Pages 647-655

INFORMATION FROM THE CONTRACTING / EXTENSION STATES

DE Germany

Judgment of the Bundesgerichtshof (Federal Court of Justice), 10th Civil Senate, dated 12 May 1998

(X ZR 115/96)1

Headword: "Shock wave lithotripter"

Article: 56 EPC

Keyword: "Limitation of patent in revocation proceedings" - "Inventive step - combination of individual features - secondary indicia" (European patent 317 507)

Headnote:

1. The obviousness of a device's individual features does not in itself mean the combination thereof is obvious.

2. When assessing inventive step, departures from the beaten track are to be taken into account.

Summary of facts and submissions

The defendant is the proprietor of European patent No. 0 317 507, German Patent Office registration number 38 69 918. This patent (language of publication: French) concerns a device for acting by ultrasonic vibrations on an object. It comprises ten claims (...)

The plaintiff submitted that the patent's subject-matter was not patentable in the light of the prior art, notably German application document 27 35 563, European patent specification 0 144 005, US patent specifications 4 589 415 and 5 161 623, and the following technical literature: Korth, "Perkutane Nierensteinchirurgie", 1984, pp. 12/13, Jocham/Schmiedt and Hepp in Ziegler (ed.), "Stoßwellenlithotripsie bei Harn- und Gallensteinen", 1987, pp. 36/37 and 60/61, and Sakulin/Schmidt-Kloiber/Schuy, "Verfahren zur Steinzerstörung in den ableitenden Harnwegen", Elektrotechnik und Maschinenbau, 1973, pp. 156-163. It requested the patent's revocation with effect for the territory of the Federal Republic of Germany.

The defendant defended the patent on the basis of five claims in German intended to replace those of the patent as granted and reading as follows (amendments to the English translation of claims 1 to 5 of the patent as granted are in italics):

"1. Shock wave lithotripter characterised in that it comprises, on the one hand, a projectile of elongate shape placed in a tube forming a blowpipe (2), to slide therein, and pneumatic means (5) disposed at one end of the blowpipe (2), to impart to this projectile (1) a to and fro movement in the blowpipe (2), of amplitude considerably greater than the transverse dimension of the projectile, and, on the other hand, a wave-guide (4, 19), of a size to fit in a renoscope or a nephroscope, exhibiting an entrance interface (9) situated at the other end of the blowpipe (2), and provided in order to be struck periodically by the projectile (1) in the course of its alternating movement and thus to generate, by ballistic effect, ultrasonic shock waves, this waveguide (4, 19) being arranged to transmit these shock waves to their place of utilization (21).

2. Shock wave lithotripter as claimed in claim 1, characterised in that the part upstream of said blowpipe (2), in relation to said projectile (1), is directly subjected to the cyclic pressure of a compressor cylinder, said projectile circulating in the forward sense during the high-pressure phase, and in the return sense during the low-pressure phase.

3. Shock wave lithotripter as claimed in claim 1 or 2, characterised in that said blowpipe is pneumatically connected, toward its downstream end, to an auxiliary reservoir (8), in order that air accumulated in the latter ensures the return of said projectile (1) towards its starting position.

4. Shock wave lithotripter as claimed in claim 2 or 3, characterised in that said compressor comprises regulable means for permitting the adjustment of the quantity of air in the propulsion circuit and, in consequence, of the amplitude of the shock waves.

5. Shock wave lithotripter as claimed in claim 1, characterised in that the projectile (1) is propelled by a sequential supply to the blowpipe (2) from a source of compressed air of a practically constant pressure."

The defendant dropped claims 6 to 10.

The Federal Patents Court dismissed the plaintiff's suit, but also revoked the patent to the extent that it "replaced" the "claims as granted" with those reproduced above.

This is the decision now appealed by the plaintiff, which maintains its request that the patent be revoked in full for the Federal Republic of Germany. The defendant opposes the appeal, and relies on the challenged judgment.

From the reasons

The appeal is admissible, but fails.

I. The Senate construes the Federal Patents Court's judgment to mean that the German wording of the claims now defended is intended not to "replace" the claims of the granted patent as the authentic text in the language of the proceedings within the meaning of Article 70(1) EPC, but simply to limit them in so far as the granted patent is broader in scope than the said defended German version (see Rogge, GRUR 1993, 284, 287 f.). It was also admissible for the proprietor to limit its patent by narrowing it down to a shock wave lithotripter - disclosed from the outset and falling within the scope of protection of the patent as granted - and by incorporating the feature - likewise disclosed from the outset and forming part of the invention in the patent as granted - that the waveguide is of a size to fit in a renoscope or a nephroscope.

II. The plaintiff has failed to show that the subject-matter of the defended claims is not patentable (...).

1. (...)

2. The patent as defended is now limited to a shock wave lithotripter as used in invasive intracorporeal fragmenting of urinary tract stones. (...)

3. (...)

4. Claim 1 of the patent in suit as defended discloses a shock wave lithotripter with the following (1) features characterising the shock wave generator:

(1.1) a tube forming a blowpipe;

(1.2) a projectile of elongate shape

(1.2.1) which is placed in said tube and can slide in it;

(1.3) and pneumatic means

(1.3.1) which are disposed at one end of the blowpipe

(1.3.2) and are capable of imparting to the projectile a to and fro movement in the blowpipe,

(1.4) the amplitude of the movement of the projectile in the blowpipe being considerably greater than the transverse dimension of the projectile.

(2) The lithotripter also comprises a waveguide with the following features:

(2.1) it is of a size to fit in a renoscope or a nephroscope and

(2.2) is arranged to transmit shock waves to their place of utilization;

(2.3) it exhibits an entrance interface

(2.3.1) situated at the other end of the blowpipe,

(2.3.2) provided in order to be struck periodically by the projectile in the course of its alternating movement and

(2.3.3) generating ultrasonic shock waves by ballistic effect.

(...)

5. The description makes no mention of further difficulties the skilled person (...) encountered with invasive intracorporeal lithotripsy as disclosed before the patent's priority date, where ultrasound or shock wave generation was the result of spark discharge between two electrodes in the bladder or outside the body, with sound energy generated by a magnetostrictive or piezoelectric transducer or in a liquid-filled chamber (see German application document 22 56 127, description p. 1; Sakulin/Schmidt-Kloiber/Schuy, "Verfahren zur Steinzerstörung in den ableitenden Harnwegen", Elektrotechnik und Maschinenbau, 1973, p. 158 ff; Austrian patent specification 309 663, description p. 1). Shock generation by intracorporeal spark discharge sometimes caused damage to tissue (German application document 22 56 127 mentions possible perforation of the bladder wall, especially if the spark is ignited in a diverticulum, ie a recess; Austrian patent specification 309 663 refers inter alia to lesions of the mucous membrane due to arc-over; expert opinion Dr. H. refers (p. 3) to the risk of heat damage to tissue); extracorporeal pulse generation required constant replenishment of the liquid in the chamber. (...); lastly, problems were also caused by the high electrical potentials generated (expert opinion Dr. H., p. 4). Hence the problem addressed by the patent also consists, objectively, in fragmenting the concretions while avoiding damage to organs.

III. 1. The subject-matter of the claim now defended is new. (...)

(a) The Sakulin et al. publication describes a shock wave lithotripter, but designed to fit in a ureteral catheter rather than a renoscope or a nephroscope, and not a device for generating shock waves within the meaning of feature group (1).

(b) The subject-matter of German application document 27 35 563 is not a shock wave lithotripter, but a surgical device with an impulse motor. Here the apparatus for generating shock waves does not involve a waveguide of a size to fit in a renoscope or a nephroscope; instead of feature group (2) it has a cutting tool or wire. As the court-appointed expert convincingly explained, this apparatus is not capable of fragmenting stones, being designed to generate a translational motion, not a shock wave (...)

None of the other citations, in so far as they belong to the prior art, come any closer to the subject-matter of claim 1 as defended.

2. The Senate is not satisfied that the said subject-matter of claim 1 was obvious to the skilled person - in this context, a physicist or a university-educated physical, biomedical or mechanical engineer who either has knowledge of medicine and medical engineering or consults other experts on such matters - from the prior art on the priority date of the patent in suit.

The invention cannot be held to be obvious solely on the basis that shock wave generation arrangements of the kind used in the patent, or waveguide arrangements for directing the shock waves at the stone to be fragmented, were - respectively - obvious to the skilled person. The obviousness of the individual features does not in itself mean the combination thereof is obvious (see Swiss Federal Court SMI 1994, 328, 332 - Slim Cigarette: EPO T 60/89OJ EPO 1992, 268, 282 = GRUR Int. 1992, 771 - Fusion proteins).

The known drawbacks of both intracorporeal and extracorporeal electrohydraulic shock wave generation, as discussed in the literature, would at first sight seem to support the plaintiff's view that it was obvious to apply to lithotripters the kind of shock wave generation arrangements already used in the medical engineering field. However, the Senate does not subscribe to the view, supported by the private expert opinion submitted by the plaintiff, that to combine a known or at least obvious pneumatic hammer with a likewise known or at least obvious waveguide designed to fit in a renoscope or nephroscope was a purely mechanical measure devoid of inventive content.

The work of Sakulin et al. on shock wave lithotripsy does show that the disadvantages inherent in shock wave generation through electrical discharges within the human body can be avoided if the shock waves are generated by arc-over in a discharge chamber located outside the body. However, this only partly eliminates the known difficulties, and in particular does not suggest the possibility, for shock wave generation purposes, of moving away from costly high-voltage electrical energy altogether and of using known or at least obvious pneumatic mechanical means instead.

In the present case, there are also a number of other aspects suggestive of inventive step. First, the apparatus in accordance with the patent in suit represents a major improvement for lithotripters, the court-appointed expert having convincingly shown that it can be built with simpler technology while providing at least the same performance. Although this in itself does not normally constitute conclusive proof of inventive step (see Schulte, PatG, 5th ed., Section 4 para. 47), it may nonetheless be regarded as indicative of it (see Senate Liedl 1965/66, 77, 95 ff - "Flaschenblasen"; GRUR 1978, 98, 99 - "Schaltungsanordnung"). Furthermore, as the court-appointed expert has convincingly explained, to arrive at the solution embodied in the invention it was necessary to depart from the beaten track of technical thought. Modern lithotripsy began at a relatively high technological level, which was necessary and justified for non-contact lithotripsy but was then also used fairly uncritically in contact lithotripsy, where pressure wave generation ultimately produces only a normal mechanical shock. The court-appointed expert observed that technological development was hampered by tunnel vision, focusing on greater complexity and "more modern" techniques and failing to spot the potential for simpler techniques; and the technical literature ("Biomedizinische Technik", Volume 2, pp. 396-399) devoted a number of pages to non-mechanical shock generation, whilst curtly dismissing the mechanical variety as offering insufficient reproducibility. Even if this is not, as the court-appointed expert assumes, necessarily indicative of general, deep-seated technical misconceptions as defined in the Senate's case law (BGHZ 133, 57, 67 f = GRUR 1996, 857 - Rauchgasklappe; Benkard/Bruchhausen, PatG Section 4, para. 20), his testimony does constitute evidence of a departure from the beaten track which is to be taken into account when assessing inventive step (see Senate Liedl 1978/80, 173, 182 - explosionsgeschütztes elektrisches Schaltgerät; EPO T 229/85, OJ EPO 1987, 237, 240 f. - Etching process; Benkard/Bruchhausen, loc. cit., para. 23). He has also aptly pointed out that the presence of the necessary compressed air in operating theatres and the comparable use of sliding hammers in orthopaedic surgery - interpreted by the plaintiff as signs of obviousness - can also - and in the Senate's opinion equally justifiably - be seen as indicating that there was a big obstacle to overcome in getting away from the conventional line of technical thought. Lastly, it must also be remembered that the shock wave generation problems which were only partly solved by Sakulin et al. had been known for a long time, and that almost fifteen years elapsed between the publication of Sakulin et al. and the priority date of the patent in suit even though there was clearly a need for simpler stone fragmentation devices. In the light of all the above considerations, the Senate cannot refute the existence of inventive step within the meaning of Article 56 EPC, even if individual elements of the invention were already known or at least obvious. (...)

DE 2/99