CN101176802A - Pulsation core pump in analog bloodstream revolving - Google Patents

Abstract

The invention relates to a simulation pulsation heart pump in the circulation of simulation blood flow, comprising a main shaft, a heart pump cam fixed on the rotary main shaft, a lever, and a piston pump, The invention is characterized in that: a cam slideway with a cam curve is positioned on the heart pump cam; a knockout pin with reciprocating movement is connected with the heart pump cam through the cam slideway; the lever resistance arm is connected with the drive end of the lever; an adjustable pivot capable of enlarging or reducing the reciprocating movement is arranged in the middle of the lever; the power arm of lever is connected with the piston of the piston pump; the centerline 1 of the knockout pin is parallel with the centerline 2 of the piston, and the distance between the lines is a constant. The invention has the advantages of capability of realizing the blood pump function of heart, and reproducing the output pressure waveform of left ventricular, being suitable for the simulation device for heart-coronary artery-myocardial bridge, also being suitable for the other simulation devices of blood circulation, having compact structure of machinery, stable pressure and low cost.

Description

Pulsation core pump in the circulation of simulation blood flow

Technical field

The present invention relates to a kind of clinical research and zooperal blood flow circulating analog device, the pulsation core pump in especially a kind of blood flow circulating analog device.

Background technology

The cardiac muscle bundle that covers on the myocardial surface coronary artery is called as myocardial bridge.Be the clinical meaning of objective evaluation myocardial bridge, it is very important to understand wall hemodynamics feature coronarius.People inquire into this by number of ways, but because in the past research majority is to carry out, exist some inevitable limitation in clinical patient and laboratory animal: (1) lacks systematicness: influence the randomness that hemodynamic parameter (as the width of myocardial bridge, wall coronary artery pressurized degree, blood pressure, heart rate etc.) occurs in the clinical research object and make clinical be difficult to carry out system and comprehensively research.(2) mensuration of blood flow: blood flow coronarius is the most important factor of decision myocardial blood flow perfusion state, but therefore the method that does not also have gratifying measurement coronary artery blood flow at present clinically causes the variation of wall coronary artery blood flow still to lack enough understanding to myocardial bridge.Therefore, need development one cover " heart-coronary artery-myocardial bridge " analog (shown in Figure 1) to be used for replenishing clinical research and zooperal limitation and not enough.

This device should be able to be achieved as follows target:

1. set up the mechanical pressure of myocardial bridge and the quantitative relationship between the coronary blood supply, for the existence of judging myocardial bridge and the relation between the myocardial ischemia provide foundation.

2. the mechanical pressure of research myocardial bridge is to the influence of the nearly section of wall coronary artery, section pressure far away.State in realization on the basis of target, further seek the variation of blood flow parameter and the relation between the coronary atherosclerosis, explain the higher reason of atherosclerotic plaque incidence rate of the nearly section of myocardial bridge from mechanism.

Whole device can be divided into power, heart pump, myocardial bridge, pipeline and five subsystems of measurement by function.Finish mensuration jointly to hemodynamic parameters such as pressure, flows.Its central pump is the critical component of whole analog, and its function mainly is: realize the blood-pumping function of heart, and reappear the output pressure waveform of left ventricle as far as possible.At present, also there is not a kind of heart pump can satisfy the above-mentioned functions requirement fully.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of pulsation core pump of simulating in the blood flow circulation, this pump can be realized the blood-pumping function of heart, and can reappear the output pressure waveform of left ventricle, be applicable to " heart-coronary artery-myocardial bridge " analog, also be applicable to other blood flow circulating analog devices.

For achieving the above object, the technical solution used in the present invention is:

A kind of pulsation core pump of simulating in the blood flow circulation, comprise main shaft, be fixed on the heart pump cam on the rotary main shaft, lever, plunger displacement pump, be characterized in: be provided with cam chute above the heart pump cam with cam curve, heart pump cam connects reciprocating push rod by the cam chute on it, the top rod driving end connects the lever resistance arm, be provided with the adjustable fulcrum that the reciprocating motion of push rod is amplified or dwindled in the middle of the lever, lever moving arm connects the piston of plunger displacement pump, and push rod centrage 1 is parallel with the centrage 2 of piston, and the distance between it is a definite value.

Main shaft links to each other with the buncher reduction gearbox output shaft by shaft coupling.

Heart pump cam curve is the displacement curve integration type by piston:

$S\left(t\right)={\∫}_0^{T}v\left(t\right)\mathrm{dt}={\∫}_0^T\frac{P\left(t\right)}{R\×A}\mathrm{dt},$ Obtain,

Wherein: P (t)=R * A * U (t),

In the formula: T is the heart rate cycle, and A is the plunger displacement pump cross-sectional area; U (t) is a pump chamber inner fluid mean flow rate; T is the time.

Heart pump discharge is the position by mobile adjustable fulcrum, changes lever moving arm L ₁With resistance arm L ₂Ratio, pilot plunger pump piston stroke S ₂Form, that is:

S ₁/L ₁＝S ₂/L ₂，

S ₂＝S ₁×L ₂/L ₁

In the formula: S ₁Be cam stroke.

Heart pump frequency is to change by regulating buncher, and its speed adjustable range is 18～240 rev/mins.

When the stroke of push rod is 15mm, by changing fulcrum with respect to centrage 2 positions of push rod centrage 1 with piston, the ratio excursion of lever resistance arm L1 and power arm L2 is between the 0.375-2.667, and the stroke mobility scale of plunger displacement pump piston is 5.7mm-40mm.The invention has the beneficial effects as follows:

Heart pump of the present invention can be realized the blood-pumping function of heart, and can reappear the output pressure waveform of left ventricle, is applicable to " heart-coronary artery-myocardial bridge " analog, also is applicable to other blood flow circulating analog devices.

Reach following main target through the experiment of analog heart pump system of the present invention:

1. simulate the left ventricular pressure waveform;

2. the blood-pumping function of simulation heart is keeping under the constant prerequisite of left ventricular pressure waveform, and the pump blood volume of heart can be regulated within the specific limits;

3. frequency adjustable.

In addition, mechanical device structure compactness of the present invention, pressure stability, with low cost.

Description of drawings

Fig. 1 is a myocardial bridge analog block diagram;

Fig. 2 is a heart pump system sketch map of the present invention;

Fig. 3 is a human body left ventricular pressure oscillogram;

Fig. 4 is a heart pump pressure oscillogram;

Fig. 5 is nearly section of people's body wall coronary artery and section pressure figure far away;

Fig. 6 is nearly section of simulation wall coronary artery and section pressure figure far away.

The specific embodiment

The present invention is further illustrated below in conjunction with accompanying drawing and embodiment.

As shown in Figure 2, the pulsation core pump in the simulation blood flow circulation of the present invention comprises main shaft 5, heart pump cam 4, lever 8, plunger displacement pump 10.

Main shaft 5 links to each other with the buncher reduction gearbox output shaft by shaft coupling, and heart pump cam 4 is fixed on the rotary main shaft 5.

Have cam chute 6 above the heart pump cam 4 with cam curve, heart pump cam 4 connects reciprocating push rod 3 by the cam chute on it 6, push rod 3 drive ends connect lever 8 resistance arm L1, be provided with the adjustable fulcrum 7 that the reciprocating motion of push rod 3 is amplified or dwindled in the middle of the lever 8, lever 8 power arm L2 connect the piston 9 of plunger displacement pump 10, push rod 3 centrages 1 are parallel with the centrage 2 of piston 9, and the distance between it is a definite value.

Heart pump structure and function:

Heart pump is by heart pump cam 4, lever 8, plunger displacement pump 10 3 is partly formed. and the heart pump cam 4 that is fixed on the main shaft 5 pivots, thereby driving push rod 3 moves reciprocatingly along centrage 1 by the displacement curve that cam chute 6 is limited, lever 8 between centrage 1 and centrage 2, by adjusting the position of fulcrum 7, the reciprocating motion of push rod 3 is amplified or dwindled, to reach the purpose of pilot plunger pump piston 9 strokes, and piston 9 is moved reciprocatingly along centrage 2 (plunger pump cylinder body centrage), the displacement curve of heart pump cam 4 is changeless, make the stroke of push rod 3 also immobilize (15mm), and the distance of centrage 1 and centrage 2 also is fixed, change the position of fulcrum 7 with respect to two centrages, the ratio of lever 8 resistance arm L1 and power arm L2 is changed between 0.375 to 2.667, and make the stroke of plunger displacement pump piston 9 change to 40mm from 5.7mm.

The heart pump system design principle:

(1) design of heart pump cam curve

The pressure waveform of heart adopts the mechanical analogue scheme, and the design of cam curve is most important.Its design considerations is: heart pump is when work, and total peripheral resistance R remains unchanged.As preliminary analysis and research, blood vessel is considered as the rigid uniform pipe, permanent Laminar Flow.In the rigid uniform pipe, the pressure of permanent Laminar Flow and discharge relation are that Charles Robert Richet Poiseuille at first provides accurate description:

P＝R×Q，

$R=\frac{8\mathrm{\&eta;L}}{{\mathrm{\&pi;<figure-callout\; id="4"\; label="r"\; filenames="S2007101710084E00011.png"\; state="\{\{state\}\}">r</figure-callout>}}^4}$

In the formula: R is a Peripheral resistance, and η fluid viscosity, L are pipe range, and r is the then output pressure of heart pump of pipe radius:

P(t)＝R×Q(t)，

P(t)＝R×A×U(t)，

In the formula: A is the plunger displacement pump cross-sectional area; U (t) is a pump chamber inner fluid mean flow rate; T is the time.Because piston movement speed v (t) equals pump chamber inner fluid mean flow rate U (t), then has:

P(t)＝R×A×v(t)，

Because plunger displacement pump cross-sectional area A and Peripheral resistance R remain unchanged, so P (t) ∝ v (t), and the waveform of output pressure P (t) the needed cardiac pressure waveform that is exactly us, it is easy to record, and has had it to be equivalent to obtain the wavy curve of piston speed v (t).In view of the above, integration once just can obtain the displacement curve of piston:

$S\left(t\right)={\&Integral;}_0^{T}v\left(t\right)\mathrm{dt}={\&Integral;}_0^T\frac{P\left(t\right)}{R\&times;A}\mathrm{dt}$

In the formula: T is the heart rate cycle.

In view of the above, but the cam curve of our this piston stroke of design driven.

(2) adjusting of heart pump discharge

It is that fidelity is higher that the cardiac pressure waveform adopts the advantage of mechanical analogue scheme, and wavy curve is stable.In case but after cam carried out, its curve shape and piston stroke were all determined unique.Want to change pressure waveform or stroke volume, in addition machining cam.This has brought inconvenience for the adjusting of experiment parameter.This device utilizes leverage to connect cam and piston rod, by the position of mobile fulcrum, changes power arm L ₁With resistance arm L ₂Ratio, reach pilot plunger pump piston stroke S ₂Purpose, that is:

S ₁/L ₁＝S ₂/L ₂，

S ₂＝S ₁×L ₂/L ₁

In the formula: S ₁Be cam stroke.

Thereby under the preceding topic of waveform unanimity that keep-ups pressure, realized adjusting to stroke volume.

Certainly, want to change pressure waveform, also must change cam in addition.

(3) adjusting of frequency

Adopt buncher.Main shaft 5 links to each other with the buncher reduction gearbox output shaft by shaft coupling, and, drive heart pump and myocardial bridge respectively by being installed in two cams on the main shaft 5. because the rotating speed of the rotating speed of main shaft 5 and output shaft is identical, promptly 18～240 rev/mins, it is a cardiac frequency, also is the frequency of exerting pressure of myocardial bridge.

Use the result:

After the development of " heart pump-coronary artery-myocardial bridge " blood circulation model was finished, test result showed that this device has reached designing requirement, stable performance substantially.

(1) pressure waveform:

A. left ventricular pressure waveform: the curve of contrast Fig. 3, Fig. 4 shows that analog pressure waveform curve and human body left ventricle wavy curve are comparatively identical.

Wall coronary artery pressure wave shape when B. myocardial bridge exists:

Pressure figure that records behind the pipeline pressurized and the myocardial bridge patient's that measures with coronary artery cavity pressure seal wire clinically nearly section of wall coronary artery and far away section pressure figure feature identical (Fig. 5, Fig. 6).

(2) flow of heart pump: stroke volume at 2.8ml between the 19ml, with minimal heart rate 40 times/minute, maximum heart rate 200 times/minute is calculated, the range of flow that actual device can provide 0.11 liter/assign between 3.9 liters/minute, enlarged many than 0.25～1.25 liter/minute of requirement of experiment.

(3) frequency of heart pump: experiment shows that the speed governing knob can be adjusted to frequency needed frequency exactly on the motor by regulating.One of major parameter of determining with requirement of experiment, heart rate is compared for 40～200 rev/mins, the heartbeat scope that actual device can provide bigger (18～240 rev/mins).

Claims (6)

1. pulsation core pump of simulating in the blood flow circulation, comprise main shaft (5), be fixed on the heart pump cam (4) on the main shaft (5), lever (8), plunger displacement pump (10), it is characterized in that, be provided with cam chute (6) above the described heart pump cam (4) with cam curve, heart pump cam (4) connects reciprocating push rod (3) by the cam chute (6) on it, push rod (3) drive end connects lever (8) resistance arm (L1), be provided with the adjustable fulcrum (7) that the reciprocating motion of push rod (3) is amplified or dwindled in the middle of the lever (8), lever moving arm (L1) connects the piston (9) of plunger displacement pump, push rod (3) centrage 1 is parallel with the centrage 2 of piston (9), and the distance between it is a definite value.

2. the pulsation core pump in the simulation blood flow circulation according to claim 1 is characterized in that described main shaft (5) links to each other with the buncher reduction gearbox output shaft by shaft coupling.

3. the pulsation core pump in the simulation blood flow circulation according to claim 1 is characterized in that described heart pump cam curve is the displacement curve integration type by piston:

$S\left(t\right)={\&Integral;}_0^{T}v\left(t\right)\mathrm{dt}={\&Integral;}_0^T\frac{P\left(t\right)}{R\&times;A}\mathrm{dt},$ Obtain,

Wherein: P (t)=R * A * U (t),

In the formula: T is the heart rate cycle, and A is the plunger displacement pump cross-sectional area; U (t) is a pump chamber inner fluid mean flow rate; T is the time.

4. the pulsation core pump in the simulation blood flow circulation according to claim 1 is characterized in that described heart pump discharge is the position by mobile adjustable fulcrum (7), changes lever moving arm (L ₁) and resistance arm (L ₂) ratio, pilot plunger pump piston (9) stroke S ₂Form, that is:

S ₁/L ₁＝S ₂/L ₂，

S ₂＝S ₁×L ₂/L ₁

In the formula: S ₁Be cam stroke.

5. the pulsation core pump in the simulation blood flow circulation according to claim 1 is characterized in that, described heart pump frequency is to change by regulating buncher, and its speed adjustable range is 18～240 rev/mins.

6. according to the pulsation core pump in claim 1 or the 4 described simulation blood flow circulations, it is characterized in that, when the stroke of described push rod (3) is 15mm, by changing fulcrum (7) with respect to centrage (2) position of push rod centrage (1) with piston, the ratio excursion of lever resistance arm (L1) and power arm (L2) is between the 0.375-2.667, and the stroke mobility scale of plunger displacement pump piston (9) is 5.7mm-40mm.

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