WO2015100909A1

WO2015100909A1 - Monitor and method and device for automatically switching signals of a plurality of leads thereof

Info

Publication number: WO2015100909A1
Application number: PCT/CN2014/077333
Authority: WO
Inventors: 姚祖明; 刘立汉
Original assignee: 深圳迈瑞生物医疗电子股份有限公司
Priority date: 2013-12-31
Filing date: 2014-05-13
Publication date: 2015-07-09
Also published as: CN104739371A; CN104739371B

Abstract

A method for automatically switching signals of a plurality of leads. The method comprises: respectively collecting vital sign signals detected by a plurality leads (101); selecting one path of signals from the vital sign signals output by the plurality of leads to be an analysis signal, the analysis signal being a signal used for subsequently conducting monitoring analysis and processing (103); and detecting, in real time, whether the current analysis signal is abnormal, and if so, selecting another path of vital sign signals output by a lead to be an analysis signal (104). Also disclosed is a device for automatically switching signals of a plurality of leads, comprising a signal acquisition unit (201), a signal selection unit (203) and a judgement unit (204). Also disclosed is a monitor comprising the device for automatically switching signals of a plurality of leads. The monitor and the method and device for automatically switching signals of a plurality of leads thereof can automatically switch a lead corresponding to the current analysis signal to another normal lead when the lead is abnormal, so as to obtain correct vital sign signals, and thereby avoiding the situation of a false alarm caused by a single abnormal lead.

Description

Monitor and multi-lead signal automatic switching method and device

Technical field

The present application relates to a monitor, and more particularly to a method and apparatus for automatically switching a multi-lead signal of a monitor.

Background technique

Medical monitoring equipment (such as monitors) can provide medical personnel with real-time and accurate vital information such as vital signs of patients, so that clinicians can more comprehensively, timely and accurately grasp the changes of patients' conditions, and develop treatment plans and emergency treatments. It provides an important basis for patients to obtain the best therapeutic effect, so it is widely used in hospitals such as ICU, CCU, anesthesia operating room and other related clinical departments.

The monitor usually has multiple leads, and the medical staff selects only one of the leads as the analysis lead according to observation and human judgment, and only the signal output by the analysis lead is treated as a valid signal in subsequent detection or monitoring. The problem with this way of fixing the analysis lead is that it will cause an alarm when the signal output from the lead is abnormal, but in some cases, the signal abnormality is not caused by the patient's condition change, but the analysis lead is Caused by poor contact with the patient's skin during the monitoring process or other interference caused by weak signals, etc., in this case, it will cause false alarms, which brings a lot of inconvenience to clinical operation and monitoring.

Summary of the invention

The present invention provides a monitor and a multi-lead signal automatic switching method and apparatus thereof, which can automatically switch to a vital sign signal outputted by other normal leads as an analysis signal when detecting an abnormality of the current analysis signal.

According to the first aspect of the present application, the present application provides a method for automatically switching a multi-lead signal, including:

Collect vital signs signals detected by multiple leads.

One of the vital sign signals outputted from the plurality of leads is selected as an analysis signal, which is a signal for subsequent monitoring analysis and processing.

Real-time detection of whether the current analysis signal is abnormal, if yes, select the vital sign signal output by the other one lead as the analysis signal.

According to a second aspect of the present application, the present application provides a multi-lead signal automatic switching device, including:

The signal acquisition unit is configured to separately collect vital sign signals detected by the plurality of leads.

The signal selection unit is connected to the signal acquisition unit for selecting one of the vital sign signals outputted from the plurality of leads as an analysis signal, and the analysis signal is a signal for subsequent monitoring analysis and processing.

The judging unit is connected to the signal selecting unit for detecting whether the current analysis signal is abnormal in real time, and if so, controlling the signal selecting unit to select another vital sign output vital sign signal as the analysis signal.

According to a third aspect of the present application, the present application provides a monitor comprising:

A plurality of leads for detecting and outputting vital sign signals.

a host coupled to an output of the lead, the host including a processor for monitoring analysis and processing of the vital sign signal and information for monitoring analysis and processing of the vital sign signal by the display processor Display.

The processor includes the above-described multi-lead signal automatic switching device.

In the monitoring device and the multi-lead signal automatic switching method and device provided by the application, the monitor determines whether the current analysis signal is abnormal in real time, and if so, selects the vital sign signal outputted by the other one lead as the analysis signal, therefore, It is possible to automatically switch to other normal leads when an abnormality occurs in the current lead (current analysis signal) to obtain a correct vital sign signal, thereby avoiding a false alarm due to a single lead abnormality.

DRAWINGS

1 is a schematic flowchart of a method for automatically switching a multi-lead signal according to an embodiment of the present application;

2 is a schematic block diagram of a multi-lead signal automatic switching device according to an embodiment of the present application.

detailed description

The monitor includes a plurality of leads for detecting and outputting vital sign signals and a host connected to the outputs of the respective leads. The lead is connected to the patient's site to be measured during use. The host includes a processor for monitoring analysis and processing of vital sign signals and a display for displaying information about the monitoring and processing of vital sign signals by the processor. The processor of the monitor provided by the embodiment of the present application further includes a multi-lead signal automatic switching device. The multi-lead signal automatic switching device can automatically switch to other normal leads when an abnormality occurs in the current lead (current analysis signal) to obtain a correct vital sign signal, thereby avoiding a false alarm due to a single lead abnormality.

The present application will be further described in detail below with reference to the accompanying drawings.

Embodiment 1

Referring to FIG. 1, the embodiment provides a method for automatically switching a multi-lead signal, including:

Step 101: Collect vital signs signals detected by multiple leads separately.

Preferably, the embodiment further includes step 102: adaptively filtering the vital sign signals output by the respective leads, specifically: acquiring the frequency of the vital signs and the interference signals in real time, according to the frequency characteristics of the vital signs and the interference signals, And adaptively adjust the average number of filtered points by detecting the change of the frequency of the interference signal in real time, and adaptively filtering the vital sign signal by adjusting the average number of filtered points. Specifically, an adaptive smoothing filter may be used in step 101 to implement adaptive filtering.

The adaptive (smoothing) filter is designed according to the frequency characteristics between the required vital sign signal and the interference signal to be filtered. In this embodiment, the filter average point number N=f _s /f _{0 is set} , and the spectral characteristics are set. : The signal with frequency f ₀ passes through the filter and the output amplitude is zero. Where f _s is the signal sampling frequency (set according to the frequency range of the desired acquisition signal), and f ₀ is the frequency of the interference signal.

The following describes the adaptive filtering in step 102 by taking the impedance respiration signal as the vital sign signal and the cardiac signal as the interference signal as an example. In other embodiments, the vital sign signal may be other signals (eg, PACE signals), and correspondingly, the parameters of the vital sign signal select parameters that best reflect the characteristics of the vital sign signal (eg, PACE signal selection amplitude or slope, for life) When the sign signal is a digital signal, the parameter can select the signal to noise ratio).

The impedance waveform of the clinically acquired impedance is often mixed with the heartbeat waveform (the heartbeat will cause changes in respiratory impedance). The presence of the dynamic wave in the respiratory waveform not only affects the aesthetics of the respiratory waveform, but also seriously affects the accuracy of the calculation of the respiratory rate. When the human body is breathing normally, if the amplitude of the cardiac wave is too large, it will cause the heartbeat waveform to be falsely detected as a respiratory waveform, so that the calculated respiratory rate is too large. When the detected respiratory rate is close to the heart rate, it will trigger the breathing (cardiac interference). ) Alarm; if the human body breathes into suffocation, if the amplitude of the heartbeat waveform is slightly larger, it is easy to cause a true suffocation alarm to be reported. In the case of filtering using conventional filtering methods (for example, using FIR filters and IIR filters), in order to meet the requirements of real-time adjustment and variation, users need to design multiple filters with different frequencies, and the filtering method is computationally intensive. . Since the frequency components of the heartbeat waveform in the respiratory waveform are not the same, it is necessary to design a wide notch bandwidth. If the bandwidth is too large, the waveform overshoot will be severe. If the bandwidth is too small, the notch effect will be poor, and there is also a large amount of computation. The problem. Therefore, the use of a conventional fixed filter point average filter will make the filtering effect at different heart rates poor.

The adaptive filtering method provided in this embodiment is based on the fact that the actual human respiratory frequency is mostly lower than half of the heart rate, and the heart rate of the human body changes in real time, and the average number of filtered points is adaptively adjusted to ensure the comparison at different heart rates. Good filtering effect. In this embodiment, the adaptive filtering average point number N=f _s /f ₀ = f _s *60/HR, where HR is the heart rate detected in real time. Specifically, the initial value of HR can be set to 390 bpm. The spectral characteristics of the adaptive filter are: the point where the signal frequency f=f ₀ =HR/60=f _s /N, and the output signal amplitude is 0. This frequency is the frequency of the cardiac interference signal and will be completely filtered out. For a signal with a frequency of f/2, the output signal amplitude is 63% of the original signal. Since the heartbeat waveform frequency is often twice the frequency of the respiratory waveform, this filtering method has no effect or minimal effect on the respiratory waveform.

The adaptive filtering method provided in this embodiment can be well adapted to the situation in which the interference signals of different frequency bands are mixed in the signal, improve the filtering effect, avoid false alarm caused by the interference signal or cover the real alarm.

Step 103: Select one of the vital sign signals outputted from the plurality of leads as the analysis signal, and analyze the signal as a signal for subsequent monitoring analysis and processing.

In this embodiment, after collecting the vital sign signals detected by the plurality of leads respectively, the vital signs of the best quality are selected as the analysis signals. Specifically, when judging the quality of the vital sign signal, the quality of the vital sign signal detected by the lead can be determined according to the parameters (amplitude, slope, signal to noise ratio, etc.) of the vital sign signal detected by each lead. For example, the vital sign signal of the lead output with the largest signal amplitude or the largest signal to noise ratio is selected as the current analysis signal. In other embodiments, the vital sign signal output according to the preset lead may also be used as the current analysis signal.

Step 104: Detect whether the current analysis signal is abnormal in real time, if yes, go to step 105, if otherwise, continue to use the vital sign signal output by the current lead as the analysis signal.

In this embodiment, detecting whether the current analysis signal is abnormal in real time includes: obtaining a parameter of the vital sign signal according to the current analysis signal, and comparing the parameter with the parameter threshold to determine whether the parameter satisfies the threshold condition, and if satisfied, determining the current guide Normally, if it is not satisfied, it is judged as the current lead abnormality; the parameters of the vital sign signal include the amplitude, slope or signal to noise ratio of the vital sign signal.

It should be noted that the parameter threshold matches the parameter of the vital sign signal. If the parameter of the vital sign signal adopts the amplitude, the parameter threshold is also the amplitude. Similarly, taking the respiratory waveform as an example, the parameter of the respiratory waveform can be an amplitude. When determining whether the amplitude of the respiratory waveform satisfies the threshold condition, compare it with the parameter threshold. If the amplitude is greater than the parameter threshold, the signal quality is better, that is, the current The lead (current analysis signal) is normal. If the amplitude is less than the parameter threshold, the signal quality is poor, and the current lead (current analysis signal) may be in an abnormal state.

In a specific embodiment, the threshold condition may be that the parameter of the vital sign signal is greater than the parameter threshold, or the parameter of the vital sign signal is less than the parameter threshold, and the selection of the threshold condition is determined according to the meaning of the parameter of the selected vital sign signal.

Step 105: When it is detected that the current lead (current analysis signal) is abnormal in step 104, the current analysis lead is switched, and the vital sign signal outputted by the other one lead is selected as the analysis signal.

In step 105 of this embodiment, after determining that the current analysis signal is abnormal, the best quality of the vital sign signals output by the other leads is selected as the analysis signal. The method for judging the quality of the vital sign signal is the same as that in step 103. In other embodiments, the leads may be sequentially switched according to a preset order when switching the leads.

Preferably, the embodiment further includes step 106: adaptively adjusting the parameter threshold in step 103 according to the attenuation characteristic of the adaptive filtering in step 102 and/or the feature of the detected object. It should be noted that the characteristics of the object to be detected include the age, sex, physical condition, and the like of the object to be detected.

Step 106 will be described below by taking an impedance breathing waveform and a cardiac waveform as an example.

The amplitude of the impedance respiration waveform is not fixed in clinical practice. The respiratory amplitudes of different ages, genders, heart rate, and physical conditions are also different. It is difficult to monitor with a constant parameter threshold or uniform standard. In step 106 of the embodiment, a plurality of factors are fitted according to a large amount of clinical data, and a plurality of factors such as the physiological characteristics of the adult and the newborn and the filtering of the respiratory waveform of the different heart rate segments are comprehensively analyzed to adaptively adjust the parameter threshold. The parameter threshold will be compensated or adjusted in real time according to different types of detected objects (adult or newborn) and the range of real-time heart rate. The following is a specific implementation: assuming the initial parameter threshold is TH ₀ , the real-time adaptive adjustment The parameter threshold TH=TH ₀ *(ab*HR/minHR), where a and b are fitting coefficients, which can be set in advance according to clinical data, and minHR is a minimum heart rate value set according to the characteristics of the object to be detected. The above-mentioned parameter threshold adaptive adjustment method is real-time compensation and adjustment according to the range in which the real-time heart rate is located.

In step 106, the parameter threshold may be adaptively adjusted according to the attenuation characteristic of the adaptive filtering in step 102. For example, in step 102, the amplitude of the vital sign signal is attenuated to 63% of the original signal in the adaptive filtering, and correspondingly, in step 106. The parameter threshold of the middle is also attenuated to 63%.

It should be understood that different parameter threshold adaptive adjustment methods can be designed for different vital sign signals.

In the following, the multi-lead signal automatic switching method provided by the embodiment is used to illustrate the alarm mechanism by taking the respiratory waveform as an example.

Taking the two leads (I lead and II lead) as an example, the initial lead configuration is the one with the best signal quality in the I and II leads, assuming I lead (current lead).

(1) When the amplitude of the I-guide signal is judged to be higher than the parameter threshold, it indicates that the vital sign signal of the I-guide output is better, and the I-guide is normal, the lead does not need to be switched.

(2) When the amplitude of the I-guide signal is judged to be lower than the parameter threshold (including no signal output), and lasts for T/2 (T is the signal suffocation alarm delay time), indicating that the vital sign signal of the I-guide output is poor, and the I-conduction is abnormal. .

At this point, there are two ways to switch to select the next lead: 1. First, determine whether the amplitude of the vital sign signal output by other leads outside the I lead (here only the II lead) is greater than the parameter threshold, if the amplitude is greater than The lead of the parameter threshold is selected as the lead with the largest amplitude of the vital sign signal output as the next lead to be switched to. If there is no lead whose amplitude is greater than the parameter threshold, the patient may have suffocation. A suffocation alarm is issued. 2. According to the preset switching sequence, directly switch the I guide to the II guide. At this time, if the magnitude of the vital sign signal output by the II guide is greater than the parameter threshold, it indicates that the I guide may be abnormal due to shedding or other reasons, and does not need to be performed. Alarm, if the amplitude of the vital sign signal output by the II lead is also less than the parameter threshold or no signal, it indicates that the patient may have suffocation, and a suffocation alarm may be issued at this time.

In the multi-lead signal automatic switching method provided by this embodiment, the adaptive filtering step can effectively filter out the interference signal, and compare the parameter of the vital sign signal with the parameter threshold to determine whether the current lead is abnormal, and if abnormal, Automatically switch to other normal leads, and the parameter threshold can also be adaptively adjusted to obtain real vital sign signals, ensuring the accuracy of the lead abnormality judgment, so it can effectively avoid the occurrence of a single lead abnormality. The phenomenon of false alarms.

Embodiment 2

Referring to FIG. 2, corresponding to the first embodiment, the embodiment provides a multi-lead signal automatic switching device, which includes a signal acquiring unit 201, a signal selecting unit 203, and a determining unit 204.

The signal acquisition unit 201 is configured to separately collect a plurality of lead-detected vital sign signals. The signal selection unit 203 is connected to the signal acquisition unit 201 for selecting one of the vital sign signals outputted from the plurality of leads as an analysis signal, and the analysis signal is a signal for subsequent monitoring analysis and processing. The judging unit 204 is connected to the signal selecting unit 203 for detecting whether the current analysis signal is abnormal in real time, and if so, the control signal selecting unit 203 selects the vital sign signal outputted by the other one lead as the analysis signal.

In this embodiment, when the signal selection unit 203 selects one of the vital sign signals outputted from the plurality of leads as the analysis signal, the vital sign signal of the best quality is selected from the vital sign signals outputted from the plurality of leads as an analysis. signal.

The determining unit 204 determines that the current analysis signal is abnormal, and the signal selecting unit 203 selects the vital sign signal outputted by the other one lead as the analysis signal: the signal selecting unit 203 selects the best quality of the vital sign signal outputted by the other lead as the path Analyze the signal.

The determining unit 204 determines whether the current analysis signal is abnormal: the determining unit 204 obtains the parameter of the vital sign signal according to the current analysis signal, and compares the parameter with the parameter threshold to determine whether the parameter satisfies the threshold condition, and if yes, determines that the current condition The lead is normal, and if it is not satisfied, it is judged to be the current lead abnormality; the parameters of the vital sign signal include the amplitude, slope or signal to noise ratio of the vital sign signal.

Preferably, the apparatus provided in this embodiment further includes an adaptive filtering unit 202 disposed between the signal acquiring unit 201 and the signal selecting unit 203. The adaptive filtering unit 202 is configured to acquire the frequency of the vital sign signal and the interference signal in real time, and adaptively adjust the average number of filtered points according to the frequency characteristics of the vital sign signal and the interference signal, and detect the frequency of the interference signal in real time, and the average number of filtered points Adaptive filtering of vital sign signals.

The apparatus provided in this embodiment further includes a parameter threshold adjusting unit connected between the adaptive filtering unit 202 and the determining unit 204. The parameter threshold adjustment unit 205 is configured to adaptively adjust the parameter threshold according to the attenuation characteristic of the adaptive filtering unit 202 and/or the characteristic of the detected object.

The monitor and the multi-lead signal automatic switching method and apparatus provided by the embodiments of the present application have the following advantages:

1. When there is an abnormality in the current lead, it can automatically switch to other normal leads to ensure that accurate vital signs are obtained, and at the same time, false alarms due to single lead abnormalities can be avoided.

2. Perform adaptive filtering on the vital sign signals output by the current lead, which can effectively filter out interference signals of different frequency bands mixed in the signal.

3. The parameter threshold is adaptively adjusted according to the attenuation characteristics of the adaptive filtering and/or the characteristics of the detected object, thereby obtaining a real vital sign signal and ensuring the accuracy of the lead abnormality judgment.

A person skilled in the art may understand that all or part of the steps of the various methods in the above embodiments may be completed by a program to instruct related hardware, and the program may be stored in a computer readable storage medium, and the storage medium may include: a read only memory, Random access memory, disk or optical disk, etc.

The above content is a further detailed description of the present application in conjunction with the specific embodiments, and the specific implementation of the present application is not limited to the description. For those skilled in the art to which the present invention pertains, several simple deductions or substitutions can be made without departing from the inventive concept.

Claims

A method for automatically switching a multi-lead signal, comprising:

Collecting vital signs signals detected by multiple leads separately;

Selecting one of the vital sign signals obtained from the plurality of leads as an analysis signal, wherein the analysis signal is a signal for subsequent monitoring analysis and processing;

Real-time detection of whether the current analysis signal is abnormal, and if so, selecting the vital sign signal obtained by the other lead as the analysis signal.
The method according to claim 1, wherein after collecting the vital sign signals detected by the plurality of leads respectively, selecting the vital sign signal of the best quality as the analysis signal;

After detecting the abnormality of the current analysis signal in real time, the best quality one of the vital sign signals output by the other leads is selected as the analysis signal.
The method according to claim 1 or 2, wherein detecting whether the current analysis signal is abnormal in real time comprises:

Obtaining a parameter of the vital sign signal according to the current analysis signal, and comparing the parameter with the parameter threshold, determining whether the parameter satisfies a threshold condition, and if yes, determining that the current lead is normal, and if not, determining that the current lead is current. Abnormal; the parameters include the amplitude, slope, or signal to noise ratio of the vital sign signal.
The method of claim 1, wherein after the step of separately acquiring a plurality of lead-detected vital sign signals, the method further comprises:

Adaptive filtering of the collected vital sign signals.
The method according to claim 4, wherein the step of adaptively filtering the collected vital sign signals comprises: acquiring real-time vital sign signals and interference signal frequencies in real time, according to vital signs signals and interference signals Frequency characteristics, and adaptively adjusting the filtered average points by detecting the change of the interference signal frequency in real time, and adaptively filtering the vital sign signals by the filtered average points.
The method of claim 5, further comprising adaptively adjusting the parameter threshold based on an attenuation characteristic of the adaptive filtering and/or a characteristic of the detected object.
The method according to claim 6, wherein the vital sign signal is an impedance respiration signal, and the interference signal is a cardiac signal; the filtered average point is a ratio of an impedance respiration signal frequency to a real-time detected cardiac signal frequency. .
The method according to claim 7, wherein the parameter threshold is adaptively adjusted according to the attenuation characteristic of the adaptive filtering and/or the characteristic of the detected object, specifically: the parameter threshold is according to the formula TH. =TH 0 *(ab*HR/minHR) performs adaptive adjustment, where TH is the adaptively adjusted parameter threshold, TH 0 is the initial parameter threshold, a and b are preset fitting systems, and HR is real-time detection. The heart rate value, minHR is a minimum heart rate value set in advance according to the characteristics of the object to be detected.
A multi-lead signal automatic switching device, comprising:

a signal acquisition unit, configured to separately collect vital sign signals detected by the plurality of leads;

a signal selection unit, the signal selection unit is connected to the signal acquisition unit, and is configured to select one path from the vital sign signals outputted by the plurality of leads as an analysis signal, where the analysis signal is a signal for subsequent monitoring analysis and processing;

The judging unit is connected to the signal selecting unit for detecting whether the current analysis signal is abnormal in real time, and if so, controlling the signal selecting unit to select another vital sign output vital sign signal as the analysis signal.
The apparatus according to claim 9, wherein said signal selecting unit selects one of the vital sign signals outputted from the plurality of leads as the analysis signal: selecting a quality from the vital sign signals outputted from the plurality of leads The best vital sign signal is used as the analysis signal;

The judging unit judges that the current analysis signal is abnormal, and the signal selection unit selects the vital sign signal outputted by the other one lead as the analysis signal: the signal selection unit selects the best quality one of the vital sign signals output by the other leads as the analysis signal.
The device according to claim 9 or 10, wherein the determining unit determines whether the current analysis signal is abnormal: the determining unit obtains a parameter of the vital sign signal according to the current analysis signal, and the parameter and the parameter The threshold is compared to determine whether the parameter satisfies the threshold condition. If it is satisfied, it is determined that the current lead is normal, and if not, it is determined to be the current lead abnormality; the parameter includes the amplitude, slope or signal to noise ratio of the vital sign signal.
The apparatus according to claim 10, further comprising an adaptive filtering unit disposed between the signal acquisition unit and the signal selection unit for adaptively filtering the collected vital sign signals.
The apparatus according to claim 12, wherein said adaptive filtering unit is configured to acquire the frequency of the vital sign signal and the interference signal in real time, according to the frequency characteristics of the vital sign signal and the interference signal, and detect the frequency of the interference signal in real time. The change adaptively adjusts the filtered average points, and adaptively filters the vital sign signals by the filtered average points.
The apparatus according to claim 12, further comprising a parameter threshold adjusting unit connected between the adaptive filtering unit and the determining unit, wherein the parameter threshold adjusting unit is configured to perform attenuation characteristic according to the adaptive filtering unit And/or the characteristics of the detected object adaptively adjust the parameter threshold.
The device according to claim 14, wherein the vital sign signal is an impedance respiration signal, and the interference signal is a cardiac signal; the filtered average point is a ratio of an impedance respiration signal frequency to a real-time detected cardiac signal frequency. .
The device according to claim 15, wherein the parameter threshold adjusting unit is configured to adaptively adjust the parameter threshold according to an attenuation characteristic of the adaptive filtering unit and/or a feature of the detected object. : the parameter threshold adjustment unit according to the formula

TH=TH 0 *(ab*HR/minHR)

The parameter threshold is adaptively adjusted, wherein TH is an adaptively adjusted parameter threshold, TH 0 is an initial parameter threshold, a and b are preset fitting systems, HR is a real-time detected heart rate value, and minHR is based on The minimum heart rate value set in advance by the feature of the detected object.
A monitor characterized by comprising:

a plurality of leads for detecting and outputting vital sign signals;

a host coupled to an output of the lead, the host including a processor for monitoring analysis and processing of the vital sign signal and information for monitoring analysis and processing of the vital sign signal by the display processor Display

The processor includes the multi-lead signal automatic switching device of any one of claims 9-16.