Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
At present, hypertension is the most common disease in the category of cardiovascular diseases, and the incidence rate increases with the age of human beings. Long-term hypertension is prone to heart disease, enlargement of the heart, and heart failure. And may cause swelling or sagging in the vessel wall, thereby causing obstruction or rupture. Therefore, accurate measurement of blood pressure is beneficial to early discovery of hypertension, prevention of cardiovascular and cerebrovascular diseases and early screening. Clinically, blood pressure detection is divided into two methods, namely a direct measurement method and an indirect measurement method, wherein the direct method is to puncture a human blood vessel through invasive blood pressure detection equipment and detect dynamic blood pressure waveforms through a built-in sensor. The indirect measuring method is a non-invasive blood pressure measuring method, which is characterized in that a cuff containing a pressure sensor is directly contacted with the surface of a human body, a measuring system is formed by matching a catheter, an inflator pump, a deflation valve, a control center and the like, a pulse wave signal is lifted by the blood pressure change relation which is shown in the process from blocking to unblocking of blood at a local position (an upper arm, a fingertip and the like), and the pulse wave signal is processed and analyzed, so that the pressure value of the position is measured. The method has the advantages of convenience, simplicity, no need of a dissected surgical operation, but low accuracy, and common indirect measurement methods comprise a pulse wave velocity measurement method, a constant volume method, an ultrasonic method, an arterial tension method, a Korotkoff sound method, an oscillometric method and the like.
Oscillometric measurement methods have been widely used in blood pressure monitors and home blood pressure monitors. The oscillometric blood pressure measuring system is characterized in that a cuff connected with a rubber catheter is sleeved on the upper arm of a tested person, a pressure sensor is arranged in the cuff, a microprocessor rapidly processes the measured value of the pressure sensor to obtain the condition that the arterial pressure continuously changes along with the static pressure of the cuff, and the systolic pressure (SBP, systolic blood pressure) and the diastolic pressure (DBP, diastolic blood pressure) are further calculated through an algorithm. The method is not easy to be interfered by external sound, has good repeatability and less measurement error, so the oscillography is a non-invasive automatic blood pressure measurement method which is generally accepted by monitors at home and abroad.
However, in the oscillometric method, the algorithm finds the position of the mean arterial pressure by fitting the pulse wave waveform peak value, and then finds the positions of the systolic pressure and the diastolic pressure by an amplitude coefficient method. The process of fitting the pulse wave waveform peak, i.e. extracting the envelope curve, determines the accuracy of the final blood pressure value. Due to the universality of the tested population and the freedom of the testing process, the waveform quality of the pulse wave under the specific condition is possibly poor, so that the fitted envelope curve is deformed, the situation such as the situation that the mean arterial pressure position is wrongly fitted, the envelope curve is deformed in a left-right shifting way, the situation that the envelope curve is not smooth, the situation that the blood pressure value calculated by an amplitude coefficient method deviates from a true value greatly occurs, and the accuracy of measuring the blood pressure value by an oscillography method is reduced.
In view of the above, the blood pressure measuring method, the blood pressure measuring device and the electronic blood pressure meter provided by the embodiment of the invention can acquire a pulse wave signal by utilizing a pressure sensor of the electronic blood pressure meter, extract a quality parameter of the pulse wave signal, judge the quality of the pulse wave signal based on the quality parameter, correct the pulse wave signal by eliminating abnormal points of the pulse wave signal, extract corresponding envelope lines, respectively calculate the mean arterial pressure, the diastolic pressure and the systolic pressure in the envelope lines by utilizing an amplitude coefficient method, and treat different signals in different modes according to the waveform characteristics of the signals, thereby extracting accurate envelope lines and measuring accurate corresponding blood pressure values.
For the convenience of understanding the present embodiment, a method for measuring blood pressure disclosed in the embodiment of the present invention will be described in detail.
The embodiment of the invention provides a blood pressure measuring method, which is applied to an electronic sphygmomanometer, and fig. 1 is a flow chart of the blood pressure measuring method provided by the embodiment of the invention, as shown in fig. 1, and the method specifically comprises the following steps:
step S101, acquiring pulse wave signals acquired by an electronic sphygmomanometer, and extracting quality parameters of the pulse wave signals;
Specifically, the method can firstly perform routine collection on pulse wave signals of a person to be detected, perform signal collection by using a preset sensor in an electronic sphygmomanometer, wherein the signals collected by the sensor comprise a cuff static pressure original signal and a pulse wave original signal, and can sequentially perform preprocessing on the two types of signals, including signal amplification, signal filtering and pulse wave signal separation, so that a processed pulse wave signal is obtained, and the processed pulse wave signal corresponds to a peak value, a valley value and a corresponding time stamp sequence to be used as quality parameters of the pulse wave signal.
Step S103, judging whether the quality parameter meets the preset signal quality judgment condition;
Specifically, after a pulse wave signal is obtained, firstly extracting a peak value and a valley value in a pulse wave signal target interval, and judging the signal quality of the extracted peak value Pi and valley value Vi sequences and a corresponding time stamp sequence t;
The maximum values max_peak, max_valley and the minimum values min_peak, min_valley of the peak sequence Pi and the valley sequence Vi are determined, and the following relationship is satisfied:
the Th1 is a preset minimum threshold value meeting signal detection, and is related to the air pressure value at the baseline position. If the conditions are met, judging that the preset signal quality judging conditions are met, specifically, the waveform image is characterized by a waveform with poor signal quality, otherwise, continuing to judge according to the following method;
performing fluctuation analysis on the time stamp sequence of the pulse wave signal, and firstly calculating the average value of the adjacent time stamp difference values of the peak values according to the following formula, namely:
Where u is the average of the neighbor timestamp differences of the peaks, N is the sequence length of the peak sequence, and i refers to the ith timestamp ti.
And then calculating the standard deviation of the neighbor timestamp difference value of the peak value, namely:
wherein std is the standard deviation of the difference value of the neighboring time stamps of the peaks, N is the sequence length of the peak sequence, and i refers to the ith time stamp ti;
and judging whether the condition std < Th2 is met, wherein Th2 is a preset minimum threshold meeting the fluctuation detection and can be related to the heart rate at the beginning of the test.
If the above condition is satisfied, it is judged that the preset signal quality judgment condition is satisfied, specifically, the waveform image is characterized as a waveform of poor signal quality.
Step S105, if yes, carrying out outlier screening on the pulse wave signals to obtain first outliers in the pulse wave signals;
specifically, for the pulse wave signal satisfying the preset signal quality judgment condition, that is, the waveform image is characterized as a waveform image with poor signal quality, firstly, pulse wave peak value rationality judgment (i.e., outlier screening) is performed, and because a waveform with poor signal quality may have a continuous outlier time sequence, screening by using a method of gaussian waveform approximation screening may be performed by adopting the following function to determine the upper and lower bounds of the gaussian function of the pulse wave signal, which is specifically expressed as follows:
Upper bound:
the lower bound: Wherein y1 is the upper bound of the Gaussian function of the pulse wave signal, y2 is the lower bound of the Gaussian function of the pulse wave signal, a represents the peak height of the waveform curve of the pulse wave signal, b represents the half-peak width of the waveform curve of the pulse wave signal at the peak position c of the waveform curve of the pulse wave signal. The value of a1,a2 is related to the maximum value max_peak of the pulse wave signal peak value sequence Pi, and is respectively set to be 1.1max_peak and 0.6max_peak, the value of b1 is determined by the abscissa corresponding to max_peak, and the value of c is determined by the difference between the time stamp tmax at the highest point of the peak and the initial time stamp t1 of the peak value sequence, and the relationship is that:
After the upper and lower bounds are determined, detecting whether an abnormal point exists by adopting a method of bringing the time stamp of the cross axis of the peak sequence into the upper and lower bounds of the Gaussian function, and judging that the abnormal point is the first abnormal point when the peak position corresponding to the time stamp of the cross axis of the peak sequence exceeds the preset upper and lower bounds.
Step S107, eliminating the first abnormal point to obtain a first pulse wave signal to be corrected corresponding to the pulse wave signal;
Specifically, after determining that the peak position corresponding to the time stamp of the horizontal axis of the peak sequence exceeds the preset upper and lower bounds, removing the corresponding first abnormal point, and obtaining a corresponding first pulse wave signal to be corrected.
Step S109, performing linear correction on the first pulse wave signal to be corrected to obtain a first corrected pulse wave signal;
in practical application, after the first abnormal point is removed, if the surrounding adjacent points (the previous points and the next points) are not abnormal values, performing linear correction, wherein the new value is Pi＝(Pi-1+Pi+1)/2;
If the surrounding adjacent points have abnormal values, correcting the abnormal values to be the midpoint values of the upper and lower bounds, namely, Pi = (y 1-y 2)/2;
the abnormal points at the first end and the last end of the Gaussian curve can be not processed, and the influence on the subsequent calculation of the blood pressure value by an amplitude coefficient method is not great.
Step S111, extracting a first envelope of the first modified pulse wave signal;
After the abnormal points are corrected, nonlinear interpolation is carried out on peak point groups, spline (x, y) functions are called in Matlab to carry out cubic spline interpolation smoothing, and then a polynomial fitting method is adopted to extract an envelope curve corresponding to the first corrected pulse wave signals, namely a first envelope curve.
Step S113, calculating a blood pressure value according to the first envelope, wherein the blood pressure value comprises at least one of an average arterial pressure, a diastolic pressure and a systolic pressure.
In practical application, the average arterial pressure, the diastolic pressure and the systolic pressure can be respectively obtained by using an amplitude coefficient method;
The method comprises the steps of firstly acquiring the data length of a first envelope curve, a pulse wave peak value sequence and a cuff static pressure sequence, acquiring the maximum value of the pulse wave peak value and the ratio coefficients of systolic pressure and diastolic pressure, simultaneously acquiring the position corresponding to the maximum value of the pulse wave peak value, searching the maximum value of the pulse wave peak value from the first value, calculating average pressure, and acquiring the corresponding static pressure position after acquiring the average pressure of the maximum value of the pulse wave peak value, wherein the position is the average arterial pressure;
After the average arterial pressure is obtained, the systolic pressure and the diastolic pressure proportion coefficient can be utilized to continuously search the diastolic pressure position backwards, the static pressure value corresponding to the diastolic pressure position is obtained, the position is the diastolic pressure, the systolic pressure position can also be searched forwards, the static pressure value corresponding to the systolic pressure position is obtained, and the position is the systolic pressure.
On the basis of the above-described embodiment, fig. 2 shows a flowchart of another blood pressure measurement method, mainly describing a process of judging whether or not a quality parameter satisfies a preset signal quality judgment condition, as shown in fig. 2, the method specifically includes the steps of:
Step S201, acquiring pulse wave signals acquired by an electronic sphygmomanometer, and extracting quality parameters of the pulse wave signals;
In practical application, the method can utilize a preset sensor in the electronic sphygmomanometer to acquire signals, acquire pulse wave signals of a person to be detected in a conventional manner, the signals acquired by the sensor comprise a cuff static pressure original signal and a pulse wave original signal, the signals can be preprocessed in sequence, the signals comprise signal amplification, signal filtering and pulse wave signal separation, and therefore processed pulse wave signals are obtained, and the processed pulse wave signals correspond to peak values, valley values and corresponding timestamp sequences and serve as quality parameters of the pulse wave signals.
Step S203, obtaining the peak value and the valley value of the pulse wave signal;
After the pulse wave signal is acquired, the maximum values max_peak, max_valley and the minimum values min_peak, min_valley of the peak sequence Pi and the valley sequence Vi may be obtained, respectively.
Step S205, judging whether the difference value between the peak value and the valley value of the pulse wave signal is smaller than a preset threshold value;
specifically, whether the following relationship is satisfied is aligned:
the Th1 is a preset minimum threshold value meeting signal detection, and is related to the air pressure value at the baseline position.
Step S207, if the difference value is smaller than a preset threshold value, determining that the quality parameter meets a preset signal quality judgment condition;
specifically, if it is determined that the difference between the peak value and the valley value is smaller than the preset threshold value, it may be determined that the pulse wave signal is a waveform with poor signal quality.
Step S209, if the difference value is larger than a preset threshold value, calculating the standard deviation of the neighboring time stamps of the peak value and the valley value;
specifically, if the difference between the peak value and the valley value is determined to be greater than the preset threshold value, the quality of the pulse wave signal is further determined by determining the standard deviation of the neighboring time stamps of the peak value and the valley value.
Specifically, the average value of the neighbor timestamp difference values of the peaks can be obtained by performing a volatility analysis on the timestamp sequence according to the following formula:
Where u is the average of the neighbor timestamp differences of the peaks, N is the sequence length of the peak sequence, and i refers to the ith timestamp ti.
And then calculating the standard deviation of the neighbor timestamp difference value of the peak value, namely:
wherein std is the standard deviation of the difference value of the neighboring time stamps of the peaks, N is the sequence length of the peak sequence, and i refers to the ith time stamp ti;
step S211, if the standard deviation is smaller than a preset minimum standard deviation threshold, determining that the quality parameter meets a preset signal quality judgment condition;
specifically, after the standard deviation is obtained, it is determined whether it satisfies a condition std < Th2, where Th2 is a minimum threshold preset to meet the detection of fluctuation, and may be related to the heart rate at the start of the test.
Step S213, if the quality parameter is determined to meet the preset signal quality judgment condition, performing outlier screening on the pulse wave signal to obtain a first outlier in the pulse wave signal;
And if the quality parameter meets the preset signal quality judgment condition, judging that the pulse wave signal is a waveform with poor signal quality, and screening abnormal values of the pulse wave signal.
The step S213 is specifically implemented by the following steps A1-A6:
Step A1, extracting a Gaussian waveform curve of a pulse wave signal, and obtaining the peak height, the peak position and the half-peak width of the Gaussian waveform curve;
A3, obtaining the upper and lower bounds of the Gaussian waveform curve according to a preset upper and lower bound formula by using the peak height, the peak position and the half-peak width;
step A4, obtaining a time stamp of a peak point of the Gaussian waveform curve, and bringing the time stamp into the Gaussian waveform curve;
step A5, judging the relation between the peak value point corresponding to the time stamp and the upper and lower bounds;
and step A6, if the peak value point exceeds the upper and lower limits, eliminating the peak value point, and carrying out anomaly correction on the Gaussian curve to complete anomaly value screening on the pulse wave signals.
Step S215, eliminating the first abnormal point to obtain a first pulse wave signal to be corrected corresponding to the pulse wave signal;
Specifically, after the peak position corresponding to the cross axis timestamp of the peak sequence is determined to exceed the preset upper and lower bounds, a method of bringing the cross axis timestamp of the peak sequence to the upper and lower bounds of the Gaussian function is adopted to detect whether an abnormal point exists, if the abnormal point exists, the point is removed, and if the surrounding adjacent points (the previous points and the next points) are not abnormal values, linear correction is carried out. And eliminating the corresponding first abnormal points to obtain corresponding first pulse wave signals to be corrected.
Step S217, a first peak point group of a first pulse wave signal to be corrected is obtained;
Specifically, after the pulse wave signal is corrected, a peak point group of the corrected pulse wave signal is acquired.
Step S219, nonlinear interpolation is carried out on the first peak point group to obtain a nonlinear first peak point group;
specifically, after correcting the abnormal points, nonlinear interpolation can be performed on the peak point group;
Step S221, performing cubic spline interpolation and smoothing on the nonlinear first peak point group by using a preset function to obtain a first corrected pulse wave signal;
step S223, extracting a first envelope curve of the first modified pulse wave signal;
In practical application, spline (x, y) functions can be called in Matlab to conduct cubic spline interpolation smoothing, and then a polynomial fitting method is adopted to extract an envelope curve.
In step S225, a blood pressure value is calculated from the first envelope, the blood pressure value including at least one of an average arterial pressure, a diastolic pressure, and a systolic pressure.
On the basis of the above-described embodiment, fig. 3 shows a flowchart of another blood pressure measurement method, mainly describing a blood pressure measurement method if the quality parameter does not satisfy the preset signal quality judgment condition, as shown in fig. 3, the method specifically includes the steps of:
step S301, acquiring pulse wave signals acquired by an electronic sphygmomanometer, and extracting quality parameters of the pulse wave signals;
Step S303, judging whether the quality parameter meets a preset signal quality judgment condition;
step S305, if yes, carrying out outlier screening on the pulse wave signals to obtain first outliers in the pulse wave signals;
Step S307, the first abnormal point is removed, and a first pulse wave signal to be corrected corresponding to the pulse wave signal is obtained;
step S309, performing linear correction on the first pulse wave signal to be corrected to obtain a first corrected pulse wave signal;
step S311, extracting a first envelope curve of the first modified pulse wave signal;
Step S313, calculating a blood pressure value according to the first envelope curve, wherein the blood pressure value comprises at least one of mean arterial pressure, diastolic pressure and systolic pressure;
Step S315, if the quality parameter does not meet a preset signal quality judgment condition, performing outlier screening on the pulse wave signal to obtain a second outlier in the pulse wave signal;
In practical application, firstly, abnormal value screening is carried out on pulse wave signals, rationality judgment is carried out on pulse wave data points of the abnormal value screening, the process is to eliminate and correct unreasonable pulse wave peak points without affecting the fitting precision of pulse wave envelopes, and pulse wave values are more uniform and smooth, so that the fitting precision of the envelopes is improved, and the measuring accuracy of blood pressure values is improved.
If the difference is not within a certain range, the point Ri is judged to be an unreasonable point, the point Ri is required to be removed and subjected to linear correction, and if the difference is within a certain range, the point Ri is judged to be a reasonable point, and no correction is required.
Specifically, the process of screening the abnormal value of the pulse wave signal can be implemented by the following steps B1-B2:
step B1, acquiring a pulse wave interpolation sequence of the second corrected pulse wave signal, and comparing the pulse wave interpolation sequence with a preset range;
and B2, if the interpolation sequence is not in the preset range, the interpolation sequence is the second abnormal point.
The method specifically comprises the steps of comparing a pulse wave interpolation sequence Ri to be judged with values at each point before and after, judging that the point Ri is an unreasonable point if the difference value is not in a certain range, eliminating the point Ri and carrying out linear correction, and judging that the point Ri is a reasonable point if the difference value is in a certain range, and not needing correction.
The following two criteria can be used for the determination:
standard 1:0.8Ri-1<Ri<1.2Ri-1
Standard 2:0.8Ri+1<Ri<1.2Ri+1
Where R is the peak Gu Chazhi sequence amplitude, Ri represents the peak length of the i-th peak point, Ri-1 represents the previous peak, and Ri+1 represents the next peak.
If the above criteria are met, Ri is considered reasonable and no treatment is needed, otherwise Ri is considered unreasonable and correction is needed. The point is removed and a linear correction is performed, and the new value is Ri＝(Ri-1+Ri+1)/2. The abnormal points at the first end and the last end can be not processed, and the influence on the subsequent calculation of the blood pressure value by the amplitude coefficient method is not great.
Step S317, the second abnormal point is removed, and a second pulse wave signal to be corrected is obtained;
step S319 is to correct the second pulse wave signal to obtain a second corrected pulse wave signal.
Specifically, the process of correcting the pulse wave signal to obtain the second corrected pulse wave signal may be implemented by the following steps C1-C3:
step C1, obtaining a second peak point group of the second pulse wave signal to be corrected;
Step C2, performing linear interpolation on the second peak point group to obtain a linear second peak point group;
And C3, correcting the linear interpolation and smoothing of the linear second peak point group by using a preset function, and obtaining a second corrected pulse wave signal.
Specifically, the obtained peak point group can be subjected to linear interpolation and smoothing, an envelope curve is extracted by adopting polynomial fitting, and the mean arterial pressure, the diastolic pressure and the systolic pressure of the second corrected pulse wave signal are respectively obtained by using an amplitude coefficient method.
Corresponding to the above method embodiment, the embodiment of the present invention provides a blood pressure measuring device, and fig. 4 shows a schematic structural diagram of the blood pressure measuring device, and as shown in fig. 4, the blood pressure measuring device includes:
the acquisition module 401 is configured to acquire a pulse wave signal acquired by the electronic sphygmomanometer, and extract a quality parameter of the pulse wave signal;
A judging module 402, configured to judge whether the quality parameter meets a preset signal quality judgment condition;
the screening module 403 is configured to screen the pulse wave signal for an outlier if the pulse wave signal is abnormal, so as to obtain a first outlier in the pulse wave signal;
the rejecting module 404 is configured to reject the first outlier to obtain a first pulse wave signal to be corrected corresponding to the pulse wave signal;
The correction module 405 is configured to perform linear correction on the first pulse wave signal to be corrected to obtain a first corrected pulse wave signal;
an extracting module 406, configured to extract a first envelope of the first modified pulse wave signal;
a calculation module 407, configured to calculate a blood pressure value according to the first envelope, where the blood pressure value includes at least one of an average arterial pressure, a diastolic pressure, and a systolic pressure.
An embodiment of the present invention further provides an electronic sphygmomanometer (not shown in the accompanying drawings), which includes the blood pressure measuring device described above, and the blood pressure measuring device may execute instructions to implement the method according to any one of the above.
The embodiment of the present invention further provides an electronic device, as shown in fig. 5, which is a schematic structural diagram of the electronic device, where the electronic device includes a processor 51 and a memory 52, and the memory 52 stores machine executable instructions that can be executed by the processor 51, and the processor 51 executes the machine executable instructions to implement the above blood pressure measurement method.
In the embodiment shown in fig. 5, the electronic device further comprises a bus 53 and a communication interface 54, wherein the processor 51, the communication interface 54 and the memory 52 are connected by means of the bus.
The memory 52 may include a high-speed random access memory (RAM, random Access Memory), and may further include a non-volatile memory (non-volatile memory), such as at least one disk memory. The communication connection between the system network element and at least one other network element is implemented via at least one communication interface 54 (which may be wired or wireless), which may use the internet, a wide area network, a local network, a metropolitan area network, etc. The bus may be an ISA bus, a PCI bus, an EISA bus, or the like. The buses may be classified as address buses, data buses, control buses, etc. For ease of illustration, only one bi-directional arrow is shown in FIG. 5, but not only one bus or type of bus.
The processor 51 may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in the processor 51 or by instructions in the form of software. The processor 51 may be a general-purpose processor, including a central Processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), a digital signal processor (DIGITAL SIGNAL Processing, DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable GATE ARRAY (FPGA), a Programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The disclosed methods, steps, and logic blocks in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be embodied directly in the execution of a hardware decoding processor, or in the execution of a combination of hardware and software modules in a decoding processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor 51 reads the information in the memory 52, and in combination with its hardware, performs the steps of the blood pressure measurement method of the foregoing embodiment.
The embodiment of the invention also provides a machine-readable storage medium, which stores machine-executable instructions that, when being called and executed by a processor, cause the processor to implement the above blood pressure measurement method, and the specific implementation can be found in the foregoing method embodiment, and the details are not repeated here.
The computer program product of the blood pressure measurement method provided by the embodiment of the invention comprises a computer readable storage medium storing a program code, and the instructions included in the program code can be used for executing the blood pressure measurement method described in the foregoing method embodiment, and specific implementation can be referred to the method embodiment and will not be repeated here.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a non-volatile computer readable storage medium executable by a processor. Based on this understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. The storage medium includes a U disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, an optical disk, or other various media capable of storing program codes.
In addition, in the description of embodiments of the present invention, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected via an intermediate medium, or in communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
It should be noted that the foregoing embodiments are merely illustrative embodiments of the present invention, and not restrictive, and the scope of the invention is not limited to the embodiments, and although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that any modification, variation or substitution of some of the technical features of the embodiments described in the foregoing embodiments may be easily contemplated within the scope of the present invention, and the spirit and scope of the technical solutions of the embodiments do not depart from the spirit and scope of the embodiments of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.