JPH01297073A - Medical pump driver - Google Patents

Abstract

PURPOSE:To correctly synchronize the heart of an organism and an auxiliary pump even at the time of an arhythmia by switching the expanded condition and contracted condition of the auxiliary pump synchronizing to the time when a heart contraction start time passes and a heart expansion start time passes since an R wave is detected. CONSTITUTION:A correlation between the repeating period (R-R interval) of the R wave to appear on an electrocardiogram and a time PEP(Pre-Ejection Period) since the R wave appears on the electrocardiogram until the heart of the organism starts the contraction, and the correlation between the R-R interval and a time PEP+ET (ET: Ejection Time) since the R wave appears on the electrocardiogram until the heart of the organism starts the expansion are analyzed and obtained beforehand. In the real drive of a baloon pump 60B. The R-R interval is measured each time the R wave appears, the numeric value of the R-R interval measured is applied to the correlation, the times PEP and PE+ET predicted at such a time are obtained, and the baloon pump is contracted when the time PEP passes since the R wave is detected. When a time PEP+HT passes since the R wave is detected, the baloon pump is expanded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention] [Industrial Application Field] The present invention relates to a device for driving a medical pump such as an intra-aortic balloon pump or an auxiliary artificial heart, which assists the function of a living body's heart.

[Prior Art] Intra-aortic balloon pumps and auxiliary artificial hearts have been known as medical pumps that assist the weakened heart of a living body.

When driving an intra-aortic balloon pump or an auxiliary artificial heart, it is necessary to synchronize the timing of its inflation/deflation with the operation of the heart of the living body. That is.

Particularly in the case of intra-aortic balloon pumps, timing discrepancies not only lead to a decline in auxiliary function;
This is a very important problem in maintaining life because it interferes with the pumping action of the heart of living organisms.

When driving an intra-aortic balloon pump, conventionally, the inflation start timing and contraction start timing of the balloon are set as follows, and the operation is synchronized with the heart of the living body.

Balloon inflation start timing (2 types): (a) Monitor the electrocardiogram waveform to determine the RR interval (R
The moving average of the wave period) is measured, and the time difference between the appearance of the R wave and the start of expansion is determined by multiplying the measured average RR interval by a predetermined ratio.

(b) Set the time difference between the appearance of the R wave and the start of expansion as an absolute time.

Balloon deflation start timing (3 types): (c) Monitor the electrocardiogram waveform to determine the RR interval (R) of the past few heartbeats.
The moving average of the wave period) is measured, and the time difference between the appearance of the R wave and the start of contraction is determined by multiplying the measured average RR interval by a predetermined ratio.

(d) Set the time difference between the appearance of the R wave and the start of contraction as an absolute time.

(e) Start contraction immediately after detecting the appearance of the R wave.

[Problems to be Solved by the Invention] In conventional balloon pump control, the pump's inflation and deflation timings are set on an average or fixed basis, so there is a possibility that the timing may deviate from the movement of the heart of the living body. is high. That is, when the body's heart beats regularly, it is easy to synchronize the movement of the balloon pump with it, but arrhythmia, especially atrial fibrillation,
tion), the heart makes irregular movements, and the occurrence of deviations in their timing has hitherto been an unavoidable problem.

According to the results of the inventors' study of aortic pressure and electrocardiogram waveforms in clinical cases, when currently commercially available drive devices are used, the dispersion of the difference in inflation timing between the heart and the balloon is linear. It was found that good results could be obtained.

Model for method (a): 43 to 54 m5ec Model for method (b): 14 to 19 m5ec When using method (b), the operator sets the time according to the patient's condition at that time. , requires a skilled operator.

In any case, there is a high possibility that atrial fibrillation will occur in patients who require the use of an in-door balloon pump or an auxiliary artificial heart, so synchronization between the heart and the auxiliary pump should It is a very important issue to reduce the deviation.

An object of the present invention is to provide a practical medical pump drive device that can accurately synchronize the heart of a living body and an auxiliary pump even during arrhythmia.

[Structure of the Invention] [Means for Solving the Problems] In order to achieve the above-mentioned object, in the present invention, the cycle of the R wave (R-R interval) included in the electrocardiogram waveform and the contraction start point of the heart of the living body are The correlation between the cycle of the R wave and the start of expansion of the heart of the living body is determined in advance, and when controlling an auxiliary pump such as a balloon pump, the cycle of the R wave measured just before and the correlation between the above correlation are determined in advance. Based on this, the cardiac systole start time and the cardiac diastole start time are determined, and the auxiliary pump is expanded in synchronization with the time when the cardiac systole start time and the cardiac diastole start time have passed since the detection of the R wave. Switch between the state and the contracted state.

[Effect] According to the analysis by the present inventors, there is a positive correlation between the time from when the R wave appears until the heart of the living body starts contracting and the cycle of the R wave immediately before that, It was found that the correlation could be approximated by a predetermined quadratic equation. In addition, an inverse correlation is observed between the time from the appearance of the R wave until the heart of the living body begins to expand and the period of the immediately preceding R wave, and this correlation can be approximated by a predetermined quadratic equation. Do you get it. Of course, these correlations differ for each patient, but for the same patient, large changes do not occur over a relatively long period of time.

Therefore, if these correlations are determined in advance as approximate formulas, and each time an R wave of an electrocardiogram is detected, the R wave period is measured, and if the period matches the above correlation, an R wave is generated. It is possible to know the time Tl from when the R wave occurs until the heart starts to contract, and the time T2 from when the R wave occurs until the heart starts to expand.

Therefore, when driving a balloon pump, for example,
By starting deflation of the balloon when T1 has elapsed after the R wave appears, and inflating the balloon when T2 has elapsed, deflation/expansion of the balloon can be precisely synchronized with contraction/expansion of the heart.

The actual contraction/diastole operation of the heart can be known from the blood pressure waveform in the aorta, which is located particularly close to the heart. Therefore, by detecting the blood pressure waveform, identifying the points of contraction and diastole of the heart from the waveform, measuring the time from the R wave at those points, and sampling the measurement results and the period of the R wave a large number of times, , their correlation can be approximately determined.

This type of control is most effective when driving an intra-aortic balloon pump, but it may be more effective when driving other pumps such as an auxiliary artificial heart by synchronizing the drive with the body's internal organs. can also be applied.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[Example 2] FIG. 2 shows the structure of a mechanical part of a type of balloon pump driving device for implementing the present invention.

This will be explained with reference to FIG. The balloon pump 60B inserted into the patient's aorta is repeatedly inflated and deflated by positive pressure and negative pressure alternately applied via fluid. The air pressure control mechanism ADU generates driving air pressure that alternately changes between predetermined positive pressure and negative pressure. That is, compressor 7
A relatively large positive pressure generated by the electromagnetic valve 5 is applied to the pressure accumulator ACI via the pressure regulating electromagnetic valve 51.
The pressure in Ac1 is maintained at a predetermined positive pressure by the opening/closing control of Ac1. In addition, a relatively large negative pressure generated by the vacuum pump 72 is applied to the pressure accumulator AC2 via the pressure regulating solenoid valve 54, and A
The pressure within c2 is maintained at a predetermined negative pressure. PSl and P
S2 is a pressure sensor that detects the pressure within each pressure accumulator.

When the solenoid valve 52 opens and the solenoid valve 55 closes, a predetermined positive pressure is output, and when the solenoid valve 52 closes and the solenoid valve 55 opens, a predetermined negative pressure is output from the pneumatic control mechanism ADU, and the gas drive mechanism GDU is input.

The gas drive mechanism GDU is equipped with a fluid isolator AGA whose internal space is separated into a primary side and a secondary side by a diaphragm 83 that shifts according to the applied pressure. Air pressure from the control mechanism ADU is applied. A space on the secondary side of the fluid isolator AGA is filled with helium gas that is safe for living organisms, and a balloon pump 60B is connected to a pipe 90 connected to this space.

! -ITA is a helium tank. The amount of helium gas in the space on the secondary side of the fluid isolator AGA is always maintained constant by controlling the opening and closing of the solenoid valves 58 and 59.

Therefore, when the air pressure applied to the space on the primary side of the fluid isolator AGA changes between positive pressure and negative pressure, the diaphragm 83 shifts in accordance with the change, and the balloon pump 60
The fluid pressure applied to B changes.

That is, when the solenoid valve 52 is opened and the solenoid valve 55 is closed, positive pressure is applied to the balloon pump 60B, causing it to expand.

Further, when the solenoid valve 52 is closed and the solenoid valve 55 is opened, negative pressure is applied to the balloon pump 60I3, and the pressure is reduced.

FIG. 3 shows the configuration of an electrical component that controls the drive device shown in FIG. 2.

Referring to FIG. 3, this circuit includes a microcomputer 100. Pressure sensor 105° detection electrode 11
O2 electrocardiograph 120. Signal processing circuit 130, blood pressure monitor 140
．． Signal processing circuit tSO.

Δ/D converter 1609 oscillator 170. Buffer 18
0, driver 185, 1.90. Buzzer 195° Operation board 200. The desk electrocardiograph 120, which is equipped with an operation board control unit 300 and a display control unit 400, outputs an electrocardiogram signal Vacg based on an electric signal obtained from a detection electrode 110 attached to a predetermined position of a living body. This electrocardiogram signal is waveform-shaped by the signal processing circuit 130 and then sent to the A/D converter 160.
is converted into a digital signal and applied to the microcomputer 100. . As described later, the microcomputer 100 detects an R wave from an electrocardiogram signal,
Also, measure the green cycle of the R wave.

Sphygmomanometer 140 generates a blood pressure signal based on the electrical signal obtained from pressure sensor 105. In this example, a pressure sensor 105 for detecting blood pressure is embedded in the tip of a cannula (not shown), and the blood pressure in the aorta is detected by inserting the cannula into the aorta of the living body (as close as possible to the heart). It looks like this. Pressure sensor 105
An electrical signal corresponding to the blood pressure outputted by the cannula is guided to a blood pressure monitor 140 located outside the living body through a lead wire embedded in the peripheral wall of the cannula. The blood pressure signal output from the blood pressure monitor 140 is applied to the A/D converter 160 via the signal processing circuit 150, converted into a digital signal, and applied to the microcomputer 100.

Although not shown, the operation board 200 is equipped with many key switches and many indicators. The key switch includes a start key that instructs to start driving the balloon pump and reset the correlation equation. The solenoid valves 51, 52, 54, 55, 58 and 59 shown in FIG. 2 are connected to the output port of the microcomputer 100 via a driver 185.

The microcomputer 100 shown in FIG. 3 controls the opening and closing of the solenoid valve 51 according to the pressure detected by the pressure sensor PS1, and maintains the pressure in the pressure accumulator Act at a target value. Further, the solenoid valve 54 is operated according to the pressure detected by the pressure sensor PS2.
The pressure inside the 1M pressure vessel AC2 is maintained at the target value by controlling the opening and closing of the 1M pressure vessel AC2. Furthermore, the opening and closing of electromagnetic valves 58 and 59 is controlled according to the pressure detected by pressure sensor PS3, and fluid isolator AG
The amount of helium gas on the secondary side of A is maintained constant. Since these controls are similar to the operations of conventionally known balloon pump drive devices, explanations will be omitted.

A characteristic feature of the control of this device is the opening/closing control of the electromagnetic valves 52 and 55 that switch between positive and negative pressures of the drive air pressure in order to switch between inflation and deflation of the balloon pump 60B, and a particular feature is the timing setting. There is.

That is, in the device of this embodiment, the repetition period (R-R interval) of the R wave appearing on the electrocardiogram and the time P from when the R wave appears on the electrocardiogram until the heart of the living body starts contracting.
E P (Pre-Ejection Period)
as well as the R-R interval and the time from when the R wave appears on the electrocardiogram until the living heart begins to expand, P E
P + ET (ET: Ejection T
ime) is analyzed and found in advance, and when actually driving the balloon pump, the R-R interval is measured every time an R wave appears, and the measured R-R
Applying the interval value, the predicted time PE at that time
Calculate P and PEP+ET, and calculate the time P after detecting the R wave.
Deflate the balloon pump when the EP has passed, and
The balloon pump is inflated when a time period PEP+ET has elapsed since the R wave was detected. In other words, the timing of deflation/inflation of the balloon pump is set according to the R-R interval detected immediately before and the pre-measured correlation condition, so the R-R interval of the heart may be affected due to reasons such as irregular thighs. If there is a change, the deflation/inflation timing of the balloon pump is immediately updated accordingly.

The ideal timing to start inflation of the balloon pump is immediately after the completion of left ventricular ejection (DN: Dicrotic Notch), and when the time period of PEP+ET has elapsed after the appearance of the R wave. However, the PEP+ET time is not constant and varies greatly as the RR interval changes.

That is, the time ET is related to the blood filling time of the left ventricle, and since the blood filling time is strongly related to the preceding R-R interval,
Consequently, ET is correlated with the preceding RR interval.

In addition, the contraction start timing of the balloon pump is the point at which left ventricular contraction starts after the appearance of the R wave and the internal pressure rises to exceed the aortic diastolic pressure, that is, the point at which left ventricular ejection into the aorta starts (ED: End-Diast, ole) is ideal. By the way, the longer the preceding RR interval, the more blood fills the left ventricle and the left ventricular volume, so ejection from the left ventricle to the aorta begins in a short time (PEP) after the appearance of the R wave. It is considered that Therefore 5 hours PEP
A correlation occurs between the RR interval and the preceding RR interval.

As a result of actually analyzing electrocardiograms and aortic pressure waveforms in clinical cases, a positive correlation was observed between time PEP+ET and the preceding RR interval, and a positive correlation was observed between time PEP and the preceding RR interval. An inverse correlation was observed, and these correlations were found to vary from case to case. Figure 6a shows the R-R interval and PE
An example of the correlation with P+ET is shown, and FIG. 6b shows an example of the correlation between the RR interval and PEP.

According to the analysis of the present inventors, it has been found that these correlations can be approximated by an approximation formula using a quadratic function without producing a large error.

Therefore, in this embodiment, before driving the balloon pump, an electrocardiogram waveform and an aortic pressure waveform are sampled and analyzed in advance, an approximate expression (quadratic function) indicating the correlation is determined and stored, and the balloon pump is Used to control the drive of That is, when driving the balloon pump, the R wave of the electrocardiogram is detected, the R-R interval is measured, and the measured R-R interval is substituted into the above approximate equation as the preceding R-R interval, and the time P
Find EP and PEP+ET, detect R wave, and then calculate PE
The balloon pump is deflated when P has passed, and the balloon pump is inflated when PEP+ET has passed after detecting the R wave.

FIG. 5 shows the processing performed by the microcomputer 100 to obtain the approximate expression representing the correlation. This will be explained with reference to FIG.

In step 1, the balloon pump 60B is on standby in a deflated state.

In step 2, the process waits for the start key on the operation board 200 to be pressed.

In step 3, the contents of register N that holds the number of samplings are cleared to 0.

In step 4, monitor the electrocardiogram waveform and wait until the R wave appears.As the R wave has a very large amplitude and slope, as shown in Figure 4, the slope and level of the signal change. Discrimination distinguishes R waves from other waves. Furthermore, the switching from positive to negative slope is detected to detect the peak position of the R wave, that is, the timing at which the R wave appears.

If the R wave is detected in step 4, then in step 5.

Start counting by internal timer TM.

Until the signal is sampled a predetermined number of times (MAX times), N<MAX, and the process proceeds to step 7 after step 6.

In step 7, the waveform of the aortic pressure is monitored to detect the completion of cardiac expansion ED shown in FIG.

ED is the point on the aortic pressure waveform when its level is at its lowest, and the change in it switches from decreasing to increasing.

If ED is detected in step 7, the process proceeds to step 8. In step 8, the contents of the timer TM at that time are referred to, and the sampled time is stored in the memory M indicated by the register N.
e Store in (N). That is.

Since the timer TM starts from O when the peak of the R wave is detected, the contents of TM at this time are time P in Fig. 4.
It corresponds to EP and is stored in memory. However, R
In wave peak detection and ED detection, level changes in the signal waveform are identified based on data sampled multiple times, so the difference between the actual R wave peak time and the time it was detected, and the actual There is a time lag between the time of ED and the time of detection. Therefore, a value obtained by correcting the time lag using the correction value α is stored in the memory Me(N).

In step 9, the waveform of the aortic pressure is monitored to detect the time DN at which the contraction of the heart completes as shown in FIG.

DN is a notch portion that appears on the aortic pressure waveform after the level exceeds the maximum peak, and is the point where the level change switches from decreasing to increasing.

If the DN is detected in step 9, proceed to step IO.
In step 10, the sampled time is stored in the memory M d (N) indicated by register N with reference to the contents of the timer TM at that time. That is, timer TM is R
Since it starts from 0 when the peak of the wave is detected, the contents of TM at this time correspond to time PEP+ET in FIG. 4, and are stored in the memory. However, in R-wave peak detection and DN detection, level changes in the signal waveform are identified based on data sampled multiple times, so there may be a difference between the actual R-wave peak time and the time it is detected. , and a time lag between the actual DN time and the time it is detected. Therefore, a value obtained by correcting the time difference using the correction value β is stored in the memory M d (N).

In step 11, the electrocardiogram waveform is monitored again and waits until the next R wave appears.

When an R wave is detected in step 11, the process proceeds to step 12, where a value corresponding to the contents of the timer TM is stored in the memory M r (N) corresponding to the contents of the register N. That is, since the timer TM starts from O when the peak of the R wave is detected, the contents of TM at this time correspond to the elapsed time from the peak of the previous R wave, that is, the R-R interval. However, in this case as well, R is based on data sampled multiple times.
Since the peak of the wave is detected, a time lag may occur, and the value corrected by the correction value γ is stored in the memory M r (N).

In step 13, the contents of the timer TM are cleared to 0,
In step 14, the contents of register N are incremented, and the process returns to step 6.

Thereafter, the processes of steps 6 to 14 are repeatedly executed until they are executed MAX times. When it is finished, i.e. when proceeding from step 6 to step 15, the memory M
e (N), M d (N) and Mr (N)
MAX pieces (for example, 50) of sampling data are each held. Memory M 8 (N), M d (N
) and M r (N) are the time PEP
, sampling data of time PEP+ET and RR interval.

In step 15, “correlation analysis processing I II,” the memory M
The PEP sampling data stored in e (N) and the R-R interval (
The correlation between them is analyzed based on the sampling data of Trr). This analysis can be performed, for example, by a least squares calculation process. In this analysis, an approximate expression indicating the correlation between PEP and Trr, that is, a quadratic function f 1 (Trr) is obtained as a calculation result. Obtained function f1
An example of this is the following equation (1).

PEP= 0.00003 (Trr)” -0,10
53 (Trr) + 182.43 - (1) However, 45
0≦Trr≦1000 [m5ecl step 16''
In the correlation analysis process 2'', the PEP+ET sampling data stored in the memory M d (N) and the memory M
Based on the sampling data of the R - R interval (Trr) stored in r (N), their correlation is analyzed. This analysis can be performed, for example, by a least squares calculation process. In this analysis, as a result of calculation, PEP+
An approximate expression indicating the correlation between ET and Trr, that is, a quadratic function f2(Trr) is obtained. An example of the obtained function f2 is as shown in the following equation (2).

PIEP+1ET=-0,00017(Trr)” +
0.286 (Trr) +243.3...
・(2) However, 450≦Trr≦1000 [m5ec
] The next step 17 is actually inflating the balloon pump/
This is a subroutine that controls contraction.

The contents of this subroutine are shown in FIG.

Each step will be explained with reference to FIG.

In step 21, the balloon pump is kept in a deflated state.

In step 22, the electrocardiogram waveform is monitored and waits until an R wave appears.

When an R wave is detected in step 22, the process proceeds to step 23, where the timer TM is cleared to 0.

In step 24, the electrocardiogram waveform is monitored again.

Wait until the R wave appears.

When the R wave is detected in step 24, the process proceeds to step 25, where the content of the timer TM is corrected by the correction value γ, that is, the R wave is detected.
- Store the R interval as time Trr and clear timer TM to O.

In step 26, the R-R detected in the previous measurement process is
A function f2 is calculated using the interval, ie, time Trr, as a parameter. That is, for example, by substituting the measurement result into Trr of the function expressed by the above equation (2), the time PEP
Find +ET and store it in register T2.

In step 27, the process waits until the content of the timer TM becomes equal to or greater than the content of the register T2, that is, equal to or greater than PEP+ET.

When TM≧T2 in step 27, that is, when the systolic phase of the heart is completed and the heart moves to the diastolic phase, the process proceeds to step 28. In step 28, the solenoid valve 52 is opened and the solenoid valve 55 is closed to apply positive pressure to the balloon pump and inflate the balloon pump.

In step 29, the process waits until the R wave of the electrocardiogram is detected again.

When an R wave is detected in step 29, the process proceeds to step 30. At this time, the content of the timer TM is the time from detecting the previous R wave to detecting the current R wave, that is, R
- Corresponds to the R interval. Therefore, in step 30, the result of correcting the contents of the timer TM by the correction value γ, that is, the R-R interval, is stored as time Trr, and the timer TM is cleared to 0.

In step 31, the time Tr detected in step 30 is
For example, a function f1 as expressed by the above equation (1) is calculated using r as a parameter, and the result, that is, time PE
Store P in register TI.

In step 32, the process waits until the content of the timer TM becomes equal to or greater than the content of the register T1, that is, equal to or greater than PEP.

If TM≧T1 in step 32, the process proceeds to step 33 and the balloon pump is deflated. That is, the solenoid valve 52 is closed and the solenoid valve 55 is opened to apply negative pressure to the balloon pump.

In step 34, the start key on the operation board 200 is checked to see if there is an instruction to update the correlation equation (1) Normally, the start key is off.

Next, the process returns to step 26 and thereafter the processes of steps 26-34 are repeated to drive the balloon.

That is, each time step 30 is executed, the latest R-R interval of the electrocardiogram waveform is measured, and based on the measurement result,
The times PEP and PEP+ET are set at step 31, respectively.
and 26, deflation of the balloon pump is started when time PEP has elapsed since the appearance of the R wave, and inflation of the balloon pump is started when time PEP+ET has elapsed since the appearance of the R wave.

An example of this control timing is shown in FIG. 4, so please refer to it.

Here, the times PEP and PE generated as predicted values
P+ET is calculated from a correlation equation obtained in advance by measurement based on the R-R interval measured immediately before, and the difference from the actual time is extremely small.
The timing of the start of contraction and start of inflation of the balloon pump is precisely synchronized with the start of contraction and expansion of the heart, respectively. This feature is particularly noticeable when the heart beats irregularly, as in atrial fibrillation.

When the atrial fibrillation tracking characteristics of the device of this embodiment and a conventional model were actually measured and compared, the following results were obtained.

The aortic pressure waveform and electrocardiogram waveform of a patient with atrial fibrillation are recorded in advance on a data recorder, and based on this information, the conventional models A and B and the device C of the embodiment are driven in a simulated manner to detect D N on the aortic waveform. (Dicrot, ic Not, ch)
When the appearance point was set as the zero point and the deviation of the balloon expansion time of each model was sampled with respect to the zero point, the results shown in FIG. 7 were obtained. Comparing the fA standard deviation (S, D,) numerically, conventional models A and B have 54 m5 and 4 m5, respectively.
ec and 43.69 m5ec, whereas in the example device it is 8.50 m5ec. this is.

This shows that the device of the example has extremely good tracking ability for atrial fibrillation. The conventional model used for the comparison in Figure 7 is:
This method controls the balloon pump based on the average value of the R-R intervals of the preceding several heartbeats. Therefore, we also measured two conventional models that control the balloon pump by fixing the R-R interval for control.
The standard deviation was 19.56 m5ec for one model and 14.89m5ec for the other model. In comparison with these models, it can be seen that the device of the example is superior in atrial fibrillation tracking characteristics.

In this example, the correlation functions f1 and f24! , can be updated at any time by pressing the start key on the operation board. That is, even after starting to drive the balloon pump, if you press the start key on the operation board, the balloon drive subroutine will end in step 34 of FIG. 1 and return to the main routine of FIG. 1, so the balloon pump will not be driven. is temporarily interrupted, samples the R-R interval, PEP, and PEP+ET a predetermined number of times, analyzes their correlation, and updates the contents of functions fl and f2.

In addition, in the above embodiment, the R-R interval and the time PEP
Analyze the correlation between the R-R interval and the time PEP+ET, generate two quadratic functions that approximate them, and calculate the R-R
Each time the interval is measured, the function is calculated to calculate PEP and P.
Although EP+ET is being determined, for example, data indicating the relationship between them may be provided as a reference table on a read/write memory, and the table may be referred to using the measured RR interval as a parameter to determine PEP and PEP+ET. Further, the function of the correlation equation may be changed to, for example, a cubic function.

However, in terms of control, there is no big difference from using a quadratic function.

Further, in the embodiment, an intra-aortic balloon pump is shown as the control target, but an auxiliary artificial heart may be controlled instead. Furthermore, an intra-aortic balloon pump and an auxiliary artificial heart may be used in combination. In that case,
For example, the contraction of the auxiliary artificial heart starts at the point when the contraction (blood ejection) of the living heart ends (DN), and then when a predetermined time k·(Trr-ET) has elapsed (0≦to≦1).
At the same time as the auxiliary artificial heart finishes deflating, the balloon pump starts inflating, and when the living heart finishes expanding (
ED) Just start deflating the balloon pump. In any case, the inflation/deflation of the balloon pump and/or the auxiliary artificial heart is controlled so as to be synchronized with the end of diastole (ED) and the end of systole (DN) of the living heart.

[Effect] As described above, according to the present invention, even when atrial fibrillation occurs, the inflation/deflation of an auxiliary pump such as a balloon pump is switched to accurately follow the movement of the living body's heart, so that the living body's It is possible to prevent interference with the pumping action of the heart and a decrease in assist efficiency, resulting in a significant effect in preserving the patient's life.

[Brief explanation of the drawing]

1 and 5 are flowcharts showing part of the processing of the microcomputer 100 shown in FIG. 3. FIG. FIG. 2 is a block diagram showing the configuration of a mechanical section of one type of balloon driving device that implements the present invention. FIG. 3 is a block diagram showing the configuration of the electrical equipment section of the device shown in FIG. 2. FIG. 4 is a timing chart showing an example of the operation timing of the device shown in FIG. FIG. 6a is a graph showing an example of the correlation between the RR interval and the time PEP+ET, and FIG. 6b is a graph showing an example of the correlation between the RR interval and the time PEP. Figure 7 shows the commercially available equipment! A, B and Example device C
3 is a graph showing the time lag in and the variation in time. 60B: Intra-aortic balloon pump (medical pump means) 5
1 to 59: Solenoid valve 72: Vacuum pump 73: Compressor 100: Microcomputer (electronic control means) 105
: Pressure sensor (blood pressure detection means) 110: Detection electrode (electrocardiogram detection means) 120: Electrocardiograph 140: Sphygmomanometer 160: A/D
Converter ADU: Pneumatic control mechanism (pump drive means) GDU: Gas drive mechanism PS1 to PS3: Pressure sensor door 68 Figure R-RFfl''I% (msec) Voice 6b Figure R-R11% (msec) East 7 figure

Claims (3)

[Claims] (1) Electrocardiogram detection means for detecting an electrocardiogram waveform; medical pump means for assisting the function of the heart of a living body; pump drive means for driving expansion and contraction of the medical pump; R from the electrocardiogram waveform detected by the electrocardiogram detection means; Detect the wave and R
The cycle of the wave is repeatedly measured, the cardiac contraction start time and the cardiac diastole start time are determined based on the latest measured cycle and a preset correlation, and after detecting the R wave, the cardiac contraction start time is determined. A medical pump drive device comprising: electronic control means for switching the medical pump means between an expanded state and a contracted state in synchronization with when the cardiac diastole start time has elapsed and when the cardiac diastole start time has elapsed. (2) The electronic control means includes a blood pressure detection means for detecting blood pressure in the aorta, and identifies the start point of cardiac contraction and the start point of cardiac diastole based on the blood pressure waveform, and determines the period of the R wave of the electrocardiogram waveform, A time corresponding to the start of contraction and a time corresponding to the start of cardiac diastole are sampled multiple times and stored, and based on the plurality of stored sampling results, the period of the R wave and the time corresponding to the start of cardiac contraction are determined. The medical pump drive device according to claim 1, wherein the medical pump drive device calculates and stores the correlation between the period of the R wave and the time corresponding to the start of cardiac diastole. (3) The electronic control means includes a blood pressure detection means for detecting the blood pressure in the aorta, and identifies the start point of cardiac contraction and the start point of cardiac diastole based on the blood pressure waveform, and determines the period of the R wave of the electrocardiogram waveform, A time corresponding to the start of contraction and a time corresponding to the start of cardiac diastole are sampled multiple times and stored, and based on the plurality of stored sampling results, the period of the R wave and the time corresponding to the start of cardiac contraction are determined. A first approximation equation showing the correlation with the corresponding time and a second approximation equation showing the correlation between the period of the R wave and the time corresponding to the start of cardiac diastole are determined and memorized, and the R wave is Each time the R wave is detected, the cycle of the R wave is measured, and the cardiac contraction start time is calculated based on the cycle and the first approximation formula, and the cardiac diastole start time is calculated based on the R wave cycle and the second approximation formula. calculating time and switching the medical pump means between an expanded state and a contracted state in synchronization with the time when the cardiac contraction start time and the cardiac diastole start time have passed after detecting the R wave; A medical pump drive device according to claim (1).