T 1022/19 24-10-2022

I. The opponent filed an appeal against the decision of the opposition division to reject the opposition against the patent No. 2 318 071.

II. Oral proceedings before the board took place on 24 October 2022.

III. The appellant (opponent) requested that the decision be set aside and that the patent be revoked.

The respondent (patent proprietor) requested that the appeal be dismissed and that the patent be maintained as granted or, alternatively, on the basis of one of the first to fifth auxiliary requests filed with the reply to the statement of grounds of appeal.

IV. Claim 1 of the main request reads as follows.

"A dialysis system (10) comprising:

at least one dialysis fluid pump actuator; and a disposable cassette (50) including at least one pump chamber (62) operable with the at least one pump actuator, the disposable cassette further including a plurality of fluid ports (56) configured to be connected fluidly to a plurality of fluid containers (66a, 66b, 66c, 66d, 68, 70);

characterised in that it further comprises

a processor programmed to cause the at least one pump actuator to operate the at least one pumping chamber to collect an effluent dialysis fluid sample by pumping a first number of pump strokes to a drain/drain container (68) followed by a second number of pump strokes to a sample container (70)."

V. The following documents are referred to in this decision.

D1 EP 0 815 882 A2

D2 US 5,670,057

D3 WO 03/063929 A1

D4 WO 99/06082 A1

D5 Patient Guidelines til PDC test - procedure til

CAPD, Gambro 2006

VI. The arguments of the appellant may be summarized as follows.

Main request - Added subject-matter

In the application documents as originally filed it was not disclosed that both the first and the second number of pump strokes were used to collect an effluent dialysis fluid sample, as defined in claim 1.

Furthermore, according to claim 1 the pump actuator operated the at least one pumping chamber, whereas in claim 10 of the application as originally filed the pump actuator operated with the pumping chamber. The direct actuation as defined in claim 1 could not be derived from the original application documents. Claim 10 as originally filed, on which claim 1 was based, included the wording "to operate with the...". This could not be equated with "to operate the...".

Therefore, claim 1 did not meet the requirements of Article 123(2) EPC.

Sufficiency of disclosure

Claim 1 defined that the sample of dialysis solution was collected by pumping both a first number of pump strokes to a drain and a second number of pump strokes to a sample container. However, the person skilled in the art was not able to reproduce this teaching.

Furthermore, the claim covered embodiments with only one pump chamber and without any valves for controlling fluid flow. However, with such an arrangement it was not possible to selectively pump the effluent dialysate flow into the drain and into the sample container. Hence, in such an embodiment, it was technically nonsensical to program the processor in such a manner as defined in claim 1.

Hence, the invention was not sufficiently disclosed over its whole scope to be carried out by the person skilled in the art.

Novelty

D1 disclosed a dialysis system according to claim 1 having, in particular, two pump actuators PA1 and PA2 operating two pump chambers P1, P2, (column 13, lines 27 to 35; Figures 8 and 13) and a processor (controller 16, column 5, lines 38 to 41).

Claim 1 did not require that the amount or duration of the operation of the pump chambers was defined in the program of the processor. Hence, any processor programmed to control a pump actuator fell under the scope of claim 1. Therefore, its subject-matter lacked novelty over D1.

Inventive step starting from D1

D1 disclosed a dialysis system comprising the features of the preamble of claim 1 (column 13, lines 27 to 36; Figures 1, 3, 8A, 8B, 12A, 13 and 14A). Furthermore, the system of D1 comprised a processor programmed to cause the pump actuator to operate the pumping chamber by pumping single pump strokes (column 14, lines 50 to 57, column 29, lines 20 to 24; column 40, lines 25 to 31).

D1 further disclosed that a volume of spent dialysate was diverted into the inspection bag during the first drain cycle, i.e. not at the beginning of the drain cycle (column 7, lines 3 to 17). Since it was mentioned in D1 that the sample should be inspected for cloudy effluent as a sign of peritonitis (column 7, lines 15 to 17), it was obvious for the person skilled in the art that the sample should be taken only after a first number of pump strokes had been pumped into the drain.

Furthermore, claim 1 did not require that the first number of pump strokes was pumped exclusively to the drain and the second number was pumped exclusively to the sample container.

Hence, D1 disclosed that a first number of pump strokes was used to pump the dialysis fluid to a drain and afterwards a second number of pump strokes was used to pump the fluid at least partly to a sample container. The subject-matter of claim 1 differed from this only in that the processor was programmed to control the pump actuator correspondingly.

Starting from D1, the objective technical problem to be solved was to render the probe sampling easier and more secure.

- in combination with D3

The solution to this problem, i.e. the automation of the sampling process, was obvious in view of D3.

D3 disclosed a peritoneal dialysis system with an automatic sampling system. To collect a fluid sample, a certain quantity of fluid was directed exclusively to a specific sampling container (page 7, lines 22 to 33) This was done during the drain cycle at predetermined times (page 7, lines 35 to 37). These predetermined times corresponded to a certain number of pump strokes.

The person skilled in the art would implement this teaching in the system of D1, thereby arriving at a system according to claim 1.

- in combination with the common general knowledge

The programming of the processor according to claim 1 represented merely an automation of the manual sampling process of D1. This was also obvious in view of the common general knowledge since the person skilled in the art would generally aim to automate a manually performed process.

Hence, the subject-matter of claim 1 was not inventive in view of D1 in combination with the common general knowledge.

- in combination with D2

The solution to the above-mentioned problem was also obvious in view of D2 disclosing a method and device for performing an automatic Peritoneal Equilibrium Test (PET). After one minute of draining a sample was taken automatically from the T-connection (column 7, lines 22 to 28, Figure 2). Hence, the person skilled in the art was taught to automate the sampling process and to take the sample only after part of the dialysis fluid was pumped to the drain.

Such an arrangement would fall under the scope of claim 1 as, during a first number of pump strokes, dialysis fluid was delivered exclusively to the drain and, during a second number of pump strokes, the fluid was delivered at least partly to the sample container.

Thus, the combination of D1 with D2 would result in a system according to claim 1.

- in combination with D4

D4 disclosed an automatic sampling after detecting that the effluent was cloudy, i.e. after directing a certain volume of dialysis fluid to the drain (paragraph bridging pages 19 and 20). Hence, during a first number of pump strokes, dialysis fluid was delivered exclusively to the drain and, during a second number of pump strokes, the fluid was delivered at least partly to the sample container. This teaching would prompt the person skilled in the art to program the processor of D1 such as to pump dialysis fluid to the drain as long as the fluid was not cloudy, and to open the clamp in the branch line 28A to pump at least one pump stroke to the sample container.

Thus, the combination of D1 with D4 would result in a system according to claim 1.

- in combination with D5 and the common general knowledge

D5 described a system for manually performing a PDC test. It was mentioned that a certain volume of fluid was discarded before the sample was taken from a bag of drained dialysis fluid (page 5, step 10). It was obvious for the person skilled in the art to automate this procedure and to apply this teaching to the system of D1 by programming the processor to perform this sampling after a certain volume of fluid had been conveyed to the drain.

Claim 1 did not require that the drain container and the sample container were separate containers. An embodiment having only one container in which both the draining fluid and the sample fluid were pumped would also fall under the scope of the claim.

Thus, the combination of D1 with D5 and the common general knowledge would result in a system according to claim 1.

Consequently, the subject-matter of claim 1 lacked an inventive step.

Admittance of the inventive step-objection starting from D4 in combination with D5

D4 was highly relevant since it disclosed that a sample was automatically pumped exclusively to the sample container. In view of its prima facie relevance, this objection should be admitted even in the absence of any further exceptional circumstances.

VII. The arguments of the respondent may be summarized as follows.

Added subject-matter

When claim 1 was construed properly, it was clear that only the second number of pump strokes was used for collecting the sample in the sample container and that the first number of pump strokes was used to pump spent dialysis solution to a drain before collecting the sample. This was disclosed in claim 10 as originally filed.

The terms "to operate with the at least one pumping chamber" and "to operate the at least one pumping chamber" were used interchangeably throughout the application as filed. Indeed, claims 1 and 6 as originally filed used the latter.

Hence, there was clear support in the application as filed for "a processor programmed to cause the at least one pump actuator to operate the at least one pumping chamber".

For these reasons claim 1 complied with Article 123(2) EPC.

Sufficiency of disclosure

It was clear that only the second number of pump strokes was used for collecting the sample in the sample container and that the first number of pump strokes was used to pump spent dialysis solution to a drain before collecting the sample. Thus, there was no volume pumped by either the first number of pump strokes or the second number of pump strokes that ended up going to the drain and also to the sample container.

Therefore, when claim 1 was construed correctly by a mind willing to understand, it was clear that the skilled person would have had no difficulty implementing the invention.

The fact that claim 1 covered dialysis systems with single and multiple pump chambers and dialysis systems that had valves as well as those that did not, did not give rise to an insufficiency problem.

Even with a single pump chamber one could collect the effluent dialysate fluid as claimed without having valves, for example by using an automated clamping system with a clamp arranged on tubing leading to the drain and on tubing leading to the sample container.

In conclusion, the requirements of Article 83 EPC were met.

Novelty

Granted claim 1 required a specifically programmed processor, namely one that was programmed to cause the at least one pump actuator to operate the at least one pumping chamber to collect an effluent dialysis fluid sample by pumping a first number of pump strokes to a drain/drain container followed by a second number of pump strokes to a sample container.

The processor in D1 was simply programmed to cause a pump actuator to operate a pumping chamber until the drain cycle was completed. Furthermore, the teaching at column 7, lines 7 to 17 of D1 did not make it clear whether the step of diverting a volume of spent dialysate to the inspection bag took place right at the beginning of a drain cycle or after a certain amount of fluid had been drained. In any case, there were no separately programmed pumping operations as required by claim 1.

Thus, the subject-matter of claim 1 did not lack novelty over D1.

Inventive step starting from D1

D1 disclosed a peritoneal dialysis system comprising the features of the preamble of claim 1 and a processor that was programmed to control the pump actuators to operate the pumping chambers.

However, D1 did not disclose that its controller was "programmed to cause the at least one pump actuator to operate the at least one pumping chamber to collect an effluent dialysis fluid sample by pumping a first number of pump strokes to a drain/drain container followed by a second number of pump strokes to a sample container". In D1, manual operation of the clamps shown in Figure 3 controlled when effluent was sent to a drain and when a sample was collected.

The wording "during the first drain cycle" (column 7, lines 13 to 17) did not exclude that the sample was collected right at the beginning of the first drain cycle before any spent dialysate was sent to the drain.

Furthermore, it was clear from the wording of claim 1 that the first number of pump strokes was used to pump effluent dialysis fluid to a drain and not to a sample container and the second number of pump strokes was used to pump effluent dialysis fluid to a sample container and not to a drain. Thus, the effluent dialysis fluid was pumped to a particular destination to the exclusion of the other depending on whether it was the first number of pump strokes or the second.

- in combination with D3

D3 disclosed a peritoneal dialysis system with an automated sampling system which was able to automatically sample dialysate contained in the peritoneal cavity of the patient at specific time intervals (page 2, lines 7 to 16).

If the person skilled in the art was motivated to replace the drain tube 28A depicted in Figure 3 of D1 with the automatic sampling system of D3, he would not arrive at a dialysis system as claimed, as D3 did not teach or suggest to control the pump to pump a first number of pump strokes exclusively to a drain followed by a second number of pump strokes exclusively to a sample container as required by claim 1. In D3, as in D1, the sampling could take place right at the beginning of the drain cycle. Furthermore, D3 was silent on the basis on which the predetermined time was defined.

- in combination with the common general knowledge

Any automation of the procedure taught in D1 would not lead the person skilled in the art to arrive at a dialysis system as defined in claim 1. If the skilled person was motivated to automate what was described at column 7, lines 13 to 15 of D1, he would replace the manually operated clamps shown in Figure 3 of D1 with some form of automated clamping system which provided for automatic opening and closing of the drain tube 28 and the branch tube 28A. He certainly would not reprogram the software on the system controller so as to "cause the at least one pump actuator to operate the at least one pumping chamber to collect an effluent dialysis fluid sample by pumping a first number of pump strokes to a drain/drain container followed by a second number of pump strokes to a sample container".

- in combination with D2

D2 disclosed an apparatus for automatically sampling dialysis fluid as it dwells in the peritoneal cavity after which the patient is drained (Abstract; col. 3, lines 1 to 6, 23 to 26 and col. 4, lines 17 to 29).

If the person skilled in the art turned to D2 for assistance in developing an improved system, he would, at best, merely replace the manually operable clamps shown in Figure 3 of D1 with an automated clamping system as taught in D2. He would not reprogram the software on the system controller so as to "cause the at least one pump actuator to operate the at least one pumping chamber to collect an effluent dialysis fluid sample by pumping a first number of pump strokes to a drain followed by a second number of pump strokes to a sample container" as required by granted claim 1.

- in combination with D4

D4 disclosed an automated peritoneal dialysis system comprising an effluent detector and a sample collection port 6 from which a fluid line led to a sample container 30 (page 19, second complete paragraph and Fig. 9). If the effluent detector detected that the spent dialysate was cloudy during a drain cycle, the system automatically opened sample collection port 6 and sent a sample of the cloudy spent dialysate to the sample container.

If the person skilled in the art was motivated to modify the system of D1 in light of the teaching of D4, he would not arrive at a dialysis system as presently claimed, as the resulting 'combined' system would simply remove a sample by selective operation of the occlusion chamber (Figure 9 of D4) on detection of a cloudy effluent dialysate by the effluent detector. Thus, the resulting system would not have a processor as claimed which was programmed to sample spent dialysate automatically by "causing the at least one pump actuator to operate the at least one pumping chamber to collect an effluent dialysis fluid sample by pumping a first number of pump strokes to a drain followed by a second number of pump strokes to a sample container".

- in combination with D5 and the common general knowledge

D5 described a system for taking samples from a bag of collected spent dialysate for PDC testing. At Step 10 on page 5, the first 300 ml of spent dialysate was discarded and then samples were collected. It would not be obvious to automate this procedure and to combine the thus automated sampling with the system of D1 to arrive at a peritoneal dialysis system as presently claimed since the bag system shown in D5 had been disconnected from the dialysis system after completion of the drain cycle.

Hence, the subject-matter of claim 1 was inventive over the above-mentioned combinations of documents.

Admittance of the inventive step-objection starting from D4 in combination with D5

The objection was submitted for the first time at oral proceedings before the board. Since there were no exceptional circumstances justifying the late submission, this objection should not be taken into account.