation of the ventilator.

[0007] The technical solutions of the present invention are as follows:

[0008] A method for calculating tidal volume of a ventilator, comprising:

[0009] Real-time collection of ventilator flow rate;

[0010] Integrating the ventilator flow rate, and stopping integration when the ventilator flow rate meets a stop integration rule;

[0011] Output the ventilator tidal volume based on the integration result.

[0012] In one embodiment, after collecting the flow rate of the ventilator in real time, the method further includes:

[0013] Assigning an initial value to the negative maximum flow rate to obtain the ventilator flow rate;

[0014] When the ventilator flow rate is less than the initial value of the negative maximum flow rate and the ventilator flow rate is maintained for a specified time without iteration, the ventilator flow rate is used as the negative maximum flow rate.

[0015] In one embodiment, integrating the ventilator flow rate comprises:

[0016] Presetting a flow rate integration threshold of the ventilator, wherein the flow rate integration threshold is used to determine a range for integrating the flow rate of the ventilator;

[0017] The ventilator flow rate is compared with the flow rate integration threshold, and the ventilator flow rate is integrated according to the comparison result.

[0018] In one embodiment, the step of integrating the ventilator flow rate comprises:

[0019] When the absolute value of the ventilator flow rate is greater than the flow rate integration threshold, the ventilator flow rate is integrated.

[0020] In one embodiment, when the ventilator flow rate satisfies a stop integration rule, stopping integration comprises:

[0021] After identifying the negative maximum flow rate, when the ventilator flow rate reaches a specified preset flow rate, start timing;

[0022] When the timing reaches the specified time threshold, the integration stops.

[0023] In one embodiment, when the ventilator flow rate satisfies a stop integration rule, stopping integration comprises:

[0024] When the negative maximum flow rate and the designated preset flow rate are identified, and the absolute value of the ventilator flow rate is less than the flow rate integration threshold, integration is stopped.

[0025] In one embodiment, after the negative maximum flow rate is identified, when the ventilator flow rate reaches a specified preset flow rate, starting timing, further comprising:

[0026] Obtaining the two ventilator flow rates at adjacent moments;

[0027] Whether to start timing is determined based on the two ventilator flow rates at adjacent moments and the specified preset flow rate.

[0028] A device for calculating tidal volume of a ventilator, the device comprising:

[0029] Acquisition module, used to collect ventilator flow rate in real time;

[0030] an assigning module, configured to integrate the ventilator flow rate and stop integration when the ventilator flow rate satisfies a stop integration rule;

[0031] The calculation module is used to output the tidal volume of the ventilator according to the integration result.

[0032] A system for calculating tidal volume of a ventilator, the system comprising at least one processor; and

[0033] a memory communicatively connected to the at least one processor; wherein,

[0034] The memory stores instructions that can be executed by the at least one processor. The instructions are executed by the at least one processor to enable the at least one processor to perform the above-mentioned method for calculating the tidal volume of the ventilator.

[0035] A non-volatile computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are executed by one or more processors, the one or more processors can execute the above-mentioned method for calculating the tidal volume of a ventilator.

[0036] Beneficial effects: The present invention discloses a method, device, system and medium for calculating the tidal volume of a ventilator. Compared with the prior art, the embodiments of the present invention integrate the ventilator flow rate, and when the stop integration rule is met, calculate the tidal volume of the ventilator according to the integration result, thereby solving the problem of inaccurate flow rate caused by AD zero drift, avoiding jump changes in the tidal volume of the ventilator, and improving the accuracy of the tidal volume calculation of the ventilator. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0038] Figure 1 A flow chart of a method for calculating tidal volume of a ventilator provided in an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of the functional modules of a device for calculating tidal volume of a ventilator provided in an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of the hardware structure of a ventilator tidal volume calculation system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and effects of the present invention more clear and distinct, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. The embodiments of the present invention are described below with reference to the accompanying drawings.

[0042] See also Figure 1 , Figure 1 The flowchart of one embodiment of the method for calculating the tidal volume of a ventilator provided by the present invention. Figure 1 As shown, the method includes the following steps:

[0043] S100 collects ventilator flow rate in real time;

[0044] S200 integrates the ventilator flow rate, and stops integration when the ventilator flow rate meets a stop integration rule;

[0045] S300 outputs the ventilator tidal volume based on the integration result.

[0046] In this embodiment, due to the problem of zero drift in the end-expiratory flow rate of the ventilator, which affects the calculation of tidal volume. Therefore, the integration threshold for starting the calculation of the ventilator tidal volume VT is raised to a certain range. However, when the baseline shifts, it shifts positively and negatively, which will cause sudden jumps in the tidal volume. Therefore, a flow rate threshold method is proposed to prevent the baseline drift from affecting the tidal volume calculation. It is determined when reverse integration is no longer required. The flow rate Flow of the ventilator is collected in real time. First, a negative maximum flow rate is identified based on the flow rate of the ventilator. After identifying the negative maximum flow rate, the specified preset flow rate of the ventilator is identified. After identifying the specified preset flow rate of the ventilator, the flow rate of the ventilator is collected in real time, and the ventilator is integrated. When a certain time has passed, the flow rate should normally return below the flow rate integration threshold. Therefore, later, it is judged whether the flow rate can stop integrating based on the set residence time and whether it reaches within the flow rate integration threshold. Meeting either of the two conditions is sufficient. By this method, the above problem of the tidal volume jumping back and forth can be avoided. The tidal volume VT is calculated by integrating the flow rate of the ventilator, Solve the problem of tidal volume jumping.

[0047] In one embodiment, after the step S100, it further includes:

[0048] Assign an initial value to the negative maximum flow rate and obtain the flow rate of the ventilator;

[0049] When the flow rate of the ventilator is less than the initial value of the negative maximum flow rate and the flow rate of the ventilator remains uniterated for a specified time, then this flow rate of the ventilator is used as the negative maximum flow rate.

[0050] In this embodiment, a negative maximum flow rate needs to be identified first in the expiratory phase of the control phase. The negative maximum flow rate is identified using the preset flow rate real-time iteration method. When the maximum preset flow rate of the current ventilator has not continued to iterate for a specified time, then the current maximum preset flow rate of the ventilator is identified as the negative maximum flow rate. That is, the initial value of the negative maximum flow rate is set to 0, i.e., FlowMax = 0. Obtain the maximum preset flow rate of the ventilator at this moment, and compare the maximum preset flow rate of the ventilator with the initial value. If the maximum preset flow rate of the ventilator is less than the initial value of the negative maximum flow rate IfFlow < FlowMax, and the maximum preset flow rate of the ventilator remains unchanged for a specified time, for example, the maximum preset flow rate of the ventilator has not changed for 200 ms, then this maximum preset flow rate of the ventilator is used as the negative maximum flow rate.

[0051] In one embodiment, the step S200 includes:

[0052] Preset the flow rate integration threshold of the ventilator, and the flow rate integration threshold is used to determine the range for integrating the flow rate of the ventilator;

[0053] The ventilator flow rate is compared with the flow rate integration threshold, and the ventilator flow rate is integrated according to the comparison result.

[0054] In this embodiment, a ventilator flow rate integration threshold is set based on the ventilator's zero AD offset. The flow rate integration threshold represents the flow rate threshold for integrating the flow rate. Integration begins when the ventilator's flow rate satisfies the condition. For example, the zero AD offset of an EV5 ventilator is generally within ±3 L / min, so the ventilator flow rate integration threshold is set to 3 L / min. The ventilator flow rate is compared with the integration threshold. If the absolute value of the ventilator flow rate is less than the integration threshold of 3 L / min, no integration is assigned. If the absolute value of the ventilator flow rate is greater than the integration threshold of 3 L / min, a corresponding integration is assigned.

[0055] In one embodiment, step S200 includes:

[0056] When the absolute value of the ventilator flow rate is greater than the flow rate integration threshold, the ventilator flow rate is integrated.

[0057] In this embodiment, the ventilator integration threshold is set to a L / min, a>0, and the ventilator flow rate is obtained. When the absolute value of the ventilator flow rate is greater than the flow rate integration threshold, the ventilator flow rate is integrated. When the absolute value of the ventilator flow rate is less than the flow rate integration threshold, the ventilator flow rate is not integrated. That is:

[0058]

[0059] Therefore, integration is performed only when the absolute value of the flow rate is greater than the flow rate integration threshold, and when calculating the tidal volume, the actual flow rate value is used for calculation. When the absolute value of the ventilator flow rate is less than the flow rate integration threshold, it is directly regarded as zero and no integration is performed.

[0060] In one embodiment, step S200 includes:

[0061] After identifying the negative maximum flow rate, when the ventilator flow rate reaches a specified preset flow rate, start timing;

[0062] When the timing reaches the specified time threshold, the integration stops.

[0063] In this embodiment, to obtain the flow rate of the ventilator, it is first necessary to identify the negative maximum flow rate of the ventilator. When the ventilator flow rate reaches the negative maximum flow rate, the specified preset flow rate of the ventilator -5L / min is identified. When the specified preset flow rate -5L / min is identified, the timing Cnt is started. When the Cnt timing reaches the specified time threshold, for example 200ms, it is considered that there is no need to integrate the expiratory phase anymore, and the integration is stopped.

[0064] In one embodiment, step S200 includes:

[0065] When the negative maximum flow rate and the designated preset flow rate are identified, and the absolute value of the ventilator flow rate is less than the flow rate integration threshold, integration is stopped.

[0066] In this embodiment, after identifying the ventilator's negative maximum flow rate and a specified preset flow rate, the ventilator flow rate is identified. When the absolute value of the ventilator flow rate is less than the flow rate integration threshold, integration is discontinued. Furthermore, after identifying the ventilator's negative maximum flow rate and a specified preset flow rate, integration is discontinued if either the timer reaches the time threshold and / or the absolute value of the ventilator flow rate is less than the flow rate integration threshold. This method can avoid the aforementioned problem of tidal volume jumping back and forth.

[0067] In one embodiment, after the negative maximum flow rate is identified, when the ventilator flow rate reaches a specified preset flow rate, starting timing, further comprising:

[0068] Obtaining the two ventilator flow rates at adjacent moments;

[0069] Whether to start timing is determined based on the two ventilator flow rates at the adjacent moments and the specified preset flow rate.

[0070] In this embodiment, after the negative maximum flow rate of the ventilator is identified, the specified preset flow rate of the ventilator is identified, and the ventilator flow rate at this time and the flow rate at the last operating moment of the ventilator are obtained. FlowLast is recorded as the flow rate at the last operating moment. When the condition that the ventilator flow rate Flow at this time is greater than the specified preset flow rate and FlowLast is less than the specified preset flow rate is met, the timing Cnt is started. For example, the specified preset flow rate is -5L / min. When Flow>-5L / min and FlowLast<-5L / min, the timing Cnt is started when this condition is met.

[0071] Another embodiment of the present invention further provides a device for calculating the tidal volume of a ventilator, such as Figure 2 As shown, the device includes:

[0072] Acquisition module 11, used for real-time acquisition of ventilator flow rate;

[0073] an assigning module 12, configured to integrate the ventilator flow rate and stop integration when the ventilator flow rate satisfies a stop integration rule;

[0074] The calculation module 13 is used to output the ventilator tidal volume according to the integration result.

[0075] The module referred to in the present invention refers to a series of computer program instruction segments that can perform specific functions, which are more suitable for the execution process of calculating the tidal volume of the ventilator than the program. For the specific implementation of each module, please refer to the corresponding method embodiment above, which will not be repeated here.

[0076] Another embodiment of the present invention further provides a system for calculating the tidal volume of a ventilator, such as Figure 3 As shown, the system 10 includes:

[0077] One or more processors 110 and memory 120, Figure 3 In the description, a processor 110 is used as an example. The processor 110 and the memory 120 may be connected via a bus or other means. Figure 3 The bus connection is taken as an example.

[0078] The processor 110 is used to implement various control logics of the system 10. It can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a single-chip microcomputer, an ARM (Acorn RISC Machine) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components. In addition, the processor 110 can also be any traditional processor, microprocessor, or state machine. The processor 110 can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP, and / or any other such configuration.

[0079] Memory 120, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as program instructions corresponding to the method for calculating ventilator tidal volume in the embodiments of the present invention. Processor 110 executes the non-volatile software programs, instructions, and modules stored in memory 120 to perform various functional applications and data processing of system 10, thereby implementing the method for calculating ventilator tidal volume in the above-mentioned method embodiment.

[0080] Memory 120 may include a program storage area and a data storage area. The program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of system 10, etc. In addition, memory 120 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory 120 may optionally include memory remotely located relative to processor 110, and such remote memory may be connected to system 10 via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0081] One or more units are stored in the memory 120, and when executed by one or more processors 110, perform the method for calculating the tidal volume of the ventilator in any of the above method embodiments, for example, perform the above described Figure 1 Method steps S100 to S300 in .

[0082] An embodiment of the present invention provides a non-volatile computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, which are executed by one or more processors, for example, to execute the above-described Figure 1 Method steps S100 to S300 in .

[0083] As examples, non-volatile storage media can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) as external cache memory. By way of illustration and not limitation, RAM can be obtained in many forms such as synchronous RAM (SRAM), dynamic RAM, (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM). The disclosed memory components or memories of the operating environment described herein are intended to include one or more of these and / or any other suitable types of memory.

[0084] It should be noted that there is not necessarily a certain order between the above steps. A person skilled in the art can understand, based on the description of the embodiments of the present invention, that in different embodiments, the above steps may have different execution orders, that is, they may be executed in parallel, or may be executed interchangeably, etc.

[0085] In summary, the present invention discloses a method, device, system, and medium for calculating ventilator tidal volume, comprising: real-time acquisition of ventilator flow rate; integration of the ventilator flow rate, and stopping integration when the ventilator flow rate satisfies a stop-integration rule; and outputting the ventilator tidal volume based on the integration result. This application integrates the ventilator flow rate and, when the stop-integration rule is met, calculates the ventilator tidal volume based on the integration result, thereby resolving the flow rate inaccuracy caused by AD zero drift, while also preventing jumps in the ventilator tidal volume and improving the accuracy of ventilator tidal volume calculation.

[0086] What has been described in this specification and the accompanying drawings includes examples of calculation methods, devices, systems and media that can provide ventilator tidal volume. Of course, it is not possible to describe every conceivable combination of elements and / or methods for the purpose of describing the various features of the present disclosure, but it will be appreciated that many additional combinations and permutations of the disclosed features are possible. Therefore, it will be apparent that various modifications can be made to the present disclosure without departing from the scope or spirit of the present disclosure. In addition, or in the alternative, other embodiments of the present disclosure may be apparent from consideration of this specification and the accompanying drawings and from the practice of the present disclosure as presented herein. It is intended that the examples set forth in this specification and the accompanying drawings be considered in all respects to be illustrative and not restrictive. Although specific terms are employed herein, they are used in a general and descriptive sense and not for limiting purposes.

Claims

1. A method for calculating the tidal volume of a ventilator, characterized in that: include: Real-time collection of ventilator flow rate; Integrating the ventilator flow rate, and stopping integration when the ventilator flow rate meets a stop integration rule; Output the ventilator tidal volume according to the integration result; After the real-time acquisition of the flow rate of the ventilator, the method further comprises: Assigning an initial value to the negative maximum flow rate to obtain the ventilator flow rate; When the ventilator flow rate is less than the initial value of the negative maximum flow rate, and the ventilator flow rate is maintained for a specified time without iteration, the ventilator flow rate is used as the negative maximum flow rate; The step of integrating the ventilator flow rate comprises: Presetting a flow rate integration threshold of the ventilator, wherein the flow rate integration threshold is used to determine a range for integrating the flow rate of the ventilator; The ventilator flow rate is compared with the flow rate integration threshold, and the ventilator flow rate is integrated according to the comparison result.

2. The method for calculating the tidal volume of a ventilator according to claim 1, wherein: The step of integrating the ventilator flow rate comprises: When the absolute value of the ventilator flow rate is greater than the flow rate integration threshold, the ventilator flow rate is integrated.

3. The method for calculating the tidal volume of a ventilator according to claim 1, wherein: When the ventilator flow rate satisfies a stop integration rule, stopping integration comprises: After identifying the negative maximum flow rate, when the ventilator flow rate reaches a specified preset flow rate, start timing; When the timing reaches the specified time threshold, the integration stops.

4. The method for calculating the tidal volume of a ventilator according to claim 1, wherein: When the ventilator flow rate satisfies a stop integration rule, stopping integration comprises: When the negative maximum flow rate and the designated preset flow rate are identified, and the absolute value of the ventilator flow rate is less than the flow rate integration threshold, integration is stopped.

5. The method for calculating the tidal volume of a ventilator according to claim 3, wherein: After the negative maximum flow rate is identified, when the ventilator flow rate reaches a specified preset flow rate, starting timing, further comprising: Obtaining the two ventilator flow rates at adjacent moments; Whether to start timing is determined based on the two ventilator flow rates at adjacent moments and the specified preset flow rate.

6. A device for calculating tidal volume of a ventilator, characterized in that: The device comprises: Acquisition module, used to collect ventilator flow rate in real time; an assigning module, configured to integrate the ventilator flow rate and stop integration when the ventilator flow rate satisfies a stop integration rule; A calculation module, used for outputting the tidal volume of the ventilator according to the integration result; After the real-time acquisition of the flow rate of the ventilator, the method further comprises: Assigning an initial value to the negative maximum flow rate to obtain the ventilator flow rate; When the ventilator flow rate is less than the initial value of the negative maximum flow rate, and the ventilator flow rate is maintained for a specified time without iteration, the ventilator flow rate is used as the negative maximum flow rate; The step of integrating the ventilator flow rate comprises: Presetting a flow rate integration threshold of the ventilator, wherein the flow rate integration threshold is used to determine a range for integrating the flow rate of the ventilator; The ventilator flow rate is compared with the flow rate integration threshold, and the ventilator flow rate is integrated according to the comparison result.

7. A ventilator tidal volume calculation system, characterized in that: The system includes at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method for calculating the tidal volume of the ventilator according to any one of claims 1 to 5.

8. A non-volatile computer-readable storage medium, characterized in that: The non-volatile computer-readable storage medium stores computer-executable instructions, which, when executed by one or more processors, enable the one or more processors to execute the method for calculating the ventilator tidal volume according to any one of claims 1 to 5.

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