Abbott Laboratories v Corbridge Group Pty Ltd

[21]

· Claim 1 (of which Claim 2 is a variant) is concerned with two electrodes of small dimensions extending as, or supported on, an elongate member to facilitate manipulation of the elongate member during contact with live tissue or withdrawn body fluid. · Claim 3 is concerned with an elongate member on which the two electrodes are supported and which is dipped into a liquid medium containing the substance of interest. · Claim 4 (of which Claims 5 and 6 are variants) describes two flat electrodes on the same surface small enough to be completely coverable by a smear of blood produced from a non-expressed drop of blood generated by a needle prick. Claim 4 was revoked because there is no mention of the material of the sensitive electrode that is an essential integer of the invention of the Sensor Patent, being the enzyme and the mediator compound. · Claim 7 is concerned with a needle probe electrode carrier for placement through tissue into a measurement location, such as a blood vessel, in the form of a generally cylindrical pointed needle. · Claim 8 (of which Claims 9, 10 and 11 are variants) relates to a metallic needle, constituting the reference electrode, which surrounds the sensitive electrode. · Claim 12 (of which Claims 13, 14 and 15 are variants) involves a sensor where the sensitive electrode and the reference electrode are located on opposite faces of an elongate support. · Claim 16 describes a two-part cell assembly, each part containing an elongate recess such that, when assembled, the recesses oppose each other and define a channel through which a liquid will flow thereby contacting the electrodes accommodated in each elongate recess. · Claim 20 is a combination of an assembly of circuitry and display means for use in producing a read-out value of blood glucose level, in the form of a pen-like hollow housing, coupled with a strip test electrode carrier that is inserted into a socket at one end of the housing. · Claim 21 describes analytical equipment comprising a cell, the parts of which, on assembly, jointly define a low volume liquid chamber, together with a pump causing liquid mixtures to flow into the chamber, the inner surfaces of which contain the two electrodes. Claims 22, 23, 24, 25 and 26 are variants of the earlier Claims in which the material of the active electrode, the reference electrode, the enzyme or the mediator compound are specified.

[99]

· the party seeking revocation carries the onus of proving obviousness; · the question is whether, at the relevant date, the claimed invention would have been obvious to the unimaginative and non-skilled technician in the trade in Australia equipped with the common general knowledge of those in that trade; · Corbridge and Inverness had failed to establish that there was an identity between the common general knowledge as it existed in Australia at the relevant time and as it existed in other places in the world; · the only evidence which addressed the state of knowledge in Australia at the priority date was some literature searches and the evidence of Professor Alexander; · prior art does not equate to common general knowledge. A publication is not part of common general knowledge unless evidence establishes that it is. It is not appropriate to make a mosaic of prior publications to compare with the invention in order to test obviousness; · Professor Alexander was a research scientist, rather than the required skilled but unimaginative non-inventive technician and was not representative of such a party. His knowledge at the time does not represent the common general knowledge; · Corbridge and Inverness failed to establish the relevant common general knowledge that is the baseline from which to judge the obviousness of the invention. That is not surprising, as there was no commercial entity involved in the field in Australia at the priority date. The field was entirely theoretical in Australia at the relevant time; · in any event: "there would have been serious contra-indications at the time in relation to choice of a two-electrode system and in relation to the electrodes being in direct contact with the solution to be analysed, particularly blood and particularly if the electrodes were on the one support member of roughly the same size." (emphasis added) A two-electrode system, with both electrodes of roughly equal size in direct contact with the solution on the one support, was not obvious.

[124]

RELEVANT CLAIMS DEFINING THE INVENTION OF THE SENSOR PATENT

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 (of electrically conductive 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 of the elongate member before or during contact with live tissue or a small withdrawn sample of body fluid. ………………………
A sensor for contact with a liquid mixture of components for detecting the presence of, measuring the amount of an/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.
A sensor means comprising (a) a flat first electrode area of known areas 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. ………………………
A needle probe electrode carrier for placement through tissue into a measurement location such as a blood vessel, in the form of a generally cylindrical pointed needle having formed therein near the pointed end two flat depressions spaced apart longitudinally, each depression with a floor at right angles to the needle radius and each with a protective shoulder at each end of that floor: wherein the floor of one such depression is coated with an adherent layer comprising an enzyme and a mediator compound to transfer charge from the enzyme when it is contacted with its specific substrate and hence catalytically active; the floor of the other such depression is coated with an adherent reference electrode layer; and separate conductive elements are provided along the surface of the needle, communicating one with each electrode layer, for connection to signal readout means attachable at the outer end of the needle.
A sensor for selective detection, determination or monitoring of a given dissolved substrate in a mixture of dissolved substrates, of the type in which an electrode is provided with an enzyme catalytic of said substrate and with a mediator compound to transfer charge to the electrode to provide a read-out signal against a reference electrode: wherein the reference electrode is a metallic needle surrounding, insulated from, and made of or coated with suitable reference electrode material to, the sensitive electrode. ………………………
A sensor for selective detection, determination or monitoring of a given dissolved substrate in a mixture of dissolved substrates, of the type in which an electrode is provided with an enzyme catalytic of said substrate and with a mediator compound to transfer charge to the electrode to provide a read-out signal against a reference electrode: wherein the sensitive electrode and the reference electrode are located on opposite faces of an elongate non-conductive support of rectangular cross-section. ………………………
A two-part cell assembly, each part containing an elongate recess accommodating one elongate electrode, the first electrode comprising an enzyme and charge-transferring mediator on a conductive support and the second electrode being a reference electrode: the said parts, when assembled with the recesses opposed, defining a through flow liquid channel between the thereby located and spaced electrodes, whereby the combination is sensitive to the substrate of the enzyme passing through the channel. ……………………… 20. The operative combination of: (I) an assembly of circuitry and display means for use in producing a readout value of blood glucose level as a diagnostic aid in treatment or control of diabetes, comprising: (a) a pen-like hollow elongate housing; (b) an electrically conductive socket one end of said housing suitable to receive a detachable strip electrode carrier, and (c) a digital readout window towards the other end of said housing connected to said socket for exhibiting a numerical value corresponding to the said glucose level; and (II) a strip test electrode carrier held at one end in said socket, carrying: (a) a flat electrode of area not greater than 25 sq. mm and comprising a glucose catalytic enzyme and a metallocene mediator whereby it is sensitive to blood glucose levels, (b) a reference electrode area non-contiguous with but closely adjacent to the said sensitive electrode area and (III) separate conductive elements extending along the strip communicating one with each electrode for connection to the socket.
Analytical equipment for detecting the presence of, measuring the amount of and/or monitoring the level of one or more selected components of a liquid mixture, comprising: · a cell the parts of which on assembly jointly define a low-volume liquid chamber, at least one of the said cell parts being provided with liquid inlet and outlet ports communicating with the said defined chamber when the parts are assembled; · a selectively operable pump for causing the liquid mixture to flow into the inlet means and out of the outlet means either continuously or intermittently; · a first electrode in the form of a thin expanse of conductive material and comprising at least at an external surface thereof the combination of an enzyme and a mediator compound which transfers electrons to the electrode when the enzyme is catalytically active; · a second, reference, electrode also in the form of a thin expanse of conductive material; · each said electrode presenting an operative surface within said defined low-volume liquid chamber; · a potentiostat for poising a predetermined voltage difference between the electrodes; · means for detecting or measuring current flow between the electrodes when a liquid sample is introduced in to the chamber; and · signal storage and/or readout means operatively connected to the means for measuring current flow.

Abbott Laboratories v Corbridge Group Pty Ltd - [2002] FCAFC 314 - FCAFC 2002 case summary — Zoe

At a glance

Court

Decision date

Before

Source

Judgment (124 paragraphs)

Parties

Legislation Cited (2)

Cases Cited (5)