CN116112107A

CN116112107A - Multi-PD signal selection method and related equipment thereof

Info

Publication number: CN116112107A
Application number: CN202310391838.7A
Authority: CN
Inventors: 孙小玄; 李玉春
Original assignee: Shenzhen Fenda Intelligent Technology Co ltd
Current assignee: Shenzhen Fenda Intelligent Technology Co ltd
Priority date: 2023-04-13
Filing date: 2023-04-13
Publication date: 2023-05-12
Anticipated expiration: 2043-04-13
Also published as: CN116112107B

Abstract

The invention belongs to the technical field of signal processing, and provides a signal selection method of multiple PDs and related equipment thereof.

Description

Multi-PD signal selection method and related equipment thereof

Technical Field

The present invention relates to the field of signal processing technologies, and in particular, to a method for selecting a signal with multiple PDs and related devices.

Background

For a physiological feature calculation method using photoplethysmographic (PPG) as a signal input, human physiological information carried in the PPG signal used is critical. The measurement principle is that light generated by a light source is reflected and absorbed by blood vessels and tissues of a human body, and the light is received by a Photo-Diode (PD), so that the oxygen content and other components of blood in the blood vessel tissues of the human body at different moments are different, and the received signals at different moments show periodic changes. Therefore, in order to acquire signal input with better quality, the PD is set to be a plurality of by partial wearable equipment, so that the detection area of signal reflected light is increased, and the possibility of acquiring effective signals is increased. Currently, the signal selection method for multiple PDs mainly includes average weighting, selecting a certain fixed channel, weighted summation, or outputting multiple signals respectively. For average weighting, the output of the method is relatively stable, as long as one of the channels has an effective signal, the output signal must contain the effective signal, but when a certain channel works abnormally or light leakage and other phenomena occur, the signal of the channel is basically unavailable, and the duty ratio of the effective signal in the output signal is pulled down by the noise; for selecting a certain fixed channel, the method does not switch channels after obtaining the optimal signal channel through certain preprocessing methods, and takes the channel signal as a signal to be output; the method adopted by the different weighted summation is different, the influence of the signal-to-noise ratio lower channel on the signal output can be greatly reduced by weighting in each buffer window, but the method has the jump problem between adjacent windows; for the method of outputting the multipath signal, in principle, the larger the information amount acquired by the subsequent algorithm is, the higher the operability of the subsequent algorithm is, the higher the limit can be reached, but the memory occupation and the consumption of the computing resource caused by the subsequent algorithm are increased by times.

In summary, the existing multi-PD signal selection technology has the technical problems that multiple signals coexist, each algorithm consumes large computing resources under the multi-PD condition, occupies a large amount of memory, and has long algorithm adaptation and migration time.

Disclosure of Invention

In order to solve the above technical problems, in one aspect, the present invention provides a signal selection method for multiple PDs, including the following steps:

s1, responding to a service starting request for selecting a plurality of paths of PD signals, and carrying out initial configuration confirmation on current and gain;

s2, when the current and gain initialization fails, adopting default current and gain to perform PPG measurement; when the initial configuration of the current and the gain is completed, acquiring multiple paths of PPG data and ACC data to obtain multiple paths of PD signals;

s3, judging whether dimming is needed for the multi-path PD signals, dimming the multi-path PD signals when dimming is needed, and entering a signal selection model to select and output the multi-path PD signals after dimming is completed.

Further, step S3 includes the steps of:

s30, directly entering a signal selection model when dimming is not needed;

s31, selecting and outputting the multipath PD signals through the signal selection model.

Further, step S3 includes the steps of:

s32, current adjustment evaluation is carried out on the current to judge whether the current adjustment meets the requirement;

s33, when the current adjustment does not meet the requirement, performing gain adjustment evaluation on the gain to judge whether the gain adjustment meets the requirement;

and S34, updating the parameter configuration of the current and the gain when the gain adjustment meets the requirement.

Further, the step S32 includes the following steps:

and S320, when the current adjustment meets the requirement, entering a signal selection model, and selectively outputting the multipath PD signals through the signal selection model.

Further, step S3 includes the steps of:

s35, initializing the signal selection model to reset parameters.

Further, the step S35 includes the following steps:

s350, counting the signal output state of the signal selection model when the signal selection model is initialized to pass;

s351, judging whether the signal output state meets preset conditions, and when the signal output state does not meet the preset conditions, maintaining an original output signal channel.

Further, step S351 includes the following steps:

s3510, switching signal channels when the signal output state meets a preset condition;

s3511, initializing the signal selection model again when the signal channel switching is completed;

s3512, ending the current measurement service and ending the selection of the multipath PD signals.

In one aspect, the present invention provides a signal selection apparatus of a multi-PD, comprising:

the starting initialization module is used for responding to the service starting request selected by the multipath PD signals and carrying out initial configuration confirmation on the current and the gain;

the multipath PD signal acquisition module is used for carrying out PPG measurement by adopting default current and gain when the current and gain initialization fails; when the initial configuration of the current and the gain is completed, acquiring multiple paths of PPG data and ACC data to obtain multiple paths of PD signals;

and the multi-path PD signal selection module is used for judging whether the multi-path PD signal needs to be dimmed, dimming the multi-path PD signal when the dimming is needed, and entering a signal selection model to select and output the multi-path PD signal after the dimming is completed.

In one aspect, the present invention provides an electronic device, comprising:

a memory storing a computer program;

a processor running the computer program to implement the method of any one of the above.

In one aspect, the invention provides a readable storage medium having stored therein a computer program which when executed by a processor implements the method of any of the above.

Compared with the prior art, the invention has the beneficial effects that:

according to the multi-PD signal selection method and the related equipment, initial configuration confirmation is carried out on current and gain through responding to a service starting request for multi-path PD signal selection, PPG measurement is carried out through adopting default current and gain when the current and gain initialization fails, multi-path PPG data and ACC data are collected when the current and gain are subjected to initial configuration so as to obtain multi-path PD signals, whether the multi-path PD signals need to be dimmed is judged, dimming is carried out on the multi-path PD signals when dimming is needed, and after dimming is finished, a signal selection model is entered to carry out selection output on the multi-path PD signals, so that the multi-path signals are integrated into one path on the premise of guaranteeing the quality of output signals, and the subsequent related algorithm is convenient to use.

Drawings

FIG. 1 is a flow diagram of a method of signal selection for multiple PDs;

FIG. 2 is a schematic diagram of an architecture of a multi-PD signal-selection apparatus;

fig. 3 is a schematic diagram of an architecture of an electronic device.

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 embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, 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.

The terms "first," "second," "third," "fourth" and the like in the description and in the claims and in the above drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. It should be understood that, in various embodiments of the present invention, the sequence number of each process does not mean that the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention. It should be understood that in the present invention, "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements that are expressly listed or inherent to such process, method, article, or apparatus. It should be understood that in the present invention, "plurality" means two or more. "and/or" is merely an association relationship describing an association object, and means that three relationships may exist, for example, and/or B may mean: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship. "comprising A, B and C", "comprising A, B, C" means that all three of A, B, C comprise, "comprising A, B or C" means that one of the three comprises A, B, C, and "comprising A, B and/or C" means that any 1 or any 2 or 3 of the three comprises A, B, C. It should be understood that in the present invention, "B corresponding to a", "a corresponding to B", or "B corresponding to a" means that B is associated with a, from which B can be determined. Determining B from a does not mean determining B from a alone, but may also determine B from a and/or other information. The matching of A and B is that the similarity of A and B is larger than or equal to a preset threshold value. As used herein, "if" may be interpreted as "at … …" or "at … …" or "in response to a determination" or "in response to detection" depending on the context. The technical scheme of the invention is described in detail below by specific examples. The following embodiments may be combined with each other, and some embodiments may not be repeated for the same or similar concepts or processes.

Example 1

Referring to fig. 1, the present embodiment provides a signal selection method for multiple PDs, including the following steps:

It should be noted that, the signal selection method for multiple PDs provided in this embodiment may be operated in an electronic device, where the electronic device is used as an execution body of all or part of the steps in the signal selection method for multiple PDs, and may execute part or all of the steps of the method referred to below in addition to the steps S1, S2, and S3 in this embodiment. In this embodiment, initial configuration of current and gain is confirmed by responding to a service start request for selecting multiple paths of PD signals, and PPG measurement is performed by adopting default current and gain when the current and gain initialization fails, multiple paths of PPG data and ACC data are acquired when the current and gain complete initial configuration, so as to obtain multiple paths of PD signals, and then the multiple paths of PD signals are dimmed when dimming is required by judging whether dimming is required, and then the multiple paths of PD signals are selected and output by entering a signal selection model after dimming is completed, so that multiple paths of signals are integrated into one path on the premise of guaranteeing output signal quality, and the subsequent correlation algorithm is convenient to use.

In step S1, the electronic device performs initial configuration confirmation on the current and gain in response to a service start request selected for the multi-path PD signal. In some preferred embodiments, the service is onIn the initial current and gain confirmation process after starting, the embodiment sets different gain parameters for different PDs, the corresponding gain coefficient table is A, and simultaneously sets 2 current gears including but not limited to, and current is adopted first when the service is started

The corresponding led lamp 1s is turned on to calculate the baseline value +.>

Wherein->

For PD sequence number, calculate all baseline values and preset baseline value +.>

The difference is recorded as->

Calculate->

Sum->

If S is greater than 0, will +.>

Decreasing, if S is less than or equal to 0, +.>

Increasing the regulated value to a preset value, and regulating the regulated current to +.>

Simultaneously using gain coefficient table A, turning on led lamp 1s to calculate base line values of different PDs +.>

Since the current, gain and collected PPG data satisfy the following formulas:

in the above formula, CTR is a current transmission ratio (Current Transfer Ratio), and the difference value is made between the PPG data collected under different current values corresponding to the same PD, so as to obtain the product of the current and gain of the PD

：

Calculating all baseline values and preset baseline values of the current

The difference between them is marked as->

Find +.>

And (3) with

The minimum value of the absolute values of (a) is selected as the default gain +.>

Estimating the default current as

If->

Outside the preset range, current selects +.>

And->

Is a smaller value of (a). After obtaining the default gain and current, the embodiment calculates the mean and variance of the combined acceleration of the tri-axial acceleration sensor ACC in the process at the same time, thereby determiningWhether motion exists in the process or not, and the like, the current gain initialization deviation is overlarge due to the fact that part of uncertain factors are reduced, and the judgment standard is as follows: 1) Judging whether the absolute value of the difference between the average value and the preset gravity acceleration exceeds a threshold value 1; 2) It is determined whether the variance exceeds a threshold 2. If there is one out of range, the gain current confirmation fails

And->

Setting to a preset value, if the current is not beyond the range, confirming success, and setting the current in the configuration table to +.>

Setting the respective PD gains to +.>

。

In step S2, when the initialization of the current and the gain fails, the electronic device performs PPG measurement by using a default current and gain; and when the current and the gain are initially configured, acquiring multiple paths of PPG data and ACC data to obtain multiple paths of PD signals. After the current gain configuration is completed, the data acquisition of the PD signal is performed in the step, and the acquired original data mainly comprises multiple paths of PPG data and multiple paths of ACC data.

In step S3, the electronic device determines whether dimming is required for the multiple PD signals, and when dimming is required, the electronic device performs dimming on the multiple PD signals, and after dimming is completed, enters a signal selection model to perform selection output on the multiple PD signals. When judging whether dimming is needed, judging that the signal object is the average value ppgmean of all channel signals, if ppgmean is smaller than a threshold value 3 and the duration exceeds a threshold value 4, or if ppgmean is larger than a threshold value 5 and the duration exceeds the threshold value 4, triggering a dimming mechanism to perform dimming, otherwise, triggering is not performed.

In some preferred embodiments, the specific dimming comprises:

obtaining the current gain configuration, if the current is

When the current value is larger than or equal to a threshold value 6 or smaller than or equal to a threshold value 7, dimming operation is not performed, and the main purpose of the operation is to prevent the set current value from being too large to burn a tested person, or the current value is too small to collect signals, so that the anti-interference performance is low, and the effective signal duty ratio is too low;

using the obtained

Current baseline->

Reference baseline->

Current gain

Current +.>

Estimating the current value currently required +.>

The estimation method comprises the following steps:

in the above-mentioned method, the step of,

is the difference between the calculated value and the actual measured value.

If it is

Greater than or equal to threshold 6 or less than or equal to threshold 7, the current alone does not achieve the desired result, i.e., the current adjustment does not meet the pre-determined criteriaThe phase requirement, otherwise, the current adjustment can reach the final expected requirement, and gain adjustment evaluation is carried out, wherein the evaluation method comprises the following steps:

if it is

If the gain is equal to or greater than the threshold value 8, the gain adjustment cannot meet the requirement. When the current regulation meets the requirement, if the current value +.>

Is +.>

The absolute value of the difference is greater than the threshold value 9, the updated current value is +.>

. The main purpose of this operation is to reduce +.>

The current adjustment amplitude is too large due to the excessively large equivalent estimation deviation, and the gain adjustment also has adjustment amplitude limitation.

In some preferred embodiments, the selecting and outputting the plurality of PD signals by the signal selection model includes: initializing a signal selection model; the signal selection model may refer to a hidden markov model, where hidden states include, but are not limited to, 3 kinds of, hold states, switch states, and full-selection states;

updating the initial state of the hidden Markov model to a full-selection state;

classifying the observed signal phenomena according to the characteristics of the baseline, the mutation points, the signal to noise ratio, the signal amplitude and the ACC amplitude of the PPG signals, classifying the observed phenomena into 32 types according to whether the baseline meets the requirement of a threshold range, whether the number of the mutation points exceeds the requirement, whether the signal to noise ratio meets the requirement, whether the signal amplitude meets the requirement, whether the ACC amplitude meets the requirement and whether the signal quality is optimal, and classifying the observed phenomena into the full selection stateWhether the signal quality is the optimal reference signal is the signal after all channels are weighted averagely, the reference signals in the hold state and the switch state are the signals of the current selected channel, wherein the reference signal is more than a threshold value 3 and less than a threshold value 5 for a base line, if so, the base line requirement is met, otherwise, the base line requirement is not met; the specific operation for the mutation point is to first perform reference signal

Performing first order difference to obtain differential signal +.>

Then median filtering is carried out on the differential signals to obtain signals +.>

Wherein->

For signal index, calculate +.>

Statistics of +.>

Number greater than threshold 10

If->

If the number of the mutation points is larger than the threshold value 11, the number of the mutation points exceeds the requirement, otherwise, the requirement is met;

regarding the signal-to-noise ratio, bandpass filtering the intermediate value filtered signal to obtain a filtered signal

Differential signal->

High-pass filtering is performed to obtain a filtered signal +.>

Inside the calculation window +.>

Sum of squares and->

The ratio of the square sums is approximated to the signal to noise ratio of the serial signal, and if the signal to noise ratio is greater than a threshold value 12, the signal to noise ratio meets the requirement;

regarding signal amplitude, for within window

Calculating the average value after the absolute value is calculated, taking the average value as the approximate signal amplitude, if the average value is larger than a threshold value 13, the signal amplitude meets the requirement, otherwise, the signal amplitude does not meet the requirement;

regarding ACC amplitude, calculating the sum acceleration of triaxial acceleration, differentiating the sum square root of the sum square, calculating the absolute value of the differential signal, and calculating the average value of the differential signal, wherein if the value is larger than a threshold value 14, the ACC amplitude does not meet the requirement, otherwise, the ACC amplitude does not meet the requirement;

regarding signal quality optimization, a signal value optimization mark mainly considers signal to noise ratio and signal amplitude, if the signal amplitude of a reference signal meets the requirement, the signal amplitude of all channel signals is larger than 1.5 times of the signal amplitude of the reference channel, and the signal quality of the channel is not smaller than the signal to noise ratio of the reference channel, if the signal amplitude of the reference signal does not meet the requirement, the signal amplitude of all channel signals is required to be larger than 2 times of the signal amplitude of the reference signal, and the signal quality of the channel is not smaller than a threshold value 15, and if the signal amplitude of the reference signal meets the requirement, the signal quality of the reference signal is optimal, and the main purpose of the step of carrying out signal amplitude related limitation is to reduce the problems of frequent switching of the reference signal among channels with small signal quality difference, signal distortion caused by frequent switching, and the like.

When the output state is the switching state, counting the duration of continuous switching state, and when the duration of switching state exceeds the threshold value 10, the signal quality is the mostThe optimal channel and the duration thereof exceed a threshold value 11, and a preset condition is met; when the preset condition is met, switching the output signal channel to the channel with the optimal signal quality

Simultaneously performing hidden Markov model initialization, setting initial state as hold state, and setting reference signal channel as +.>

Simultaneously, the variable of each statistic duration is cleared to 0, and in order to reduce signal mutation caused by channel switching, the output signal is subjected to baseline adjustment with the adjustment value of +.>

；

；

For the last value of the output signal before switching, +.>

The first data of the signal acquired for the channel to be switched. The adjusted ppg signal data is +.>

When the acquired +.>

Above threshold 16 or below threshold 17 +.>

The main purpose of this operation is to prevent the adjusted output value from being too large or too small, resulting in abnormal inputs to the baseline dependent class algorithm. The adjusted ppg data greatly reduces the jump caused by the baseline difference before and after channel switching, and reduces the abnormal signal input caused by the jump. It should be noted thatBaseline adjustment value of data when service pull-up is first initialized +.>

Set to->

,/>

For baseline value and->

First data of the channel signal with the smallest difference, < ->

Refers to the first data of all channel-averaged weighted signals.

It should be noted that, by the method provided by the above embodiment, the abnormal signal can be removed, and the physiological signal with high signal-to-noise ratio is output on the premise of ensuring the stability of the signal, so as to provide data guarantee for the subsequent physiological parameter calculation algorithm. In some preferred embodiments, step S3 comprises the steps of: s30, directly entering a signal selection model when dimming is not needed; s31, selecting and outputting the multipath PD signals through the signal selection model. In some preferred embodiments, step S3 comprises the steps of: s32, current adjustment evaluation is carried out on the current to judge whether the current adjustment meets the requirement; s33, when the current adjustment does not meet the requirement, performing gain adjustment evaluation on the gain to judge whether the gain adjustment meets the requirement; and S34, updating the parameter configuration of the current and the gain when the gain adjustment meets the requirement. In some preferred embodiments, step S32 is followed by the steps of: and S320, when the current adjustment meets the requirement, entering a signal selection model, and selectively outputting the multipath PD signals through the signal selection model. In some preferred embodiments, step S3 comprises the steps of: s35, initializing the signal selection model to reset parameters. In some preferred embodiments, step S35 is followed by the steps of: s350, counting the signal output state of the signal selection model when the signal selection model is initialized to pass; s351, judging whether the signal output state meets preset conditions, and when the signal output state does not meet the preset conditions, maintaining an original output signal channel. In some preferred embodiments, step S351 is followed by the steps of: s3510, switching signal channels when the signal output state meets a preset condition; s3511, initializing the signal selection model again when the signal channel switching is completed; s3512, ending the current measurement service and ending the selection of the multipath PD signals.

Example two

Referring to fig. 2, the present embodiment provides a signal selecting apparatus with multiple PDs, including:

In this embodiment, initial configuration of current and gain is confirmed by responding to a service start request for selecting multiple paths of PD signals, and PPG measurement is performed by adopting default current and gain when the current and gain initialization fails, multiple paths of PPG data and ACC data are acquired when the current and gain complete initial configuration, so as to obtain multiple paths of PD signals, and then the multiple paths of PD signals are dimmed when dimming is required by judging whether dimming is required, and then the multiple paths of PD signals are selected and output by entering a signal selection model after dimming is completed, so that multiple paths of signals are integrated into one path on the premise of guaranteeing output signal quality, and the subsequent correlation algorithm is convenient to use.

Example III

Referring to fig. 3, the present embodiment provides an electronic device, including:

a memory for storing a computer program, which memory may also be a flash memory (flash). The computer program is, for example, an application program, a functional module, or the like that implements the above-described method.

A processor for executing the computer program stored in the memory to implement the steps of the above method. Reference may be made in particular to the description of the embodiments of the method described above.

In the alternative, the memory may be separate or integrated with the processor. When the memory is a device separate from the processor, the apparatus may further include: and the bus is used for connecting the memory and the processor.

Example IV

The present embodiment provides a readable storage medium having a computer program stored therein, which when executed by a processor is configured to implement the methods provided by the various embodiments described above. The readable storage medium may be a computer storage medium or a communication medium. Communication media includes any medium that facilitates transfer of a computer program from one place to another. Computer storage media can be any available media that can be accessed by a general purpose or special purpose computer. For example, a readable storage medium is coupled to the processor such that the processor can read information from, and write information to, the readable storage medium. In the alternative, the readable storage medium may be integral to the processor. The processor and the readable storage medium may reside in an application specific integrated circuit (Application Specific Integrated Circuits, ASIC for short). In addition, the ASIC may reside in a user device. The processor and the readable storage medium may reside as discrete components in a communication device. The readable storage medium may be read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tape, floppy disk, optical data storage device, etc. In the above embodiment of the apparatus, it should be understood that the processor may be a central processing unit (english: central Processing Unit, abbreviated as CPU), or may be other general purpose processors, digital signal processors (english: digital Signal Processor, abbreviated as DSP), application specific integrated circuits (english: application Specific Integrated Circuit, abbreviated as ASIC), or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in connection with the present invention may be embodied directly in a hardware processor for execution, or in a combination of hardware and software modules in a processor for execution.

In this embodiment, a computer program is stored in a readable storage medium, and when the computer program is executed by a processor, the method provided by the various embodiments is implemented, by responding to a service start request for selecting multiple paths of PD signals, performing initial configuration confirmation on current and gain, performing PPG measurement by using default current and gain when the current and gain are failed in initialization, collecting multiple paths of PPG data and ACC data when the current and gain are configured initially, so as to obtain multiple paths of PD signals, determining whether dimming is needed for the multiple paths of PD signals, dimming the multiple paths of PD signals when dimming is needed, and entering a signal selection model to perform selection output on the multiple paths of PD signals after dimming is completed, so that multiple paths of signals are integrated into one path on the premise of guaranteeing the quality of output signals, and a subsequent correlation algorithm is convenient to use.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims

1. A method for selecting a signal for a plurality of PDs, comprising the steps of:

2. The multi-PD signal selection method of claim 1, wherein step S3 includes the steps of:

s30, directly entering a signal selection model when dimming is not needed;

3. The multi-PD signal selection method of claim 1, wherein step S3 includes the steps of:

4. The multi-PD signal selection method of claim 3, wherein after step S32, comprising the steps of:

5. The multi-PD signal selection method of claim 3, wherein step S3 includes the steps of:

s35, initializing the signal selection model to reset parameters.

6. The multi-PD signal selection method of claim 5, wherein after step S35, comprising the steps of:

s350, counting the signal output state of the signal selection model;

7. The multi-PD signal selection method of claim 3, wherein after step S351, comprising the steps of:

8. A multi-PD signal selection apparatus, comprising:

9. An electronic device, comprising:

a memory storing a computer program;

a processor running the computer program to implement the method of any one of claims 1-7.

10. A readable storage medium, characterized in that the readable storage medium has stored therein a computer program which, when executed by a processor, implements the method according to any of claims 1-7.