US3513486A

US3513486A - Heart assistance pump

Info

Publication number: US3513486A
Application number: US641005A
Authority: US
Inventors: Michel Cotton De Bennetot; Maryvonne Estevenon Epo Cottin; Christian Cabrol; Edouard Coraboeuf
Original assignee: LE MATERIEL MAGNETIQUE
Current assignee: LE MATERIEL MAGNETIQUE
Priority date: 1966-05-24
Filing date: 1967-05-24
Publication date: 1970-05-26
Anticipated expiration: 1987-05-26
Also published as: GB1141446A; FR1504494A; FR94306E; DE1566360A1

Description

M .2 1970 M; COTTON DE BENNETOT ETAL 3 513 486 HEART ASSISTANCE PUMP Filed May 24, 1967 7 Sheets-Sheet 1 M 26, 1970 M. COTTON DE BENNETOT ErAL. 3,513,486.

HEART ASSISTANCE PUMP Filed May 24, 1967 7 Sheets-Sheet 2 May 1970 M. COTTON DE BENNETOT ETA!- v $513,486

HEART AS S ISTANCE PUMP 7 Sheets- Sheet :5

2 4 3 a. 4 m 1 M 4 W "y ll B P A NA 6 4 b 3 O A 3 6 4 H w 5 9 N F V/ ///1 Z i fiflwm 7 7 4 2 5 7 2 Z 2 May 26, 1970 M. COTTON DE BENNETOT ET AL 3,513,486

HEART ASSISTANCE PUMP Filed May 24, 1967 v Sheets-Sheet 4 May 26, 1970 M. COTTON DE BENNETOT 3,513,486

HEART ASS ISTANCE PUMP '7 Sheets-Sheet 5 Filed May 24, 1967 FIG? y 2 M. COTTON DE BENNETOT ETA!- HEART ASSISTANCE PUMP Filed May 24, 1967 7 Sheets-Sheet 6 F/GE May 26, 1970 M. COTTON DE BENNETOT ETA!- 3,513,486

HEART ASSISTANCE PUMP Filed May 24, 1967 7 Sheets-Sheet 7 3,513,486 HEART ASSISTANCE PUMP Michel Cotton de Bennetot and Maryvonne Estvenon pouse Cottin, Brest, Christian Cabrol, Paris, and Edouard Corahoeuf, Massy, France, assignors to Le Materiel Magnetique, Puteaux, Hauts-de-Seine, France Filed May 24, 1967, Ser. No. 641,005 Claims priority, applicrtion France, May 24, 1966,

2,667 Int. Cl. A611? 1/24 US. C]. 3-1 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to intracorporal pumps for the purpose of assisting or replacing the heart either temporarily or permanently.

Intracorporal blood-circulation pumps comprise one or a number of pouches which are connected into the circulation system; the contraction of said pouches effects the expulsion of blood whilst the expansion produces suction of blood. The deformation of said pouches (contraction and expansion) has been obtained in prior art by a number of different means, among which can be mentioned the injection of compressed air, hydraulic transmission of the pressure exerted by diaphragms actuated by electromagnets, the action of a pendulum.

These known solutions are relatively complex and do not provide a satisfactory answer to the difficult problem of supplying energy to an intracorporal pump which continuously utilizes a power of the order of several watts. In view of the fact that the removal of heat dissipated in the body sets a problem which is very diflicult to solve in the present state of the art, all expedients entailing the use of an intracorporal motor having a relatively low output such as an electric motor serve very little practical purpose. In point of fact, the known solutions comprising an extracorporal motor of the type which is associated, for example, with a pneumatic transmission system entail perforation of the skin tissue.

Accordingly it is an object of the present invention to provide wholly mechanical means for deforming the pouch, said means being particularly simple and designed in addition to permit of operation by means of an extracorporal source of power, without any passage of wires or tubes through the skin tissue.

It is another object of the present invention to provide a heart assistance pump including a rotary shaft entirely contained inside the body and acting through the intermediary of a simple motion conversion device so as to initiate the alternating translational motion of a member which is in turn adapted to drive a device for producing action on the outer wall of the pouch in such manner as to compress and release said pouch in alternate sequence.

In accordance with a preferred embodiment of the invention, the drive to the rotary intracorporal shaft is effected from an extracorporal source of power by means of a rotating magnetic field transmission system.

A better understanding of the invention will be gained United States Patent from the description which now follows, reference being made to the accompanying drawings, in which:

FIGS. 1 and 2 are diagrammatic views looking in a profile direction and frontal direction respectively and showing a blood-circulation pump in accordance with a preferred embodiment of the invention;

FIG. 3 is a longitudinal sectional view of a heart assistance pump in accordance with a second embodiment execution, in the diastole position, as well as the power generator and transmitter which are associated therewith;

FIG. 4 is a sectional view of the power transmitter, this view being taken along the line A-A of FIG. 3;

FIG. 5 is a partial view of said pump in the systole position;

FIG. 6 is a longitudinal sectional view of a heart assistance pump in accordance with an alternative to the embodiment shown in FIGS. 1 and 2;

FIG. 7 is a sectional view showing a detail of the device of FIG. 6;

FIG. 8 shows in the systole position the pump which is shown in FIG. 6 in the diastole position; and

FIG. 9 is a diagrammatic view of a pump in accord ance with the invention in which said pump is mounted as a left ventricular bypass.

The pump which is shown in FIGS. 1 and 2 is intended to deform periodically a flexible pouch 1 which is intended to be connected by means of its inlet orifice 2 and out let orifice 3 to natural or artificial organs for the purpose of establishing an intracorporal blood circulation.

The flexible pouch 1 or artificial ventricle is for instance fabricated of inert plastic and compatible with the blood, or even of animal or human tissue.

The above mentioned pouch is contained in a rigid casing 4 formed of a material which is tolerated by the body and attached at 5 to said casing in such a manner that the tractive forces exerted on the lower end of the pouch for the purpose of deforming this latter are not transmitted to the connection which is provided at 3. In fact, it is highly desirable to ensure that no stress is transmitted to the vein or artery which is joined to the pouch at 3. Moreover, the pouch is attached at several points to two

flexible strips

16a and 16b, the mode of attachment adopted being similar to the method described in detail in reference to the alternative form of FIGS. 6 to 8. The design function of said flexible strips is to produce the contraction of the pouch until the systole position is reached as indicated diagrammatically in chain-dotted lines in FIG. 2 and to restore the pouch to the diastole position as shown in full lines in FIG. 2.

The outlet orifice 3 is located at the upper end of the pouch and is substantially centered on the vertical axis of this latter, thereby permitting the possibility of propelling the blood current in the axis of the artificial ventricle as thus constituted and preventing any danger of vortices which would otherwise be liable to cause serious physiological disturbances.

The inlet orifice 2 is located on one of the two faces, namely the front face or rear face which are practically not subjected to any deformation during the deformation of the lateral faces 1a and 1b.

There have been shown in the drawings ball valves 7 and 6 respectively in the blood vessels which terminate in the above mentioned orifices. The device can be fitted with different types of valves, in particular valvulae which are taken either from an animal or human body or such valves may be dispensed with, depending on the applications which are contemplated. The different modes of connection of the pump herein described and illustrated are within the capacity of anyone versed in the art and it would consequently be feasible to effect the association of pumps of the same type which perform respectively the Patented May 26, 1970v functions of the left heart and right heart. The two artificial ventricles will advantageously be coupled and controlled by a common stem.

One exampie of connection is illustrated in FIG. 9.

The control of the deformation of the pouch in accordance with a cycle which comprises a contraction (systole) and a relaxation (diastole) of suitable duration for the purpose of reproducing a cardiac revolution is obtained by means of a stem 8 (or equivalent member) which is driven in reciprocating translational motion by a cam 9 (or other equivalent member) which is mounted on a rotating shaft 10.

In the preferred embodiment shown in FIGS. 1 and 2, the shaft 10 is the output shaft of a reduction unit 12, the input shaft 13 of which is driven by means {not shown) at a speed of the order of 1,800 r.p.m., for example. A reduction in the ratio of 30:1 accordingly makes it possible to reduce the speed of rotation of the shaft 10 to 60 rpm.

The means adopted for the purpose of driving the shaft 13 consist, for example, of an extracorporal electric motor associated with a synchronous magnetic coupling having an extracorporal driving rotor and an intracorporal driven rotor, or alternatively, a synchronous motor having a stationary extracorporal winding and an intracorporal rotor which is preferably of the permanent magnet type. These solutions which are given without any implied limitation are nevertheless of particular interest by virtue of the fact that an intracorporal rotary shaft can thus be driven by means of an extracorporal power source at speeds of rotation which can be selected from a wide range and with particularly low intracorporal heat losses. The useful power is transmitted to the interior of the body at a relatively high speed, therefore by means of a device which can be of small overall size; and the shaft 10 is driven at the desired speed by means of the reduction unit.

One particularly advantageous embodiment of the power transmitter is shown in FIGS. 3 and 4 and will be described hereinafter.

It will be readily apparent that any other system could be adopted for the purpose of driving the shaft 10 without thereby departing from the scope of the invention.

The means for converting a rotational movement to an alternating translational movement and for controlling the deformation of a pouch from said translational movement can also permit of alternative forms of execution.

The preferred form of execution which is illustrated in FIGS. 1 and 2 comprises the cam 9, two

rollers

14 and 15 which are carried by the stem 8 and with which the cam is adapted to cooperate, and two

springs

16a and 16b, the lower ends of which are attached to the stem 8 and the upper ends of which are attached to the casing 4 at 17a and 17 b respectively.

This form of execution calls for the use of a minimum number of parts and its very simplicity endows it with particularly reliable operation for a very long period of time.

The rotation of the cam produces an alternating translational movement of the stem 8 in the downward direction, said stem being guided in this movement by means of

bearings

18 and 19 contained in a rigid tube 20 which is integral with the casing 4. The tractive force exerted by the stern on the springs reduces the deflection of these latter. Inasmuch as said springs completely surround the lateral faces of the pouch, this latter is accordingly compressed. As and when the stem 8 moves upwards, the springs expand and are accompanied in this motion by the lateral faces of the pouch which then returns completely to its maximum volume.

In order to prevent any direct contact of the springs with the lateral faces of the pouch, provision is made for an elastic: material which is interposed at 21a-21b so as to form a cushion.

The cam profile can readily be determined so that the ratio of the outgoing motion to the return motion of the stem and consequently the ratio of the duration of the diastole to the duratoin of the systole should have a suitable value.

By way of alternative, the spings could be replaced by a link-rod system whereby components which closely conform to the shape of the lateral faces of the pouch are applied against this latter.

In the second form of execution which is illustrated in FIGS. 3 to 5, the artificial deformable ventricle 22 has a cylindrical shape at the top portion thereof whilst a pushplate 23 actuated by a control rod 24 is applied against the base of said ventricle.

The control rod 24 is driven in alternating motion by a connecting-rod 25, the lower end of which is pivotally coupled to a crank 26. Said crank is rotatably mounted within a casing 27 which contains the motion conversion system and the artificial ventricle and is driven in rotation by the output shaft 28 of a reduction-gear unit 29 having a ratio of 30:1, for example.

The input shaft 30 of the reduction-gear unit is driven, for example, at 1800 rpm. by the mild-steel driven motor 31 of a rotating magnetic field power transmitter.

The power transmitter comprises a driving rotor 32 and associated permanent magnets 33 to 36 fitted with polepieces 37 to 40 which define active air-gaps with the teeth 31a to 31d of the driven rotor (as shown in FIG. 4).

The driving rotor is driven by the output shaft 41 of a direct-current electric motor 42. Said motor can be supplied from a portable generator such as a rechargeabie storage cell or else it can be connected to a mains supply point. A feeding Wire 63 has been shown in FIG. 3.

The motor 42 and the driving rotor are contained in an extracorporal casing 43, the front face 43a of which is so shaped as to permit the concentric engagement therein of the intracorporal transmitter casing 44 and houses a bearing 45 which supports the driving rotor.

The intracorporal casing 44 also houses a bearing 46 which supports the driven rotor.

The skin P which is inserted between the concentric and interengaged cylindrical portions of the two

casings

43 and 44 is slightly deformed. A skin elevation of this kind is perfectly feasible and the synchronous magnetic coupling with a cylindrical active surface which is thus formed does not have any tendency to flatten the skin by compression by virtue of the fact that the resultant of the continuous forces of attraction between the two rotors is zero.

By reason of the synchronism of the magnetic coupling, the speed of rotation of the output shaft of the reduction unit is controlled in dependence on the speed of the motor. The speed of the internal elements can consequently be varied by modifying the supply voltage of the motor.

The top edge of the pouch 22 is inserted in the cover 7d of the casing 27. Said casing is provided with an inlet orifice 47 in which is fitted a clapper-vaive 48 and with an outlet oriiice 49 in which is fitted a ball valve 50. The ball 50' is retained by means of two or a number of arcuate members such as the member 51 which are respectively disposed in planes at right angles to each other. Two ends 52 and 53 permit the connection of the pump to the patients heart; as shown in FIG. 9, an admission tube which is connected to the pump at 52 is adapted to penetrate, for example, into the left a'uricle whilst an outlet tube which is connected to the pump at 53 is connected to the aorta.

The intracorporal casing 44 is provided at its periphery with an annular flange 54 (as shown in FIGS. 3 and 6). Said flange is pierced by approximately ten holes (not shown) which are intended to permit of its attachment in the body. This attachment can be performed as follows:

An incision is made for instance in the abdominal wall and the intracorporal casing is introduced within the subcutaneous pouch which is thus formed; the casing can be fastened to the muscle M by means of a number of nylon sutures, the skin incision being then closed up. The extracorporal casing 43 is then placed in position on the abdominal wall and maintained, for example, by means of a waistcoat fitted with straps.

In FIG. 6, the pouch 22 and the

valves

48 and 50 are shown in the systole position. The volume of blood which is expelled at each pulsation may be of the order of 30 to 80 cubic centimeters, according to the size of the arti ficial ventricle and will practically be independent of the pulsation frequency.

There is also shown in FIG. 6 a pump of the same type as the one shown in FIGS. 1 and 2 but in which the motion conversion device is the same as in the second form of execution, namely the embodiment of FIG. 3 (the main components thereof are designated in FIG. 6 by the same reference numerals as in FIG. 3 to which are assigned the index a).

It is apparent that the flexible pouch or artificial venritcle 55 is attached by means of its top edge 56 to a member 57 which is integral with the rigid casing 58 and with the endpiece 53a: the lower ends of the

springs

59 and 60 are attached to the stem 24a whilst the upper ends of said springs are pivotally mounted in said member 57.

The walls of the pouch 55 are attached to the

springs

59 and 60 by means of nipple-shaped

members

61, 62 which are adapted to penetrate into elongated slots formed in said springs, as shown in FIG. 7.

What is claimed is:

1. A heart assistance device including at least one artificial ventricle, said ventricle being made of resilient flexible material and having an outer wall; means for connecting said ventricle into the circulation system; a source of power; motor means supplied from said source; a mechanical deformation device engaging said outer wall for periodically producing action on the said outer wall so as to compress and release said ventricle in alternate sequence and driving means operatively connecting said motor means to said mechanical deformation device, said driving means including a rotating shaft; a rotating magnetic field transmission system operatively connecting said rotating shift to said motor means, a mechanical transmission member attached to said mechanical deformation device and a rotating to-alternating motion conversion device connecting said mechanical deformation device to said transmission system member, said rotating magnetic field transmission system being a synchronous magnetic coupling, including a driving rotor connected to said motor means and a driven rotor, a speed reducer connecting said driven rotor to said rotating shaft, a first casing lodging the driven rotor, the speed reducer, the rotating shaft, the motion conversion device, the mechanical transmission member, the mechanical deformation device and the ventricle, wherein the said rotors have concentric cylindrical facing surface portions, said casing has a substantially cylindrical portion in which the driven rotor is lodged, a further casing having a further substantially cylindrical portion in which the driving rotor is lodged, the said further substantially cylindrical portion having a substantially annular projection which is adapted for being concentrically arranged about the said substantially cylindrical portion of said first casing, and radially spaced therefrom, whereby a clearance is provided for lodging a substantially cylindrical skin projection which is concentric with the rotating shaft and located between the said concentric cylindrical surface portions of the two rotors.

2. A heart assistance device as claimed in claim 1, wherein the said mechanical deformation device essentially consists of two flexible strips and means for rigidly attaching said two flexible strips to the said ventricle respectively at opposite surface portions of the outer wall thereof, said mechanical transmission member essentially consisting of a control rod having one end connected to said flexible strips.

3. A heart assistance device as claimed in claim 2, wherein the said ventricle is an elongated pouch having a longitudinal plane of symmetry, said means for connecting the ventricle into the circulation system including an outlet and an inlet, said outlet and the two flexible strips being substantially symmetrically arranged with respect to said plane of symmetry, said inlet being connected to the outer wall of the ventricle outside the said opposite surface portions thereof.

4. A heart assistance device as claimed in claim 2, wherein the said flexible strips are pivotally mounted in the upper end portion of the casing.

References Cited UNITED STATES PATENTS 3,097,366 7/1963 Winchell 31 3,127,846 4/1964 Kerns 128273 XR FOREIGN PATENTS 1,355,682 2/1964 France. 1,458,525 10/ 1966 France.

OTHER REFERENCES The Use of a Magnetic Field to Remotely Power an Implantable Blood Pump, by B. K. Kusserow, Transactions ASAIO, vol. VI, 1960, pp. 292-294.

Air-Driven Artificial Hearts Inside The Chest, by W. Seidel et al., Transactions ASAIO, vol. VII, 1961, pp. 378-385.

High-Amplitude Pulsatile Pump in Extracorporeal Circulation, by K. Nakayama et al., Surgery, vol. 54, No. 5, November 1963, pp. 798-809.

RICHARD A. GAUDET, Primary Examiner R. L. FRINKS, Assistant Examiner US. Cl. X.R.