FEDERAL COURT OF AUSTRALIA

Abbott Laboratories v Corbridge Group Pty Ltd

[2000] FCA 1713

PATENTS– construction of claims

WORDS AND PHRASES – “comprising”

ABBOTT LABORATORIES and ABBOTT AUSTRALASIA PTY LIMITED v CORBRIDGE GROUP PTY LIMITED and SELFCARE PTY LIMITED

N 1252 OF 1999

GYLES J

SYDNEY

24 NOVEMBER 2000

THE COURT ORDERS THAT:

1.                  Application dismissed.

2.                  Costs of the application reserved.

3.         Cross-claims stood over for further argument.

Note:    Settlement and entry of orders is dealt with in Order 36 of the Federal Court Rules.

REASONS FOR JUDGMENT

1                     The first applicant, Abbott Laboratories (“Abbott”) is the registered proprietor of Australian patent number 572138 (“the patent”), and the second applicant, Abbott Australasia Pty Limited (“Abbott Australia”) is a licensee of Abbott in Australia.

2                     The first respondent, Corbridge Group Pty Limited (“Corbridge”) has imported for sale and supplied in Australia quantities of the product known as the “Excel ET blood glucose test strip” (“the Selfcare strip”).  The second respondent, Selfcare Pty Limited (“Selfcare Australia”)  sponsored that importation and supply of the Selfcare strip into Australia by Corbridge and thereby authorised the importation and sale of the product.

3                     The applicants claim that the Selfcare strip infringes the patent and seek injunctive and monetary relief.  This is denied, and Corbridge and Selfcare Australia have cross-claimed for revocation of the patent by reason of invalidity.  There is also a cross-claim for breach of ss 52 and 53 of the Trade Practices Act 1974 (Cth), and for breach of s 46 of the Trade Practices Act 1974 (Cth).

4                     The Selfcare strip is designed to be used in conjunction with an electronic meter made by the applicants (“the Exactech meter”) for the measurement of glucose in blood.  Those meters are distributed to members of the public who suffer from diabetes so that they can test their blood glucose levels as and when required.

5                     The description of the Selfcare strip in the applicants’ submissions  suffices to explain it for present purposes:

(a)                It is a rectangular shaped plastic strip on which there are two electrodes.

(b)               The first of the electrodes is a working electrode which includes, inter alia, the enzyme glucose oxidase, a mediator compound and carbon, an electrically conductive material.

(c)                The second electrode functions as a reference electrode and consists of silver and silver chloride.

(d)               The two electrodes on the strip are not in physical or electrical contact.  Each terminates in a contact at that end of the strip which is intended to be inserted into the applicants’ Exactech meter.

(e)                When a drop of blood is placed on the Selfcare strip in contact with both of the electrodes it becomes an electrochemical cell.

(f)                 Within the electrochemical cell glucose oxidase, as a constituent material of the working electrode and operating as an enzyme catalytic of glucose, transfers electrons from glucose in the blood to the mediator compound, which is also a constituent of the working electrode.

(g)                In use, when a voltage is applied across the two electrodes by the Exactech meter, the mediator compound transfers its charge to the carbon included in the working electrode.  The resultant current flows around the completed circuit made by the two electrodes, the blood with which they are in contact and the circuitry of the Exactech meter;

(h)                when current flows around the circuit in that manner, the Exactech meter gives a reading which reflects the concentration of glucose in the blood previously applied to the strip.

6                     There is no controversy as to the physical configuration of the Selfcare strip.  The dispute turns on the proper construction of the claims of the patent which are relied upon.  The applicants plead that five claims of the patent (each being a product claim) are infringed.   As there is no separate dispute about claims 22 and 23, argument has concentrated upon claims 1, 3 and 19.  Although not in suit, claim 4 is relevant to the argument.  Claims 1, 3, 4 and 19 are as follows:

“Claim 1:

1.         Sensor means for selective detection, measurement or monitoring of a given dissolved substrate in a mixture of dissolved substrates, comprising:

(a)               an area of first electrode material comprising an enzyme catalytic of the said substrate and a mediator compound to transfer charge to the electrode when the enzyme is catalytically active, adjacent to but non-contiguous with;

(b)               an area of reference electrode material both electrodes being of small dimension, and extending as or supported on an elongate member to facilitate manipulation before or during contact with live tissue or a small withdrawn sample of body fluid.

Claim 3:

3.                   A sensor for contact with a liquid mixture of components for detecting the presence of, measuring the amount of and/or monitoring the level of one or more selected components capable of undergoing an enzyme catalysed reaction, the sensor comprising:

(a)               an elongate support member,

(b)               on a surface thereof towards one end an expanse of a first electrode of electrically conductive material comprising at least at an outer surface thereof the combination of an enzyme and a mediator compound which transfers electrons to the first electrode when the enzyme is catalytically active,

(c)               on a surface of the elongate support member and also towards the said end thereof an expanse of a second, reference, electrode, and

(d)               separate electrical connection to each electrode for attachment to a read-out means denoting presence, amount, or monitored level of the said one or more selected components in a liquid medium into which the support member is dipped to contact both electrodes.

Claim 4

4.                  A sensor means comprising:

(a)               a flat first electrode area of known area small enough to be completely coverable by the smear of blood produced from a non-expressed drop of blood generated from a needle-prick at a bodily extremity,

(b)               a reference electrode area on the same surface separate from but sufficiently close to the sensitive electrode area that the said blood smear also reaches the reference electrode to establish electrical communication, and

(c)                separate conductive elements extending along the same surface of the elongate support member, communicating one with each electrode for connection to signal read-out means attachable to one end of the member.

Claim 19:

19.              An assembly as claimed in claim 1 in further combination with a flat strip electrode as an external non-invasive test member for a blood droplet.”

claim 1

7                     This is a difficult claim to construe.  The first issue is the sense in which the word “comprising” is used.  In my opinion, in each place it is used in the sense of including or containing the integers described, rather than in the sense of being composed only of them.  Either is open as an ordinary English primary meaning, and it is a matter of gleaning sense from the context.  The former construction best accords with the body of the specification and commonsense.  It is obvious that the sensor means cannot operate without something like integer (d) in claim 3, namely, a separate electrical connection to each electrode for attachment to a readout means.  It is also quite apparent from the body of the specification that, as the description implies, the first electrode must include conductive material.  The other construction would, without question, result in a claim of no practical use.  This would be an absurd result.

8                     The next issue is whether what is claimed must be capable of being an invasive sensor, such as described in the specification as generally needle-like in nature, or fitting within a hollow needle.  The applicants, which resist this construction of the claim, suggest that the structure of the specification is inconsistent with it.  The equivalent of claim 1 is introduced early in the specification and before there is any division of sensors into external, invasive or dual capacity.  It is suggested on behalf of the applicants that claim 1 is the broadest of claims, with all of the other claims being embodiments or manifestations of it.  The applicants put that this argument is assisted by the fact that the purpose of elongation, according to the specification, was

“either to fit within a pointed needle, or for ready handling as an electrode for ready assembly to equipment on the other hand and contact with the sample on the other.”  (emphasis added)

9                     It is submitted for the respondent that the arrangement and expression of claims indicate that claims 1, 3 and 4 were each separate principal claims for different devices, adapted for different purposes.  It is suggested that claim 1 is for a needle or needle-like device which can both invade live tissue and be utilised in order to dip into a small withdrawn sample of body fluid;  claim 3 is for a device for dipping into a larger quantity of liquid medium;  and claim 4 is for a flat strip with the two electrodes on the same surface, being of such dimensions and relationship that a non-expressed drop of blood generated from a needle prick of the body extremity may completely cover the first electrode and also contact the reference electrode.

10                  I find this analysis by the respondent helpful, although by no means decisive.  Generally speaking, not too much can be taken from the way individual claims are drawn because there may be overlap between various claims and each claim must be construed on its own.  However, this patent relates to analytical equipment or apparatus and does not purport to disclose any new electro-chemical principle or any novel chemistry.  Thus, the sensor electrodes which are disclosed and claimed are devices for use in the analytical equipment or apparatus.  This focuses attention on the practical rather than the theoretical.  That being so, it is not unreasonable to expect that different claims may involve different devices.

11                  Returning to the words of claim 1, the respondents place emphasis upon the words “during contact with live tissue”.  They rely upon the fact that the only relevant contact with live tissue described in the specification is invasive contact, and, in this context, that must involve a needle or needle-like structure.  In my opinion, this argument is compelling.  Counsel for the applicants pointed to the alternative of manipulation before or during contact with a small withdrawn sample of body fluid.  However, it seems to me that the device in question must be capable of the relevant contact with live tissue, even though it may also be capable of manipulation before or during contact with a small withdrawn sample of body fluid.

12                  It was submitted for the applicants that an unexpressed blood droplet clearly falls within the description “a small withdrawn sample of body fluid”.  It is submitted on behalf of the respondents that the expression “withdrawn sample” is used in the body of the specification as “a withdrawn sample (using a syringe)” and is to be  contrasted with the expressions “a non-expressed drop of blood generated from a needle-prick at a bodily extremity” and “an expressed sample (eg using a needle-prick device)” which are used in other parts of the specification.

13                  The point  is explained in the specification where, after outlining the Colourmetric test strip, the following words appear:

            “Since blood samples, on a self-treatment basis are taken from body extremities (fingers, toes, earlobes) they are normally not large enough when obtained by a simple needle-prick, and must in fact be expressed ie squeezed or massaged out to form a larger drop.  Progressively, the tissue of the extremities becomes scarred and coarsened by such treatment to an extent whereby finding fresh testing sites presents a problem.

In order to embody the invention on a home-diagnostic basis a main object of the present invention in one aspect is as described above the provision of small scale non-traumatic test pieces, either as a small diameter invasive probe electrode or as an external test electrode strip capable of using the naturally-arising small blood droplet from a needle-prick tester, without tissue massage”

14                  It is clear, in my opinion, from this material that there is a distinct difference between an expressed or non-expressed drop of blood, on the one hand, and a small sample of body fluid withdrawn by syringe, on the other.  The kind of device which would be capable of invasion would be easily adapted to dipping into a withdrawn sample of blood, but hardly adapted to dipping into an unexpressed drop of blood for the purposes of forming a circuit.

15                  These pointers lead me to accept the submission that the claim relates to an invasive sensor.  It follows that the Selfcare strip does not infringe claim 1, because it is not capable of being an invasive probe in the sense described in the specification.

claim 3

16                  The first thing to note about claim 3 is that it does not refer to blood, live tissue or body fluids – the liquid medium is not restricted except by function, that is, having one or more selected components capable of undergoing an enzyme catalysed reaction.  This links with the statement in the body of the specification:

“Use may be made of such electrodes in chemical industry, especially where complex mixtures are encountered, eg, in food chemistry or biochemical engineering.”

17                  The respondents claim that the use of the word “expanse” should be given its ordinary meaning of  “wide uninterrupted area”.  Whilst I do not agree with this, the use of the word “expanse” does not involve any restriction or limitation in relation to area.

18                  Next,  there is no reference to dimensions of the electrodes, such as “small” in claim 1 or “small enough to be completely coverable by a smear of blood produced from a non-expressed drop of blood generated from a needle-prick at a bodily extremity” in claim 4.  Furthermore, there is no indication of any particular relationship between the position of the electrodes such as “adjacent to but non-contiguous with” in claim 1 or “separate from but sufficiently close to the sensitive electrode area that the said blood smear also reaches the reference electrode to establish electrical communication” as in claim 4.

19                  Then there is, again, the use of the word “comprising”.  Whilst the answer is not, perhaps, as clear as it was in relation to claim 1, in my opinion the word is again used in the sense of including or containing in claim 3.  It is a primary meaning of the word, and the drafter of these claims, and the specification, in my view, uses it in that sense.  Furthermore, in relation to this claim, if the word is construed as exhaustively stating all integers or components, the claim would exclude, for example, a membrane cover for the electrode, which is identified in the body of the specification as a valuable constructional feature.  This would be a surprising result.

20                  The respondents submit (in my opinion, correctly) that, according to the claim, the elongate support member is not limited to a flat surface and that the electrodes do not have to be on the same surface of the elongate support member.  The respondents also submit that the first, or working, electrode claimed consists of electrically conductive material and that, contained within, or as part of, that material are a mediator compound and enzyme – in other words, the conductive material is homogenous.  I do not agree.  Reading integer (b) as a whole, in the light of the specification, it seems to me that it is not essential that the material be homogenous in this sense, but that what is necessary is that there be an outer surface or layer which combines an enzyme and a mediator compound which transfers electrons to the first electrode when the enzyme is catalytically active.  The respondents’ alternative submission is that the layer is fixed to the conductive material by chemical bonding.  I cannot read this requirement into the claim.

21                  There was significant debate between the parties as to the meaning and significance of the words “in a liquid medium into which the support member is dipped to contact both electrodes”.  It is argued for the respondents that these words make it clear that the device should be adapted or designed for dipping as the method of contacting the electrodes.  It is put for the applicants that the claim is a claim for a product not a process, and that the reference to dipping does not define the product;  that the claim does not, in terms, say that the device must be adapted or designed for dipping and so does not add any features to the device the subject of the claim;  and that the sense is captured if it is read as saying  “into which the support member may be dipped”.  The applicants call in aid the words in the body of the specification that external sensors are used by “dipping into or similarly contacting a liquid substrate … with both electrodes”.  It is suggested that the phrase “dipped to contact” means no more than “brought into contact”, which may be achieved by dipping.

22                  Whilst it is true that the claim is not a process claim, the words in question are not, in my view, mere surplusage.  It would be a mistake to construe claim 3 with a drop of blood in mind.  As I have pointed out, it is not restricted in relation to size, dimensions and shape, and the constraints of configuration are few.  There is no limitation to the size of the liquid sample or its composition.  A device in accordance with the claim could be quite large and used in the food or chemical industry. The reference to dipping identifies that as the means of contact between the sensor and the liquid mixture.  That is what claim 3, and the corresponding portions of the body of the specification, teach the skilled addressee.  It follows that the device must be at least suitable for dipping in this way.

23                  It follows that the Selfcare strip does not infringe claim 3.  Its size, the dimensions of its components and their physical relationship, together with the instructions for use, make it clear that it is designed, adapted and suitable for the utilisation of a drop of blood placed upon it.  This is recognised in various parts of the body of the specification as being a particular problem or situation which needed to be dealt with and was specifically addressed by a description similar to that which later appears in claim 4 and the explanation of figure 4.  Claim 4 is expressly directed to this point.  This is not to read down claim 3 by reference to claim 4 – it is to recognise that claim 3 should be accorded its ordinary meaning without any strained construction to pick up the claimed infringement.  The applicants do not allege infringement of claim 4, and there is no occasion to consider why that claim took the particular form that it did.  The Selfcare strip is not designed, adapted or suitable for dipping into blood.

24                  The evidence which was called from Dr Sanghera as to use of the Selfcare strip for dipping does not alter my view.  The experiment was not carried out in blood, in particular it did not deal with a droplet of blood, and the results, although they may have been consistent in themselves, were not shown to be consistent with the results obtained by use in the manner for which the strips were designed.  Professor Hibbert’s evidence indicates that no such assumption can be made.  Even if the tests had shown that the strip would work when dipped in blood, I would not regard that as establishing infringement.  A device which is designed,  adapted and suitable for a very particular and narrow form of use would not, in my opinion, normally infringe a very wide claim for a device designed and adapted for a different use, albeit with the same ultimate purpose.

claim 19

25                  As claim 19 includes an assembly as claimed in claim 1, there is no infringement of it.  It might also be said that this claim recognises a distinction between a claim 1 (potentially invasive) assembly on the one hand, and a flat strip non-invasive electrode on the other.

claims 22 and 23

26                  As these claims are dependent upon claims 1 and 3, there is also no infringement of either of them.

conclusion

27                  I propose, therefore, to dismiss the application.  I will hear further submissions as to what should occur in relation to the cross-claims in the light of these reasons.  I will hear argument as to costs when that decision is made.

28                  The orders will be:

1.                  Application dismissed.

2.                  Costs of the application reserved.

3.                  Cross-claims stood over for further argument.

Associate:

Dated:              24 November 2000