Title:
CARDIAC ASSISTANCE DEVICE
United States Patent 3692018


Abstract:
A cardiac assistance device is disclosed which produces a uni-directional pumping action assisting the heart when the device is activated after it has been introduced into a blood vessel by conventional surgical procedures.



Inventors:
Goetz, Robert H. (Scarsdale, NY)
Goetz, Lionel J. (Scarsdale, NY)
Application Number:
05/010452
Publication Date:
09/19/1972
Filing Date:
02/11/1970
Assignee:
ROBERT H. GOETZ
LIONEL J. GOETZ
Primary Class:
Other Classes:
417/389, 417/475, 604/914
International Classes:
A61M1/10; (IPC1-7): A61B19/00
Field of Search:
128/1R,214,344,325,349B 417
View Patent Images:
US Patent References:
3592183HEART ASSIST METHOD AND APPARATUS1971-07-13Watkins et al.
3505987INTRA-AORTIC HEART PUMP1970-04-14Heilman
3504662INTRA-ARTERIAL BLOOD PUMP1970-04-07Jones
3266487Heart pump augmentation system and apparatus1966-08-16Watkins et al.



Foreign References:
FR15864E1912-10-10
Other References:

Laird et al. Trans. Amer. Soc. Artif. Int. Organs. Vol. XIV, 1968 pp. 338-342.
Primary Examiner:
Truluck, Dalton L.
Claims:
We claim

1. A cardiac assistance device comprising:

2. expansion means on said support means for occluding the blood vessel;

3. blood moving means positioned on one side of the expansion means on said support means adjacent said insertable end for displacing blood within the vessel on said one side;

4. means for sequentially activating the expansion means and blood moving means in that order to produce a uni-directional flow of blood within the blood vessel away from the point of occlusion and toward the heart, and

5. The cardiac assistance device according to claim 1 wherein:

6. The cardiac assistance device according to claim 2 wherein:

7. a single balloon member held against expansion at an intermediate point along its length to thereby form the occluding chamber on one side of said point and the pumping chamber on the other side of said point; and

8. holding means attached to the balloon member for maintaining the relative position of the occluding chamber and pumping as they are introduced into the patient.

9. The cardiac assistance device according to claim 3 wherein:

10. The cardiac assistance device according to claim 4 wherein:

11. The cardiac assistance device according to claim 5 wherein:

12. The cardiac assistance device according to claim 5 wherein:

13. The cardiac assistance device according to claim 5 wherein:

Description:
BACKGROUND OF THE INVENTION

Heart failure is medically defined, in its broadest sense, as the inability of the heart to pump blood throughout the body. For purposes of describing the present invention a failing heart is defined as one that is not sufficiently healthy to pump blood at the rate needed to maintain adequate blood flow and continued well-being of its owner but which is nevertheless, capable of pumping some blood.

A cardiac assistance device is one that aids a failing heart. One presently known device used for this purpose comprises a single inflatable balloon which is adapted to be inserted into an appropriate blood vessel, as for example, the aorta. When such a device is inflated and deflated, a pumping action within the blood vessel occurs and when the inflation and deflation cycle is appropriately timed to the heartbeat, the device acts to assist the failing heart.

While this type of cardiac assistance device has significantly contributed to the progress of medical science, it is inherently inefficient. This is due to the fact that the balloon acts as an omni-directional pump thus making it impossible to direct its force in a single direction so that blood is pumped only to those regions of the body where adequate blood flow is most critical as for example, to the brain and the muscles of the heart itself.

SUMMARY OF THE INVENTION

In accordance with the teachings of the present invention a cardiac assistance device is provided which is constructed to create an artificially induced uni-directional "pumping action" within a blood vessel of the patient to aid the failing heart. In construction, the device includes an inflatable occluding chamber and one or more inflatable pumping chambers disposed on one side of the occluding chamber in communicating relationship therewith. The occluding and pumping chambers are adapted to be inserted into the blood vessel of the patient and both are inflated and deflated on a cyclical basis out of phase with the beat of the failing heart but sequentially with respect to each other by a pneumatic power source positioned externally of the patient.

The occluding chamber has a diameter greater than the diameter of the blood vessel within which it lies so that when inflated it occludes the blood vessel. Since the occluding chamber is inflated before the pumping chamber, the pressure created in the blood vessel when the pumping chamber is later inflated causes the blood to flow in a single direction away from point of occlusion between the inflated occluding chamber and the wall of the blood vessel. Thus the cardiac assistance device of the present invention acts as a uni-directional pump and when properly positioned the direction of blood flow created by the device can be effectively controlled according to the dictates of sound medical practice to be most beneficial to the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of the cardiac assistance device of this invention disposed within a blood vessel.

FIG. 2 is a cross-sectional view of the cardiac assistance device of this invention disposed within a blood vessel showing an alternative embodiment of the structure within the occluding chamber.

FIGS. 3 and 4 are elevation views of the cardiac assistance device of this invention showing progressive stages of the operation of the device.

FIG. 5 is a diagrammatic illustration of a human heart showing the placement of the cardiac assistance device within the aorta.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, the cardiac assistance device includes a pumping structure indicated generally by reference numeral 10 which is adapted to be inserted within a blood vessel 2 of the patient by conventional surgical procedures. The pumping structure is specially constructed to produce a uni-directional flow of blood within the blood vessel. For this purpose the pumping structure operates to first occlude the blood vessel and then to create pressure within the blood vessel on one side of the point of occlusion to thereby cause the blood within the vessel to flow in one direction away from the point of occlusion. In construction, the pumping structure includes expansion means for internally occluding the blood vessel and blood moving means positioned on one side of the expansion means for displacing blood on that side of the expansion means. As shown, the expansion means comprises an inflatable occluding chamber 3 and the blood moving means comprises one or more inflatable pumping chambers 4 which communicate in series with the occluding chamber. The occluding chamber 3 and the pumping chamber 4 are defined by a balloon structure which consists of a balloon member 5 mounted on a tubular conduit 6 extending longitudinally through the balloon member 5. Each end of the balloon is disposed in fluid-gas tight relationship about the tubular conduit by suitable sealing means as for example, silk threads 7 tied tightly about the terminal ends of the balloon member. As shown, an intermediate portion of the balloon member 5 is held against expansion in fluid-gas tight relationship to the tubular conduit 6 by silk threads 7' similar to the ones used for sealing each end of the balloon member. A metallic pellet 13 seals the end of the tubular conduit at a point located near the end of the pumping chamber 4 remote from the occluding chamber. The use of a metallic pellet for this purpose advantageously permits the position of the pumping structure within the blood vessel to be visually monitored by the use of standard X-ray techniques after it has been introduced into the patient.

The balloon member 5 and the tubular conduit are made of nonthrombogenic material so that the danger of blood clotting is eliminated. Also the silk sealing threads are coated with a nonthrombogenic material and the assembled pumping structure is dipped into a bath of molten nonthrombogenic material. An example of nonthrombogenic material is polyurethane. In addition to being nonthrombogenic, the balloon member is also inelastic or nonstretchable so that the danger of fatigue failure due to stretching when the balloon member is repeatedly inflated and deflated is avoided. In other words, no stretching of the balloon member occurs when it is inflated. Rather the balloon merely expands upon inflation to its natural but relaxed inflated state.

The tubular conduit serves a dual purpose. First, it acts to hold the pumping chamber on one side of the occluding chamber as the balloon structure is introduced into the patient thus preventing the balloon structure from folding back on itself. Secondly, the tubular conduit provides a convenient means for introducing gas or fluid into the balloon structure to inflate the occluding and pumping chambers. For the latter purpose those portions of the tubular conduit which extend through the occluding and pumping chambers are provided with a series of perforations 8 which permit air flow into and out of the occluding and pumping chambers. In the presently preferred embodiment of this invention, the tubular conduit has a diameter of approximately 2-3 millimeters and the perforations are approximately 1 millimeter in diameter.

The occluding chamber of the balloon has a size such as when inflated the blood vessel is internally occluded. The blood vessel is occluded by the inflated occluding chamber in the sense that a complete occlusion of the blood vessel is produced causing stoppage of the blood stream and accumulation of the pressure within the blood vessel. The pumping chamber on the other hand is slightly smaller in size than the occluding chamber and when inflated the pumping chamber acts only to increase the pressure within the blood vessel. In other words, flow of blood past the inflated pumping chamber is not prevented but blood flow past the inflated occluding chamber is prevented. In the construction shown in the drawing, the occluding chamber is substantially spherical in shape while the single pumping chamber shown is substantially cylindrical in shape. Since the construction shown in the drawing is intended for insertion within the aorta of the patient which for the average patient has an inside diameter of approximately 18-22 millimeters, it is preferred that the spherical occluding chamber be slightly greater than 22 millimeters in diameter in its inflated state and that the pumping chamber have an inflated size of approximately 16 millimeters in diameter.

The occluding and pumping chamber of the balloon are alternately inflated and deflated at a cycle which is out of phase with the heartbeat of the patient. That is, when the heart is relaxed, the chambers of the balloon are inflated and when the heart is pumping these chambers are deflated. For this purpose a pneumatic power source indicated diagrammatically by reference numeral 11 in FIG. 5 is provided. The pneumatic power source is of conventional construction having the capability of creating alternating positive and negative pressure as triggered by the electrocardiogram of the patient. As shown, the pumping machine is connected to the balloon structure via the tubular conduit 6. A suitable pumping machine for practicing the teachings of the present invention is the pneumatic pumping machine produced by the Datascope Company of New Jersey.

In order to provide uni-directional pumping action, the occluding chamber of the balloon structure is inflated prior to inflation of the pumping chamber. For this purpose an obstruction member 9 is provided. The obstruction member acts to divert the flow of gas within the balloon structure in a manner which produces sequential inflation of the occluding and pumping chambers. As shown the obstruction member is disposed within that portion of the tubular conduit extending through the occluding chamber 3 at a point located between two adjacent perforations 8' and 8". With this arrangement, gas supplied from the pneumatic power source is temporarily diverted from the tubular conduit into the occluding chamber through the perforations 8" disposed upstream of the obstruction member. This diversion is due to the presence of the obstruction member which prevents uninterrupted flow of gas through the tubular conduit. When the occluding chamber has reached a fully inflated configuration as shown in FIG. 4, the gas reenters the tubular conduit through the perforations 8' disposed downstream of the obstruction member. From this point the gas flows into the pumping chamber through the perforations disposed in the portion of the tubular conduit extending within the pumping chamber. Thereby the pumping chamber is brought to a fully inflated condition as shown in FIG. 1. Thus it will be seen that the occluding chamber and pumping chambers are repeatedly cycled in a sequential fashion from the configuration shown in FIG. 3 where both chambers are collapsed to the configuration shown in FIG. 4 where the occluding chamber is inflated and the pumping chamber deflated and finally to the configuration shown in FIG. 1 wherein both chambers are inflated causing blood within the vessel to flow in the direction of arrows 14 away from the point of occlusion in the vessel created by the inflated occluding chamber. With the solid obstruction member it will be recognized that deflation of the occluding chamber also occurs in a sequential manner. In other words, during the deflation phase a reverse flow of air out of the balloon is created first from the occluding chamber through the perforations 8' and then from the pumping chamber. The path of exit from the pumping chamber leads into the conduit 6 through the perforations disposed in the portion of the conduit 6 located within the pumping chamber and then into the occluding chamber via the perforations 8' and finally back into the tubular conduit through the perforations 8" and out of the balloon structure.

The occluding and pumping chambers may advantageously be deflated substantially simultaneously by replacing the solid obstruction member with a one-way valve such as the ball valve 12 shown in FIG. 2. With this arrangement, the ball valve is closed during the inflation cycle thereby producing the same pattern of air flow as is produced with the solid obstruction member shown in FIG. 1. However, on the deflation cycle, the ball valve is opened thus permitting air to be withdrawn from the occluding and pumping chambers through all the perforations in those portions of the tubular conduit disposed within these chambers at substantially the same time. Simultaneous deflation of the occluding and pumping chambers is advantageous since very little time is consumed between successive beats of the heart. Thus the possibility that the pumping structure will pulsate in appropriate coordination with the heartbeat is thereby greatly enhanced.

One application for the cardiac assistance device of the present invention is sown in FIG. 5. For this application the pumping structure section of the device is inserted into the femoral artery at a point below the bifurcation in the aorta and pushed upward into the aorta to the position shown. In this position the device acts to direct a flow of blood toward the heart into the coronary artery which supplies blood to the heart muscles and also into the carotid arteries which supply blood to the brain. Blood pumped by the cardiac assistance device is prevented from reentering the heart chamber by the aortic valve. It will be recognized that this particular use of the device is particularly beneficial since an adequate supply of blood to these critical organs is insured.