CN112494001B - PPG signal quality evaluation method and device, wearable device and storage medium - Google Patents
PPG signal quality evaluation method and device, wearable device and storage medium Download PDFInfo
- Publication number
- CN112494001B CN112494001B CN202011351785.9A CN202011351785A CN112494001B CN 112494001 B CN112494001 B CN 112494001B CN 202011351785 A CN202011351785 A CN 202011351785A CN 112494001 B CN112494001 B CN 112494001B
- Authority
- CN
- China
- Prior art keywords
- ppg signal
- signal
- frequency
- amplitude
- ppg
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
- A61B5/7221—Determining signal validity, reliability or quality
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Medical Informatics (AREA)
- Surgery (AREA)
- Biophysics (AREA)
- Pathology (AREA)
- Physiology (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Veterinary Medicine (AREA)
- Molecular Biology (AREA)
- Physics & Mathematics (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Cardiology (AREA)
- Artificial Intelligence (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Psychiatry (AREA)
- Signal Processing (AREA)
- Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
Abstract
The invention discloses a PPG signal quality evaluation method, a device, a wearable device and a storage medium, which are used for evaluating whether a PPG signal acquired by the wearable device can be analyzed, wherein the wearable device is provided with an acceleration sensor, and the PPG signal quality evaluation method comprises the following steps: acquiring a PPG signal acquired by wearable equipment and an acceleration signal output by an acceleration sensor; performing time domain to frequency domain conversion on the obtained PPG signal and the obtained acceleration signal to obtain a PPG signal and an acceleration signal in the frequency domain; and comparing the amplitude spectrum of the PPG signal with the amplitude spectrum of the acceleration signal in the frequency domain to obtain a quality evaluation result of the PPG signal. According to the invention, the quality of the PPG signal is obtained through the signal characteristics in the frequency domain, so that the problem that the signal quality cannot be analyzed due to the fact that the PPG signal is not obvious in the motion state of the existing wearable device is solved.
Description
Technical Field
The present invention relates to the field of digital signal processing, and in particular, to a PPG signal quality evaluation method and apparatus, a wearable device, and a storage medium.
Background
The photoplethysmography (PPG) is a noninvasive detection method for detecting blood volume change in living tissues by means of photoelectric means, can be used for estimating blood oxygen saturation (SPO 2), heart rate, blood pressure and the like, has small volume, is convenient to carry and wide in application, but has interference of motion artifacts in a PPG signal, and can mislead or prevent serious interference of the PPG signal on detection algorithms such as blood oxygen/heart rate/blood pressure and the like, so that the quality of the PPG signal is a premise of ensuring effective detection of the algorithms such as blood oxygen/heart rate/blood pressure and the like.
The existing PPG signal quality detection method is used for analyzing the signal quality through the PPG signal characteristics of a time period, but the characteristics of the PPG signal are not obvious in a motion state, and the signal quality cannot be evaluated under the motion condition.
Disclosure of Invention
The invention mainly aims to provide a PPG signal quality evaluation method, a device, wearable equipment and a storage medium, aiming at solving the problem that the existing PPG signal cannot be subjected to signal quality evaluation under the condition of motion.
In order to achieve the above object, the PPG signal quality evaluation method provided by the present invention is used for evaluating whether a PPG signal collected by a wearable device can be analyzed, the wearable device has an acceleration sensor, and the PPG signal quality evaluation method includes the following steps:
acquiring a PPG signal acquired by wearable equipment and an acceleration signal output by an acceleration sensor;
performing time domain to frequency domain conversion on the obtained PPG signal and the obtained acceleration signal to obtain a PPG signal and an acceleration signal in the frequency domain; and
comparing the amplitude spectrum of the PPG signal under the frequency domain with the amplitude spectrum of the acceleration signal to obtain a quality evaluation result of the PPG signal.
Optionally, comparing the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain to obtain a quality evaluation result of the PPG signal includes:
when the coincidence degree of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain reaches a preset coincidence degree range, determining that the quality evaluation result of the PPG signal is that the PPG signal cannot be analyzed.
Optionally, comparing the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain to obtain a quality evaluation result of the PPG signal further includes:
when the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain do not reach the preset fitness range, calculating the deviation value of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain; and
comparing the deviation value with a preset maximum deviation value, and determining that the quality evaluation result of the PPG signal is that the PPG signal cannot be analyzed when the deviation value is smaller than or equal to the preset maximum deviation value.
Optionally, the comparing the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain to obtain the evaluation result of the PPG signal quality further includes:
when the deviation value is larger than the preset maximum deviation value, subtracting the frequency domain signal of the acceleration signal from the frequency domain signal of the PPG signal to obtain a synthesized frequency domain signal; and
and acquiring the number of spectral peaks of the synthesized frequency domain signal in a preset frequency spectrum range, and determining a quality evaluation result of the PPG signal based on the number of spectral peaks.
Optionally, the determining the quality assessment result of the PPG signal based on the number of spectral peaks comprises:
the number of spectral peaks is inversely related to the PPG signal quality.
Optionally, the determining the quality assessment result of the PPG signal based on the number of spectral peaks comprises:
and when the number of the spectrum peaks is smaller than or equal to the preset minimum number of spectrum peaks, determining that the quality evaluation result of the PPG signal is that the PPG signal can be analyzed.
Optionally, when the number of spectral peaks is greater than a preset minimum number of spectral peaks, the determining the quality evaluation result of the PPG signal based on the number of spectral peaks further includes:
determining the maximum frequency spectrum amplitude in the synthesized frequency domain signal, comparing a frequency value corresponding to the maximum frequency spectrum amplitude with a preset frequency interval, and determining that the quality evaluation result of the PPG signal is that the PPG signal can be analyzed when the frequency value corresponding to the maximum frequency spectrum amplitude is in the preset frequency interval; and/or
Determining a second large frequency spectrum amplitude in the synthesized frequency domain signal, comparing a frequency value corresponding to the second large frequency spectrum amplitude with a preset frequency interval, and determining that a quality evaluation result of the PPG signal is that the PPG signal can be analyzed when the frequency value corresponding to the second large frequency spectrum amplitude is in the preset frequency interval; and/or
Determining a third large frequency spectrum amplitude in the synthesized frequency domain signal, comparing a frequency value corresponding to the third large frequency spectrum amplitude with a preset frequency interval, and determining that a quality evaluation result of the PPG signal is that the PPG signal can be analyzed when the frequency value corresponding to the third large frequency spectrum amplitude is in the preset frequency interval;
the preset frequency interval is not greater than the maximum frequency value of the synthesized frequency domain signal and not less than the minimum frequency value of the synthesized frequency domain signal.
Optionally, when the number of spectral peaks is greater than a preset minimum number of spectral peaks, the determining the quality evaluation result of the PPG signal based on the number of spectral peaks further includes:
and determining the maximum spectral amplitude, the second large spectral amplitude and the third large spectral amplitude in the synthesized frequency domain signal, wherein the PPG signal quality under the frequency values corresponding to the maximum spectral amplitude, the second large spectral amplitude and the third large spectral amplitude is decreased.
Optionally, after the step of acquiring the PPG signal acquired by the wearable device and the acceleration signal output by the acceleration sensor, the PPG signal quality evaluation method further includes:
and carrying out band-pass filtering denoising on the obtained PPG signal and the obtained acceleration signal to obtain the PPG signal and the obtained acceleration signal in the time domain.
The invention also proposes a PPG signal quality evaluation device performing a method as described above, the device comprising:
a signal generation unit for outputting a PPG signal and an acceleration signal;
a processor; and
a memory for storing said PPG signal quality assessment program executable on said processor; the PPG signal quality assessment procedure, when executed by the processor, implements the steps of the PPG signal quality assessment method as described above.
The invention also provides a wearable device, wherein the wearable device stores the device for executing the PPG signal quality evaluation method.
The invention also proposes a storage medium storing an evaluation program of a PPG signal quality device which, when executed by a processor, implements the steps of a PPG signal quality evaluation method as described above.
According to the technical scheme, the PPG signal and the acceleration signal output by the acceleration sensor are collected, the PPG signal and the acceleration signal in the time domain are converted into the frequency domain signal, the amplitude spectrum of the PPG signal in the frequency domain is compared with the amplitude spectrum of the acceleration signal in the frequency domain, and the quality of the PPG signal is obtained through the signal characteristics in the frequency domain, so that the problem that the signal quality cannot be analyzed due to the fact that the PPG signal is not obvious in the motion state of the existing wearable device is solved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flowchart illustrating an embodiment of a PPG signal evaluation method according to the present invention;
fig. 2 is a flowchart of another embodiment of a PPG signal evaluation method according to the present invention;
fig. 3 is a flowchart of a PPG signal evaluation method according to another embodiment of the present invention;
fig. 4 is a schematic hardware structure diagram of an embodiment of the PPG signal evaluation device of the present invention.
The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. 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 invention provides a PPG signal quality evaluation method which is used for evaluating whether a PPG signal acquired by wearable equipment in a motion state can be analyzed or not. The wearable device detects blood volume changes in living tissue by photoplethysmography (PPG), which may characterize parameters such as heart rate signals. The PPG signal quality corresponds to a resolution performance of the PPG signal, the better the resolution performance of the PPG signal as the PPG signal quality increases.
Referring to fig. 1, in this embodiment, the PPG signal quality evaluation method includes the following steps:
s100: and acquiring a PPG signal acquired by the wearable equipment and an acceleration signal output by an acceleration sensor.
The PPG signal and the acceleration signal output by the acceleration sensor are time domain signals. The PPG signal and the acceleration signal are signals acquired in the same time period. By synchronously acquiring the acceleration signals, the acceleration characteristics of the motion state of the wearable device can be conveniently introduced into the evaluation of the PPG signal quality.
S200: and performing time domain to frequency domain conversion on the obtained PPG signal and the obtained acceleration signal to obtain the PPG signal and the obtained acceleration signal in the frequency domain.
After the PPG signal and the acceleration signal in the same time period are obtained, the PPG signal and the acceleration in the time domain are subjected to Fourier transformation to obtain the PPG signal and the acceleration signal in the frequency domain, so that the PPG signal and the acceleration signal in the frequency domain are conveniently analyzed.
S300: comparing the amplitude spectrum of the PPG signal under the frequency domain with the amplitude spectrum of the acceleration signal to obtain a quality evaluation result of the PPG signal.
In an embodiment, the detection time period may be defined as the PPG signal and the acceleration signal of 1 st to 5 seconds, the PPG signal and the acceleration signal of 1 st to 10 seconds, and the PPG signal and the acceleration signal of 1 st to 15 seconds in the motion state, so as to perform detection evaluation, respectively.
Since the PPG signal quality characterizes the parsing performance of the PPG signal, when the PPG signal is parsed, it can be parsed when the PPG signal quality reaches a certain range. Taking the best value of the PPG signal quality as 100 as an example, when the PPG signal quality reaches or approaches the best value of 100, the PPG signal is able to be resolved; when the PPG signal quality is above a preset signal quality value and below an optimal value of 100, the PPG signal quality is below an optimal value, but the PPG signal is resolvable; when the PPG signal is lower than the preset signal quality value, the PPG signal quality is lower, and the PPG signal cannot meet the resolution requirement, and it is determined that the PPG signal cannot be resolved. Typically, when the best value of the PPG signal quality is 100, the PPG signal quality is higher than 50, the PPG signal can be resolved, and as the PPG signal quality is improved, the resolution performance thereof is gradually improved, that is, the PPG signal quality is positively correlated with the resolution performance thereof.
In this embodiment, by introducing the acceleration signal of the acceleration sensor, the signal characteristics in the frequency domain of the PPG signal are compared with the signal characteristics in the frequency domain of the acceleration signal, so that the interference of motion artifacts in the motion state is eliminated, and the reliability of signal quality detection and evaluation is improved. The signal characteristics in the frequency domain are adopted for comparison, so that the obtained signal characteristics are more obvious, further clearer comparison and analysis can be performed, the efficiency of PPG signal analysis can be improved, the clearer analysis result of the PPG signal characteristics is obtained, and the feasibility of PPG signal analysis is improved.
In an embodiment, in order to reduce the interference of the intrinsic noise of the PPG signal, optionally, after the step of acquiring the PPG signal acquired by the wearable device and the acceleration signal output by the acceleration sensor, the acquired PPG signal and acceleration signal are subjected to band-pass filtering and denoising, the PPG signal is subjected to low-pass filtering, the processable high-frequency noise is filtered, then the high-pass filtering is performed, the processable baseline drift and the low-frequency noise are filtered, the PPG signal and the acceleration signal in the time domain are obtained, and then the PPG signal and the acceleration signal in the time domain are subjected to fourier transformation, so as to avoid the interference evaluation result of the intrinsic noise in the PPG signal.
In an embodiment, in the step S300, when the matching degree of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain reaches the preset matching degree range, it is indicated that the motion artifact is serious to the PPG signal interference, and the interference of the motion artifact cannot be removed from the PPG signal, and at this time, it is determined that the quality evaluation result of the PPG signal is that the PPG signal cannot be resolved.
The PPG signal quality has an optimal value SQ, and the preset goodness-of-fit range is close to the optimal value SQ, e.g. within 10% SQ, all within the preset goodness-of-fit range. When the preset fitness range is used for different devices, a certain deviation exists in the preset fitness range, generally, taking a smart watch as an example, the preset PPG signal optimal value sq=100, when the amplitude spectrum of the PPG signal in the frequency domain is consistent with the amplitude spectrum of the acceleration signal, the frequency spectrum of the PPG signal may be aliased with the motion frequency spectrum, so that the PPG signal quality is 10, the signal quality is the worst, and the analysis performance is the worst.
When it is determined whether the amplitude spectrum of the PPG signal in the frequency domain is inconsistent or basically inconsistent with the amplitude spectrum of the acceleration signal, it is indicated that the currently obtained PPG signal is less interfered by motion artifacts, and whether the currently obtained PPG signal quality is at an optimal value is determined to determine whether the currently obtained PPG signal can be resolved, so that the current PPG signal quality is intuitively obtained.
Referring to fig. 2, in another embodiment, when the PPG signal currently obtained is interfered by motion artifacts, the matching degree between the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain may not reach the preset matching degree range, and the step S300 includes:
s310: when the coincidence degree of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain does not reach the preset coincidence degree range, calculating the deviation value of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain.
When the amplitude spectrum of the PPG signal in the frequency domain is inconsistent with the amplitude spectrum of the acceleration signal and the phase difference range exceeds the preset goodness of fit range, the current obtained PPG signal is interfered by motion artifacts. Taking the smart watch as an example, the best value sq=100 of the PPG signal quality, and when the PPG signal quality is SQ < 90, calculating a deviation value of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the contrast frequency domain.
S311: comparing the deviation value with a preset maximum deviation value, and determining that the quality evaluation result of the PPG signal is that the PPG signal cannot be analyzed when the deviation value is smaller than or equal to the preset maximum deviation value.
In a motion state, the quality of the PPG signal is interfered by motion artifacts, so when a deviation value exists between the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the comparison frequency domain, the deviation value is within a preset maximum deviation value range, which indicates a range in which the motion artifact interference in the PPG signal cannot be removed and the PPG signal cannot be analyzed. The preset maximum deviation value ranges in different devices may be different, taking PPG signal quality optimal value sq=100 as an example, where the preset maximum deviation value may be a preset threshold, and when the deviation value of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the comparison frequency domain is greater than the preset threshold, it is indicated that the PPG signal quality can be resolved.
Referring to fig. 3, further optionally, when the deviation value is greater than the preset maximum deviation value, it is indicated that the PPG signal currently obtained may be analyzed although being interfered by motion artifacts, and the step S300 further includes:
s312: when the deviation value is larger than the preset maximum deviation value, subtracting the frequency domain signal of the acceleration signal from the frequency domain signal of the PPG signal to obtain a synthesized frequency domain signal;
when the deviation value is greater than the preset maximum deviation, it is indicated that the PPG signal obtained currently may be parsed although being interfered by motion artifacts, and the PPG signal quality needs to be further analyzed according to the synthesized frequency domain signal to determine whether it can be parsed.
S313: and acquiring the number of spectral peaks of the synthesized frequency domain signal in a preset frequency spectrum range, and determining a quality evaluation result of the PPG signal based on the number of spectral peaks.
In this embodiment, the greater the number of spectral peaks, the worse the signal quality, and the number of spectral peaks is inversely related to the PPG signal quality. The current PPG signal quality can be intuitively known by acquiring the number of spectral peaks of the synthesized frequency domain signal in a preset frequency spectrum range, so that a tester can conveniently know the analysis performance of the current PPG signal.
In this embodiment, optionally, when the number of spectral peaks is less than or equal to the preset minimum number of spectral peaks, it is determined that the quality evaluation result of the PPG signal is that the PPG signal can be resolved.
Because the number of the spectrum peaks of the synthesized frequency domain signal is inversely related to the quality of the PPG signal, the number of the spectrum peaks of the synthesized frequency domain signal can be preset according to specific equipment, wherein the analysis performance of the PPG signal in a preset time period is better when the number of the spectrum peaks of the synthesized frequency domain signal in the preset frequency spectrum range is smaller in the preset time period. When the number of spectral peaks of the synthesized frequency domain signal obtained in the preset time period exceeds the maximum number of spectral peaks in the preset frequency spectrum range, the PPG signal is greatly interfered, and the obtained PPG signal cannot be analyzed.
In this embodiment, optionally, when the number of spectral peaks is greater than the preset minimum number of spectral peaks, it is indicated that the currently acquired PPG signal is greatly affected by the motion artifact, and determining the quality evaluation result of the PPG signal based on the number of spectral peaks further includes:
and determining the maximum frequency spectrum amplitude in the synthesized frequency domain signal, comparing a frequency value corresponding to the maximum frequency spectrum amplitude with a preset frequency interval, and determining that the quality evaluation result of the PPG signal is that the PPG signal can be analyzed when the frequency value corresponding to the maximum frequency spectrum amplitude is in the preset frequency interval. The preset frequency interval is not greater than the maximum frequency value of the synthesized frequency domain signal and not less than the minimum frequency value of the synthesized frequency domain signal.
When the maximum frequency spectrum amplitude in the synthesized frequency domain signal is obtained, a frequency value corresponding to the maximum frequency spectrum amplitude is obtained, and when the frequency value corresponding to the maximum frequency spectrum amplitude in the synthesized frequency domain signal is not greater than the maximum frequency value of the synthesized frequency domain signal and is not less than the minimum frequency value of the synthesized frequency domain signal, the PPG signal is indicated to be resolvable.
Optionally, when the number of spectral peaks is greater than the preset minimum number of spectral peaks, it is indicated that the currently acquired PPG signal is greatly affected by the motion artifact, and determining the quality evaluation result of the PPG signal based on the number of spectral peaks further includes:
and determining a second large frequency spectrum amplitude in the synthesized frequency domain signal, comparing a frequency value corresponding to the second large frequency spectrum amplitude with a preset frequency interval, and determining that the quality evaluation result of the PPG signal is that the PPG signal can be analyzed when the frequency value corresponding to the second large frequency spectrum amplitude is in the preset frequency interval.
And when the frequency value corresponding to the second large frequency spectrum amplitude in the synthesized frequency domain signal is not more than the maximum frequency value of the synthesized frequency domain signal and not less than the minimum frequency value of the synthesized frequency domain signal, the PPG signal is indicated to be resolvable. At this time, the PPG signal quality at the frequency value corresponding to the maximum spectrum amplitude is better than the PPG signal quality at the frequency value corresponding to the second largest spectrum amplitude, and the resolution performance of the PPG signal at the frequency value corresponding to the maximum spectrum amplitude is better than the PPG signal at the frequency value corresponding to the second largest spectrum amplitude.
Optionally, when the number of spectral peaks is greater than the preset minimum number of spectral peaks, it is indicated that the currently acquired PPG signal is greatly affected by the motion artifact, and determining the quality evaluation result of the PPG signal based on the number of spectral peaks further includes:
and determining a third large frequency spectrum amplitude in the synthesized frequency domain signal, comparing a frequency value corresponding to the third large frequency spectrum amplitude with a preset frequency interval, and determining that the quality evaluation result of the PPG signal is that the PPG signal can be analyzed when the frequency value corresponding to the third large frequency spectrum amplitude is in the preset frequency interval.
And when the frequency value corresponding to the third large spectrum amplitude in the synthesized frequency domain signal is not more than the maximum frequency value of the synthesized frequency domain signal and not less than the minimum frequency value of the synthesized frequency domain signal, the PPG signal is indicated to be resolvable. At this time, the PPG signal quality at the frequency value corresponding to the second large spectrum amplitude is better than the PPG signal quality at the frequency value corresponding to the third large spectrum amplitude, and the resolution performance of the PPG signal at the frequency value corresponding to the second large spectrum amplitude is better than the PPG signal at the frequency value corresponding to the third large spectrum amplitude.
The principle of the invention is explained in detail below with reference to fig. 1 to 3. According to the invention, the PPG signal and the acceleration signal output by the acceleration sensor are obtained, the time domain signals of the PPG signal and the acceleration signal are converted into frequency domain signals, and the quality of the PPG signal is determined by comparing the PPG signal and the acceleration signal under the frequency domain. In the motion state, the PPG signal may be affected by motion artifacts, so that the quality of the PPG signal is degraded. After the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the comparison frequency domain are obtained, if the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the comparison frequency domain in the frequency domain are basically consistent or are in a preset fitness range, the motion artifact is serious to the PPG signal, the interference of the motion artifact cannot be removed from the PPG signal, and the quality evaluation result of the PPG signal is that the PPG signal cannot be analyzed.
When the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the comparison frequency domain are inconsistent and exceed the preset fitness range, the deviation of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the comparison frequency domain in the frequency domain is smaller than the preset maximum deviation value, so that the motion artifact interference in the PPG signal cannot be eliminated, and the quality evaluation result of the signal is that the PPG signal cannot be analyzed.
When the deviation of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the comparison frequency domain in the frequency domain is larger than a preset maximum deviation value, the PPG signal is indicated to be capable of eliminating the interference of motion artifacts, the PPG signal is resolvable, the synthesized frequency domain signal is calculated, and the PPG signal quality is evaluated according to the synthesized frequency domain signal. After the synthesized frequency domain signal is obtained, the number of spectrum peaks of the synthesized frequency domain signal in a preset frequency spectrum range is obtained, the more the number of spectrum peaks is, the worse the signal quality is, and then the current PPG signal quality can be estimated according to the number of spectrum peaks.
Meanwhile, after the synthesized frequency domain signal is obtained, the frequency corresponding to the first three large frequency spectrum amplitudes of the synthesized frequency domain signal is obtained, the corresponding frequency is compared with the maximum frequency and the minimum frequency of the synthesized frequency domain signal, and when any one of the frequencies corresponding to the first three large frequency spectrum amplitudes of the synthesized frequency domain signal is located between the maximum frequency and the minimum frequency of the synthesized frequency domain signal, the analysis of the currently obtained PPG signal is indicated.
The invention also proposes an embodiment of a PPG signal quality assessment device performing a method as described in any of the embodiments above. The device comprises: a signal generating unit 1004 for outputting a PPG signal and an acceleration signal; a processor 1001; and a memory 1002 for storing said PPG signal quality assessment program executable on said processor; the PPG signal quality evaluation procedure, when executed by the processor, implements the steps of a PPG signal quality evaluation method as described in any of the embodiments above.
The signal generating unit 1004 is configured to output a PPG signal and an acceleration signal. The processor 1001 may be a CPU, and the processor 1001 may include a network interface, a user interface, a communication bus 1003, and the like. Wherein the communication bus 1002 is used to enable connected communication between these components. The user interface may comprise a Display, an input unit such as keys, and the selectable user interface may also comprise a standard wired interface, a wireless interface. The network interface may optionally include a standard wired interface, a wireless interface (e.g., WI-FI interface), a serial port, etc. The memory 1002 may be a high-speed RAM memory 1002 or a stable memory 1002 (non-volatile memory), such as a disk memory 1002. The memory 1002 may alternatively be a storage device separate from the processor 1001 described above. The processor 1001 invokes a PPG signal quality assessment procedure stored in the memory and the PPG signal and acceleration signal received by the signal generating unit, and performs PPG signal quality assessment.
The invention further provides an embodiment of the wearable device. The wearable device stores the means for performing the PPG signal quality assessment method as described in the above embodiments. The wearable device may be a smart watch or the like.
The invention also proposes an embodiment of a storage medium. The storage medium stores an evaluation program of a PPG signal quality device which, when executed by a processor, implements the steps of a PPG signal quality evaluation method as described in any of the embodiments above. The readable storage medium may be a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk, etc. that stores program codes.
Claims (7)
1. A PPG signal quality assessment method for assessing whether a PPG signal acquired by a wearable device can be resolved, the wearable device having an acceleration sensor, characterized in that the PPG signal quality assessment method comprises the steps of:
acquiring a PPG signal acquired by wearable equipment and an acceleration signal output by an acceleration sensor;
performing time domain to frequency domain conversion on the obtained PPG signal and the obtained acceleration signal to obtain a PPG signal and an acceleration signal in the frequency domain;
when the amplitude spectrum and the acceleration amplitude spectrum of the PPG signal in the frequency domain do not reach the preset fitness range, determining that the quality of the PPG signal acquired at present is likely to be analyzed; calculating the deviation value of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain;
when the deviation value is larger than a preset maximum deviation value, the PPG signal in the current frequency domain can be analyzed; subtracting the frequency domain signal of the acceleration signal from the frequency domain signal of the PPG signal to obtain a synthesized frequency domain signal; and
acquiring the number of spectrum peaks of the synthesized frequency domain signal in a preset frequency spectrum range, wherein the number of spectrum peaks is inversely related to the quality of the PPG signal; the PPG signal and the acceleration signal are signals acquired in the same time period;
when the number of the spectral peaks is larger than the preset minimum number of the spectral peaks, determining the maximum spectral amplitude, the second largest spectral amplitude and the third largest spectral amplitude in the synthesized frequency domain signal, wherein the PPG signal quality under the frequency values corresponding to the maximum spectral amplitude, the second largest spectral amplitude and the third largest spectral amplitude is decreased;
when the number of spectral peaks is greater than a preset minimum number of spectral peaks, determining a quality evaluation result of the PPG signal based on the number of spectral peaks includes:
determining the maximum frequency spectrum amplitude in the synthesized frequency domain signal, comparing a frequency value corresponding to the maximum frequency spectrum amplitude with a preset frequency interval, and determining that the quality evaluation result of the PPG signal is that the PPG signal can be analyzed when the frequency value corresponding to the maximum frequency spectrum amplitude is in the preset frequency interval; and/or
Determining a second large frequency spectrum amplitude in the synthesized frequency domain signal, comparing a frequency value corresponding to the second large frequency spectrum amplitude with a preset frequency interval, and determining that a quality evaluation result of the PPG signal is that the PPG signal can be analyzed when the frequency value corresponding to the second large frequency spectrum amplitude is in the preset frequency interval; and/or
Determining a third large frequency spectrum amplitude in the synthesized frequency domain signal, comparing a frequency value corresponding to the third large frequency spectrum amplitude with a preset frequency interval, and determining that a quality evaluation result of the PPG signal is that the PPG signal can be analyzed when the frequency value corresponding to the third large frequency spectrum amplitude is in the preset frequency interval;
the preset frequency interval is not greater than the maximum frequency value of the synthesized frequency domain signal and not less than the minimum frequency value of the synthesized frequency domain signal.
2. The PPG signal quality assessment method according to claim 1, wherein comparing the amplitude spectrum of the PPG signal in the frequency domain with the amplitude spectrum of the acceleration signal, obtaining the quality assessment result of the PPG signal comprises:
when the coincidence degree of the amplitude spectrum of the PPG signal and the amplitude spectrum of the acceleration signal in the frequency domain reaches a preset coincidence degree range, determining that the quality evaluation result of the PPG signal is that the PPG signal cannot be analyzed.
3. The PPG signal quality assessment method according to claim 1, wherein said determining a quality assessment result of said PPG signal based on said number of spectral peaks comprises:
and when the number of the spectrum peaks is smaller than or equal to the preset minimum number of spectrum peaks, determining that the quality evaluation result of the PPG signal is that the PPG signal can be analyzed.
4. The PPG signal quality assessment method according to claim 1, wherein after the step of acquiring the PPG signal acquired by the wearable device and the acceleration signal output by the acceleration sensor, the PPG signal quality assessment method further comprises:
and carrying out band-pass filtering denoising on the obtained PPG signal and the obtained acceleration signal to obtain the PPG signal and the obtained acceleration signal in the time domain.
5. PPG signal quality assessment device performing the method according to any of claims 1 to 4, characterized in that the device comprises:
a signal generation unit for outputting a PPG signal and an acceleration signal;
a processor; and
a memory for storing a PPG signal quality assessment program executable on the processor; the PPG signal quality assessment procedure, when executed by the processor, implements the steps of the PPG signal quality assessment method as claimed in any one of claims 1 to 4.
6. A wearable device, characterized in that the wearable device stores the apparatus of claim 5 that performs the PPG signal quality assessment method.
7. A storage medium storing an evaluation program of PPG signal quality means which when executed by a processor implements the steps of the PPG signal quality evaluation method of any one of claims 1 to 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011351785.9A CN112494001B (en) | 2020-11-25 | 2020-11-25 | PPG signal quality evaluation method and device, wearable device and storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011351785.9A CN112494001B (en) | 2020-11-25 | 2020-11-25 | PPG signal quality evaluation method and device, wearable device and storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112494001A CN112494001A (en) | 2021-03-16 |
| CN112494001B true CN112494001B (en) | 2023-05-26 |
Family
ID=74966476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011351785.9A Active CN112494001B (en) | 2020-11-25 | 2020-11-25 | PPG signal quality evaluation method and device, wearable device and storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112494001B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113995387B (en) * | 2021-10-28 | 2024-04-12 | 上海掌门科技有限公司 | Method, device, medium and program product for detecting pulse waveform |
| CN114676738B (en) * | 2022-05-27 | 2022-08-02 | 广东玖智科技有限公司 | PPG signal quality evaluation method and device and PPG signal processing method and system |
| CN115670397B (en) * | 2022-11-17 | 2023-06-02 | 北京中科心研科技有限公司 | PPG artifact identification method and device, storage medium and electronic equipment |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105593903A (en) * | 2014-05-16 | 2016-05-18 | 联发科技股份有限公司 | Living body determination devices and methods |
| WO2016204905A1 (en) * | 2015-06-16 | 2016-12-22 | Qualcomm Incorporated | Robust heart rate estimation |
| CN109475311A (en) * | 2016-05-10 | 2019-03-15 | 牛津大学创新有限公司 | It determines the method for subjectxperiod's property physiology course frequency and determines the device and system of subjectxperiod's property physiology course frequency |
| CN109497998A (en) * | 2018-12-14 | 2019-03-22 | 深圳和而泰数据资源与云技术有限公司 | EEG signals method for evaluating quality, eeg signal acquisition device and helmet |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10258288B2 (en) * | 2014-03-24 | 2019-04-16 | Samsung Electronics Co., Ltd. | Confidence indicator for physiological measurements using a wearable sensor platform |
| JP2016000153A (en) * | 2014-06-12 | 2016-01-07 | オムロンヘルスケア株式会社 | Pulse measuring device, pulse measuring method, and pulse measuring program |
| US11771375B2 (en) * | 2014-09-26 | 2023-10-03 | Pixart Imaging Inc. | Respiration rate detection device and breath detection device adopting motion denoising |
| US9794653B2 (en) * | 2014-09-27 | 2017-10-17 | Valencell, Inc. | Methods and apparatus for improving signal quality in wearable biometric monitoring devices |
| CN110292372B (en) * | 2014-09-30 | 2022-03-01 | 原相科技股份有限公司 | Detection device |
| CN105286845A (en) * | 2015-11-29 | 2016-02-03 | 浙江师范大学 | Movement noise elimination method suitable for wearable heart rate measurement device |
| CN106994010A (en) * | 2016-01-26 | 2017-08-01 | 深圳市新元素健康管理有限公司 | A kind of heart rate detection method and system based on PPG signals |
| EP3403574A1 (en) * | 2017-05-18 | 2018-11-21 | Preventicus GmbH | Device for reliable acquisition of photoplethysmographic data |
| EP3406189B1 (en) * | 2017-05-25 | 2024-05-29 | Tata Consultancy Services Limited | System and method for heart rate estimation |
| CN109640789A (en) * | 2017-07-21 | 2019-04-16 | 深圳市汇顶科技股份有限公司 | Interference analysis method and device, the wearable device of bio signal |
| TWI658815B (en) * | 2018-04-25 | 2019-05-11 | 國立交通大學 | Non-contact heartbeat rate measurement system, non-contact heartbeat rate measurement method and non-contact heartbeat rate measurement apparatus |
| CN110755055A (en) * | 2019-10-18 | 2020-02-07 | 上海掌门科技有限公司 | Method and equipment for determining waveform evaluation information of pulse waveform |
| CN111568399B (en) * | 2020-05-15 | 2023-01-10 | 中国人民解放军陆军军医大学 | Radar-based respiration and heartbeat signal detection method and system |
-
2020
- 2020-11-25 CN CN202011351785.9A patent/CN112494001B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105593903A (en) * | 2014-05-16 | 2016-05-18 | 联发科技股份有限公司 | Living body determination devices and methods |
| WO2016204905A1 (en) * | 2015-06-16 | 2016-12-22 | Qualcomm Incorporated | Robust heart rate estimation |
| CN109475311A (en) * | 2016-05-10 | 2019-03-15 | 牛津大学创新有限公司 | It determines the method for subjectxperiod's property physiology course frequency and determines the device and system of subjectxperiod's property physiology course frequency |
| CN109497998A (en) * | 2018-12-14 | 2019-03-22 | 深圳和而泰数据资源与云技术有限公司 | EEG signals method for evaluating quality, eeg signal acquisition device and helmet |
Non-Patent Citations (1)
| Title |
|---|
| 循环平稳算法的脉搏信号噪声评估指标;任亚莉等;自动化仪表;第40卷(第12期);29-34 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112494001A (en) | 2021-03-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112494001B (en) | PPG signal quality evaluation method and device, wearable device and storage medium | |
| EP2777485B1 (en) | Signal processor, signal processing method, and signal processing program | |
| US9504401B2 (en) | Atrial fibrillation analyzer and program | |
| CN105997043B (en) | A kind of pulse frequency extracting method based on wrist wearable device | |
| US20140081088A1 (en) | Computer-implemented method for determining physical movements of a body organ | |
| KR101849263B1 (en) | Robust Heart Rate Estimation | |
| US20200107786A1 (en) | Method for assessing electrocardiogram signal quality | |
| RU2677007C2 (en) | Apparatus and method for ecg motion artifact removal | |
| US11109794B2 (en) | Method and apparatus for processing ECG signals, and ECG machine | |
| CN110974189A (en) | Method, device, equipment and system for detecting signal quality of pulse wave | |
| JP2015116368A (en) | Pulse measuring device, pulse measuring method and pulse measuring program | |
| CN112587133A (en) | Method for measuring blood oxygen saturation | |
| CN106725415B (en) | The treating method and apparatus of electricity physiological signal | |
| WO2019146025A1 (en) | Pulse wave calculation device, pulse wave calculation method and pulse wave calculation program | |
| KR101514151B1 (en) | Noise robust algorithm for ppg signal measurement | |
| US20180000423A1 (en) | Measuring apparatus, measuring method and non-transitory computer readable medium | |
| TWI504378B (en) | Denoising method and apparatus of pulse wave signal and pulse oximetry | |
| WO2023165482A1 (en) | Method and apparatus for heart rate detection | |
| So-In et al. | Real-time ECG noise reduction with QRS complex detection for mobile health services | |
| CN113397523A (en) | Respiration rate detection method and device and medical equipment | |
| US20130211273A1 (en) | Method and apparatus for heart rate measurement | |
| EP2938247B1 (en) | Method and apparatus for reducing motion artifacts in ecg signals | |
| Canu et al. | Respiration rate calculation using low power DSP processor and SpO 2 sensor | |
| CN114159075A (en) | QRS wave optimization device, system and storage medium | |
| CN113425276A (en) | Heart rate monitoring method, earphone and computer storage medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |