JP2961557B2 - Blood pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to the field of blood pressure increasing devices used during surgery or coronary angioplasty.

BACKGROUND OF THE INVENTION In recent years, balloon angioplasty has become increasingly popular as a means of treating patients with arterial stenosis. It has also been desired to provide a catheter which is as small in profile as possible and can be inserted into the most constricted part of the blood vessel. In addition, it is desirable to continue blood flow during balloon inflation to avoid local anemia, which can occur when balloon inflation is prolonged.

Reducing the outer profile of the catheter has led to a progressive reduction in the catheter lumen that transports blood through the distal end of the balloon inflation. As a result, the pressure required to pump the required amount of blood through the reduced lumen catheter lumen was progressively higher.

The concept of incorporating a pump to pump blood during balloon inflation is described in US patent application Ser. No. 100,36, filed Sep. 23, 1987.
It is described for the first time in issue 3.

In the past, peristaltic pumps have been used to pump blood. However, such pumps have two disadvantages. First, the ability to generate output pressure is limited. In contrast, pumps of the present invention can generate pressures up to about 300 psig. Second, the tubing used in peristaltic pumps can undergo a partial collapse, which causes the resulting particles to enter the blood stream,
Produces undesirable results.

It is important not only to pump a specific volume per unit time into the catheter during coronary angioplasty, but also to be able to know the pressure generated by the pump, which can be used as a factor in determining blood flow It is.

Normally, positive displacement pumps, such as piston pumps, produce a pressure pulse on each stroke. The device of the present invention provides a pulsation mitigation mechanism in such a pump to smooth down the pressure pulse, thereby obtaining a continuous blood flow during balloon inflation and enabling precise flow measurement. The pump, including the pulsation mitigation mechanism, can be made of a disposable material body. The body of the pump can be used in combination with a reusable motor and drive. The pump body of the present invention can also be operated in any position and is small enough to be used to pump blood to the patient's heart in an emergency, for example, in emergency bypass surgery.

Pulsation mitigation devices have been used in multi-cylinder piston pumps in oil and gas wells as a means of reducing pipe vibration at the pump discharge end when pumping various well fluids.

Piston type pumps have been used to pump saline and other pharmaceuticals in intravenous catheters.

Peristaltic pumps have been used to fill the coronary arteries during heart surgery. The peristaltic pump is a very low pressure pump, ie, up to 80-120 psig. Also, peristaltic pumps are slippery pumps and cannot provide quantitatively reliable flow. With the emergence of smaller diameter angioplasty catheters, it will cause higher blood pressure
It became necessary to be able to pump a sufficient amount of blood into this small diameter catheter during PTCA. The pump of the present invention meets this need.

SUMMARY OF THE INVENTION The present invention resides in a disposable positive displacement piston pump having a polycarbonate body, piston, inlet and outlet valves. The outlet valve is connected to an outlet chamber, which is isolated from the outlet valve by an elastomeric membrane. An elastomeric membrane surrounds the storage chamber, which is filled with a fluid such as air at atmospheric pressure. The pulsation of the outlet pressure caused by the reciprocating motion of the piston is mitigated by the flexural action of the elastomer film while compressing the fluid in the storage chamber. The output of the pump is relieved to provide sufficient pressure to pump blood through a micro-section angioplasty catheter having a fill through lumen. The combination of this pump with a micro-section balloon angioplasty catheter, together with the ability to pump a sufficient amount of blood through such a micro-section catheter during balloon inflation, while at the same time sufficiently eliminating pressure pulsations in each stroke. The catheter can be passed through a narrow passage.

Description of the Preferred Embodiment As shown in FIG.
The pump P also has a boosting means M including a plunger 10, a drive motor 12, and a linkage 14. Drive motor 12
Actuation causes the plunger 10 to reciprocate in an oscillating manner.

As is apparent from FIG. 1, the main body B includes a pulsation reducing means D. The pulsation mitigation means includes a storage cavity or chamber 16 and a flexible membrane 18, preferably made of polyurethane with a Shore hardness of 60A to 55D. FIG. 1 shows the pulsation mitigation means D integrated with the main body B, but this pulsation mitigation means can be separated from the main body B without departing from the present invention.

Pump P also includes a pressurizing chamber 20. The plunger 10 reciprocates in the pressurizing chamber 20. Inlet valve 22 and outlet valve
24 is in fluid communication with each pressure chamber 20.

When the plunger 10 moves in a direction to expand the volume of the pressurizing chamber 20, this movement opens the valve 22 and closes the valve 24. Thereby, the pressure chamber 20 is filled with blood. Conversely, when plunger 10 moves in the opposite direction, valve 22 is biased to its closed position and valve 24
Opens. Thus, blood flows through valve 24 to outlet port 26. This blood flow to the outlet port creates a pressure here, which causes the flexible membrane 18 to move.
As a result, the fluid in the storage chamber 16 is compressed, and the flow communication between the outlet port 26 and the outlet chamber 28 is established. The storage chamber 16 can be filled with air at atmospheric pressure. The use of other fluids and / or initial chamber pressures above atmospheric pressure does not depart from the invention. Conversely, when the pump is on the intake stroke and the valve 24 is closed, the flexible membrane 18 completely covers the outlet chamber 28 and the outlet port 26 and does not create a flow between these two areas. This is a flexible film 18
Is sitting on the wall 30.

After the blood passes into the outlet chamber 28, it exits into the outlet opening 32. An inlet tube 34 is connected to the inlet port 36 and an outlet tube 38 is connected to the outlet opening 32.

The preferred material for body B is polycarbonate, but other materials can be used without departing from the spirit of the invention. This material of the body B should be transparent so that any air bubbles in the blood can be easily detected. In addition, the transparent body B allows the state of the flexible membrane 18 to be checked immediately.

The drive mechanism 14 is preferably of the reversible ball screw type. However, other types of oscillating motion can be used without departing from the spirit of the invention.

As shown in FIG. 2, the outlet tube 38 is connected to the fitting 40 of the vascular type catheter A. This angioplasty catheter A
Has a lumen 42 and a balloon 44 therethrough. When the balloon 44 is inflated as shown in FIG.
Block the flow of blood within. When the pump P is operated,
Blood is drawn directly or indirectly from the patient, such as from a blood source, such as a blood bag, or from, for example, a vein or artery of the kidney. This blood is in the inlet tube 34
From the pump to the outlet tube 38 and out through its lumen 42 of the angioplasty catheter A and out of its distal end 48. The movement of the pump causes blood 50 to pass through end 48 of angioplasty catheter A. Therefore, since the blood 50 flows in the artery 46 while the balloon 44 is inflated, there is no danger of local anemia due to vasoconstriction. The use of the pump P makes it possible to increase the blood pressure, and thus the smaller diameter lumen 42
And an adequate amount of blood can be sent through the angioplasty catheter.

The pump P of the present invention is portable and can be operated in any posture. This pump is about 1-1 /
The drive is as small as 2 "x 4 1/2" x 3 1/2 "and the drive is about 4" x 3 "x 10". A structure combining these is lightweight and portable. After use, the pump section is discarded and the drive motor and linkages 12 and 14 are reused in another sterilization pump.

The addition of the storage chamber 16 to the flexible membrane 18 further smoothes the blood pressure pulse, allowing for more accurate blood flow measurements and blood pressure measurements. This measurement can be performed by attaching appropriate equipment to the outlet tube 38 or between the outlet tube 38 and the fixture 40.

Alternatively, the chamber 20 and the plunger 10 can be of a double action structure, not shown. In this way, blood is pumped regardless of the type of reciprocating plunger 10. Since this structure reduces pulsation, it can be used with or without pulsation mitigation means D.

Although the present invention has been described in detail with reference to the preferred embodiments illustrated in the accompanying drawings, the present invention is not limited to this specific embodiment, and various changes and modifications may be made without departing from the spirit of the present invention. Of course, you can do it.

[Brief description of the drawings]

FIG. 1 is a sectional view of a blood pump according to the present invention, and FIG. 2 is a schematic view showing a combination of the blood pump and the blood forming balloon catheter shown in FIG. 10: Plunger, 12: Drive motor, 14: Linkage, 16: Accumulation chamber, 18: Flexible membrane, A: Angioplasty catheter, B: Body, D: Pulsation mitigation means, P …
... Pump, 20 ... Pressure chamber, 22 ... Inlet valve, 24 ... Outlet valve, 26 ... Outlet port, 28 ... Outlet chamber, 30 ... Wall, 32 ...
... outlet opening, 34 ... inlet pipe, 36 ... inlet port, 38 ...
Outlet tube, 40 ... fitting, 42 ... lumen, 44 ... balloon,
46 ... Artery.

Claims (27)

(57) [Claims] 1. A pump body, means provided on the pump body to increase the pressure of blood passing therethrough, and means in flow communication with the pump body to reduce pulsation of blood exiting the pump body. A blood pump, wherein the means for mitigating blood pulsation includes a housing defining a storage chamber and a membrane covering and closing the storage chamber. 2. The blood pump according to claim 1, wherein said pulsation reducing means is integral with said pump main body, and said membrane does not generate a dead spot where blood accumulates in a flow path in said pump main body. The blood pump is provided in the pulsation alleviating means. 3. The blood pump according to claim 1, wherein said blood pressure increasing means defines at least one inlet valve, at least one outlet valve, and a volume portion in fluid communication with both said inlet valve and said outlet valve. A blood pump, comprising: at least one pressurizing chamber to be formed; and means for changing the volume of each pressure chamber. 4. The blood pump according to claim 3, wherein said pressurizing chamber is cylindrical, and said means for changing the volume is a piston. 5. The blood pump according to claim 3, wherein said outlet valve is in flow communication with an outlet port of said body, said membrane covering said outlet port when said outlet valve is in a closed position, and wherein said reservoir is open. A chamber disposed opposite the outlet port of the membrane, wherein the body further includes an outlet chamber remote from the outlet port, wherein the outlet valve is open and the membrane flexes to provide a volume of the storage chamber. Wherein the outlet chamber is in flow communication with the outlet port when reducing pressure. 6. The blood pump according to claim 5, wherein said body further includes an outlet opening in flow communication with said outlet chamber. 7. The blood pump of claim 6, further comprising a balloon angioplasty catheter having a fill lumen of approximately 0.020 inch inside diameter adjacent and extending through the distal end and exiting said body. A blood pump wherein an opening is in flow communication with the full lumen of the catheter, thereby mitigating pulsation and allowing pressurized blood to be pumped through the catheter during balloon angioplasty. 8. The blood pump of claim 1 including a balloon angioplasty catheter having a filled lumen having an inner diameter of approximately 0.020 inches adjacent to and extending through the distal end, wherein said body is A blood pump, wherein the blood pump is in flow communication with the fill lumen of the catheter, such that pulsatile relief pressurized blood is pumped through the catheter during balloon angioplasty. 9. The blood pump according to claim 7, wherein said pulsation reducing means is integral with said main body, and said pulsation is provided such that said membrane avoids the formation of a dead spot where blood pools in a flow path in said main body. A blood pump, wherein the blood pump is disposed in the mitigation means. 10. A body defining a cavity therein, at least one double acting piston dividing said cavity into at least one first and second chamber, and said first and second pistons.
An inlet and outlet valve in flow communication with the first chamber to assist in pressurizing blood in the first chamber as the piston moves in one direction and the second as the piston moves in the opposite direction. A blood pump, wherein the two valves are selectively actuated in response to movement of the piston to permit sequence operation of the two valves to assist in pressurizing the chamber. 11. The blood pump according to claim 10, further comprising means provided on said main body for reducing the pulsation of the pressure of said blood as said blood leaves said pump, said pulsation reducing means further comprising an accumulation chamber therein. And a membrane covering the storage chamber and closing the same. 12. A blood pump comprising: a blood pump capable of producing a pressure of at least 120 psig; and a means in flow communication with the blood pump for reducing pulsation of blood as it exits the blood pump. Means include a housing defining a storage chamber therein, a membrane covering and closing the storage chamber, and a fill having an inner diameter of approximately 0.020 inches extending through and adjacent the distal end. An angioplasty catheter having a lumen, such that blood is pumped out of the lumen and the distal end of the catheter when the blood pump is used in a patient in flow communication with the fill lumen. A device for filling blood during angioplasty, characterized in that: 13. The apparatus of claim 8, wherein said pressure increasing means further comprises an inlet port adapted to be mounted in a vein or artery of a patient's kidney, thereby pumping blood during angioplasty. An apparatus characterized in that it flows continuously through the catheter. 14. The device of claim 12, wherein said pump further comprises an inlet port adapted to be mounted on a vein or artery of a patient's kidney, thereby allowing said pump to pass through said pump and said catheter during angioplasty. An apparatus characterized in that blood is made to flow continuously. 15. The apparatus of claim 1, wherein said pressure increasing means is capable of producing a pressure of at least about 120 psig. 16. The apparatus of claim 7, wherein said pressure increasing means is capable of producing a pressure of at least about 120 psig. 17. The apparatus of claim 10 wherein said pump is capable of producing a pressure of at least about 120 psig. 18. The apparatus of claim 1, wherein said pump further includes drive means connected to said pressure increasing means for selectively operating said pressure increase means, said pump including said drive means being portable. An apparatus, comprising: 19. The apparatus according to claim 7, wherein said pump further includes driving means connected to said pressure increasing means for selectively operating said pressure increasing means, said pump including said driving means being portable. An apparatus, comprising: 20. The apparatus according to claim 10, wherein said pump further comprises drive means connected to said piston for selectively operating said piston, said pump containing said drive means being portable. An apparatus characterized by the above. 21. The apparatus according to claim 12, wherein said pump further includes drive means connected to said piston for selectively operating said piston, and said pump including said drive means is portable. An apparatus characterized by the above. 22. The apparatus according to claim 18, wherein said main body, said pressure increasing means and said pulsation reducing means are disposable, and said driving means comprises an exchange unit including said main body, said pressure increasing means and said pulsating reducing means. An apparatus characterized by being reusable when worn. 23. The apparatus according to claim 19, wherein said main body, said pressure increasing means and said pulsation reducing means are disposable, and said driving means comprises an exchange unit including said main body, said pressure increasing means and said pulsation reducing means. An apparatus characterized by being reusable when worn. 24. The apparatus according to claim 20, wherein said main body is disposable, and said driving means can be used with a replacement main body. 25. The apparatus according to claim 21, wherein said main body is disposable, and said driving means can be used with a replacement main body. 26. The blood pump of claim 11, wherein said pulsation mitigation means is integral with said body, and wherein said membrane avoids the formation of dead spots in which blood accumulates in a flow path in said body. A blood pump provided in the pulsation reducing means. 27. The blood pump according to claim 12, wherein said pulsation relieving means is integral with said main body, and said membrane avoids the formation of dead spots where blood accumulates in a flow path in said main body. A blood pump provided in the pulsation alleviating means.