CN111227819B - Signal processing method of fetal heart detection sensor matrix of multidimensional channel sensor - Google Patents
Signal processing method of fetal heart detection sensor matrix of multidimensional channel sensor Download PDFInfo
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- CN111227819B CN111227819B CN202010108316.8A CN202010108316A CN111227819B CN 111227819 B CN111227819 B CN 111227819B CN 202010108316 A CN202010108316 A CN 202010108316A CN 111227819 B CN111227819 B CN 111227819B
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- 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
- A61B5/024—Detecting, measuring or recording pulse rate or heart rate
- A61B5/02411—Detecting, measuring or recording pulse rate or heart rate of foetuses
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
- A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
- A61B5/6802—Sensor mounted on worn items
- A61B5/6804—Garments; Clothes
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- 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
- A61B5/7203—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal
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- 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
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/02—Measuring pulse or heart rate
Abstract
The invention provides a signal processing method of a fetal heart detection sensor matrix of a multi-dimensional channel sensor. The invention completely avoids the potential harm of active emission to the pregnant woman and the fetus by using the passive sensor. Interference noise is effectively suppressed, so that the data of fetal heart monitoring cannot be influenced by actions in daily life. No recumbent measurement is required. Under the condition that the fetal position moves, the fetal position detector can still accurately measure signals, and is convenient for pregnant women or family members to use.
Description
Technical Field
The invention relates to the field of medical detection equipment, in particular to a fetal heart detection sensor matrix of a multi-dimensional channel sensor, a signal processing method of the fetal heart detection sensor matrix and wearable equipment.
Background
The basic principle of the traditional fetal heart monitoring mode based on an ultrasonic transmitter is to transmit signals to the abdomen of a pregnant woman, and the ultrasonic signals penetrate through different parts of human tissues to generate reflection. The ultrasonic signal is also reflected when it meets the fetal heart of the fetus, and the reflection will produce Doppler frequency shift because of the motion characteristic of the target. By observing how fast the frequency shift changes, it can be used to analyze fetal heart data.
This type of fetal heart monitoring based on ultrasound transmission is in use today. The main problems with this approach are:
1) actively transmitting signals to the abdomen of the pregnant woman. There is a potential risk. The obstetrics and gynecology of all countries do not recommend a fetal heart monitoring mode based on ultrasonic emission for a long time and for multiple times.
2) High frequency ultrasound signals require a couplant to facilitate energy penetration through the abdomen to the fetus. Typically, fetal heart monitoring uses ultrasound in the frequency range of 500kHz to 2 MHz. Such ultrasound signals decay very rapidly. Good coupling medium transmission is required. In fetal heart monitoring, the couplant is smeared on the abdomen of a pregnant woman to achieve the purpose of transmitting ultrasonic signals. This is very inconvenient to use. Nor can it be worn. The couplant can be applied to the wide-clothing and loose-clothing zones only at each time of use.
3) The monitoring instrument based on ultrasonic emission can accurately detect signals only by using the probe to be opposite to the fetal heart. Otherwise, the fetal heart reflected signal cannot be received. And when the measurement is serious, the measurement cannot be carried out, or the measurement is inaccurate. Only an experienced physician can quickly find the fetal heart position and measure with the probe. Limited possibility of self-use by the pregnant woman.
Patent document US2018296116a1 proposes a focusing method, and it is hoped that the focusing can distinguish the fetal heart sound from the heartbeat sound of the expectant mother to realize the purpose of measuring the fetal heart. However, this method is the first to use an active transmission method. There is a potential threat to the health of both the fetus and the expectant mother. Second, the focusing method adjusts the emission direction mechanically and electronically. This necessitates sufficient expertise or a priori information to identify where the direction of transmission is desired. This is extremely limited in use and needs to be done at the hospital under the direction of a doctor.
In summary, the current monitoring instrument has high operation difficulty and is difficult to realize personal and family use.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a signal processing method of a fetal heart detection sensor matrix of a multi-dimensional channel sensor.
According to the signal processing method of the fetal heart detection sensor matrix of the multi-dimensional channel sensor provided by the invention, the fetal heart detection sensor matrix of the multi-dimensional channel sensor is adopted, and the execution steps comprise:
s1, the signal collected by the single collecting channel is
x is the acquired time domain signal, the superscript i is the number of a single acquisition channel, and the subscript t is the time series number;
s2, obtaining a signal matrix A (t) by a fetal heart detection sensor matrix of the multidimensional channel sensor, wherein the signal matrix A (t) is as follows:
s3, according to the collected signals
Obtaining a numerical matrix A:
A＝XX′
x is the collected signal, and X is the collected signal,
superscript' is a conjugate transposed symbol;
s4, analyzing the characteristic vector of the numerical matrix A:
AU＝UV
wherein the feature vector
Is a characteristic value
V is a feature value diagonal matrix;
s5, dividing the characteristic vector into a fetal heart signal characteristic vector T, a pregnant woman heartbeat signal characteristic vector P and a noise signal characteristic vector E,
s6, setting space guide matrixes a and b, and constructing an energy spectrum function P (epsilon, theta):
K1、K2a weighting coefficient between 0 and 1; the superscript' is a conjugate transpose symbol, and the epsilon and theta combination which enables P (epsilon and theta) to take the peak value is taken;
s7, extracting fetal heart signals:
b′(θ)a′(ε)Aa(ε)b(θ)。
preferably, the fetal heart detection sensor matrix of the multi-dimensional channel sensor comprises: a plurality of sensors;
each sensor comprises a plurality of acoustic sensing unit groups, and the plurality of acoustic sensing unit groups adopt differential measurement to form a single acquisition channel;
each acoustic cell group comprises a plurality of acoustic cells.
Preferably, the sensor is a layered structure comprising: an acoustic coupling structural layer, a sensor structural layer, and an acoustic damping structural layer;
the sensor structural layer is disposed between the acoustic coupling structural layer and the acoustic damping structural layer.
Preferably, the sensor structure layer includes: the sound insulation material is filled between the sound-sensitive units.
Preferably, the plurality of sensors are arranged in a spatially complex manner, and when post-processing is performed on the acquired signals, the plurality of sensors are grouped in a self-organizing manner and are used for measurement and noise reduction respectively.
Preferably, the self-organizing group includes a fetal heart signal and a maternal signal.
Preferably, the differential measurement comprises:
the signal collected by a single collecting channel is the difference value of different sound sensitive unit groups.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention completely avoids the potential harm of active emission to the pregnant woman and the fetus by using the passive sensor.
2. The invention effectively inhibits interference noise, so that the movement in daily life does not influence the data of fetal heart monitoring, and the recumbent measurement is not needed.
3. The invention can still accurately measure signals under the condition that the fetal position of the fetus moves, and is convenient for pregnant women or family members to use.
4. The tailorable and self-organizing characteristics of the composite sensor matrix can be widely applied to people with different body states.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 is a schematic diagram of a single acquisition channel configuration;
FIG. 2 is a schematic diagram of the structure of four acoustic sensing unit groups of a single acquisition channel;
FIG. 3 is a cross-sectional view of the sensor;
FIG. 4 is a schematic diagram of a sensor structure layer;
FIG. 5 is a schematic structural diagram of a fetal heart detection garment;
FIG. 6 is a schematic view of the spatial distribution of sensors;
FIG. 7 is a schematic view of the spatial distribution of sensors;
FIG. 8 is a schematic diagram of the operation of the present invention;
fig. 9 is a flow chart of the operation of the present invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
The invention provides a fetal heart detection sensor matrix of a multi-dimensional channel sensor, which comprises a plurality of sensors. Each sensor comprises a plurality of acoustic cell groups, each acoustic cell group comprising a plurality of acoustic cells 1, as shown in figure 1. In the embodiment shown in fig. 2, the 16 sound-sensitive units 1 are divided into four groups, but the invention is not limited thereto. The multiple acoustic sensing unit groups adopt differential measurement to form a single acquisition channel.
As shown in fig. 3, the sensor is a layered structure including: the acoustic damping structure comprises an acoustic coupling structure layer 11, a sensor structure layer 12 and an acoustic damping structure layer 13, wherein the sensor structure layer 12 is arranged between the acoustic coupling structure layer 11 and the acoustic damping structure layer 13. As shown in fig. 4, the sensor structure layer includes: sound insulation material 14 and a plurality of sound-sensitive cells 1, sound insulation material 14 is filled between sound-sensitive cells 1.
As shown in fig. 6 and 7, the plurality of sensors are spatially combined, and when post-processing is performed on the acquired signals, the plurality of sensors are self-organized and grouped for measurement and noise reduction, respectively.
The invention provides a signal processing method of a fetal heart detection sensor matrix of a multi-dimensional channel sensor, which adopts the fetal heart detection sensor matrix of the multi-dimensional channel sensor and comprises the following steps:
1) each acoustic sensor unit receives a signal
2) The signal received by each group of sound sensitive units is
M1.., M, assuming M groups for a single acquisition channel. Without loss of generality, we choose here M ═ 2.
3) The signal collected by each collection channel is
A differential measurement is completed.
4) Obtaining signals by a single acquisition channel
x is the acquired time domain signal. i is the number of the individual acquisition channels. t time series numbers.
5) The signal obtained by the composite sensor matrix is
6) According to the collected signal
A matrix of correlation values can be obtained
A＝XX′
7) The feature vectors of the symmetric a matrix are analyzed.
AU＝UV
The characteristic values are arranged, the largest ones represent the sources of several main sound signals, and generally, the heartbeat sound of the pregnant woman, the heartbeat sound of the fetus and the environmental noise generate the largest ones. Wherein
Is the result of the ranking of the eigenvalues. The corresponding signal and noise space is also formed by the corresponding feature vector.
8) The main three signal sources, fetal heart, maternal heartbeat, and environmental noise, are uncorrelated signals between them. The feature vector column vector can be divided into a fetal heart signal feature vector, a pregnant woman heartbeat signal feature vector and a noise signal feature vector;
9) setting spatial guide matrixes a and b and constructing energy spectrum function
The above formula P is combined by epsilon and theta of peak values, and the space propagation relative direction of the fetal heart signals is given.
10) Using the obtained spatial steering matrix information, the processing is performed as follows:
b′(θ)a′(ε)Aa(ε)b(θ)
11) here, fetal heart signals are extracted and two kinds of interference information are weakened
12) The steps (1) to (11) are a self-organizing multiple-input multiple-output SMIMO (self-organizing multiple-input multiple-output) collection processing method. The method may be reused multiple times over a sampling period. The results of multiple times may be accumulated for the purpose of improving the signal-to-noise ratio. The process of using SMIMO is shown in fig. 9.
Because of the SMIMO, the pregnant woman may use the inventive fetal heart measuring device in a complex noisy environment. Such as daily activities, such as working, interacting with others, purchasing outside, etc. The complex noise environment created and faced in these activities is problematic for typical measurement equipment. And SMIMO solves the problem of extracting fetal heart information in a complex environment.
As shown in fig. 5, based on the fetal heart detecting sensor matrix of the multidimensional channel sensor, the invention further provides a fetal heart detecting garment, which can be a wearing garment or equipment used by pregnant women, such as an abdominal belt, an underwear, a waistband, a corsage and the like. The sensors are arranged in a specified distribution on the soft material. In this embodiment, the garment is divided into an upper garment and a lower garment. The upper garment is provided with a sensor for detecting signals of a pregnant woman, and the lower garment is provided with three sensors, the positions of which surround the abdomen of the pregnant woman and are used for detecting signals of fetal heart.
The signals acquired by the composite acquisition matrix will be used for calculations based on the fetal heart rate. The self-organizing function of the multiple sensors is completed, background noise is weakened, non-fetal heart signal energy is weakened, and the output result is fetal heart rate and fetal heart direction. This is achieved using a rotational noise space based signal processing technique. And meanwhile, self-organization of a plurality of sensor groups is realized. The self-organization of the composite matrix of sensors is achieved by an algorithm. A typical example of self-organization here is that several sensor signals near the fetus will be concentrated to extract fetal heart information, while multiple sensor signals near the maternal heart will be concentrated to extract maternal heart beat information, which will be used to attenuate the associated non-fetal heart signal energy. And selecting which sensors to use as a measurement group is automatically performed by the algorithm. No manual selection is required. On the other hand, the self-organizing array enables the pregnant woman to wear a plurality of sensors without accurate positioning, and the sensors can automatically adapt. At the same time, the position of the fetus can be self-adaptive. The fetal heart information cannot be captured because the fetus moves. In addition, due to the influence of the change of the human body posture characteristics, the technology can be widely applied.
In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.
Claims (6)
1. A signal processing method for a fetal heart detection sensor matrix of a multi-dimensional channel sensor is characterized in that the fetal heart detection sensor matrix of the multi-dimensional channel sensor is adopted, and the execution steps comprise:
s1, the signal collected by the single collecting channel is
x is the acquired time domain signal, the superscript i is the number of a single acquisition channel, and the subscript t is the time series number;
s2, obtaining a signal matrix A (t) by a fetal heart detection sensor matrix of the multidimensional channel sensor, wherein the signal matrix A (t) is as follows:
s3, according to the collected signals
Obtaining a numerical matrix A:
A＝XX′
x is the collected signal, and X is the collected signal,
superscript' is a conjugate transposed symbol;
s4, analyzing the characteristic vector of the numerical matrix A:
AU＝UV
wherein the feature vector
Is a characteristic value
V is a feature value diagonal matrix;
s5, dividing the characteristic vector into a fetal heart signal characteristic vector T, a pregnant woman heartbeat signal characteristic vector P and a noise signal characteristic vector E,
s6, setting space guide matrixes a and b, and constructing an energy spectrum function P (epsilon, theta):
K1、K2a weighting coefficient between 0 and 1; the superscript' is a conjugate transpose symbol, and the epsilon and theta combination which enables P (epsilon and theta) to take the peak value is taken;
s7, extracting fetal heart signals:
b′(θ)a′(ε)Aa(ε)b(θ)；
the fetal heart detection sensor matrix of the multi-dimensional channel sensor comprises: a plurality of sensors;
each sensor comprises a plurality of acoustic sensing unit groups, and the plurality of acoustic sensing unit groups adopt differential measurement to form a single acquisition channel;
each acoustic cell group comprises a plurality of acoustic cells.
2. The method of claim 1, wherein the sensor is a layered structure comprising: an acoustic coupling structural layer, a sensor structural layer, and an acoustic damping structural layer;
the sensor structural layer is disposed between the acoustic coupling structural layer and the acoustic damping structural layer.
3. The method of signal processing for a fetal heart detection sensor matrix of a multi-dimensional channel sensor as claimed in claim 2, wherein the sensor structure layer comprises: the sound insulation material is filled between the sound-sensitive units.
4. The method as claimed in claim 1, wherein the sensors are spatially arranged in a complex manner, and the sensors are self-organized and grouped for measurement and noise reduction during post-processing of the acquired signals.
5. The method of claim 4, wherein the self-organizing groups comprise a division into fetal heart signals and maternal signals.
6. The method of signal processing for a fetal heart detection sensor matrix of a multi-dimensional channel sensor as claimed in claim 1, wherein the differential measurement comprises:
the signal collected by a single collecting channel is the difference value of different sound sensitive unit groups.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105940445A (en) * | 2016-02-04 | 2016-09-14 | 曾新晓 | Voice communication system and method |
| CN106890008A (en) * | 2017-02-15 | 2017-06-27 | 北京大学第三医院 | A kind of cerebrovascular analysis system |
| WO2019216320A1 (en) * | 2018-05-08 | 2019-11-14 | 国立大学法人徳島大学 | Machine learning apparatus, analysis apparatus, machine learning method, and analysis method |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8064991B2 (en) * | 2008-01-08 | 2011-11-22 | The General Electric Company | Method of fetal and maternal ECG identification across multiple EPOCHS |
| US20130245436A1 (en) * | 2009-04-22 | 2013-09-19 | Joe Paul Tupin, Jr. | Fetal monitoring device and methods |
| GB201305937D0 (en) * | 2013-04-02 | 2013-05-15 | Monica Healthcare Ltd | Fetal movement monitor |
| US9763583B2 (en) * | 2015-03-16 | 2017-09-19 | Nuvo Group Ltd. | Electrodes for abdominal fetal electrocardiogram detection |
| CN106236043A (en) * | 2016-08-30 | 2016-12-21 | 衢州学院 | A kind of interactive intelligent Medical hand loop systems |
| US10758146B2 (en) * | 2017-04-12 | 2020-09-01 | Qinshan Yang | System and method for fetal heartbeat sound monitoring and recording by propagation and spacial location analysis by a sensor matrix |
| CN107468232A (en) * | 2017-09-05 | 2017-12-15 | 苏州风尚智选医疗科技有限公司 | Fetal heart monitoring device and method |
| US20190101984A1 (en) * | 2017-09-29 | 2019-04-04 | Facebook Technologies, Llc | Heartrate monitor for ar wearables |
| CN110123296A (en) * | 2018-02-02 | 2019-08-16 | 冯卫忠 | One kind is fetal monitoring system and its wearing clothing based on Internet of Things |
| WO2019159010A1 (en) * | 2018-02-19 | 2019-08-22 | Nuvo Group Ltd. | Wet electrode for abdominal fetal electrocardiogram detection |
| CN109830245B (en) * | 2019-01-02 | 2021-03-12 | 北京大学 | Multi-speaker voice separation method and system based on beam forming |
| CN109497985A (en) * | 2019-01-03 | 2019-03-22 | 合肥京东方光电科技有限公司 | A kind of fetal rhythm monitoring device and system |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105940445A (en) * | 2016-02-04 | 2016-09-14 | 曾新晓 | Voice communication system and method |
| CN106890008A (en) * | 2017-02-15 | 2017-06-27 | 北京大学第三医院 | A kind of cerebrovascular analysis system |
| WO2019216320A1 (en) * | 2018-05-08 | 2019-11-14 | 国立大学法人徳島大学 | Machine learning apparatus, analysis apparatus, machine learning method, and analysis method |
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