JPH07194694A - Heart blood vessel flow enhancer - Google Patents

Abstract

PURPOSE: To provide a heart support device without necessitating connection through the skin accompanied by the fear of infection. CONSTITUTION: A centrifugal pump 26 is provided with one or more pump inlets 28 and a pump outlet 29. An inlet conduit 40 and an outlet conduit 42 are connected to the pump inlet 28 and the pump outlet 29 in terms of fluid. The inlet conduit 40 delimits an inlet chamber 205 which practically surrounds a part of the pump at the position of the pump inlet 28, and the outlet conduit 42 delimits an expanded outlet chamber 206 which receives the blood from the pump outlet 29. An emergency bypass channel 207 bypasses the pump in an emergency. The emergency bypass channel 207 is usually kept in an almost closed state by a collar 208, and flow rate which is enough to prevent the coagulation and is enough to provide a blood channel between the inlet chamber 205 and the outlet chamber 206 is maintained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to cardiovascular flow enhancers specifically intended for permanent implantation in patients in need of cardiac support.

[0002]

BACKGROUND OF THE INVENTION Many heart patients have partial cardiac function and have long benefited from ventricular assist devices. Today, such long-term ventricular assist devices are not used, and fully assisted or partially assisted artificial hearts are implanted as a bridge to heart transplantation, but these devices do not assist normal heart function. Rather, it is an alternative. Two main types of ventricular assist devices have been developed and investigated. One is to use a part of an artificial heart or equivalent device connected between the heart and the aorta. This device, which is implanted and uses an internal power supply, is intended for short-term connections before implantation. The other is a counterpulsation device attached to the aorta. Blood passively flows into the collapsed form of the chamber during systole, and is then pushed back into the aorta when the chamber collapses. There are two main types of short-term ventricular assist devices currently in use, neither of which is used in the long term. One of them operates by counterpulsation, and an intra-arterial balun is used in a specific example. This intra-arterial balun is contracted or collapsed during systole, providing a space for the blood from the heart to fill. The existence of this space reduces the resistance force that the heart receives when acting. The intra-arterial balloon then expands, forcing blood through the arterial system. This type of ventricular assist device is not suitable for long-term use because it requires air pressure to be inflated and deflated in the arterial balun through the patient's skin, which can cause infections. The second type of short-term ventricular assist device uses an extracorporeal pump as a biomedical centrifugal pump, but again requires the pump's inlet and outlet to be percutaneously connected with the risk of infection. .

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cardiac assist device that includes a cardiovascular flow enhancer that does not require a transcutaneous connection with the risk of infection.

[0004]

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided an implantable cardiac assist device for long term use.
Minimal anticoagulant therapy during use of the device is required because the heart assist device of the present invention does not use valves that can cause extensive coagulation. In particular, the main feature of the present invention is the flow enhancer. The flow enhancer includes an implanted centrifugal pump with its inlet connected to the node site of the descending thoracic aorta. This nodal site is a unique site that provides unique benefits. That is, when the auxiliary pump is connected to the first pressure / flow node site, the blood flow proceeding from the left ventricle is accelerated and complemented at this site. First pressure /
In the region immediately adjacent to the flow node region, the reflected waves from the two main regions, that is, the abdominal aorta-iliac junction and the peripheral arteriolar confluence region are combined to disturb the flow greatly. When connected to the pressure / flow node part of
Since the reflected wave and the pressure wave from the two main parts are eliminated, its adverse effect can be eliminated. Improving blood flow in the portion of the descending thoracic aorta is particularly beneficial because approximately 70 percent of the blood flows through this portion of the aorta.

Connecting the centrifugal pump to the first pressure / flow node site of the descending thoracic aorta has the additional benefit of eliminating the adverse effects of aortic stiffness or lack of elasticity. Most of the myocardial energy is consumed to fill the expanding aorta with blood. Elasticity is a major factor in determining aortic impedance or resistance. By connecting the centrifugal pump to the initial pressure / flow of the descending thoracic aorta, it is possible to create the effect of the invention on the basis of elasticity. When the blood flow from the ventricle reaches the aorta, the work of the heart is further reduced because the centrifugal pumping effect naturally causes the aorta to expand. Thus, according to the present invention, the cardiovascular pressure / flow dynamics are enhanced rather than nullifying or interfering with those dynamics as in the prior art.

[0006] Another benefit of connecting a centrifugal pump to the initial pressure / flow node site of the descending thoracic aorta is that the working force of the heart is dramatically reduced. This allows the heart to operate with improved loading and contraction properties, and its function can be restored and improved. In contrast, the use of conventional systems not only promotes recovery of myocardial function, but may also further impair myocardial function. The ventricular bypass system weakens the heart and causes the heart muscle to atrophy. While counterpulsation devices are useful during systole, counterpulse flow is completely retrograde and severe to the heart during diastole. Centrifugal pump to the first pressure of the thoracic descending aorta
Coupling to the flow node site also provides the benefit of eliminating the need for device insertion into or around the heart, keeping the pericardial sac intact. This benefit is a significant safety factor for subsequent surgery, such as coronary artery bypass surgery when heart function is improved or heart transplant is possible, and heart transplant surgery when proper improvement is not achieved. Be beneficial.

By connecting a centrifugal pump to the first pressure / flow node site of the descending thoracic aorta, all connections to the aorta are made downstream of the arteries around the brain, lungs and heart. Otherwise, the pump or related components will solidify or build up,
When these clots or deposits are released into the bloodstream downstream of these critical arteries, the cerebrum, lungs or heart become embolized. As another feature, the pump is implanted in the lower posterior thorax, specifically either the lower left hemithoracic above the diaphragm or the upper posterior thorax behind the upper lobe. Each site occupies a less important part of the left hemithoracic. Note that the site of implantation can be changed, but the site of connection is not changed. First, because the centrifugal pump does not include a valve, there is less blood-damaged machinery, and second, such a pump is used in conjunction with a pump speed control device to supplement and pump the heart. The benefit is that the pump speed can be varied depending on the physiological situation being addressed.

The flow enhancer or emergency bypass flow path of the present invention is used to allow normal blood flow in the event of mechanical failure of the pump or blockage of the flow path within the pump due to its bypassability. To be done. There are many such bypasses to address patients at any stage of arterial deterioration, some of which have also typically obtained aortic support to obtain blood flow. For example, a flow enhancer may be connected to a portion of the thoracic aorta or graft conduit in series with the aorta to provide a bypass that runs parallel to the flow path within the pump. During normal operation of the pump, the amount of blood flow through this bypass channel is minimal and sufficient to prevent coagulation.
However, in the event of a pump failure or blockage, this bypass channel opens and blood flows through it. Thus,
The installation of the emergency bypass flow channel is as follows: When the pump flow channel malfunctions, it opens and the patient simply returns to the state before surgery and can sit or sleep as necessary and has failed. It is beneficial in that it cannot be further harmed by the implantable device.

An alternative emergency bypass flow path uses a controllable collar that opens when the flow rate through the pump is below a minimum level. The collar may be provided on the graft in the aorta, in series with the aorta, or between the inlet and outlet conduits of the pump.
A second alternative example of an emergency bypass flow path is an almost closed long tube. This pipe functions as a small bypass flow path with a minimum flow rate during normal operation, but when the pump fails or is blocked, it elastically engages a wide short pipe to complete the bypass flow. In the third alternative example, a weighted check valve is used in the aorta. The check valve is closed during normal operation, but is opened by normal aortic flow pressure when the pump fails, and also prevents the reverse flow of blood discharged from the centrifugal pump.

[0010]

EXAMPLE Many patients have damaged myocardium and have reduced pumping capacity of the heart. This limits the patient's physical activity and promotes damage to other organs, thus compromising the patient's health. And in the most severe cases, patients become bedridden and need to consider heart transplants. These detrimental factors are involved in the dynamics of pressure waves created by the beating of the heart. The beating of the heart creates flow and pressure wave trains that travel downward through the aorta and vascular bed. When the aorta is divided into small-diameter branches at the iliac junction 10 (see FIG. 1) and flows further downstream, the pressure wave train and flow reflected not only from the iliac junction 10 but also from the vascular bed itself. The wave train travels backwards toward the heart. These flow trains and pressure wave trains traveling backwards interfere with the flow wave trains and pressure wave trains incidentally created by the heartbeat, and reduce the heart efficiency. Another adverse factor relates to the stiffness of the descending thoracic aorta. Lack of rigidity or elasticity of the descending thoracic aorta increases resistance or impedance of blood flow from the aorta. In the present invention, adverse factors such as those mentioned above are eliminated by linking blood flow enhancers at unique sites in the aorta. Transplantation of a blood flow enhancer allows long-term support for a weakened heart. For the patient, the risk of heart transplantation is avoided and costs are saved. Briefly, a pump, preferably a variable speed centrifugal pump, a power supply, and a controller are implanted. The pump is connected to the patient's vasculature in a novel manner as detailed below.

Although the connection to the aorta is always made in the same position in each embodiment of the present invention, other connection positions for the implant 20 are illustrated in FIGS. 1 and 2, implant 2
0 is located in the upper posterior chest behind the upper lobe. 4 and 5, the implant 20 is positioned behind and below the heart 32 and the left lung (not shown). For details, see FIGS.
It is positioned above the diaphragm 21 as shown in FIG. 1 and at a low position laterally in front of the diaphragm in the thoracic cavity. Each of these areas occupies an unimportant part of the left hemithoracic. In all cases, the graft 20 is connected to the descending thoracic aorta 27 as will be described.

Various forms of implants can be used with the present invention. The capsule-enclosed implant 2 illustrated in FIG.
0 is a centrifugal pump 2 driven by a drive motor 202 that receives power and control via an electric wire 203 in an outer case 201 made of a biologically inert material.
Includes 6. The pressure equalizing pipe 204 is the outer case 2
01, and terminates in, for example, a subcutaneous gas exchange unit (not shown). Centrifugal pump 26 includes one or more axial inlets 28 (hereinafter also simply pump inlet 28).
And a tangential outlet 29 (hereinafter, also simply referred to as a pump outlet 29). Inlet conduit 40 and outlet conduit 42 are in fluid communication with pump inlet 28 and pump outlet 29.
Inlet conduit 40 defines an inlet chamber 205 at pump inlet 28 that substantially surrounds a portion of the pump, and outlet conduit 42 defines an expanded outlet chamber 206 that receives blood from pump outlet 29. The emergency bypass channel 207 bypasses the pump in an emergency. This emergency bypass channel 207 is normally held almost closed by the collar 208 and its flow rate is sufficient to prevent coagulation and to provide a blood channel between the inlet chamber 205 and the outlet chamber 206. It will be the amount.

Various shapes of capsule-encapsulated implants are available. Certain capsule-encapsulated implants may include more or fewer components than those shown in FIG. 3, may have various blood flow channels, and may not have bypass channels therein. Furthermore, the pump does not have to be encapsulated with other components. As illustrated in FIGS. 5-21, centrifugal pump 26 with pump inlet 28 and pump outlet 29 is preferably coated with or includes a biologically inert material, but other components. Does not need to be encapsulated. In all illustrated embodiments, the pump 26 is a centrifugal pump, preferably U.S. patent application Ser. No. 402, filed Sep. 5, 1989.
No. 676 and its partial continuation application, February 2, 1991
A centrifugal pump having a two-stage structure described in U.S. Patent Application No. 659,859 (U.S. Pat. No. 5,174,726) filed on the 2nd. The centrifugal pump is of a design that does not include valves that could damage blood.

1, 2 and 6 there is shown an aorta 33 extending upward from the heart 32. The brachiocephalic artery 34 (see FIGS. 2 and 6) extends upward from the aorta 33 and extends to the pulmonary artery 3
It extends above 6. Left subclavian artery 3 of brachiocephalic artery 34
4A is closest to the connection between the pump inlet 28 of the pump and the descending thoracic aorta. Inlet conduit 40 connects pump inlet 28 to inlet portion 41 of the descending thoracic aorta.
The pump outlet 29 is connected to an outlet portion 43 of the descending thoracic aorta via an outlet conduit 42. The connection between each conduit and the pump is completed using a ring clamp 45. The connection between the aorta and each conduit is completed by ring clamps 45 or stitches.

In the present invention, cardiovascular flow benefits as well as other benefits are partially achieved through the connection of a centrifugal pump to a unique site in the aorta. This unique connection not only mechanically assists the pumping function of the heart, but also reduces the resistance or impedance to the blood supply by the heart and keeps the sac around the heart intact. It brings substantial benefits. Keeping the pericardial sac intact is a subsequent surgery, for example, coronary artery bypass surgery when heart function is improved or heart transplant is possible, and heart transplant when proper improvement is not achieved. It is beneficial because it is a great safety factor for surgery.

As shown in FIGS. 1-6, pump 26
The inlet and outlet of the thoracic artery are in the thoracic descending aorta 27 outside the pericardial sac, downstream from the brachiocephalic artery 34 and
Located close to. A preferred connection between the inlet conduit 40 of the pump and the descending thoracic aorta 27 is at the first pressure / flow node site of the descending thoracic aorta, ie, the site of minimum pressure or site of minimum flow variation in the upper portion of the descending aorta. The outlet conduit 42 is connected to the outlet portion 43 of the descending thoracic aorta at the non-flow node 43A position. That the blood flow is accelerated in the most efficient flow morphology at these connections,
The efficiency of assisting the blood flow from the heart of the pump 26 is particularly good, since the adverse effects of pressure and flow wave reflections are negated.

The patient's first pressure / flow node and non-node regions of the descending thoracic aorta vary primarily with heart rate, with the non-node region upstream of the initial pressure / flow node of the thoracic descending aorta. It may come. The connection of the inlet and outlet conduits is therefore not critically defined and can be made within a length of 3 to 5 inches of the aorta (about 7.6 to 12.7 cm). Generally, the first pressure / flow node portion of the descending thoracic aorta has a length of 4-5 cm, is within the range of 8-10 cm and begins 1-2 cm downstream of the left subclavian artery 34A. And terminates in the brachiocephalic artery 34. The first pressure / flow node site of the patient's thoracic descending aorta presents an important site of hemodynamics. This part of the aorta is explained in various ways, i.e., where the total amount of reflexes of sinusoidal capillaries is the smallest, or even where there is no reflex, the ventricular unit discharge fills the aorta and expands. It has been explained that the aorta is the site that gives the latent energy for the next forward motion of blood in the cardiac cycle (“Windkissel theory”).

Immediately below, or perhaps coincident with, the first pressure / flow node of the descending thoracic aorta is the last non-nodal site at which the pressure wave from the aortic bifurcation and surrounding vascular bed. And the total reflected wave of the current wave arrives. The blood discharged from the centrifugal pump returns to the aorta at this non-nodal site. Thus, the present invention eliminates the effect on the heart of the combined reflection of flow and pressure waves from the arterial bifurcation and surrounding vascular bed.

It has been found that the use of this first thoracic descending aortic primary pressure / flow node site of the descending thoracic aorta provides unique benefits to an actuation device, such as the centrifugal pump of the present invention. Blood is pumped at this site in the aorta for pumping, and at the same time backflow of blood is prevented at this site, so that a centrifugal pump connected to this site allows the abdominal aorta-iliac junction and the surrounding area to Prevents the delay of the forward flow of blood due to the reflected waves of pressure waves and flow waves from the arteriolar confluence and other locations, and these reflected waves weaken the accompanying beat created by the beating of the heart. To prevent. In addition, by providing auxiliary pumping from the initial pressure / flow node site of this descending thoracic aorta, resistance or impedance to flow to regions downstream of this site as viewed from the heart side is eliminated. To be done. The heart workload is dramatically reduced since 70% blood flow and most of the heart workload is directed to this region. Moreover, the workload of the heart is further reduced because the supplemental pumping at this site provides the volumetric capacity of the aorta to receive the respective ventricular drainage.

As a cardiovascular surgeon, the inventor of the present application has an experience of implanting a Hufnagel valve at this nodal site as a therapeutic measure for a patient with heart valve dysfunction. Hu
The fnagel valve is a passive device, containing a caged ball and valve seat, originally a check valve to prevent blood flow back into the heart. The inventor has placed this valve in the descending thoracic aorta at the above-mentioned nodal / non-nodal site outside the pericardium, beyond the brachiocephalic artery. The valve incorporated in the site not only replaced the role of the impaired heart valve, but also eliminated the adverse effects of pressure and stream waves at the non-nodal site, thereby producing a surprising effect.

The lower major portion of the descending thoracic aorta 27, close to the diaphragm, visually vibrates and undulates along its length. With that knowledge, it is possible to find a substantially waveless or mild site just downstream of the left subclavian artery. This quiet area is the first and last non-nodal site of the descending thoracic aorta. Experiments on dogs could benefit from connecting a pump to this nodal site without disrupting the hemodynamics necessary to maintain blood flow through the brachiocephalic artery 34 and coronary arteries (not shown). Was demonstrated.

As shown in FIG. 1, the pump 26 has an inlet 28 for receiving blood from the descending thoracic aorta at the nodal site 27A and an outlet at a position downstream of the thoracic descending aorta for the descending thoracic aorta. It was connected in series with the heart 32 with blood drained to 27. A ring clamp connector 45 of the type used with devices such as the Hufnagel valve may be used to connect the aorta to the pump.

Implantation of a pump as described and shown in FIGS. 1 and 2 can effectively achieve the cardiovascular flow benefits as described above, but if the pump fails or becomes clogged, for example, There is some mechanical problem, solidification,
In the event of a failure due to deposits or other factors that reduce or stop the flow through the pump or its inlet or outlet, the blood flow delivered through the aorta with means to bypass the pump It is desirable to have a safety mechanism that can be maintained in an emergency. Blood will still flow to some extent through an unobstructed but non-rotating pump, but the presence of an emergency bypass channel will safeguard the system from failure situations.

Various configurations of the emergency bypass flow path dysfunction system may be used in combination with a centrifugal pump connected to the thoracic descending aortic nodal site to provide an emergency bypass system to ensure continuous blood flow. . By connecting the pump 26 to the emergency bypass channel, the relative flow of blood in the two channels can be controlled. Generally, one channel will pass blood flow from the first pressure / flow node site of the descending thoracic aorta through the pump and back to the aorta downstream of the inlet of the pump, while the other channel will generally be The emergency bypass flow paths are parallel. For example, a portion of the descending thoracic aorta 27 (or a conduit implanted in-line with the aorta) may be connected bypassing the pump. When the mechanical or power failure as described above occurs, the emergency bypass channel opens and blood flows there. The accompanying drawings illustrate several alternative emergency bypass systems. Various forms of pump connections, emergency bypass channels to assist the role of the aorta at various stages of disease, calcification and friability
Color is illustrated.

An alternative emergency bypass system is illustrated in FIGS. 6 and 7, where a controllable collar is used,
The secondary flow path is opened when the primary flow path is clogged or a defect occurs. As shown in FIG. 6, a collar 85 is incorporated into the wall of the emergency bypass channel 86 of the in-line graft 87. The maximum flow rate in the pump is the emergency bypass flow path 86
At the time of normal operation in which the flow rate inside is minimum, the collar is operated by the pressure inside the line 88, and the emergency bypass flow path 86 is collapsed to the state shown by numeral 86 'in FIG. In an emergency, the pressure in the line 88 is released, the operation of the collar is cut off, and the emergency bypass flow path 86 is opened.

An alternate version of the emergency bypass system illustrated in FIGS. 8 and 9 uses a nearly closed long tube. This long tube is externally retained in its shape and normally functions as a small-diameter bypass flow path, allowing only a minimal amount of blood flow to prevent coagulation, but in the event of pump failure or occlusion, the heart beats. Due to the pressure, it expands elastically into a wide short tube and bypasses the entire volume. As shown in FIG. 8, a graft 65 is connected in series between an inlet portion 41 and an outlet portion 43 of the subclavian aorta. The upper section 66a of the first channel 66 of the implant is connected to the inlet of the pump 26 and the lower section 66b is connected to the outlet. The accordion type second flow path 67 bypasses the pump 26. The relative flow characteristics through the pump and the emergency bypass channel can be controlled by selecting the length and diameter of the two channels. In FIG. 8, the second flow path, that is, the emergency bypass flow path 27 is the flow path 6 of FIG.
7'longer and smaller diameter. Therefore, FIG. 8 illustrates a general state of transplantation in which blood flows through the first flow path 66 including the pump 26. In this case, the blood flow rate through the second flow path 67 is minimum, and the first flow path and the pump 2
The blood flow rate through 6 is maximum. When the blood flow rate through the first flow path 66 falls below the minimum level, the second flow path 67 expands and shortens based on the pressure, and the implant becomes the state illustrated in FIG. The diameter of the blood in the first flow path 66 is bypassed.

The shape of the emergency bypass channel shown in FIG.
Similar to those shown in FIGS. 8 and 9, it is advantageous in that the tubular member of the composite unit can be made prior to implantation and the connection to the aorta can be made at the time of implantation. Such an arrangement allows for rapid connection by an experienced surgeon. FIG. 10 illustrates another embodiment of the emergency bypass connection unit. Here, an inlet conduit 50 and an outlet conduit 51 are connected to the subclavian aorta 27 at side and end positions via suture grafts 52,53. A controllable collar 70 is attached to the portion of the aorta between the two grafts. The collar 70 has control lines 7 as shown in FIGS.
2 to a pressurized fluid source (not shown). The diameter of the flow path through the aorta 71 can be controlled by varying the fluid pressure inside this collar 70. Figure 1
At 1, the aorta is opened, allowing maximum flow as in an emergency situation. In FIG. 12, the pressure in collar 70 is increased and the diameter of aorta 71 is decreased to allow sufficient blood flow for anticoagulation only, such as during normal operation of the system.

In FIG. 13, the collar 75 is located in the aortic, unbranched section 76. The collar 75 completely surrounds the aorta 76, and when the line 77 is pressurized, the aorta is almost completely collapsed into a state as illustrated in FIG. FIG. 16 shows a two-section collar 80 that compresses the aortic section 81 in an anterior-posterior position. The two-section collar 80 includes two pads 80a and 80b which are secured onto the aorta by elastic filaments 82 as shown in FIGS. These pads are particularly effective when the patient's aorta is partially calcified as shown at 84, as it pressurizes through line 83 and collapses to flatten the aortic section 81 as shown in FIG. Is.

In an alternative emergency bypass system illustrated in FIG. 19, a variable collar 23 is attached to the section 24 of the descending thoracic aorta between the inlet conduit 40 and the outlet conduit 42. By controlling this collar as previously described, blood is blocked between the pump 26 and the aortic section 24 through the aortic section 24 during normal operation and section 2 when the collar is opened.
A relative flow is established which allows an emergency flow through 4. To prevent clotting, the collar always allows some blood to flow into the aorta. FIG. 20 shows a graft 47 of the subclavian aorta 27.
Another example of connection of the pump 26 by circumventing is illustrated. Here, the inlet conduit 50 and the outlet conduit 51 are connected to the aortic wall using grafts 52, 53 sewn on their sides and ends, respectively. Collar 23 controls blood flow through implant 47.

In an alternative emergency bypass system shown in FIGS. 22 and 23, a weighted flap type check valve 60 is used in the subclavian aorta 27. The flap check valve is almost closed during normal operation, but opens when the flow rate through the pump falls below a minimum level due to normal aortic flow pressure. The flap check valve 60 also prevents backflow of blood through the aorta. As shown in FIG. 22, the inlet conduit 50 and the outlet conduit 51 are connected to the aortic wall using grafts 52, 53 sewn on their sides and ends, and the flap check valve 60 is described above. It is disposed in the subclavian aorta 27 at a position between the connecting portions. Instead of implants 52, 53 sewn to the sides and ends, the pump outlet conduit 51 '
Can be connected to the aorta using a T-insert and an end-to-end graft 56 as shown in FIG. FIG. 23
In this embodiment, the outlet conduit 51 'is a T-shaped insert 55
Flap type check valve 61 connected to the aorta using
Are arranged in this T-shaped insert. Other alternatives are available, for example, a flap-type reverse for closing a flow through a forked channel, such as that illustrated in FIG. 6, typically through a secondary or emergency bypass channel. It can be used with stop valves. Similarly, in a capsule-encapsulated pump as illustrated in FIG. 3 in which the emergency bypass passage 207 is encapsulated, a flap-type check valve can be used instead of the collar.

The cardiovascular flow enhancer may be controlled to complement the pumping action of the heart. In particular, the use of a pump allows a wide range of flow rates to be obtained by varying the input of the pump with rotational speed and its output with the input and outlet resistance. A single controller to control the speed of rotation of the pump,
The pump can be set to operate at many different preselection levels. By percutaneously accessing the device, the patient can control the pump speed based on expected activity. More complex controllers such as illustrated in Figure 24 can also be used. Computer 90 for detecting and implanting a selected physiological condition of a patient
And a detection system such as that used in modern cardiac pacemakers. The computer provides the pump speed control signal, as shown in FIG.
Provide a signal for color control of the emergency bypass channel if necessary, eg, 1) in front of the heart in response to either directly measured left atrial pressure or indirectly measured diaphragmatic diastolic pressure. 2) Physiological requirements such as the display of signals created by increased cerebral potential for muscle activity and emotional expression, or saturation in the mixed venous circuit (at the bifurcation of the pulmonary artery) Increase or decrease the oxygen level (decreases with increased peripheral oxygen withdrawal in response to decreased cardiac output or increased peripheral or tissue demand).

In addition, the pump speed may be adjusted to limit systolic and diastolic beats. In particular, beats may be timed with systolic and diastolic key segments. The cardiovascular flow enhancer is preferably embodied in a system such as that shown in FIG. A battery 95, a rectifier 96, a charge controller 97 and a switch 98 are implanted, along with a pump, computer and collar. This system uses a power switching package that is readily available percutaneously. External RF power source 90 is transmitter coil 1
00 is connected. The receiving coil 101 is the skin 10 of the patient.
Immediately below 2 is implanted and connected to the rectifier 96. The battery is charged by placing the transmission coil 100 outside the skin 102 and disposing the transmission coil 100 at a position adjacent to the reception coil 101. R
The F source can be transmitted via the switch 103 by either a selected battery or an AC power source. RF power is coupled from the transmitter coil 100 to the receiver coil 101. Rectifier 96 rectifies the RF power and provides DC power from switch 98 to the pump, collar, and to heavy electricity 97. When the battery 95 is charged, the external RF source is removed and the pump, computer, collar receives power from the battery 95 via the switch 98.

[0033]

EFFECTS OF THE INVENTION A cardiac assist device is provided that does not require transcutaneous connection with the risk of infection.

[Brief description of drawings]

FIG. 1 is a perspective side view of a human body incorporating a capsule-enclosed pump, an emergency bypass flow path, a drive motor and a blood flow channel in the upper thorax.

2 is a partially enlarged perspective view of the heart and the descending thoracic aorta in a state where the pump of FIG. 1 is connected to a node part of the descending thoracic aorta. FIG.

FIG. 3 is a cross-sectional view of a pump encapsulating a drive motor, a blood flow channel, an emergency bypass channel and a collar.

FIG. 4 is a perspective side view of an alternative embodiment of the pump positioned within the lower thorax but connected to the aorta at the same location as in FIGS. 1 and 2, where the pump has an emergency bypass flow. The tract is not encapsulated and the emergency bypass channel is illustrated separately.

5 is a perspective view of a human body incorporating the pump of FIG.

FIG. 6 illustrates the pump being connected to the aorta in parallel with the flow control collar on the implant to provide an emergency blood flow path in the event of a failure of the primary blood flow path within the pump. FIG. 5 is a perspective view of the heart and descending thoracic aorta.

FIG. 7 is a plan view showing the operating state of the collar, taken along line 4-4 in FIG.

FIG. 8 is an illustration of an example of an emergency bypass flow path system, with a pump and an accordion-like implant that is connected in parallel to the pump and externally retained in an extended (closed) position to act as an emergency bypass flow path. Provide an emergency bypass flow path in the event of a failure of the main blood flow route within the pump.

FIG. 9 is an illustration of an emergency bypass channel system similar to that of FIG. 8 where the accordion-like implant downstream of the pump has failed and the blood pressure from the heartbeat has opened the emergency bypass channel. Is shown.

FIG. 10 is a part illustrating a state in which a pump is connected in parallel with a flow control collar on an aorta so as to provide an emergency bypass flow path in the case where a failure occurs in a primary blood flow path in the pump. It is a perspective view.

FIG. 11 is a plan view illustrating the operating state of the collar, taken along line 8-8 in FIG.

FIG. 12 is a plan view illustrating the operating state of the collar, taken along the line 8-8 in FIG.

13 is a partial perspective view similar to FIG. 10 in an alternative collar.

FIG. 14 is a plan view similar to FIG. 11 with an alternative collar.

FIG. 15 is a plan view similar to FIG. 12 with an alternative collar.

FIG. 16 is a partial perspective view similar to FIG. 10 with an alternative collar.

FIG. 17 is a plan view similar to FIG. 11 with an alternative collar.

FIG. 18 is a plan view similar to FIG. 12 with an alternative collar.

FIG. 19 is a partially enlarged perspective view of the heart and descending thoracic aorta with the pump connected in parallel with the descending thoracic aorta, which is occluded during normal operation and Provides an emergency bypass flow path in the event of a failure of the primary blood flow path through.

FIG. 20 is a partial perspective view of an example of an emergency bypass flow path system in which a pump is connected in parallel with a collar implant in the aorta, where blood flow during normal operation is severely restricted. As a result, an emergency bypass flow path is provided when the primary blood flow path in the pump fails.

FIG. 21 is a partial perspective view showing the outlet conduit of the pump connected to the aorta using a T-graft.

22 is a partial perspective view similar to FIG. 19, but with a check valve attached to the aorta.

FIG. 23 is a view showing a check valve in a state of being implanted in a T-shape.
It is a partial perspective view similar to FIG.

FIG. 24 is a diagram showing the control of the pump and the control of the collar of the emergency bypass flow path when such control is required.

FIG. 25 is a diagram of an electrical system for driving a cardiovascular flow enhancer pump as well as a collar when power is required to operate the collar.

[Explanation of symbols]

 20 graft 26 centrifugal pump 27 thoracic descending aorta 28 pump inlet 29 pump outlet 32 heart 33 aorta 34 brachiocephalic artery 34A left subclavian artery 40 inlet conduit 42 outlet conduit 43A non-node part 45 ring clamp 201 outer case 202 drive motor 203 electric wire 204 Pressure equalizing pipe 205 Inlet chamber 206 Outlet chamber 207 Emergency bypass flow passage 208 Color

Claims (5)

[Claims] 1. A cardiovascular flow enhancer comprising a centrifugal pump 26 having an inlet 28 and an outlet 29, and an inlet conduit 40 having one end thereof in fluid communication with the inlet of the centrifugal pump. An outlet conduit 42 having one end in fluid communication with the outlet of the centrifugal pump, the outlet conduit 42 comprising the centrifugal pump, the inlet conduit and the outlet conduit defining a primary blood flow path; And parallel flow conduits (207, 86, 87) extending between the outlet conduits to provide an emergency blood flow path for a certain level of blood flow when the blood flow rate through the centrifugal pump is below a minimum level. However, during normal operation of the centrifugal pump, it provides a secondary blood flow path for a lower level of blood flow and comprises a cardiovascular flow channel comprising a parallel flow conduit parallel to the primary blood flow path. Nsa. 2. A centrifugal pump including a controllable collar (208) operatively associated with the parallel flow conduit to limit the blood flow through said parallel flow conduit during normal operation of the centrifugal pump. The cardiovascular flow enhancer of claim 1, wherein a greater amount of blood is allowed to flow through said parallel flow conduits when the blood flow rate through said flow is below a minimum level. 3. The parallel flow conduits 67, 67 'are expandable and have an inner diameter that allows a minimum flow rate of blood therethrough during normal operation of the centrifugal pump so that the blood flow rate through the centrifugal pump is minimal. 2. The cardiovascular flow enhancer of claim 1, wherein the cardiovascular flow enhancer is capable of passing a larger amount of blood there by expanding when it falls below a level. 4. A flap-type valve 60, 61 for limiting the blood flow through the parallel flow conduits, said flap-type valve being provided when the blood pressure upstream of the flap-type valve reaches a pre-determined maximum level. The cardiovascular flow enhancer of claim 1, wherein blood is allowed to flow through the parallel flow conduit by opening a valve of the mold. 5. A centrifugal pump 26 and a parallel flow conduit 207 are retained within the housing 201 and include an inlet conduit, the housing 201 being sized and shaped to be implanted in a patient and made from a biologically inert material. 40 defines an inlet chamber 205 which is in fluid communication with the inlet of the centrifugal pump, and outlet conduit 42 defines an outlet chamber 206 which is in fluid communication with the outlet of the centrifugal pump, the inlet chamber and the outlet chamber being the housing. The cardiovascular flow enhancer of claim 1, wherein the cardiovascular flow enhancer is internally retained and wherein the parallel flow conduit extends between the inlet chamber and the outlet chamber.