WO2015003509A1

WO2015003509A1 - Method and system for monitoring depth of external chest compression and defibrillator

Info

Publication number: WO2015003509A1
Application number: PCT/CN2014/074069
Authority: WO
Inventors: 李传林; 王启; 李利亚; 左鹏飞; 岑建
Original assignee: 深圳迈瑞生物医疗电子股份有限公司
Priority date: 2013-07-07
Filing date: 2014-03-26
Publication date: 2015-01-15
Also published as: CN104274172A; CN104274172B

Abstract

Disclosed are a method and a system for monitoring the depth of external chest compression. The monitoring system comprises: a signal acquisition unit (11) for acquiring a reference acceleration signal and a reference thoracic cavity impedance signal when calibrating the external chest compression and for acquiring a real-time thoracic cavity impedance signal when measuring the external chest compression; a correlation determination unit (12) for calculating a reference compression depth using the reference acceleration signal and determining the correlation between the reference thoracic cavity impedance signal and the reference compression depth; and a compression depth calculation unit (13) for calculating a compression depth during measuring external chest compression using the real-time thoracic cavity impedance signal and the determined correlation. Since a thoracic cavity impedance signal can not easily be interfered with by an outside movement, monitoring a compression depth by using the thoracic cavity impedance and the correlation thereof with a compression depth can effectively prevent the interference of external acceleration and help to obtain a more accurate monitoring result. When measuring a thoracic cavity impedance signal, there is no need to excessively adjust the hardware and software of the monitoring system, thus reducing the system complexity.

Description

Monitoring method for chest compression depth, monitoring system and defibrillator

[Technical Field]

The invention belongs to the field of medical devices and relates to cardiopulmonary resuscitation (Cariopulmonary Resuscitation, CPR) A method of monitoring the depth of chest compressions, a monitoring system, and a defibrillator including the monitoring system.

【Background technique】

Cardiopulmonary resuscitation (CPR) is a key rescue measure for emergency patients with cardiac arrest. The basic life support procedures for adults, children, and babies recommended in the 2010 American Heart Association Cardiopulmonary Resuscitation and Cardiovascular First Aid Guide are CAB (chest). External compression - open airway - artificial respiration), which emphasizes the important role of chest compressions in improving patient survival.

The CPR pressing parameters mainly include the magnitude of the pressing, the frequency, and the interval between pressing and the like. Obtaining these parameters and monitoring them in real time to the rescuer can guide the rescuer to complete the CPR operation correctly and with high quality. The existing CPR parameter monitoring techniques and their disadvantages are as follows:

An acceleration sensor is used to measure the compression depth. In the case of external acceleration interference, such as CPR during patient transfer, the road surface undulation will superimpose other motion acceleration disturbances. At this time, the measured value of the acceleration sensor cannot reflect the actual compression acceleration, so the compression depth cannot be accurately measured.

An acceleration sensor is used to measure the depth of the press, and a force sensor is used to measure the magnitude of the pressing pressure. When the patient is in a static state, the acceleration sensor signal is used to calculate the compression depth, and the correlation between the pressure magnitude and the compression depth is established. The actual compression depth is calculated using the magnitude of the pressure and its dependence on the depth of compression while the patient is in motion. This method adds a set of force sensors and their detection circuits, which increases the system complexity.

[Summary of the Invention]

Based on this, it is necessary to provide a monitoring method, a monitoring system, and a defibrillator including the monitoring system, which have low system complexity and can accurately measure the depth of compression.

A method for monitoring the depth of chest compression, comprising:

Obtaining a reference acceleration signal and a reference chest impedance signal of the chest compression calibration process;

Calculating a reference compression depth using the reference acceleration signal, and determining a correlation of the reference chest impedance signal with the reference compression depth;

Obtaining a real-time chest impedance signal from the chest compression measurement process;

The compression depth of the chest compression measurement process is calculated using the real-time chest impedance signal and the determined correlation.

A monitoring system for chest compression depth, comprising:

a signal acquisition unit, configured to obtain a reference acceleration signal and a reference chest impedance signal of the chest compression calibration process, and a real-time chest impedance signal for acquiring the chest compression measurement process;

a correlation determining unit, configured to calculate a reference pressing depth using the reference acceleration signal, and determine a correlation between the reference chest impedance signal and the reference pressing depth;

Pressing a depth calculation unit for calculating a compression depth of the chest compression measurement process using the real-time chest impedance signal and the determined correlation.

A defibrillator comprising a defibrillator body, and an acceleration sensor electrically coupled to the defibrillator body and at least two electrode sheets. The acceleration sensor is configured to collect a reference acceleration signal of a chest compression calibration process, and the electrode piece is used to collect a reference chest impedance signal of the chest compression calibration process and a real-time chest impedance signal of the chest compression measurement process. The defibrillator body also includes the above-described monitoring system for chest compression depth.

In the above monitoring method of the chest compression depth, the monitoring system and the defibrillator including the monitoring system, since the signal acquisition process can be completed by the acceleration sensor and the electrode piece provided by the defibrillator, no additional hardware configuration or modification is required. System complexity is significantly reduced. Further, since the thoracic impedance signal is not easily affected by external motion interference, after the chest compression calibration process determines the correlation between the thoracic impedance and the compression depth, the thoracic impedance signal is used in the measurement of the chest compression and its correlation with the compression depth. The monitoring of the depth of compression can basically avoid the interference of external motion, and can more accurately monitor the effect of CPR implementation, thereby more effectively controlling the defibrillation intensity, thereby obtaining more accurate monitoring results and providing better guidance effects.

[Description of the Drawings]

In order to more clearly illustrate the embodiments of the present invention, the drawings, which are used in the embodiments, will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention. For the personnel, other drawings can be obtained based on these drawings without paying creative labor.

1 is a flow chart of a method for monitoring chest compression depth according to an embodiment;

2 is a flow chart of a method for monitoring a chest-external compression depth according to another embodiment;

3 is a flow chart of a method for monitoring a chest-external compression depth according to an embodiment;

4 is a schematic view of a monitoring system for chest compression depth according to an embodiment;

FIG. 5 is a schematic diagram of a monitoring system for a chest-external compression depth according to another embodiment; FIG.

6 is an exemplary block diagram of a defibrillator of an embodiment;

Fig. 7 is a schematic diagram showing an acceleration sensor and an electrode sheet of a defibrillator applied to an object to be monitored according to an embodiment.

【detailed description】

The following description provides specific details for the complete understanding of the various embodiments and the embodiments of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without such detail. In some instances, well known structures and functions are not shown or described in detail in order to avoid obscuring the description of the embodiments. Unless the context clearly requires, the terms throughout the specification and claims ' Include ' , ' include ' etc . shall be interpreted in an inclusive sense rather than an exclusive or exhaustive meaning, ie, meaning 'including, but not limited to' . In the detailed description, the terms singular or plural refer to the plural or singular.

The present invention provides a correlation based on chest impedance and compression depth to monitor CPR compression parameters The system and method (hereinafter referred to as monitoring system and monitoring method), and provides a defibrillator with the above monitoring performance. As used herein, 'correlation' refers to the correlation (or proportional relationship) of both the chest impedance signal (the measured value or the change value) and the compression depth calculated by the acceleration. For convenience of description, the correlation established by the measured value of the thoracic impedance signal and the depth of compression is hereinafter referred to as direct correlation, and the correlation established by the change value of the thoracic impedance signal and the depth of compression is referred to as indirect correlation. The thoracic impedance signal is not easily interfered by external motion factors. Therefore, as long as the correlation between the compression depth and the chest impedance signal can be accurately determined, the measurement of the compression depth can be performed indirectly by measuring the chest impedance signal.

1 is a flow chart of a monitoring method of an embodiment. After performing chest compression on the monitored object, first in step S11 The reference chest impedance signal and the reference acceleration signal of the chest cavity being pressed during the calibration of the chest compression are obtained respectively. This signal acquisition process typically yields a curve that reflects the reference acceleration and reference chest impedance as a function of time.

Correlation analysis is performed on the change value of the reference thoracic impedance signal and the reference compression depth during the chest compression calibration process to determine the indirect correlation between the thoracic impedance and the compression depth (step S12):

(1) A double integral operation is performed on the reference acceleration signal obtained during the chest compression calibration process to obtain a reference compression depth. The compression depth calculated according to the acceleration signal can be implemented by a software algorithm, or can be implemented by a hardware circuit. (Reference) The integral calculation formula corresponding to the pressing speed v(t) and the (reference) pressing displacement S(t) is (a represents the value of the (reference) acceleration signal, v represents (reference) pressing speed, and S represents (reference) pressing Displacement):

v(t)=∫adt;

S(t)=∫v(t)dt.

(2) Calculate the change value of the reference thoracic impedance signal during the calibration of the chest compression. The change value referred to herein refers to the difference between the measured value of the reference thoracic impedance signal acquired during chest compression and the initial value of the reference thoracic impedance signal acquired before chest compression (ie, measured value - initial value). For a specific monitored subject, the initial value of the reference thoracic impedance signal before chest compression is a fixed value, and the measured value of the reference thoracic impedance signal during a single chest compression is a variable that can be represented by a curve, so With the progress of chest compression, the change value of the reference chest impedance signal obtained based on the above calculation method is also a variable in a single compression process.

(3) Determine the indirect correlation between the change value of the reference thoracic impedance signal and the reference compression depth. In a specific example, this indirect correlation can be approximated as a proportional relationship or a linear relationship, ie, S = K2 × Δ Z, where S Indicates the compression depth, Δ Z represents the change value of the thoracic impedance signal, and K2 represents the ratio of the compression depth to the change value of the thoracic impedance signal.

During the chest compression calibration process, according to the need of monitoring accuracy, the present invention can obtain the reference acceleration signal and the reference chest impedance signal of the chest compression calibration process according to a specific frequency. For example, the reference chest impedance signal (Z _T1 ) at time _{T1 is obtained} , and the change value Δ Z1 (Z _T1 -Z _initial ) of the reference chest impedance signal at the time point is calculated, and the reference compression depth S1 corresponding to the time point T1 is calculated; The ratio of the reference compression depth to the change value of the reference chest impedance signal (S1/ΔZ1) is the K2 value corresponding to the change value of the reference chest impedance signal. Through the above calculation process, N corresponding K2 values can be obtained by taking N values.

The real-time chest impedance signal of the monitored subject during the chest compression measurement process is acquired in the next step S13.

In step S14, the real-time chest impedance signal obtained by the chest compression measurement process is used to calculate the change value of the real-time chest impedance signal, and the corresponding K2 value is found according to the change value, and then based on the correlation with the compression depth (S=K2). ×△ Z) Calculate the compression depth of the chest compression measurement process.

The calculation of the change value of the real-time thoracic impedance signal is the same as the calculation of the change value of the reference thoracic impedance signal in step S12, and thus the compression depth calculated based on the determined correlation is also a variable. In the specific implementation process, the curve of the compression depth can be obtained, which plays a role of real-time monitoring. The pressing frequency and the pressing time interval are further calculated by pressing the peak time of the depth curve.

2 is a flow chart of a monitoring method in another embodiment of the present invention. Different from the above embodiment, in this embodiment, the correlation value of the reference chest impedance signal and the reference compression depth are directly analyzed during the chest compression calibration process (step S22), so when monitoring the compression depth The measurement of the real-time chest impedance signal is used directly for calculation. Similarly, this direct correlation can be approximated as a proportional or linear relationship, ie S = K1 × Z , where S is the compression depth, Z is the measured value of the chest impedance signal, and K1 is the ratio of the compression depth to the measured value of the chest impedance signal.

During the chest compression calibration process, the reference acceleration signal and the reference thoracic impedance signal of the chest compression calibration process can be obtained according to the specific frequency according to the monitoring accuracy. For example, the measured value of the reference chest impedance signal at the time point T1 is obtained, and the reference pressing depth S1 corresponding to the time point T1 is calculated; the ratio (S1/Z1) of the reference pressing depth to the measured value of the reference chest impedance signal is the reference chest cavity. The K1 value corresponding to the measured value of the impedance signal. Through the above calculation process, N corresponding K1 values can be obtained by taking N values.

In the process of confirming the K1/K2 value, whether the measured value of the reference thoracic impedance signal or the change value is used, the determined correlation can be obtained in the following ways: 1. The K1/K2 value is correlated with the thoracic impedance signal (measurement) a smooth curve of change in value or change value; 2. a line of K1/K2 value that varies with the chest impedance signal (measured value or change value); 3. a correspondence between the K1/K2 value and the chest impedance signal (measured value or change value) table.

Manner 1: The value of N times is used to obtain N corresponding K1/K2 values. The measured value or change value of the thoracic impedance signal is the abscissa, and the corresponding N points are obtained on the x-y coordinate system corresponding to the K1 value or the K2 value as the ordinate. A smooth curve is used to connect the above N points, that is, a smooth curve reflecting the change of the K1 value or the K2 value corresponding to the measured value or the change value of the chest impedance signal.

Manner 2: Take N values for N corresponding K1/K2 values. Taking the measured value or change value of the thoracic impedance signal as the abscissa, corresponding to the K1 value or the K2 value as the ordinate, obtaining the corresponding N points on the xy coordinate system, and establishing the fitting curve of the above N points; fitting The curve is also a smooth curve reflecting the change in the K1 value or the K2 value corresponding to the measured or changed value of the chest impedance signal.

Manner 3: Take N values for N corresponding K1/K2 values. The measured value or change value of the thoracic impedance signal is the abscissa, and the corresponding N points are obtained on the x-y coordinate system corresponding to the K1 value or the K2 value as the ordinate. The two adjacent points are connected, that is, a line indicating that the K1 value or the K2 value corresponds to the measured value or the change value of the chest impedance signal.

Method 4: Establish a correspondence table between the measured value/variation value of the thoracic impedance signal and the K1 value/K2 value. For a specific example, see the following table:

Measurement/change value of thoracic impedance signal	K1 value / K2 value
[Z ₁ , Z ₂ ) / [ △ Z ₁ , △ Z ₂ )	K1 ₁ /K2 ₁
[Z ₂ , Z ₃ ) / [ △ Z ₂ , △ Z ₃ )	K1 ₂ /K2 ₂
......	......
[Z _N-1 , ZN) / [ △ Z _N-1 , △ ZN)	K1 _N-1 /K2 _N-1

The above four K1/K2 values are determined only to clarify the technical solution of the present invention, and do not constitute any limitation to the present invention. Preferably, in the above second manner, the curve obtained by the method can better reflect the variation of the K1/K2 value on the one hand, and avoid the thoracic impedance signal (or its variation value) during the calibration of the chest compression on the other hand. The maximum value is smaller than the actual measured value.

Although the proportional relationship of the K1/K2 value is used to express the correlation between the chest impedance signal (measured value or change value) and the compression depth, those skilled in the art can also understand that other models can be used to characterize the chest impedance signal (or The relationship between the change value and the depth of compression. The monitoring method proposed by the present invention focuses on the one-to-one correspondence between the chest impedance signal and the compression depth which is not affected by the external environment, and further determines the compression depth by acquiring the thoracic impedance signal. Therefore, regardless of the operational transformation of the thoracic impedance signal, such as square, integral, etc., as long as the correlation (or the corresponding relationship) of the two can be established, the accurate monitoring desired by the present invention can be achieved.

The "chest external compression calibration process" involved in the above monitoring method may be a process in which the rescuer performs the first complete CPR chest compression operation on the monitored object, and may be preset, and the rescuer implements the monitored object. The Nth CPR chest compression operation may be a preset N-th CPR chest compression operation performed by the rescuer on the subject to be monitored. The present invention preferably uses the first chest compression operation as its calibration process. The "thoracic compression measurement process" involved in the above monitoring method may be a chest compression operation performed after or at the same time determining the correlation between the chest impedance change and the compression depth, that is, may be a subsequent operation or a parallel operation. For example, when the first chest compression is used as the calibration process, if the measurement process is a subsequent operation, the output monitoring value discards the compression depth generated by the first chest compression; if the measurement process is set to parallel operation, the compression obtained by the calibration process is obtained. Depth is taken as the first measurement. It should be noted that when the K1/K2 value is obtained by the second method described above, if the measurement process is set to operate in parallel, it is necessary to further recalculate the compression depth of the calibration process using the established correlation.

The monitoring method of the above embodiment uses the thoracic impedance signal to complete the monitoring after determining the correlation between the thoracic impedance and the compression depth. Since the thoracic impedance signal is not interfered by external motion, the above monitoring method can well solve the prior art acceleration sensor. Defects in the depth of compression cannot be accurately measured in a moving environment.

3 is a flow chart of a monitoring method of another embodiment. Different from the above embodiment, before the calculation of the compression depth of the chest compression measurement process, the monitoring method of the present embodiment further includes acquiring a real-time acceleration signal of the chest compression measurement process (step S34) and determining the chest compression measurement process. The external environment (step S35). The real-time acceleration signal acquired during the chest compression measurement process is also the change associated with the chest impedance signal.

Specifically, determining an external environment of the chest compression measurement process includes determining whether the external environment of the process is a motion environment, that is, whether there is interference of external motion acceleration. If the obtained real-time acceleration signal is non-zero and the real-time chest impedance signal changes at the same time, it is judged that the external environment at this time is a static environment; if the acquired real-time acceleration signal is non-zero, and the real-time chest impedance signal is simultaneously If it remains unchanged, it is judged that the external environment at this time is a sports environment. This is because the external motion acceleration can only affect the measured value of the real-time acceleration signal without causing a change in the real-time chest impedance. This step does not involve new sensor components, which is advantageous for cost control of the monitoring process of the present invention.

Through this step, the signal basis for the subsequent calculation of the depth of compression during the measurement of the chest compression is determined. When the monitored object is in a static environment, the acquired real-time acceleration signal has low noise, which can reflect the acceleration information actually implemented on the monitored object, and can also determine the compression depth through the real-time acceleration signal. When the object to be monitored is in a sports environment, such as an ambulance transport and other pre-hospital emergency situations, the motion acceleration caused by the motion of the road surface is disturbed by the actual acceleration signal, so that the real-time acceleration signal is noisy and cannot be directly applied to the compression depth. Accurate monitoring.

If the external environment of the chest compression measurement process is a static environment, the chest compression depth is directly calculated using the acquired real-time acceleration signal (S36a). As described above, the real-time acceleration signal is double-integrated to obtain the compression depth, and the pressing frequency and the pressing time interval are further calculated by pressing the peak time of the depth curve. If the external environment of the chest compression measurement process is a motion environment, the compression depth and other compression parameters are calculated using the real-time chest impedance signal and the correlation determined in step S32. Since the correlation between the measured value or the change value of the thoracic impedance signal and the compression depth has been established, when the real-time thoracic impedance signal is acquired, the real-time compression depth of the chest compression measurement process can be calculated by the correlation determined above. Then, other parameter values such as the pressing frequency are also calculated by pressing the peak time of the depth curve.

In another embodiment, the monitoring method described above may further include a monitored object determining step. It should be understood by those skilled in the art that the thoracic impedance reflects the physiological parameter values of a particular monitored object, and must have individual differences, and thus have different correlations with respect to the same acceleration signal. After calculating the compression depth of the measurement process, the monitoring method further determines whether the monitored object has changed. If a change occurs, the correlation between chest impedance and compression depth needs to be redefined. Preferably, the subject being monitored is judged once a single chest compression is completed.

The present invention does not impose any restrictions on how to determine whether a monitored object has changed. The present invention can compare the chest impedance signal at the beginning of each chest compression without adding any sensors or signal acquisition units. The thoracic impedance signal of the same monitored subject at the beginning of chest compression should remain unchanged; if the change exceeds a certain range (for example, 5%), the thoracic impedance signals of different monitored subjects are considered to be acquired. In other embodiments, the present invention may require input of the monitored object ID, acquisition of fingerprint information of a specific monitored object, time at which a measurement signal can be detected or acquired, and the like before the first chest compression is performed. As long as the present invention is capable of acquiring parameter values reflecting the unique attributes of the monitored object, it is possible to determine whether the monitored object changes based on a simple comparison of the parameter values.

In another embodiment, the above monitoring method further considers the external environment of the chest compression calibration process. Before establishing the correlation between chest impedance and compression depth, the initial environmental environment type of the chest compression calibration process is first determined. The role of determining the starting external environment is to perform a correlation analysis (ie, re-determine the K1/K2 of the chest compression calibration process) if the external environment of the subsequent measurement process changes from the initial motion environment to the stationary environment. Value) and update the results of the correlation analysis. The correlation obtained in the static environment can more accurately reflect the relationship between the two variables of the chest impedance and the compression depth because there is no external disturbance. Therefore, the present invention preferably uses the correlation analysis result obtained in a static environment.

As shown in FIG. 4, the monitoring system includes a signal acquisition unit 11, a correlation determination unit 12, and a compression depth calculation unit 13. The signal acquisition unit 11 is configured to acquire a reference acceleration signal and a reference chest impedance signal of the chest compression calibration process, and a real-time chest impedance signal for acquiring the chest compression measurement process. The above signals acquired by the signal acquisition unit 11 are all variables that vary with time. Among them, the reference acceleration signal and the reference thoracic impedance signal are used for correlation analysis of chest impedance and compression depth, and the real-time chest impedance signal is the signal basis for calculating the compression depth. The correlation determination unit 12 is for determining the correlation between the chest impedance and the compression depth. The determining operation includes calculating a change value of the reference chest impedance signal, calculating a reference compression depth using the reference acceleration signal, and determining a proportional relationship (ie, a K2 value) of the reference compression depth to a change value of the reference chest impedance signal. As mentioned above, the K2 value obtained by the monitoring system changes with the chest impedance. The pressing depth calculation unit 13 is for pressing the calculation operation of the depth. After determining the K2 value, the calculation unit can determine the compression depth by calculating the change value of the real-time chest impedance signal.

Although in the monitoring system of FIG. 4, the correlation determining unit itself can complete the calculation of the change value of the reference chest impedance signal and the reference pressing depth, the change value of the chest impedance signal can also be performed only by the pressing depth calculating unit in the monitoring system. The calculation operation of the compression depth (including the calibration process and the correlation calculation of the measurement process), the correlation determination unit acquires the required calculation result by interaction with the compression depth calculation unit.

Of course, the correlation determining unit can also directly establish the correlation between the reference chest impedance signal and the reference pressing depth; the pressing depth calculating unit thus directly calculates the pressing depth using the obtained real-time chest impedance signal (as in the second embodiment).

In another embodiment, the correlation determining unit may have the operability to determine the above direct correlation or indirect correlation. The monitoring system at this time may further include a correlation mode selection unit for selecting whether to use the chest impedance signal or the change value as a signal basis in the correlation determination process, and thus the calculation operation of the compression depth calculation unit.

As shown in FIG. 5, the monitoring system of another embodiment includes a signal acquisition unit 11, an external environment determination unit 14, a correlation determination unit 12, and a compression depth calculation unit 13. The example lower signal acquisition unit 11 is further configured to acquire a real-time acceleration signal of the chest compression measurement process, and the external environment determination unit 14 determines the external environment of the chest compression measurement process according to the acquired real-time acceleration signal and the real-time chest impedance signal. Specifically, when the real-time acceleration signal is non-zero and the real-time chest impedance signal changes, it is determined that the external environment of the chest compression measurement process is a stationary environment. When the real-time acceleration signal is non-zero and the real-time chest impedance signal remains unchanged, the external environment of the chest compression measurement process is determined to be a sports environment; the real-time acceleration acquired at this time is not generated by chest compression.

In another embodiment, the monitoring system may further include a monitored object determining unit. The monitored object determining unit is configured to determine whether the monitored object has changed. For example, the monitored object determination unit may employ the above-described signal acquisition unit to determine whether the monitored object has changed by comparing the chest impedance signal before the start of the chest compression. The correlation determining unit is further configured to re-determine the correlation between the chest impedance and the compression depth when the monitored object changes.

Figure 6 further illustrates a defibrillator comprising an embodiment of the above described monitoring system. The defibrillator 10 includes a defibrillator body 101, and an acceleration sensor 102 and at least two electrode sheets 103, 104 electrically connected to the defibrillator body 101. In addition, the defibrillator body 101 further includes the above-described monitoring system for the chest compression depth. As described above, the monitoring system of the chest compression depth includes the signal acquisition unit 11, the correlation determination unit 12, and the compression depth calculation unit 13. The signal acquisition unit 11 of the chest compression depth monitoring system is connected to the acceleration sensor 102 and the electrode sheets 103, 104. In addition, the monitoring system may further include an external environment determining unit not illustrated. The monitoring system has been described in detail in Figure 4-5 and will not be repeated here.

The acceleration sensor 102 and the electrode sheets 103, 104 are electrically connected to the defibrillator body 101, so that the auxiliary measurement of the pressing parameter can be realized by the defibrillator. The acceleration sensor 102 is used to obtain a reference acceleration signal of the chest compression calibration process. Of course, the acceleration sensor 102 can also be used to acquire a real-time acceleration signal of the chest compression measurement process. The electrode sheets 103, 104 are used to obtain a reference chest impedance signal of the chest compression calibration process and a real-time chest impedance signal of the chest compression measurement process. The acceleration sensor and the electrode sheets (for example, two) applied to the object to be monitored during the monitoring are as shown in FIG. The acceleration sensor is disposed directly above the chest of the object to be monitored, and the rescuer applies pressure to the object to be monitored through the acceleration sensor 102. The two electrode sheets 103, 104 are respectively disposed outside the chest of the object to be monitored, and the impedance measurement circuit of the defibrillator body 101 itself is used to measure the chest impedance. In the above signal acquisition process, the measurement of the thoracic impedance signal does not require a separate set of sensors and detection circuits, and the system complexity can be significantly reduced compared to the prior art using the acceleration sensor and the force sensor.

In addition, the defibrillator main body 101 further includes a defibrillation intensity adjusting unit electrically connected to the pressing depth calculating unit 13. Chest compression is usually performed before defibrillation in vitro, and the CPR effect can be reflected to some extent by monitoring the compression depth. In the initial defibrillation, the amount of defibrillation current can be appropriately adjusted according to the specific value and/or the trend of the compression depth, and the defibrillation effect is ensured while the damage to the myocardium is minimized. The defibrillator 10 of the present invention can provide a more reliable guiding effect for the regulation of defibrillation intensity by improving the accuracy of the compression depth monitoring.

In addition to the above-mentioned compression depth, compression frequency, and compression time interval, the present invention can also monitor parameters such as artificial respiratory ventilation. Feedback of these compression parameters to the rescuer in a timely manner can guide the rescuer to implement high quality CPR first aid measures.

In addition, although the correlation between the chest impedance and the compression depth is described above, since the compression depth is calculated from the acceleration signal, the correlation between the chest impedance and the compression depth may also indirectly reflect the correlation between the chest impedance and the acceleration signal. The correlation determining step or correlation determining unit of the present invention is not limited to determining only the correlation between the pressing depth and the chest impedance, and the pressing parameter monitoring based on the correlation of the chest impedance and the acceleration signal is also included in the scope of the present invention.

It should also be noted that although the above description distinguishes between "real-time acceleration signal" and "reference acceleration signal", and "real-time chest impedance signal" and "reference acceleration impedance signal", it can be known from the description of the defibrillator that the acceleration The signals are obtained by the acceleration sensor, and the chest impedance signals are all acquired by the electrode sheets. The distinction in the description only highlights the difference in the signal acquisition stage, and does not indicate that the real-time and reference signals have different sources, different acquisition paths or different attributes. The correlation determined by the calibration process can therefore be applied to the corresponding calculation of the measurement process.

The above-mentioned embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A method for monitoring the depth of chest compression, characterized in that it comprises:

Obtaining a reference acceleration signal and a reference chest impedance signal of the chest compression calibration process;

Calculating a reference compression depth using the reference acceleration signal, and determining a correlation of the reference chest impedance signal with the reference compression depth;

Obtaining a real-time chest impedance signal from the chest compression measurement process;

The compression depth of the chest compression measurement process is calculated using the real-time chest impedance signal and the determined correlation.
The method for monitoring the chest compression depth according to claim 1, wherein the correlation is a direct correlation between the measured value of the reference chest impedance signal and the reference compression depth or the reference chest impedance signal The indirect correlation of the change value with the reference compression depth.
The method for monitoring the chest compression depth according to claim 2, wherein the direct correlation is:

S=K1×Z;

Where S represents the compression depth, Z represents the measured value of the chest impedance signal, and K1 represents the ratio of the compression depth to the measured value of the chest impedance signal.
The method of monitoring the chest compression depth according to claim 2, wherein the indirect correlation is:

S=K2 ×△ Z;

Where S represents the depth of compression; Z represents the change value of the chest impedance signal, and K2 represents the ratio of the compression depth to the change value of the chest impedance signal.
The method of monitoring the chest compression depth according to claim 1, wherein the monitoring method further calculates a compression depth of the chest compression measurement process using the real-time chest impedance signal and the determined correlation. include:

Obtain real-time acceleration signals from the chest compression measurement process, and

Determine the external environment of the chest compression measurement process.
The method for monitoring the chest compression depth according to claim 5, wherein the external environment for determining the chest compression measurement process comprises:

When the real-time acceleration signal is non-zero and the real-time chest impedance signal changes, determining that the external environment of the chest compression measurement process is a static environment; the real-time acceleration signal is non-zero, and the real-time When the thoracic impedance signal remains unchanged, it is determined that the external environment of the chest compression measurement process is a sports environment.
The method for monitoring the chest compression depth according to claim 6, wherein after determining the external environment of the chest compression measurement process, calculating the compression depth of the chest compression measurement process comprises:

When the external environment of the chest compression measurement process is a sports environment, the real-time chest impedance signal and the determined correlation are used to calculate a compression depth of the chest compression measurement process;

When the external environment of the chest compression measurement process is a stationary environment, the real-time acceleration signal is used to calculate the compression depth of the chest compression measurement process.
A monitoring system for chest compression depth, characterized in that it comprises:

a signal acquisition unit, configured to obtain a reference acceleration signal and a reference chest impedance signal of the chest compression calibration process, and a real-time chest impedance signal for acquiring the chest compression measurement process;

a correlation determining unit, configured to calculate a reference pressing depth using the reference acceleration signal, and determine a correlation between the reference chest impedance signal and the reference pressing depth; and a pressing depth calculating unit configured to use the real-time chest impedance The signal and the determined correlation are used to calculate the depth of compression of the chest compression measurement process.
The monitoring system for chest compression depth according to claim 8, wherein the correlation is a direct correlation between a measured value of a reference chest impedance signal and the reference compression depth or a reference value of a reference value of a chest impedance signal. The indirect correlation of the reference compression depth.
The monitoring system for chest compression depth according to claim 8, wherein the monitoring system further comprises an external environment determining unit for determining an external environment of the chest compression measuring process.
The monitoring system for the chest compression depth according to claim 10, wherein the signal acquisition unit is further configured to acquire a real-time acceleration signal of the chest compression measurement process;

When the external environment determining unit determines that the external environment of the chest compression measurement process is a sports environment, the pressing depth calculation unit calculates the chest compression measurement process using the real-time chest impedance signal and the determined correlation Pressing the depth; when the external environment determining unit determines that the external environment of the chest compression measurement process is a stationary environment, the pressing depth calculation unit calculates the pressing depth of the chest compression measurement process using the real-time acceleration signal.
The monitoring system for the chest compression depth according to claim 8, further comprising a monitored object determining unit, wherein the monitored object determining unit is configured to determine whether the monitored object has changed.
A defibrillator comprising a defibrillator body, an acceleration sensor electrically connected to the defibrillator body, and at least two electrode sheets; the acceleration sensor is configured to collect a reference acceleration signal of a chest compression calibration process, The electrode sheet is used for acquiring a reference chest impedance signal of the chest compression calibration process and a real-time chest impedance signal of the chest compression measurement process; wherein the defibrillator body further comprises the chest compression according to claim 8. Deep monitoring system.
The defibrillator according to claim 13, further comprising a defibrillation intensity adjusting unit electrically connected to said pressing depth calculating unit for appropriately regulating defibrillation according to a specific value and/or a trend of the pressing depth Electricity flow.