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England and Wales High Court (Patents Court) Decisions
You are here: BAILII >> Databases >> England and Wales High Court (Patents Court) Decisions >> Thoratec Europe Ltd v AIS GmbH Aachen Innovative Solutions  EWHC 2637 (Pat) (28 October 2016)
Cite as:  EWHC 2637 (Pat)
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Fetter Lane, London EC4A 1NL
B e f o r e :
| THORATEC EUROPE LIMITED
|- and -
|AIS GMBH AACHEN INNOVATIVE SOLUTIONS
James Mellor QC and Ben Longstaff (instructed by Ropes & Gray International LLP) for the Defendant
Hearing dates: 5-7, 11-13, 17 October 2016
Crown Copyright ©
MR JUSTICE ARNOLD :
|Legal expert witnesses||12|
|Technical expert witnesses||13-23|
|Circulatory anatomy and function||25|
|Aortic anatomy and branches||30-33|
|The cardiac cycle||34-41|
|Treatment of heart failure by artificial hearts and VADs||45-50|
|The intra-aortic balloon pump||56-61|
|Types of VADs||62-69|
|First generation VADs||70-73|
|Second generation VADs||74-85|
|The skilled person||118|
|Common general knowledge||119-120|
|A magnetic clutch with a proximal and a distal magnet unit||122-136|
|Sliding bearing/friction bearing||137-139|
|Relationship between the features of claims 1, 5, 7 and 8 and the features of claims 21 and 22||142-150|
|The prior art||151-190|
|The prior use||160-178|
|Johnson & Johnson||187|
|Novelty of claims 1 and 5||191-194|
|The prior use||194|
|Obviousness of claim 1||195-204|
|The attitudes and perceptions of skilled person||197-200|
|The skilled person's approach||201-202|
|Unpleaded case based on common general knowledge alone?||203|
|Johnson & Johnson||208|
|Obviousness of the subsidiary claims||212-225|
|The prior use||221-222|
|Sieß and Johnson & Johnson||223|
|Amendment of 658||227|
|Summary of principal conclusions||237|
Legal expert witnesses
Technical expert witnesses
Circulatory anatomy and function
Treatment of heart failure by artificial hearts and VADs
The intra-aortic balloon pump
Types of VADs
First generation VADs
Second generation VADs
Third generation VADs
i) The pump must be able to achieve a suitable flow rate against a given head of pressure. What flow rate was acceptable would depend on the clinical application which was envisaged, however. For example, the Impella 2.5 demonstrated that there was a market for a device that only produced a flow rate of 2.5 l/min.
ii) Insertion of a device at the end of a catheter by the Seldinger technique would limit the diameter of the device. This would place constraints upon the design of the pump and of the motor if the motor was to be located within the body.
iii) The pump must be designed to have an adequate life span, and hence to be able to withstand the mechanical stresses involved for that period. For short-term use, however, this would be less of an issue than for medium- or long-term use.
iv) Blood is sensitive and prone to damage if overstressed, in particular by excessive shear, which is apt to cause haemolysis (the rupture of blood cells). Nevertheless, the Hemopump and the Impella had shown that high rotational speeds could be achieved without high levels of haemolysis.
v) The design and placement of the device should minimise the risk of thrombosis (formation of blood clots), which can lead to strokes and other complications. I shall return to this point below.
vi) Blood should preferably not encounter the mechanical parts of the device, for the reasons explained above in relation to the Hemopump.
vii) The characteristics of the drive unit must match the characteristics of the pump, in particular in terms of the speed, torque and power required. Subject to that, however, the skilled person would appreciate that it would be possible to "mix and match" different drive units and pumps.
" The present invention is based on the problem of creating a catheter device with a drive shaft extending over virtually the whole catheter device and which may be driven at high rotary speed.
 The problem is solved by a catheter device according to claim 1. Advantageous developments of the invention are set out in the dependant claims".
" Because of the separation of the output-side clutch element up to the distal end of the catheter device, it is not necessary to guide the drive shaft to the outside via a hole. Any such feed-through would require sealing, but such sealing limits the speed. Since this catheter device has no corresponding sealing of a drive shaft feed-through, very high speeds may be transmitted to the drive shaft.
 The contribution of the transmittable torque is limited by the magnet ring bearing and the magnetic connection of the two magnet units. As soon as the settable torque is exceeded, the two magnet units separate."
" In accordance with a development, an additional magnet ring bearing is provided. On the one hand this provides further and especially radial support for the output-side clutch element, and on the other hand it is able to counteract the forces exerted by the magnet units, so that the force with which the output-side clutch element is pressed against the sliding bearing is reduced.
 The maximum torque transferable by the magnetic clutch is determined by both the distance between the two magnet units set by the sliding bearing and by the force with which the magnet ring bearing acts on the clutch element in the axial direction.
 The element rotating due to the drive shaft may be a rotor, a milling tool or another tool.
 Such a rotor is preferably designed to unfold automatically. It may be provided with a pump housing which, like the rotor, is compressible to a small diameter. …
 The combination of an automatically unfolding pump head with the magnetic clutch explained above forms a catheter device with which one the one hand, owing to the high speed and the large rotor, a high pump performance is obtained, and on the other hand a high life expectancy of several hours to several days is achieved."
" The clutch 9 is a magnetic clutch (Fig. 14, Fig. 15). The clutch 9 has a clutch housing 19 with a distal magnet unit 23.1. The clutch housing 19 is connected to the proximal catheter body element 8.2, which forms a continuous hollow space. The clutch housing 19 separates the proximal catheter body element 8.2 hermetically from a motor assembly 30. The motor assembly 30 has a proximal magnet unit 23.2. The proximal magnet unit 23.2 is connected by tension to the motor 7. The distal magnet unit 23.1 is connected to the drive shaft 4 via a clutch element 22.
 The distal magnet unit 23.1 and the proximal magnet unit 23.2 are coupled securely to one another through magnetic forces. A tension connection with non-contact rotational force transfer is ensured by the two magnet units 23.1, 23.2."
" At the distal end and at the periphery of the cylindrical section 22.2 of the clutch element 22, a shoulder 22.4 is formed . Mounted on this shoulder 22.4 is a second inner ring magnet 20.2. The shoulder 22.4 accommodates the inner ring magnet 20.2 in such a way that its outer surface lies flush with the cylindrical surface of the cylindrical section 22.2. This forms, in combination with the outer ring magnet 20.1 similarly encompassing it in the bearing section 19.9 of the clutch housing 19, a magnet ring bearing 20.3.
 In the magnet ring bearing 20.3, the two ring magnets 20.1, 20.2 are so arranged that e.g. the north pole of the outer ring magnet is oriented towards the distal end and the south pole towards the proximal end. The north and south poles of the inner ring magnets are correspondingly opposite one another. Similarly, the north and south poles of the two ring magnets may also be reversed. The magnet ring bearing 20.3 centers the drive shaft 4 axially and radially. The radial centering is effected through the radial attraction forces in the radial direction. The axial centering is effected by means of magnetic restoring forces generated by a slight offset of the inner ring magnet 20.2, which pull the inner ring magnet 20 .2 into a position coinciding axially with the position of the outer ring magnet 20.1 with a greater offset, however, repelling forces occur between the two magnet rings 20.1 and 20.2, causing them to be pressed apart."
" In the event of jamming of the rotor 3.2, the friction connection between motor 7 and drive shaft 4 must be broken, to prevent 'winding-up' of the drive shaft 4 while the rotor is stationary. 'Winding-up' of the drive shaft 4 could lead to a change in position of the pump head 3, resulting in damage to the heart and/or the aorta and veins.
 As soon as the rotor 3.2 jams, the drive shaft 4 twists and shortens, and the resistance at the distal magnet unit 23.1 increases. The magnetic fields between the proximal and the distal magnet units 23.2, 23.1 do not overlap completely in operation, since the distal magnet unit 23.1 always trails the proximal magnet unit 23.2 a little. If now the torque required at the distal magnet unit 23.1 increases, the north and south poles of the magnet units 23.1, 23.2 no longer overlap but instead abut one another. By this, the distal magnet unit 23.1 is pressed away from the proximal magnet unit 23.2 in the distal direction. The magnetic connection between the two magnet units 23.1, 23.2 is broken and the drive shaft 4 comes immediately to a stand.
 Due to the displacement of the clutch element 22 in the distal direction, the inner ring magnet 20.2 of the clutch element 22 is similarly shifted in the distal direction; the north and south poles of the two ring magnets 20.1, 20.2 of the magnet ring bearing 20.3 no longer overlap but instead abut one another. By this means, the clutch 9 is held in the decoupled state, resulting in a lasting decoupling of motor 7 and drive shaft 4.
 The amount of transferable torque is limited by the magnet ring bearing 20.3 and the magnetic connection of the two magnet units 23.1, 23.2. As soon as the set torque is exceeded, the two magnet units 23.1, 23.2 separate. Owing to the rapid rotary motion, the distal magnet unit 23.1 can no longer follow the proximal magnet unit 23.2, since the magnetic binding forces are no longer adequate. Because of this, the north and south poles no longer overlap and the magnet units 23.1, 23.2 repel one another. The connection of the magnet units 23.1, 23.2 is broken and the maximum transferable torque is limited. The magnet units 23.1, 23.2 are held in the decoupled state by the magnet ring bearing 20.3 through the mutual repulsion of the ring magnets 20.1, 20.2."
" Catheter device comprising
[a] a motor located at the proximal end of the catheter device
[b] a drive shaft, extending from the proximal end section to the distal end section of the catheter device, for driving
[c] a rotating element located at the distal end of the catheter device,
characterised in that
 at the proximal end of the catheter device, the drive shaft is connected to the motor by a clutch, and
 the clutch is a magnetic clutch with a proximal and a distal magnet unit,
[a] the proximal magnet unit is connected to the motor, and
[b] the distal magnet unit to the drive shaft, and
 the distal magnet unit is
[a] supported in a clutch housing and
[b] physically separated from the proximal magnet unit by a wall."
i) limit the "rotating element" in claim 1 to a "rotor situated in a pump housing", "wherein the rotor and pump housing are compressible, and the rotor is designed to unfold automatically from a compressed state";
ii) introduce a new claim 2 which specifies that the pump housing is "a tubular mesh structure of memory material"; and
iii) replace the term "friction bearing" in claims 7 and 8 with "sliding bearing", which is a better translation of the German term "Gleitlager", and is the term used in the claims of 872.
The skilled person
Common general knowledge
A magnetic clutch with a proximal and a distal magnet unit
Sliding bearing/friction bearing
Relationship between the features of claims 1, 5, 7 and 8 and the features of claims 21 and 22.
"24. …. before you can apply s.3 and ask whether the invention involves an inventive step, you first have to decide what the invention is. In particular, you have to decide whether you are dealing with one invention or two or more inventions. Two inventions do not become one invention because they are included in the same hardware. A compact motor car may contain many inventions, each operating independently of each other but all designed to contribute to the overall goal of having a compact car. That does not make the car a single invention.
25. Section 14(5)(d) of the Act provides (following art.82 of the EPC ) that a claim shall 'relate to one invention or to a group of inventions which are so linked as to form a single inventive concept'. Although this is a procedural requirement with which an application must comply, it does suggest that the references in the Act to an 'invention' (as in s.3) are to the expression of a single inventive concept and not to a collocation of separate inventions.
26. The EPO guidelines say that 'the invention claimed must normally be considered as a whole'. But equally, one must not try to consider as a whole what are in fact two separate inventions. What the Guidelines do is to state the principle upon which you decide whether you are dealing with a single invention or not. If the two integers interact upon each other, if there is synergy between them, they constitute a single invention having a combined effect and one applies s.3 to the idea of combining them. If each integer 'performs its own proper function independently of any of the others', then each is for the purposes of s.3 a separate invention and it has to be applied to each one separately. …"
"… A set of technical features is regarded as a combination of features [as opposed to mere aggregation of features] if the functional interaction between the features achieved a combined technical effect which is different from, e,g, greater than, the sum of the technical effects of the individual features. In other words, the interactions of the individual features must produce a synergistic effect. If no such synergistic effect exists, there is no more than a mere aggregation of features …"
The prior art
"In 2000, the intraaortic propeller pump (PP) [Reitan catheter pump; Jomed; Helsingborg, Sweden], a new device designed to continuously reduce afterload, was developed.4 It is a propeller-based pump that is placed in the high descending aorta with propeller rotational speeds of < 14,000 revolutions per minute (rpm). Like the IABP, the aim of the intraaortic PP is to reduce pressure proximal to the pump, thereby reducing the afterload of the left ventricle. A secondary proposed benefit is the augmentation of perfusion distal to the pump. In the first human application of the PP, excellent results were reported.5"
"The new intraaortic PP is a support device with a deployable propeller (Fig 2), which is driven by a flexible central driveshaft.4 The other end of the driveshaft is a permanent, disk-shaped magnet, which is placed in the driving unit. The driving unit consists of a rotating magnet that can be set between zero and 14,000 rpm. The PP can only operate continuously, so no triggering is needed.
The PP is placed in the descending aorta in a position similar to the intraaortic balloon. Once this position is reached, the propeller is deployed (Fig 2) and is ready for use. A solution of 20% glucose and 5 IU/mL heparin was used at 25 mL per hour to purge and lubricate the pump.
The propeller is guarded by a basket (Fig 2), which prevents contact between the propeller and the aortic wall. However, the aorta should have a diameter of at least 21 mm to prevent stenting. For this reason, the aortic diameter was measured with fluoroscopy before insertion of the PP. In all animals, the diameter was between 21 and 24 mm."
The prior use
i) Like English law, Dutch law recognises that duties of confidence can arise not only from express agreements, but also impliedly from the circumstances in which information is obtained or received.
ii) The test is an objective one.
iii) There is, in general, a rebuttable prima facie presumption that research carried out by a university or other academic institution for a third party is confidential.
iv) In determining whether that presumption has been rebutted, all the relevant circumstances are to be taken into account, including any documentary evidence available as to the terms under which the institution undertook to perform the work and the testimony of witnesses.
"[Dr Reitan] indicated that Jomed was not hiding anything about the product in 2001. In fact they had already patented everything they thought was inventive (he did not think that was the case with the drive unit) and that they were really trying to generate interest in the product.
They had been demonstrating the RCP at conferences since 1997. At these conferences people could have looked at, picked up and inspected the product.
At the time the interesting aspect of the product was the pump head. This was the focus of the exhibitions and conferences."
"Only since the 'Hemopump' catheter pump introduced by Richard Wampler in 1989, which works based on the rotation pump principle, an intravascular blood pump is clinically available which can substantively relieve the left heart. With the Hemopump, for the first time, it was proven that a fast-spinning rotation pump damages blood only within physiologically reasonable limits, despite the high pump-specific shear rate. The prevailing doctrine – that only slowly running radial pumps with comparably large impellers are suitable for blood transport – had to be revised after that.
In 1994, the Hemopump microaxial pump system, which is extensively suitable for left ventricular assist, completed its first clinical trial phase. The interim euphoria of having discovered a universal pump concept for cardiac assist has meanwhile given way to a more realistic evaluation of the capabilities and system-specific restrictions. In particular, the powering of the pump head via a flexible and breakable shaft as well as the flow rate, which at approximately 2.5l/min is too low at this point in time, and the diameter of the pump head, which at 7.4mm is too large for the placement of the pump through peripheral vessels, together with the long time required for putting it into action have prevented a wide acceptance of the pump in clinical routine.
Based on these system-specific disadvantages and limitations of the Hemopump system described in the literature, an improved concept of intravascular microaxial blood pumps for temporary cardiac assist is pursued at the Helmholtz Institute for Biomedical Engineering in Aachen."
"A pump insertable via the periphery may not significantly exceed a diameter of 6mm. In addition, the length of the rigid pump part has to be restricted to approx. 30mm, in order to enable an insertion of the pump via bent peripheral vessels. To avoid the disadvantages resulting from the flexible shaft, the drive unit is to be integrated directly into the pump."
"For short term use, concept IV is most suitable, since based on its structure it is the shortest system with the highest hydraulic output at the lowest complexity (lip seal)."
Johnson & Johnson
" In some embodiments, an expandable impeller is used together with a cannula which may or may not have an expandable portion. If the impeller is not stored in an expandable portion, the impeller must be moved axially for expansion to its deployed configuration. If the impeller is stored in an expandable cannula or in an expandable portion of a cannula, the impeller expands into its deployed configuration with the expansion of the cannula.
 For example, a cannula may be provided that has expandable and non-expandable· portions, and the impeller may be stored within, or proximate to, the non-expandable portion. The impeller can be urged out of the non-expandable portion of the cannula into an expanded portion of the cannula. The stored potential energy within the flexible blades of the impeller would then induce self-deployment of the impeller, and the cannula may also self-expand through stored potential energy. The expanded cannula then may have the role of a fluid conduit through which fluid flows when the impeller is rotated. An example of such system is blood pump 600 described below. …."
"A rotatable drive shaft 630 provides rotational coupling between a motor (not shown), located outside of the patient, and the impeller 605. Drive shaft 630 may have a substantially rigid portion 632 at its distal end which is connected to impeller 605, and a substantially flexible portion 634. The flexible portion 634 of the drive shaft may be housed within a flexible tube 638 which supports the flexible portion and maintains its shape as it is driven rotationally. The proximal end of· drive shaft 630 may be connected to the motor for rotating the drive shaft and with it impeller 605. Alternatively, drive shaft 630 may be omitted, and the electric power may be provided through a proximal portion of the assembly to operate a pump motor and impeller 605."
Novelty of claims 1 and 5
"The other end of the driveshaft is a permanent, disk-shaped magnet, which is placed in the driving unit. The driving unit consists of a rotating magnet …"
The prior use
Obviousness of claim 1
i) Dr Sieß and his collaborators, who were working on the Impella.
ii) Dr Reitan and his collaborators, who were working on the RCP.
iii) McBride and his collaborators, some of whom were based at Penn State Research University.
iv) A-Med Inc, which developed a device similar in many respects to the Hemopump. The successful first use of the A-Med device in man was reported in M. Ferrari et al, "Successful High-Risk Coronary Angioplasty in a Patient with Cardiogenic Shock Under Circulatory Assist with a 16F Axial Flow Pump", Catheterization and Cardiovascular Interventions, 2005, 557-561, although it did not achieve clinical acceptance in the longer term. Dr Ferrari agreed that his paper showed that there was considerable interest in devices of this kind in the mid 2000s.
v) Amy Throckmorton and her collaborators, who were based variously at Virginia Commonwealth University, Indiana University School of Medicine, University of Louisville and Purdue University. They developed a device with some similarities to the Hemopump, but with a foldable propeller with some similarities to that of the RCP, in order to treat patients with single functional ventricles: see A.L. Throckmorton et al, "Mechanical Cavopulmonary Assist for the Univentrical Fontan Circulation Using a Novel Folding Propeller Blood Pump", ASAIO J, 2007, 734-741.
vi) Terumo Cardiovascular Systems Corp patented a catheter-based pump and stated that it could suitably be driven by a maglev drive: see US Patent No 6,245,007 (2001), in particular at column 8.
vii) Khaw and Li patented a similar device: see US Patent No. 6,981,942 (2006).
Johnson & Johnson
Obviousness of the subsidiary claims
The prior use
Sieß and Johnson & Johnson
Amendment of 658
Summary of principal conclusions
i) none of the claims lacks novelty over Dekker;
ii) claims 1 and 5 of 872 (claims 1 and 4 of 658) lack novelty over the prior use;
iii) claims 1, 5, 7 and 8 of 872 (claims 1, 4, 6 and 7 of 658) are obvious over Dekker;
iv) claims 7 and 8 of 782 (claims 6 and 7 of 658) are obvious over the prior use;
v) claims 1, 5, 7 and 8 of 872 (claims 1, 4, 6 and 7 of 658) are obvious over Sieß and Johnson & Johnson;
vi) claims 1, 5, 7, 8, 21 and 22 of 872 (claims 1, 4, 6 and 7 of 658) are obvious over McBride; and
vii) claims 1, 5, 8, 21 and 22 of 872 (claims 1, 4 and 7 of 658) would be infringed by the HeartMate PHP if they were valid.