CN114343662B - A method for reading ring electrocardiographic signal data - Google Patents

Abstract

The present disclosure relates to a method for reading annular electrocardiosignal data, wherein the electrocardiosignal data is stored by an annular queue, and the method comprises the following steps: creating a queue head pointer and a pre-reading sequence number parameter for each application needing to read electrocardiosignal data; acquiring a queue head pointer and a corresponding pre-reading sequence number parameter value of the current application of electrocardiosignal data to be read; calculating the position of the electrocardio data to be read through a 'queue head pointer plus a pre-reading sequence number parameter', thereby acquiring the electrocardio signal data to be read under the condition of not moving the queue head pointer; the position of the electrocardiosignal data to be read relative to the pointer of the queue head is equal to the parameter value of the pre-reading sequence number. The method reduces the demands for computing capacity and memory when reading the electrocardio data, and is very suitable for being used on wearable electrocardio devices with low power consumption.

Description

A method for reading ring electrocardiographic signal data

technical field

The disclosure relates to medical instrument technology, equipment and medical special software, in particular to a method for reading ring ECG signal data.

Background technique

Real-time analysis of human ECG signals is of great clinical significance, but due to limitations in power consumption, memory, and computing power, it is difficult to achieve real-time analysis of ECG signals on wearable devices. Therefore, how to optimize the ECG analysis process to achieve the purpose of reducing computing power consumption, reducing memory requirements, and reducing computational complexity is extremely important. Among them, the first step of ECG signal processing is data storage: how to efficiently store and read ECG data to reduce memory requirements and computational complexity for real-time analysis of subsequent algorithms, is The current problem to be solved.

Contents of the invention

In view of this, the present invention provides a ring-shaped electrocardiographic signal storage method, which can greatly reduce the data duplication frequency and memory usage requirements of traditional storage mechanisms, thereby achieving the goals of reducing power consumption and cost. The electrocardiogram data is stored in a circular queue, and the method comprises the steps of:

S100. For each application that needs to read ECG signal data, create a queue head pointer and pre-read serial number parameters;

The queue head pointer is used to lock the initial data to be read by the current application;

The pre-read serial number parameter is used to identify the position of the pre-read data relative to the initial data, wherein the initial data position is 0;

S200. Obtain the queue head pointer and correspondingly pre-read the serial number parameter value of the application that currently needs to read the ECG signal data;

S300. Calculate the position of the ECG data to be read by using the "queue head pointer + pre-read serial number parameter", so as to obtain the ECG data to be read without moving the queue head pointer;

The position of the ECG signal data to be read relative to the queue head pointer is equal to the pre-read serial number parameter value.

In the method, the method also includes the steps of:

For each application that needs to read data, determine whether it is necessary to backtrack the read data. If it is not necessary to backtrack the read data, move the corresponding queue head pointer to the position of indexLast+1;

Among them, indexLast is the last data position of the read data;

If all applications do not need to backtrack for a piece of read data, the space for this piece of read data is released and can be used to store new data.

In the method, the length of the ring queue is determined by the following formula:

Ring queue length = minimum heart rate interval + redundancy value;

Minimum heart rate interval = sampling rate × (60/minimum heart rate value);

Wherein, the sampling rate is the sampling frequency of the ECG device;

The redundancy value is set to ensure that newly stored data does not overwrite data that has not yet been processed.

Compared with existing technology:

The disclosed method does not need to allocate another space when reading data, and shares a queue cache with data acquisition, which reduces the demand for device computing power and memory when reading data, and is very suitable for wearable and low-power consumption. However, the cost of the equipment for reading data using the disclosed method can be reduced.

Description of drawings

Fig. 1 is a schematic flow chart of a method in an embodiment of the present invention;

Fig. 2 is a schematic diagram of reading data processing in an embodiment of the present invention;

3 is a schematic diagram of releasing the read data space after reading data processing in an embodiment of the present invention;

Fig. 4 is a schematic flow diagram of ECG data storage, ECG R-wave real-time detection and reading of ECG data, and Bluetooth transmission and reading of ECG data in an embodiment of the present invention.

Detailed ways

In one embodiment, a circular ECG storage queue is adopted, and the ECG signal data is stored in a circular queue, and the method includes the following steps, as shown in Figure 1:

S100. For each application that needs to read ECG signal data, create a queue head pointer and pre-read serial number parameters;

The queue head pointer is used to lock the initial data to be read by the current application;

The pre-read serial number parameter is used to identify the position of the pre-read data relative to the initial data, wherein the initial data position is 0;

S200. Obtain the queue head pointer and correspondingly pre-read the serial number parameter value of the application that currently needs to read the ECG signal data;

S300. Calculate the position of the ECG data to be read by using the "queue head pointer + pre-read serial number parameter", so as to obtain the ECG data to be read without moving the queue head pointer;

The position of the ECG signal data to be read relative to the queue head pointer is equal to the pre-read serial number parameter value.

In the above method, the circular queue can be used to store and read at the same time, and the space can be effectively utilized. Since the electrocardiographic data often needs "backtracking" analysis during the analysis process, that is, after analyzing a period of data, it may be found that it is necessary to go back to a certain period of time before and re-analyze according to different situations. Improvements were made to ring queue reading in .

The specific implementation method is to create multiple queue heads, for example, create a queue head for a real-time detection of ECG R wave that needs to read ECG signal data, denoted as frontR, and at the same time create a queue head for another application that needs to read ECG signal data For Bluetooth transmission, create a queue head, denoted as frontBT. By using the queue head pointer to lock the initial data to be read by the current application, the data read by each application does not affect each other. At the same time, add a pre-read serial number parameter with an initial value of 0 for each ECG signal data that needs to be read. For example, create a pre-read serial number parameter indexR for real-time detection of ECG R waves, and create a pre-read serial number parameter indexR for Bluetooth transmission. The pre-read serial number parameter is denoted as indexBT. The location of the ECG data to be read is calculated by "queue head pointer + pre-reading serial number parameter", so that the ECG signal data to be read can be obtained without moving the queue head pointer. In this way, the collection and reading of ECG data can be concentrated into one queue, without additionally opening up a cache space for reading data, and even if the data is backtracked, there is no need to re-copy it to a dedicated data cache, which greatly reduces memory requirements; Due to the reduction of data duplication, additional running time during the duplication process is also reduced.

When reading data, the corresponding queue head remains unchanged temporarily, and the corresponding data is first read through the queue head combined with the pre-read serial number parameter. For example, now an ECG data reading application is recorded as A, and the queue head pointer is created for it as frontA, the pre-reading serial number parameter indexA=0, and the physical position of the queue stored in the pointer is 2, that is, frontA=2. At this time, if Read the first data, then indexA=0, the corresponding queue physical position is frontA+indexA=2+0=2; read the second data, then indexA=1, the corresponding queue physical position is frontA+indexA=2 +1=3, the ECG data stored in the corresponding physical location can be obtained by *(frontA+indexA).

During this process, frontA remains unchanged. If it is necessary to backtrack the read data, there is no need to repeat the data duplication. For example, after processing the data with indexA=100, it is found that it is necessary to go back to the previous 60th data, and only need to modify indexA to 100-60=40.

In one embodiment, while using a circular queue to store data, one is stored, and the queue tail pointer rear moves down to the next physical location. There are two ECG data reading applications A and B, respectively recorded as frontA, frontB, indexA ECG data reading application A pre-reading serial number parameters. Fig. 2 is a schematic diagram of ECG data reading application A during data processing, frontA remains unchanged, and the corresponding data is first read through the serial number indexA. Figure 3 is a schematic diagram of ECG data reading application A after data processing. After reading a piece of data, the processed data is released. At this time, frontA moves to the next physical address of the processed data. address. That is, for an application that needs to read ECG signal data, when it has read a piece of data, there is no need to trace back the read data. If it is necessary to release the space occupied by this piece of data, make the corresponding The queue head pointer can be moved to the next physical address of the last data of this piece of data.

In one embodiment, a circular queue is created, and the disclosed method is used to realize real-time detection of ECG R waves and real-time Bluetooth transmission of data. The specific method steps are as follows, as shown in Figure 4:

First, initialize the ring queue. Specifically, create a queue whose length is greater than a minimum heart rate interval. If the minimum heart rate interval is defined as the number of sampling points between two heartbeats, that is:

Minimum heart rate interval = sampling rate × (60/minimum heart rate)

Among them, the minimum heart rate is generally selected to be 30 beats/minute.

Therefore, queue length = sampling rate × (60/minimum heart rate) + redundancy value

Among them, the redundancy value is a set value, which is used to ensure that the queue length is greater than a minimum heart rate interval, so as to ensure that the algorithm can find at least one R peak, and at the same time ensure that the new data does not overwrite the data that has not yet been processed. This value Depends on algorithm complexity and processor speed.

If the sampling rate is 250Hz, the minimum heart rate is 30, and the redundancy value is 100, then:

Queue length=250×(60/30)+100=600.

Next, initialize the queue tail pointer rear and read pointers frontR, indexR, frontBT, and indexBT to 0, where frontR, indexR are the queue head pointer and pre-reading serial number parameters corresponding to R wave detection, and frontBT and indexBT are Bluetooth The transmitted queue head pointer and prefetch sequence number parameters.

Secondly, collect and write the ECG data. Specifically, the collected electrocardiographic data is read through an analog-to-digital converter and written into the queue, and the column tail pointer rear is incremented by 1 each time a piece of data is written.

Third, real-time detection of R waves. When the amount of data stored in the queue is greater than a minimum heart rate interval, the R wave is detected. Use indexR to read the data in the queue, find out all the R peaks in the cache, and save the position number of the last R wave as indexLastR.

Fourth, the release of R wave detection data. Since the previous step uses indexR to read data during R wave detection, after the analysis is completed, it is necessary to release the space of the processed data. At this point, the value of indexR is the length of the read data. Directly update frontR to the value of frontR+indexR+1. At this time, frontR points to the starting position of the ECG data to be read next time. Wait until the next time the data in the queue is greater than a minimum heart rate interval, then start the analysis directly from frontR, that is, the first data of the new data, so as to ensure that the last R wave will not be repeatedly recognized.

Since the size of a data packet transmitted by Bluetooth is much smaller than the minimum heart rate interval, its release frequency is higher than the frequency of R wave detection. Set the size of the data packet transmitted by Bluetooth. For example, the size of the data packet is 20 ECG data. When the ECG data stored in the queue is more than 20, read the ECG data to be transmitted sequentially until the reading is completed. 20 ECG data are sent one by one.

When a Bluetooth data packet is sent, modify the value of frontBT to the value of frontBT+indexBT+1 to release the storage space of the transmitted ECG data.

When all applications do not need to look back on a piece of read data, the space for this piece of read data is released and can be used to store new ECG data. That is, when a section of data space is not locked by any queue head pointer, this section of data space can be used to store new ECG data.

It can be seen from the above-mentioned embodiments that when reading data, the disclosed method adds a pre-read serial number parameter to realize pre-reading, which not only facilitates data backtracking, but also reduces data copying frequency and memory space requirements; adding multiple Read the pointer, so that a storage space can be used by multiple processing processes at the same time, reducing the data replication frequency and memory space requirements, very suitable for wearable, low-power consumption, and devices that use the disclosed method to read data Can reduce costs.

Although the disclosed method is applied to ECG data, it can theoretically be applied to any similar data acquisition and analysis equipment, such as other human physiological signal pulse wave, respiratory wave, pressure wave, brain wave, myoelectricity and other acquisition equipment. .

Through the description of the above embodiment, those skilled in the art can clearly understand that the disclosed method can be realized by means of software plus necessary general-purpose hardware, and of course it can also be realized by special-purpose hardware including application-specific integrated circuits, special-purpose CPUs, and special-purpose memory , special components, etc. to achieve. In general, all functions completed by computer programs can be easily realized by corresponding hardware, and the specific hardware structure used to realize the same function can also be varied, such as analog circuits, digital circuits or special-purpose circuit etc. However, for the purposes of the present disclosure, in most cases, a software program implementation is a preferred embodiment.

Although the embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields, and the above-mentioned specific embodiments are only illustrative, instructive, and not restrictive . Under the enlightenment of this specification and without departing from the protection scope of the claims of the present invention, those skilled in the art can also make many forms, which all belong to the protection of the present invention.

Claims (2)

1. A ring-shaped electrocardiographic signal data reading method, the electrocardiographic signal data adopts circular queue storage, it is characterized in that, described method comprises the following steps: S100. For each application that needs to read ECG signal data, create a queue head pointer and pre-read serial number parameters; The queue head pointer is used to lock the initial data to be read by the current application; The pre-read serial number parameter is used to identify the position of the pre-read data relative to the initial data, wherein the initial data position is 0; S200. Obtain the queue head pointer and correspondingly pre-read the serial number parameter value of the application that currently needs to read the ECG signal data; S300. When reading data, the corresponding queue head remains unchanged temporarily, and the position of the ECG data to be read is calculated by "queue head pointer + pre-reading serial number parameter", so that the queue head pointer is not moved , to obtain the ECG signal data to be read; The position of the ECG signal data to be read relative to the queue head pointer is equal to the pre-read serial number parameter value; For each application that needs to read data, determine whether it is necessary to backtrack the read data. If it is not necessary to backtrack the read data, move the corresponding queue head pointer to the position of indexLast+1; where , indexLast is the last data position of the read data; The length of the ring queue is determined by the following formula: Ring queue length = minimum heart rate interval + redundancy value; Minimum heart rate interval = sampling rate × (60/minimum heart rate value); Wherein, the sampling rate is the sampling frequency of the ECG device; The redundancy value is set to ensure that newly stored data does not overwrite data that has not yet been processed. 2. method according to claim 1, is characterized in that, described method also comprises the following steps: If all applications do not need to backtrack for a piece of read data, the space for this piece of read data is released and can be used to store new data.