Source: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-cand-3_04-cv-03732/USCOURTS-cand-3_04-cv-03732-73/pdf.json

Nature of Suit Code: 830
Nature of Suit: Patent
Cause of Action: 35:271 Patent Infringement

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United States District Court

For the Northern District of California

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IN THE UNITED STATES DISTRICT COURT

FOR THE NORTHERN DISTRICT OF CALIFORNIA

THERASENSE, INC.,

Plaintiff,

 v.

BECTON, DICKINSON AND COMPANY,

Defendant. /

AND CONSOLIDATED CASES. 

 /

No. C 04-02123 WHA

Consolidated with

No. C 04-03327 WHA

No. C 04-03732 WHA

No. C 05-03117 WHA

FINDINGS OF FACT AND

CONCLUSIONS OF LAW

INTRODUCTION

After a bench trial, this order constitutes the findings of fact and conclusions of law. 

Both sides have submitted lengthy proposed findings and conclusions. Rather than address

each and every proposal, this order will find its own way through the evidence and arguments. 

Any proposal that has been expressly agreed to by the opposing side, however, shall be deemed

adopted even if not expressly stated herein. That a proposal has not been expressly covered

herein does not necessarily mean it was rejected; it only means that the Court found it

unnecessary to reach. 

THE PROCEDURAL HISTORY OF THE CASE

Abbott Laboratories filed the first of these actions on May 28, 2004. Three subsequent

actions were filed. All concerned four United States patents owned by Abbott and Therasense,

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 Therasense is a wholly-owned subsidiary of Abbott Laboratories, and the exclusive owner of two of

the other patents in suit. 

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Inc.1 U.S. Patent No. 5,820,551 is the subject of this order. These actions were originally

assigned to The Honorable Martin J. Jenkins. Judge Jenkins issued a first claim construction

order for certain other patents and a separate claim construction order for the ’551 patent. 

He also issued three separate summary judgment orders. The final one, dated April 3, 2008,

involved all parties and all patents in suit. While the final summary judgment order did

eliminate several infringement counts, several other claims were still viable. Immediately after

issuing the final summary judgment order, Judge Jenkins left the federal bench, and all four

cases came to the undersigned.

All four cases were subsequently consolidated and a trial date was set for May 27, 2008. 

All defendants were permitted to file one more round of summary judgment motions and each

party was allowed motions in limine. A technology tutorial for the undersigned was also held. 

The motions for summary judgment and motions in limine were fully briefed. A first omnibus

order ruled on the motions for which oral argument was not required. Argument was then heard

for the remaining pending motions. In a second omnibus order, the final pending motions were

decided. Defendant Roche Diagnostics Corporation subsequently settled on the eve of trial.

During this time, the Court and counsel also addressed the shape of the trial. It was

decided that a trial on the ’551 patent would be held first with all defendants and would be

broken up into three separate phases: (i) invalidity and unenforceability; (ii) infringement

(if needed); and (iii) willfulness and damages (if needed). All parties then stipulated that phase

one of the ’551 trial would be tried to the bench. Defendants raised four issues for phase

one: inequitable conduct, obviousness, prosecution laches, and non-compliance with the

written-description requirement. 

When the trial on the ’551 patent began, the remaining defendants were Bayer

Healthcare, LLC, Becton Dickinson & Company, and Nova Biomedical Corporation

(collectively “BD/Nova”). Before trial began, Abbott made a request to add Attorney Lawrence

Pope as a live trial witness in its case-in-chief. During Attorney Pope’s deposition, Abbott’s

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counsel had on three separate occasions insisted to defense counsel that Attorney Pope would

not appear in person at trial. This was said in aid of repeated instructions not to answer. 

Attorney Pope was, therefore, scheduled to appear only through video-deposition. Based on

Abbott’s insistence at deposition that Attorney Pope would not appear live at trial, Abbott’s

request to have Attorney Pope appear as a live trial witness was initially denied. This denial

was on the ground that it would be unfair to defendants, who had relied on the deposition

representations to their detriment in not bringing Rule 37 motions. During trial, however,

Abbott renewed its motion to allow Attorney Pope to testify in person at trial. The Court then

asked Abbott to submit a sworn proffer showing the proposed statement of Attorney Pope’s

testimony. Abbott submitted a declaration signed by Attorney Pope detailing the facts he would

cover in his testimony. Because of the seriousness of the accusation against Attorney Pope, the

Court relented and allowed Abbott to call Attorney Pope in its case-in-chief on those topics

raised in his declaration.

After defendants closed their case-in-chief, Abbott moved for partial findings under

Rule 52(c) that defendants had failed to meet their burden of proof with respect to their defense

of prosecution laches. The motion was granted on the ground that defendants had failed to

show any intent to delay prosecution of the ’551 patent or that substantial prejudice resulted

from any such delay. Abbott also moved for partial findings as to defendants’ remaining

invalidity defenses. These motions were all denied. Abbott rested its case-in-chief on June 2

and closing arguments were heard on June 3. This order now follows. 

THE UNITED KINGDOM WORK

United States Patent No. 4,545,382 (and its European counterpart) is a decisive item of

prior art in this decision. Here is its story. In the late 1970’s and early 1980’s, two research

groups at the University of Oxford and the University of Cranfield in the United Kingdom were

working on electrochemical sensors to detect the concentration of specific components in

solutions. In particular, they were interested in developing electrochemical sensors that could

be used to test glucose levels in human blood. Doctors Irving Higgins, Hugh Hill, and Elliot

Plotkin were part of these research groups. In 1981, both groups teamed with a newly founded

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2

 Dr. Anthony Turner, the defense invalidity expert, was also involved in the initial research efforts that

took place in the United Kingdom. He joined Dr. Higgins’ team at the University of Cranfield in 1981 as a

research officer. He later became a project director in 1983 after Genetics International began working with the

group. Dr. Gordon Sanghera, as stated in more detail below, was also involved with the research efforts by the

two groups. 

4

company, Genetics International, which was co-founded by James McCann. One goal was to

create the first commercial electrochemical sensor for glucose.2

 

In 1981, the researchers filed their first patent application. This became the ’382 patent

in the United States and No. 0078,636 B2 in the European Patent Office. The specification

taught an improved electrochemical sensor for use in various liquid mixtures. The sensor was

an electrode coated with specified chemicals that generated a tiny but detectable flow of

electricity in the presence of glucose. The technology itself will be described below. In brief,

the chemicals coated onto the electrode combined with glucose or whatever other “substrate”

was being tested to generate small currents of electricity, which could then be measured by an

ammeter. The higher the concentration of substrate, the higher the electrical current, and the

higher the meter reading. The patent disclosed certain ferrocene chemistry that allowed for

fasting testing. 

Although the United States ’382 patent lived out its seventeen years without incident,

its EPO counterpart (i.e., the ’636) was eventually revoked based on a German prior-art

reference that was cited by a third party in a European opposition proceeding. That was in

the mid-1990’s. The decision to revoke the patent was appealed, however, and the patent

was eventually reissued by a technical board of appeal in the European Patent Office. 

Certain submissions made along the way by Abbott’s predecessors, however, have turned

out to be important in this proceeding by reason of their non-disclosure to the PTO during

prosecution of the ’551 patent in suit. 

The research group continued its work on sensors for testing glucose levels in blood. 

Dr. Hill and his colleagues filed several additional patent applications, which were later

combined to form a single United States patent application. All parties herein agree that the

resulting U.S. Patent No. 5,820,551 — the patent in suit — claims priority to May 1983. 

James McCann and Drs. Hill, Higgins and Graham Davis were listed as the inventors. 

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Originally, the claimed invention of the ’551 patent was the development of a disposable

electrode strip whose electrodes could be covered by a single drop of solution. These one-use

strips would be inserted into a convenient unit for digital readout of the level of a target

compound (like glucose) in a test liquid mixture (like blood). After a strip was used to generate

a readout, it could be thrown away. 

The ’551 patent was in prosecution for over fourteen years. During this period,

Genetics International changed its name to Medisense, Inc. Various claims were rejected

twelve times by the PTO examiner, David Shay. Eleven out of the twelve rejections relied on

the ’382 patent or its European counterpart, the ’636 patent. During this prolonged prosecution,

Medisense amended the proposed claims several times to overcome rejections by Examiner

Shay — all without success. At times, Medisense also submitted declarations from persons of

ordinary skill in the art to distinguish its claims from the prior art. None of the proposed

amendments ever included a limitation for a sensor without a filter or a membrane. 

In the meantime, several other companies, including defendants Bayer Healthcare, LLC,

and Becton Dickinson & Company, had begun manufacturing and selling disposable

electrochemical sensors for diabetic patients. 

In 1996 — while the ’551 patent was still pending before the PTO — Medisense was

purchased by Abbott Laboratories. After the acquisition, Abbott brought in one of its in-house

patent attorneys to take over the prosecution of the ’551. That attorney was Lawrence Pope. 

Attorney Pope worked in conjunction with several technical employees at Medisense, including

Dr. Gordon Sanghera, to “brainstorm” various arguments regarding the patentability of the

’551. Dr. Sanghera had worked at Medisense since 1990. As of 1997, he was its director of

research and development in the United States. His responsibilities included running

competitive analysis in conjunction with the marketing department and supervising Abbott’s

patent portfolio. Dr. Sanghera had also previously worked for Dr. Hill at his laboratory at

Oxford University. He had researched electrochemical sensors, but he had not been involved in

the research that led to any patents involved herein. Dr. Sanghera had, however, attended the

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European opposition hearings and had been active in crafting the submissions made in that

appeal. 

Dr. Sanghera and Attorney Pope struck upon a new point of possible novelty previously

overlooked in the pending prosecution. The new point was that the specification disclosed a

sensor for use in whole blood without any protective membrane. Trouble was, a passage in the

earlier ’382 patent already seemed to disclose membraneless sensors. That passage read

(col. 4:63–66): 

Optionally, but preferably when being used on live blood, a

protective membrane surrounds both the enzyme and the mediator

layers, permeable to water and glucose molecules. 

To address this problem, Abbott decided to assert, as a matter of extrinsic fact, that in

1983 skilled artisans would have believed that a membrane was essential even in the face of the

’382 disclosure, i.e., they would not have taken the quoted sentence literally. 

Attorney Pope then held an interview with Examiner Shay on November 4, 1997. 

Examiner Shay summarized the interview as follows (TX 469):

Applicant indicated that he would like to submit claims

specifically covering a compound specific electrode with the

filtering membrane absent. The Higgins et al. (’382) disclosure

was discussed esp[ecially] the paragraph spanning columns 4 & 5. 

It was determined that since Higgins et al. appear to require the

membrane for use with whole blood (see example 8) an affidavit

or other evidentiary showing that at the time of the invention such

a membrane was considered essential would overcome this

teaching.

As arranged in the interview, Attorney Pope submitted a declaration by Dr. Sanghera on

December 3, 1997, along with amendments to the claims. The declaration stated in relevant

part (TX 443):

THAT based on his historical knowledge he is confident that on

the filing date of the earliest application leading to the present

application on June 6, 1983 and for a considerable time thereafter

one skilled in the art would have felt that an active electrode

comprising an enzyme and a mediator would require a protective

membrane if it were to be used with a whole blood sample. 

Therefore he is sure that one skilled in the art would not read lines

63 to 65 of column 4 of U.S. Patent No. 4,545,382 to teach that the

use of a protective membrane with a whole blood sample is

optionally [sic] or merely preferred.

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 Live blood is inside the body and can only be tested in vivo. Whole blood is blood with all its

constituent parts and can be in or outside the body. In vitro refers to tests outside the body, which must, in our

context, be performed on whole blood, not live blood. 

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The entire submission was aimed at overcoming the “optionally, but preferably” sentence in the

’382 patent. 

Attorney Pope submitted parallel remarks stating that those of ordinary skill in the art

believed that the use of a protective membrane was “required” when testing whole blood and

that they would have understood the sentence in question as mere patent phraseology, not a

technical teaching. Based on Dr. Sanghera’s declaration and Attorney Pope’s remarks,

Examiner Shay finally approved the proposed claims and the patent issued on October 13, 1998. 

The foregoing findings will be amplified with many details below. 

INVALIDITY

In this action, the central axis of contention concerns membranes and, more

particularly, their use as a permeable layer surrounding the chemistry coated onto the active

electrode. Late in the fourteen-year prosecution, as stated, Abbott advanced the theory that the

’551 specification revealed a sensor without a protective membrane. However, a key prior art

reference — the inventors’ own ’382 patent — had already stated that such membranes were

optional and at most preferred in certain circumstances, as quoted above. This ’382 sentence

was raised by the examiner as having already taught that membranes were merely optional or

preferred. In response, as stated, Abbott took the position (and still maintains) that the

sentence would not have been understood in 1983 by those skilled in the art to have modified a

supposed conventional wisdom that a membrane was necessary for testing in whole blood.3

Defendants disagree. They point out that the ’382 sentence expressly stated that even for live

blood, a membrane was merely “preferred” and that for all other cases it was “optional.” In no

case was it said to be “required.” 

With this introduction of the central invalidity issue, this order will go back to square

one. It will begin by setting forth the basic technology. It will then review the ’382 patent,

focusing on its entire disclosure, including the sentence in question, so as to place that sentence

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 The word substrate is used in the ’551 patent in a second sense, namely to describe the base on which

the electrode is formed (see, e.g., col. 2:27, 33; col. 3:23). This is a second, different meaning. 

8

in full context, all from the point of view of one skilled in the art at the time of the alleged

’551 invention (in 1983). 

* * *

Although this summary of the technology is now stated in the present tense, this

summary was all known in the prior art. The electrochemistry involves an electrode coated

with an “enzyme” catalyst. The enzyme is particularly selected to react with glucose or

whatever the test substance might be. Again, the substance being tested for is sometimes, as

used by Medisense in the EPO proceedings, called a “substrate.”4

 The enzyme-substrate

chemical reaction generates electrons. The electrons are passed via yet another chemical called

a “mediator,” also coated onto the electrode, to the active electrode itself. The electrons then

flow as a tiny but measurable electrical current down the active electrode through an ammeter

and back to the other uncoated electrode. The blood droplet or other solution under test

provides an electrical path completing the circuit between the electrodes. The word “sensor” is

sometimes used interchangeably with the active electrode, i.e., the electrode painted with the

active chemistry. 

An analogy is to a battery. Battery chemicals generate electrons and thus electricity,

which can then be used to do work, such as to drive a meter. In the technology at hand, the

active chemistry is the glucose, enzyme, and mediator. Together, they generate the electricity. 

Thus, when blood is placed between and across the electrodes, the chemicals coated

onto the active electrode go to work, generating electricity or “signal.” The electricity passes

through an ammeter, which detects the current. The current will ideally be in proportion to the

concentration of glucose. In this way, the meter can be calibrated to progressive concentrations

of glucose. The user can then see when the glucose (or other substrate) is too low or too high. 

All of the foregoing was known in the prior art. 

* * *

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One of the contributions of the ’382 patent — which was concededly prior art to the

’551 patent — was a faster-acting ferrocene mediator coated onto an active electrode along

with an enzyme. Faster acting meant faster response times and quicker test results. 

In the “Background of the Invention,” the inventors stated that the ’382 invention

would have particular value for “in vivo measuring or monitoring of components in body

fluids” (col. 1:16–17) and said “the determination of glucose in a diabetic human subject” was a

primary application (col. 1:20–21). The background stated further that the invention lent itself

to temporary or permanent implantation. Although “the provision of an implantable glucose

sensor [was] a major object of the invention” the inventors noted that “other and broader objects

[were] not hereby excluded” (col. 1:23–26). A few columns later, for example, the specification

called out home-testing kits with disposable sensors. After acknowledging that in vivo glucose

sensors had already been proposed by others, the inventors stated that they had recently carried

out in vitro studies. 

Under “Summary of the Invention,” the ’382 inventors stated that they had come to

realize that mediator compounds could be associated with the sensor electrode structure itself

to make such electrodes available for use by in vivo methods. The ’382 invention was then

described as a sensor electrode composed of a combination of enzyme and mediator

(col. 1:60–63). Preferably, the electrode was designed to determine glucose in vivo

(col. 1:65–66). A long passage then described various mediators and enzymes (col. 2:1 to col.

4:55). Again, a significant contribution was the ferrocene chemistry that was faster acting than

in the prior art, thus reducing response time. 

At a few places in this passage, the inventors referenced membranes. For example,

two paragraphs stated (col. 3:53 to col. 4:2): 

In that form of the invention using polyviologens, as exemplified

in the three modifications above, it is an objective to keep loss of

active material (enzyme or mediator) to a very low level, i.e., by

the surrounding membrane, co-immobilisation or covalent

bonding. In a different form of the invention, however, still using

glucose oxidase, a rather higher level of loss of active material is

tolerated, giving a sensor electrode of reduced but still useful life,

coupled with improve [sic] sensitivity and selectivity. 

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In this form of the invention the electrode is composed of

particulate carbon mixed with a low molecular weight mediator

disseminated throughout the electrode and glucose oxidase. 

Chloranil and/or fluoranil are useful mediator substances. It is

envisaged to construct from such an electrode a replaceable sensor

tip to a needle-type probe for projecting only into the dermis so as

to allow ready replacement. 

Put differently, after describing a membrane application, the “different form” of the invention

dispensed with the membrane and thus “tolerated” a “rather higher level of loss of active

material” (due to the absence of the immobilizing membrane). It was envisaged to have

replaceable sensor tips for projecting into the dermis. 

Another version called out ferrocene-glucose oxidase as “particularly valuable” and

stated “the enzyme layer is preferably immobilised at the surface of the underlying mediator,

retained in a self-sustaining gel layer” or with “a retention layer thereover permeable to the

glucose molecule” (col. 4:13–16). “Immobilisation” was a reference to retaining the active

chemicals on the electrode so that they would not fall away into the blood or other fluid. 

Then came the main sentence at the heart of this case (col. 4:63–66): 

Optionally, but preferably when being used on live blood, a

protective membrane surrounds both the enzyme and mediator

layers, permeable to water and glucose molecules.

This allowed water and glucose to pass through, kept in the chemicals, and kept out larger blood

constituents like red blood corpuscles. 

The “Summary of the Invention” then turned to various applications and specifically

called out implanted glucose sensors, digital readout diabetic home-testing kits, devices to take

a blood sample from the finger, place it on the sensor, amplify the signal, and give a digital

readout, and a watch-type device for monitoring glucose interstitial fluid in the skin with

disposable-sensor cartridges in the back, which would plug into the electrodes. 

Next came a “Description of the Preferred Embodiments.” In total, the ’382 patent

contained thirteen working examples of preferred embodiments of the invention. Some of the

examples described various procedures for producing the working chemistry of the sensor —

i.e., the enzyme and mediator. Other examples described possible configurations of electrodes

and electrochemical sensors. Each was configured slightly differently depending on various test

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parameters, including the type of solution being tested. Some of the sensors included a

membrane and others did not. 

Examples 1 and 2 described purification processes for producing quinoprotein glucose

dehydrogenase — an enzyme used to catalyze the chemical reaction. Examples 3 and 4

explained the interaction between glucose oxidase (another enzyme) and ferrocene — the

mediator which allowed for much faster and more linear testing than the prior art.

Example 5 described the construction of an in vitro sensor with a glucose oxidase

enzyme and polyviologen mediator. A dialysis membrane was used. The purpose of the

membrane was to block larger molecules from passing through to the working chemistry. 

The sensor was tested in a buffered electromechanical cell. As the amount of glucose in the

test solution was increased, the current generated by the sensor grew, thereby indicating that the

electrode was acting as a glucose sensor. This same construction was used in Example 6,

except chloranil was used as the mediator.

Example 7 taught a sensor configured with a glucose oxidase enzyme and a dimethyl

ferrocene mediator designed for use in interstitial fluid — i.e., skin. Before the sensor was used

for testing, the electrode, mediator, and enzyme were dipped into a solution of cellulose acetate,

thereby creating a protective membrane over the working chemistry and electrode. The

example went on to state: “The small size of such an electrode and its linear response over a

large range of glucose concentrations makes it possible to use the electrode for in vivo glucose

determination on both severely diabetic and normal individuals” (col. 8:54–59). 

Example 8 — entitled “In vitro sensor” — was the most discussed embodiment at trial

(col. 8:63). The example began by describing the construction of a sensor with a glucose

oxidase enzyme and a ferrocene mediator. No membrane was applied. The example then

explained that the sensor was first tested in “nitrogen-saturated buffer solution” (col. 9:15). 

The results for the test in buffer solution were then summarized. A cellulose acetate membrane

was then applied to the sensor. The example went on to describe response times for that sensor

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in buffer and then, in a separate test, in blood. The exact language in the specification stated

(col. 9:26–33) (emphasis added):

With the same buffer, such an electrode modified by a cellulose

acetate membrane coating (produced as in Example 7) gave

response times of 36 seconds (2 mM) and 72 seconds (6 mM). 

With blood, this modified electrode gave response times of 36

seconds (blood with a known 2mM glucose content) and 72

seconds (blood at known 6mM glucose content).

The sensor constructed in Example 8 was thus tested in two solutions. The example first

described was tested in buffer solution. At this point in the specification, no membrane was

applied to the sensor. A membrane was then placed on the sensor. The response times of the

sensor with a membrane were subsequently set forth for the same buffer solution and then,

separately, for blood. It is Abbott’s contention that this example shows that a membrane was

in fact required by the invention of the ’382 patent when testing in whole or live blood.

Example 9 taught the construction of an electrode with a glucose dehydrogenase

enzyme and a ferrocene mediator. A dialysis membrane was used to cover the coated electrode. 

Examples 10 and 11 were minor variations of Example 9. Examples 12 and 13 described

further configurations for an electrode with a glucose dehydrogenase enzyme and ferrocene

mediator. 

Finally, under the ’382 claims, Claim 1 covered the sensor electrode coated with the

enzyme and mediator. All agree that Claim 1 covered electrodes without limitation to either

in vitro or in vivo use. All agree that Claim 1 covered versions with and without membranes. 

Indeed, dependent Claim 12 narrowed the claim to sensor electrodes having an outermost

protective membrane permeable to water and glucose molecules. 

In sum, the ’382 disclosed the basic structure of an active electrode and a faster-acting

chemistry, stating that the structure could optionally include a protective membrane as an outer

layer and stating that such a membrane was preferable when used with live blood, although the

examples involving blood employed a membrane. 

* * *

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 Drs. Hill, Higgins, and Plotkin are listed as the inventors on the ’382 patent. In context, McCann and

Drs. Hill, Higgins, and Davis are listed as inventors on the ’551 patent. 

13

Turning to the ’551 patent in suit, its inventor group was virtually the same as for the

’382, with slight adjustments.5

 It was directed to a home-testing kit and more specifically to a

two-electrode strip (rather than a three-electrode strip) for one-time, disposable attachment to a

handheld readout device. The electrodes were coated with enzymes and mediators (“preferably

a ferrocene”) — as in the ’382 patent. The strip was described as “elongated” for ready

handling and assembly. As with the ’382, the active electrode was “preferably formed of

carbon.” The inventors went on to say that carbon foil available commercially as GRAPHOIL

or PAPYEX was a valuable electrode material. Various “objects” of the invention were

described, none of which related to a membrane or lack thereof. Many columns were devoted

to construction of the electrodes. 

The subject of membranes was mentioned only twice in the ’551 application. 

Under “Membrane Cover for Electrode,” the inventors said that “it may be found valuable to

exclude the sensor from interfering contact with larger molecules or tissue fluid components”

and that this could be done with a “surrounding membrane” (col. 6:67–7:13). That passage

briefly described how to make a membrane in situ. Later, a step-by-step constructional

sequence was given for an electrode strip. Seven steps were listed. Adding a membrane was

not listed as a step (col. 8:35–51), an omission since given great weight by Abbott. A later,

optional modification stated: “The electrode may then be covered, on both sides, with a

semipermeable membrane of cellulose acetate (or polyurethane), not shown, to block large

interfering species from contact with the electrode” (col. 9:34–37). 

Nowhere in the ’551 specification or the original claims was there any suggestion that

treating the membrane as optional (or omitting it) was an inventive step. Nonetheless, this

order appreciates that a legitimate invention may eventually be found lurking in a disclosure

even though the inventors missed it themselves for over a decade. See Newman v. Quigg, 877

F.2d 1575, 1581 (Fed. Cir. 1989). So this order accepts Abbott’s contention, at least for

purposes of argument, that the ’551 specification disclosed an active electrode without a

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6

 U.S. Patent No. 4,388,166 (Suzuki) issued on June 14, 1983, and was filed on May 15, 1982. 

Although the various examples of electrochemical glucose sensors recited in the ’166 all included some type of

membrane, the ’166 specification did expressly recognize that a glucose sensor (for blood) could be constructed

without any membrane as long as the user could tolerate variations in measured values. The specification stated

(col. 1:31–43) (emphasis added):

In the prior art electrochemical measuring apparatus, an enzyme electrode

provided with a semipermeable-membrane indeed allows for a stable

measurement, but the measurement takes a long time due to slow response. 

On the other hand, an enzyme electrode free of a semipermeable membrane

makes a quick response, but has the drawback that measurement is accompanied

with noise, resulting in noticeable variations in the measured values. 

Whether provided with a semipermeable membrane or not, the known enzyme

electrode has the drawback that it loses stability during lengthy application.

The specification went on to explain that prior art glucose sensors (with and without membranes) could be used in

“blood, serum, or urine,” but with decreased sensitivity (col. 1:48). 

14

membrane for use with whole blood (as well as disclosing one with a membrane for use with

whole blood). The decisive question remains whether or not the same group of inventors (with

slight membership changes) had already disclosed in the ’382 patent that a membrane was

merely preferred for use with live blood and was optional in all other cases. This order now

turns to resolving that question. 

* * *

This order accepts Abbott’s proposition that prior to the ’382 patent, those skilled in the

art typically employed a membrane on a sensor used with live or whole blood, although one

exception was already in print.6

 That practice, however, was before the revelation in the

’382 patent. The ’382 patent expressly stated that a protective membrane was optional in all

cases except for live blood, in which case it was preferred. In no case did the ’382 patent state

that a protective membrane was required. 

In context, it seems clear why this was so. The invention specified a faster-acting

ferrocene chemistry. This allowed for shorter response times, i.e., measurement times. This, in

turn, reduced the raison d’ˆetre for any membrane. For example, the faster response times

reduced the probability of the active chemicals being washed away in the bloodstream and

reduced the time within which red blood corpuscles could locate and foul the electrodes. 

(Fouling refers to the larger red blood cells accumulating on the electrode and blocking the

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7

 Abbott concedes that, for example, the D1 reference in the EPO appeal described below had a

response time of five to fifteen minutes. 

8

 The parties agree that in May 1983, a person of ordinary skill in the art would have had a doctoral

degree or postgraduate experience working toward a Ph.D. Such a person would also have had some level of

experience in actually constructing electrochemical sensors or would at least be familiar with them. 

15

much smaller glucose molecules from reaching the sensor.) The indicated readings took about a

minute, even less without any membrane. There was, therefore, less need for any membrane.7

 

As a matter of sentence structure, the sentence sets up two cases — an optional case and

a preferred case:

Optionally, but preferably when being used on live blood, a

protective membrane surrounds both the enzyme and the mediator

layers, permeable to water and glucose molecules. 

Italics have been supplied here to illustrate the structure. Ignoring the italicized preferred case,

the sentence states: “Optionally, . . . a protective membrane surrounds both the enzyme and the

mediator layers . . . .” That is the general, optional case. The exception, i.e., the preferred case,

is for live blood. That phrase is italicized. The trial record is clear and convincing that persons

of ordinary skill in the art understood the words “optionally” and “preferably” in the same way

as the rest of us. There is no doubt that those skilled in the art would have understood that the

sentence was trying to say exactly what has been laid out in this paragraph.8 

Abbott contends that skilled artisans simply would not have believed the sentence and

would have had no reasonable expectation of reliance on it by reason of a prevalent view that

membranes were essential when testing in whole blood. A revelation in a public disclosure

cannot be erased from the prior art on the theory that it contradicted the conventional wisdom. 

The whole point of disclosures in patents is to reveal something new. See Atlas Powder Co. v.

Ireco, 190 F.3d 1342, 1347 (Fed. Cir. 1999). 

Abbott has tied itself in knots contorting the grammar to come up with an alternative

meaning. One example is Abbott’s Proposed Finding No. 90, which reads: 

Interpreted in light of the conventional wisdom at the time, the

“preferably” language means that the membrane is optional when

an in vivo sensor does not contact whole blood but that the

membrane is required when the sensor contacts red blood cells in

whole blood. 

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 This order also rejects Abbott’s idea that the word “optionally” referred to use of a membrane as an

alternative in lieu of some other type of whole-blood filtering member. 

16

This contortion collapses on its own weight. The sentence in question meant just what it said

and the ordinary artisan would have so understood it.9

 

Contrary to Abbott, Example 8 in the ’382 patent was consistent with the plain

meaning of this sentence. Example 8 was one of the preferred embodiments. It described a

ferrocene-glucose oxidase electrode. In the experiment described in Example 8, the sensor was

tested in a buffer solution with two different glucose concentrations, yielding response times of

24 and 60 seconds, depending on the concentration. Then a protective membrane was applied

to the sensor. While still testing the buffer concentration, the response times went to 36 and

72 seconds, respectively. The same sensor — again with a protective membrane — was tested

in blood samples with the same concentration and 36- and 72-second response times were again

obtained. It is true that when the sensor was used in blood a protective membrane was used and

that a protective membrane was not used with the first buffer solution. Nothing in Example 8,

however, stated that a membrane was required for use in blood. That a membrane was added

seems to have been little more than a way to investigate the time effect of adding a membrane. 

It is also true, as Abbott urges, that no test recited in the preferred embodiments included

a test on blood without a membrane. There were, however, too few blood examples among the

embodiments to warrant any inference from this happenstance. No doubt, the broad teaching of

the sentence in question went beyond the specifics of the preferred embodiments. That is often

true in patents. Broad teachings do not have to be supported by specific experimental examples

in order to qualify as prior art. 

The ’382 sentence was then and remains correct, a fact that even Abbott does not

challenge. Membranes were never part of the electrochemistry itself. Rather, they offered

certain mechanical advantages, provoked by two different concerns. The first was human safety. 

For in vivo use, toxic materials might break away from the coated sensor and pollute the

bloodstream. To protect against this possibility, a membrane immobilized the active ingredients,

i.e., retained them in place and thus reduced the risk of breakaway. Reduced response times

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from faster chemistry, however, reduced the breakaway risk — for the sensor could be removed

sooner than before. The second concern was the risk of “fouling.” This was the risk that red

blood particles would stick to the active electrode and prevent glucose from interacting with the

chemicals coated onto the electrodes. If enough “fouling” occurred, the signal would be

diminished below an acceptable level and an erroneous readout would occur. Fouling might

occur in live blood or whole blood. In these proceedings, the supposed problem of fouling has

been exaggerated by Abbott. After the faster chemistry disclosed in the ’382 patent, the risk

became more theoretical than practical, especially for one-use, disposable applications. 

Subsequent diabetic kits using the faster sensors have deleted the membrane with acceptable

results. In sum, the ’382 statement in question was then and remains correct. 

Abbott’s idea that skilled artisans would have read the sentence in question and

disbelieved it in 1983 is not plausible on the trial record. Skilled artisans would have known that

deleting the membrane would simply have deleted their mechanical advantages. They would

have known, however, that the electrochemistry would still have worked. They would have

known that the degree of fouling would have depended on how long the sensor was exposed to

blood. They would have known that the risk of fouling would have been reduced for

faster-acting chemistry and reduced even more for sensors used only once, i.e., disposable

sensors with no accumulation of residue. They would have known that omitting the filter would

have had the further advantage of speeding up the test time even more. 

To be sure, in making these findings in the preceding paragraph, the Court has relied on

trial testimony and materials outside the four corners of the patent and prior-art references. 

This, however, is because Abbott itself has resorted to extrinsic evidence and “conventional

wisdom.” That is, to overcome the ’382 prior-art sentence in question, Abbott has resorted to

extrinsic evidence, arguing that skilled artisans would not have understood the sentence in light

of prevailing practices. Therefore, it is entirely appropriate for the other side to likewise resort

to extrinsic evidence as to how those skilled in the art would have taken the ’382 sentence in

question. 

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Abbott next argues that one skilled in the art would have read the “optionally, but

preferably” passage of the ’382 as mere “patent phraseology.” Notably, the passage in

question stated that a membrane was preferable “when being used on live blood” (col. 4:63–64). 

Defense Expert Turner testified that even today’s implantable electrochemical sensors used for

testing glucose in live blood would use a membrane to ensure that toxic materials were not

released into the blood stream (Tr. 333). He even went as far as saying that the FDA would

likely not approve an implantable sensor without a membrane for safety reasons, which was the

reason a protective membrane was preferable for live blood. Unlike implantable sensors used to

test live blood, however, one-time disposable sensors for in vitro testing (as disclosed in the

’551 patent) had no such safety concerns. With in vitro testing, a membrane was motivated only

by the potential of fouling the electrode. As to them, the ’382 sentence in question taught that

the membrane was merely optional. 

The examiner was persuaded by Abbott’s view as a result of two considerations. 

One was the presence or absence of a membrane in the ’382 examples, particularly in

Example 8. This argument is unpersuasive and rejected by this order, for the reasons stated

above. 

The other reason was based on an extrinsic evidentiary declaration without which the

examiner said no allowance would be made. This was the now-controversial declaration of

Dr. Gordon Sanghera. Although he was not a co-inventor, he had worked at Medisense and had

become an Abbott employee at the time of his declaration. The entirety of his substantive

statement to the examiner was as follows (TX 443): 

3. THAT he is familiar with U.S. Patent No. 4,545,382 and

with the history of the development of the technology disclosed in

this patent. In particular he is familiar with the beliefs and

concerns of those skilled in the art in 1981 when the first

application leading to this patent was filed as well as in 1983 when

the first application leading to the present application was filed. 

4. THAT he is familiar with the teachings of U.S. Patent

No. 4,987,173 to Nankai et al. and in particular with the teachings

of Examples 3 and 4 with regard to the construction of sensors for

use with serum and whole blood samples. 

5. THAT based on his historical knowledge he is confiednt

[sic] that on the filing date of the earlist [sic] application leading to

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the present application on June 6, 1983 and for a considerable time

thereafter one skilled in the art would have felt that an active

electrode comprising an enzyme and a mediator would require a

protective membrane if it were to be used with a whole blood

sample. Therefore he is sure that one skilled in the art would not

read lines 63 to 65 of column 4 of U.S. Patent No. 4,545,382 to

teach that the use of a protective membrane with a whole blood

sample is optionally or merely preferred. 

6. THAT Examples 3 and 4 of U.S. Patent No. 4,897,173

provide evidence that this concern about unprotected active

electrodes for whole blood samples persisted until at least the

June 21, 1985 filing date of the earliest application leading to this

patent. The fact that the Example 3 teaching a sensor for use with

serum samples has no protective membrane but Example 4

teaching a sensor for blood has a polycarbonate membrane is

evidence that the authors of this technical disclosure still believed

that active electrodes could not be directly exposed to whole blood

samples. 

With the exception of the ’173 Nankai patent, the declaration was conclusory and

unsupported. The ’173 Nankai patent was more specific. It did, indeed, happen to use a

filtration layer with whole blood and did not use one with serum, as Abbott states. The Nankai

PCT filing date was June 19, 1986. Nankai did tend to support the “conventional wisdom”

argument advanced by Abbott. 

But Nankai was and remains subject to a very important and overriding caveat. 

The Nankai specification made no reference to the ’382 patent and said nothing about the

“optionally, but preferably” sentence. Nankai was silent on the key sentence. Nankai did not

purport to construe it. 

Although for obviousness purposes, the hypothetical person skilled in the art is presumed

to have full knowledge of all prior art, that in no way means that we must presume Nankai knew

of the ’382 sentence in question. Nankai was simply one practitioner, not someone presumed to

be omniscient. His patent in no way addressed the meaning of the key sentence. He may have

been unaware of the key sentence, for all the record shows. By contrast, for our obviousness

purposes, we must presume the hypothetical artisan knew all of the prior art, including the key

sentence at issue. See Custom Accessories, Inc. v. Jeffrey-Allan Ind., Inc., 807 F.2d 955, 962

(Fed. Cir. 1986). 

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The decisive fact remains that those skilled in the art, had they read it, would have

understood the ’382 sentence as stating that a protective membrane was preferred in the case of

live blood and optional in all other cases. They would have understood it as disagreeing with

any viewpoint that membranes were necessary when testing whole or live blood. The very

purpose of a patent is to disclose new information to persons skilled in the art. 

This order finds that the ’382 patent taught those skilled in the art that — at least when

faster chemistry was employed — a protective membrane was optional in all cases except the

case of live blood, in which case the protective membrane was preferred — but not required. 

The trial evidence and the plain language of the disclosure are clear and convincing on this point. 

Abbott’s “conventional wisdom” evidence is rejected. 

The foregoing is sufficient. To this, it must be said that the information withheld from

the examiner, discussed momentarily, eviscerates any vestige of plausibility to Abbott’s extrinsic

evidence, for that information from the applicants themselves now shows that they knew full

well the meaning of the very “optionally, but preferably” sentence at the heart of this suit. 

This evidence, revealed for the first time in these proceedings, also decidedly supports this

order’s invalidity conclusion. This order rejects the Sanghera declaration and its supposed

conventional wisdom. 

* * *

There is a different aspect to Abbott’s entire theory that deserves comment. Deletion of a

feature from a prior-art device with a corresponding deletion of its function is not an invention. 

For example, if the prior art already discloses a pencil with an eraser, one may not delete the

eraser and claim an eraserless pencil as an invention. The reason is that the deletion of the eraser

would also mean a deletion of its function. This would be true even if the conventional wisdom

was that all pencils came with erasers. See Richards v. Chase Elevator Co., 159 U.S. 477, 486

(1895). 

Similarly, deletion of the protective membrane was not inventive in the ’551 patent

because there was a corresponding deletion of its function. The loss of this function was

tolerable because the chemistry was fast enough (at least by the time of the ’382 prior-art

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disclosure) to obtain acceptable results without a membrane. But assuming arguendo that skilled

artisans had uniformly believed that a membrane was necessary (despite the ’382 patent), the

mere deletion of the membrane with a corresponding loss of its functions would not warrant a

patent. 

It would be different if the ’551 patent disclosed a specific configuration that preserved

the membrane’s function but without the membrane. Exactly what was disclosed in the

’551 patent that compensated for the deletion of the membrane and guarded against fouling? 

The Court asked this question several times during the bench trial. Clearly, the

’551 specification and prosecution history were totally silent on this point. 

At the closing argument, Abbott’s counsel argued — for the first time — that the

’551 disclosed use of certain materials for constructing the electrodes and that these materials

were less sensitive to oxygen. Whereas the ’382 patent had taught carbon as a preferred

electrode, the ’551 patent recommended carbon foil available commercially as GRAPHOIL or

PAPYEX. The argument emerged that normally red blood cells (and their oxygen content)

posed a noise hazard but that the electrodes specified in the ’551 were less sensitive to oxygen. 

Thus, it was said, a membrane could be safely deleted from an electrode constructed from

GRAPHOIL. 

Nowhere in the specification, nowhere in the prosecution history, and nowhere in the trial

evidence was this point made. It surfaced for the first time at closing argument. Still, the Court

has fully considered it. It is easy to see why it has taken so long to invent this line of argument. 

Both the ’382 and ’551 patents disclosed electrodes that exhibited immunity from

oxygen. For example, the ’382 specification stated that the electrodes exhibited “very low

oxygen sensitivity.” This would allow “omission of the dilution step involved in blood analysis

in current instruments,” the ’382 specification said (col. 5:20–22). For its part, the ’551 patent

stated that, for carbon foil, “oxygen interference is minimal, there being less than 4% change in

signal between anaerobic and fully aerobic samples” (col. 7:15–20). 

Given that the ’382 had already disclosed “very low oxygen sensitivity,” the later

statement in the ’551 patent was no improvement on that score. The ’551 statement was a

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10 Interestingly, the Exactech product (the same product Abbott contends embodies the ’551 product for

secondary consideration purposes) does not use GRAPHOIL as its electrode material, meaning whatever

purported benefit that was captured as a result of the GRAPHOIL was not present in the Exactech product. 

In fact, the Exactech product used carbon paste as its electrode material — the same material disclosed in the

’382 patent (Tr. 780).

11 Similarly, at the closing argument, Abbott’s counsel argued that the ’551 patent disclosed a method

for placing the working chemistry onto the substrate — i.e., screen printing — that may have contributed to the

purported success of the Exactech product. The only evidence on the record pertaining to this subject is the

testimony of Dr. Sanghera, who stated that the Exactech’s electrode was screen printed (Tr. 788). Other than

that, there is no evidence indicating that screen printing helped eliminate the need for a membrane or that it was

somehow novel over the prior art. Accordingly, counsel’s argument is rejected.

22

passing comment on a design consideration (concerning oxygen sensitivity) that had been

covered in the earlier patent and was covered again in the later patent. Since the earlier patent

had already achieved “very low” oxygen sensitivity, it is far-fetched to argue that the later patent

somehow solved that problem, much less solved it in a way that specifically dispensed with the

need for a membrane, a nexus nowhere made until at closing argument in 2008.10 

To return to the main point, the clear-cut fact remains that to the extent the

’551 dispensed with the membrane, it also dispensed with its function and thus no invention was

disclosed at all. This point would hold even if we indulged Abbott’s view of the conventional

wisdom about membranes at the time.11 

* * *

The main invalidity issue is the no-membrane limitation. The foregoing resolves that

key component. The inequitable-conduct issue is also anchored in the no-membrane limitation. 

This order, therefore, will now proceed directly to that issue for ease of reader convenience and

return later to the less controverted limitations and complete the obviousness analysis. 

INEQUITABLE CONDUCT

Turning to the defense of inequitable conduct, the “optionally, but preferably” sentence

remains at center stage. When Abbott acquired the pending application that led to the

’551 patent, its in-house lawyer, Lawrence Pope, took over the prosecution. That was in 1997. 

He replaced Fish & Richardson, who had been unsuccessful for twelve years in obtaining

allowance of any claims. Examiner Shay had repeatedly rejected all proposed claims over the

’382 patent. 

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Abbott “brainstorming” sessions were held to find a way to win claims on the

’551 application. These sessions included Dr. Gordon Sanghera. The original inventors were

not included. By this point, Abbott’s competitors were beginning to sell diabetic home-testing

kits in competition with the Exactech, the Medisense-Abbott product. Although Dr. Sanghera

denied it at trial, this order finds that Dr. Sanghera and Attorney Pope were motivated, in part, by

marketplace developments to find a claim to suppress competition. The very day the ’551 patent

issued, for example, Abbott asserted it in a patent-infringement action against a home diabetic kit

made by Lifescan, Inc. There is, however, nothing wrong with seeking a patent in order to stifle

competition, at least under the patent laws, so long as the patent is lawfully obtained. 

The brainstorming sessions produced an argument never before advanced by the

inventors or by prior counsel, namely that the ’551 specification taught that a protective

membrane was not necessary when testing whole blood. This argument was then presented to

Examiner Shay in an oral interview by Attorney Pope in November 1997. With respect to

novelty and the prior art, they expressly discussed the ’382 sentence. For convenience, this

now-familiar sentence is repeated: 

Optionally, but preferably when being used on live blood, a

protective membrane surrounds both the enzyme and the mediator

layers, permeable to water and glucose molecules. 

More specifically, the Interview Summary (TX 469) referenced the Higgins ’382 and

Pace ’410 patents and stated: 

Applicant indicated that he would like to submit claims

specifically covering a compound specific electrode with the

filtering membrane absent. The Higgins, et al. (’382) disclosure

was discussed esp[ecially] the paragraph spanning columns 4 & 5. 

It was determined that since Higgins et al. appear to require the

membrane for use with whole blood (see example 8) an affidavit or

other evidentiary showing that at the time of the invention such a

membrane was considered essential would overcome this teaching. 

A box was checked stating that an agreement had been reached. In short, the examiner agreed

to permit an evidentiary showing to overcome the presumed teaching of the “optionally, but

preferably” sentence. 

To this end, Attorney Pope prepared a sworn declaration for the signature of Abbott’s

Dr. Sanghera. Although he was skilled in the art by the time of the declaration, Dr. Sanghera

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12 The Suzuki ’166 patent, however, which had expressly discussed deleting the membrane in blood

tests, was not included in the Sanghera declaration (see note 6, supra). This order assumes that Dr. Sanghera

was unaware of Suzuki. 

24

had not been skilled in the art at the time of the invention (and, as stated, had not been one of

the inventors). This, of course, was not a requirement for a declaration. Dr. Sanghera read,

understood, and signed the declaration, knowing its purpose and knowing that it would be

submitted to the PTO to overcome the presumed teaching of the sentence. The declaration is

quoted above. In brief, it stated that Dr. Sanghera was sure that one skilled in the art at the time

of the invention would not have read the sentence in question to teach that the use of a

membrane with a whole-blood sample was optional or even preferred. To this end, Dr. Sanghera

did not consult with any of the inventors to learn what had been considered optional, preferred,

or essential despite the fact he still had a good relationship with at least Inventor Hill. He limited

his research to literature.12 

The declaration was filed for Examiner Shay along with an amendment and remarks by

Attorney Pope. The amendment cancelled all prior claims and proposed new claims, soon

allowed. The attorney’s remarks (TX 470) are now set forth at length with italics on the

passages of particular relevance: 

At the interview the applicants’ undersigned representative

explained that a new set of claims would be presented which focus

on the feature that the active electrode is directly exposed to a

whole blood sample without the intervention of a barrier material

such as a membrane or gel which filters out larger molecules or

other blood components expected to interfere with the active

electrode’s operation. It was agreed that this embodiment was one

of the options clearly disclosed in the present application. It was

also agreed that the art generally taught the use of such protective

barriers on the effective filing date of the present application. 

* * *

The applicants’ representative pointed out that U.S. Patent

No. 4,545,382 to Higgins et al teaches that active electrodes

designed for use with whole blood require a protective membrane. 

He noted that the general teaching to this effect at lines 63 to 66 of

column 4 of this patent was amplified and supported by the

specific working examples. In each working example in which an

active electrode was prepared for use with a whole blood sample it

was provided with a protective membrane by either deposition of a

cellulose acetate film or attachment of a dialysis membrane. 

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Example 8 at columns 8 and 9 was noted as being particularly

instructive in this regard. An active electrode was constructed by

successively coating the end of a carbon rod with ferrocene and

then glucose oxidase. This unprotected active electrode was first

tested in nitrogen saturated buffer and then in an air saturated

buffer to establish the impact, if any, of oxygen on the reaction; the

impact appears to have been minimal. Then at lines 22 to 33 the

effect of a cellulose acetate membrane on response time was

investigated when the sample was buffer and when it was blood. 

In both cases the response time appears to have increased by as

much as 50%, e.g., from 24 to 36 seconds for a low level of

glucose. Nevertheless all the succeeding examples utilized a

protective membrane. The clear implication is that the use of

protective membrane caused a slower response time but

nonetheless was needed for a whole blood sample. 

The art continued to believe that a barrier layer for whole blood

sample was necessary for a considerable period. For instance, U.S.

Patent No. 4,897,173 to Nankai et al (copy accompanies this

response), which claims priority from 1985, describes the

production of electrodes for the measurement of glucose. In

Example 3 at columns 4 and 5 an electrode structure for serum (see

line 6 of column 5) is described which does not involve a

protective membrane. In contrast Example 4 at columns 5 and 6

directed to an electrode for use with whole blood (see lines 61–62

of column 5) teaches a filtration layer 21 with a pore size of one

micron. 

One skilled in the art would not have read the disclosure of the

Higgins patent (U.S. 4,545,382) as teaching that the use of a

protective membrane with whole blood samples was optional. He

would not, especially in view of the working examples, have read

the optionally, but preferably language at line 63 of column 6 as a

technical teaching but rather mere patent phraseology. This is

supported by the Declaration under 37 C.F.R. 1.132 of Gordon

Sanghera which accompanies the present amendment. 

* * *

The Examiner is respectfully requested to indicate the allowability

of the currently pending claims and issue a Notice of Allowance. 

The applicants have established that a new claim limitation

supported by the present application provides a patentable

distinction over U.S. Patent No. 4,545,382, the key reference in the

prosecution of the present application and its predecessors. There

is no teaching or suggestion of unprotected active electrodes for

use with whole blood specimens in this patent or the other prior

art of record in this application. Furthermore, the present claims

are patentably distinct from the claims of U.S. Patent

No. 5,682,884. Therefore, this case is in condition for allowance. 

In sum, Attorney Pope’s remarks stated that the sentence in question would have been

regarded as “mere patent phraseology” rather than a “technical teaching” and that the art

believed that a membrane was “required” even for a considerable period after the ’382 patent,

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closing with: “There is no teaching or suggestion of unprotected active electrodes for use with

whole blood specimens in this patent or the other prior art of record in this application.” In

reliance on the submission, Examiner Shay allowed the new claims and the ’551 issued. 

* * *

At the time of the interview and the submission, Attorney Pope and Dr. Sanghera were

well aware of previous representations based on the same “optionally, but preferably” sentence

made by Medisense to the European Patent Office in 1994–95. Attorney Pope and Dr. Sanghera,

however, made a conscious and deliberate decision to withhold disclosure to the PTO of these

prior statements. This much is conceded. Abbott contends, however, that there was no duty to

disclose the earlier statements and that there was no intent to deceive. On these latter points, the

following was proven at trial by clear and convincing evidence. 

The ’636 patent — the European counterpart to the ’382 — had been revoked in 1993 in

an opposition proceeding based on a German prior-art reference called D1. In 1994, Medisense

appealed, arguing that D1 was distinguishable on two grounds. The centerpiece of Medisense’s

appeal relied on the very sentence in question — the “optionally, but preferably” sentence. 

Overall, the ’636 and ’382 specifications were virtually identical. In both, the “optionally, but

preferably” sentence and its immediate context were completely identical. Before the EPO,

however, Medisense had an incentive to advance the sentence as an important teaching over the

D1 reference. Medisense submitted that the “optionally, but preferably” sentence demonstrated

that the ’382/’636 invention did not need a membrane for measuring glucose in blood, whereas

the D1 device had required one. 

Specifically, D1 had disclosed an enzyme electrode usable for glucose and covered by a

semipermeable membrane. Before the EPO, Medisense argued that the D1 membrane was

essential to the D1 invention. By contrast, Medisense stated that the ’382/’636 membrane was

merely optional. Medisense relied on the “optionally, but preferably” sentence as follows

(TX 311 at AL54151): 

10. The above object is solved by a glucose sensor as defined

in claim 1 of the patent in suit [’382/’636]. Apart from the

important feature of utilizing a ferrocene or ferrocene derivative as

mediator, another important difference over D1 resides in that the

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claimed glucose sensor — contrary to that of D1 which requires a

membrane — does not have and must not have a semipermeable

membrane within the meaning of D1. Contrary to the

semipermeable membrane of D1, the protective membrane

optionally utilized with the glucose sensor of the patent [in] suit is

not controlling the permeability of the substrate (as set forth above

under IV.2), in the membrane of D1 the permeability for the

substrate must be kept on a low value to achieve a linear

relationship between the measures [sic] currency and the substrate

concentration in the test solution. Rather, in accordance with

column 5, lines 30 to 33 of the patent in suit: 

“Optionally, but preferably when being used on live blood,

a protective membrane surrounds both the enzyme and the

mediator layers, permeable to water and glucose

molecules.”

See also claim 10 of the patent in suit as granted according to

which the sensor electrode has an outermost protective membrane

(11) permeable to water and glucose molecules. Finally, see

Example 7 in column 10, lines 19 to 26 reporting that by using

such a protective membrane the response time did not increase but

from 24 to 60 sec. (without membrane) to 36 – 76 sec. (with

membrane). Accordingly, the purpose of the protective membrane

of the patent in suit, preferably to be used with in vivo

measurements, is a safety measurement to prevent any course

particles coming off during use but not a permeability control for

the substrate. 

The passage indented the “optionally, but preferably” sentence for emphasis, just as set

out above. The bolded words were bolded by Medisense, just as set out above. The foregoing

quotation is exactly the way it was made by Medisense in January 1994. 

The “safety” purpose stated in the quotation helped to show, it deserves to be said, why a

protective membrane was merely “preferred” for live blood, i.e., in vivo testing. It was optional

in all cases but when placed in a human bloodstream, a membrane was advisable to retain the

chemistry aboard the electrode and, thusly, prevent toxic particles from circulating within the

patient. 

In the same submission (TX 311 at AL54154), Medisense stated that D1 was “strongly

teaching away from the subject matter as claimed [in the ’382/’636] which not only does not

require a membrane but must not have a membrane. In other words, with the claimed subject

matter, rather than keeping the permeability for the substrate at a low level, there is free access

of the substrate to the electrode without any permeability limitation.” 

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13 Defendants have further made a plausible case that the two submissions were also inconsistent as to

their use of Example 8 (Example 7 in the ’636). This inconsistency requires extended argument to develop and,

while plausible, is not as facially and directly inconsistent as the above two points of conflict. This order does

not rely on the alleged Example 8 inconsistencies. 

28

In May 1995, Medisense further stated in the same EPO appeal, again referring precisely

to the “optionally, but preferably” sentence (TX 315): 

It is submitted that this disclosure is unequivocally clear. The

protective membrane is optional, however, it is preferred when

used on live blood in order to prevent the larger constituents of

the blood, in particular erythrocytes from interfering with the

electrode sensor. Furthermore it is said, that said protective

membrane should not prevent the glucose molecules from

penetration, the membrane is “permeable” to glucose molecules. 

This teaches the skilled artisan that, whereas the semipermeable

membrane of D1 must be constructed, for example by

crosslinking, in such a way that the membrane will in fact control

the permeability of the glucose at the required low value, the

purpose of the protective membrane in the patent in suit is not to

control the permeation of the glucose molecules. For this very

reason the sensor electrode as claimed does not have (and must

not have) a semipermeable membrane in the sense of D1. The

fact that the same material (cellulose acetate) may be used both

for the semipermeable membrane of D1 and the protective

membrane of the patent in suit is not relevant. The decisive

feature is the modification (crosslinking) of said material to an

extent so as to control the permeation of the substrate glucose. 

Finding the semipermeable membranes satisfying the

requirements set forth on page 3, lines 24 to 56 of D1 is tedious

and involves considerable trial and error work. Reproducability

of such membranes is always a critical factor. 

For the immediately quoted passage, italics have been added by this order to draw attention to a

particular statement. The bolded words, however, were bolded in the original. Medisense won

the EPO appeal, based on the very arguments described above. 

The submissions made to the EPO were inconsistent with the submissions made to the

PTO in at least two important ways:13 

• The PTO was told that the

’382 required a membrane for use

with whole blood and that those

skilled in the art would not have

understood the “optionally, but

preferably” sentence to teach to the

contrary. 

• The EPO was told that under the

’382 a protective membrane was

merely preferred and not required

when dealing with live blood and

specifically quoted the “optionally,

but preferably” sentence in

support. 

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• The PTO was told that the

“optionally, but preferably”

sentence would have been

understood by skilled artisans as

“mere patent phraseology” and not

as a “technical teaching.”

• The EPO was told that the critical

sentence was “unequivocally

clear” and taught skilled artisans

that “the protective membrane

[was] optional, however it is

preferred when used on live

blood . . . .”

Dr. Sanghera had been much involved in the EPO appeal. He had helped develop the

arguments and had even attended the oral argument before the EPO on June 20, 1995. He was

completely familiar with the points made in the EPO appeal by Medisense. Dr. Sanghera

disclosed all of the EPO submissions to Attorney Pope, who read and understood them. 

Examiner Shay was focused on whether the ’382 patent disclosed filterless devices for

use with whole blood. This, in truth, was the overriding question. The “optionally, but

preferably” sentence was the single roadblock to allowance. Attorney Pope and Dr. Sanghera

knew this was so. Both decided to withhold the EPO materials from the PTO. Both knew that

Dr. Sanghera’s declaration would be submitted to the PTO without disclosing the EPO

submissions to the contrary. Both knew that the EPO materials made affirmative statements

inconsistent with the declaration and the attorney remarks concerning the ’382 sentence in

question. 

Inasmuch as the EPO submissions centered on the same key sentence at issue in the PTO

as well as the key issue before the PTO, a reasonable examiner would have plainly considered

the EPO submissions to be highly material, given the contradictory teaching ascribed to the

sentence. 

* * *

In the United States, patent prosecutions are ex parte and non-public. This means that

applicants and their counsel are the only ones able to make presentations to examiners. 

This one-sidedness persists until an allowance and grant, whereupon the patent is introduced to

the public. In all proceedings leading up to a grant, therefore, there is no opponent to state the

counter case. Examiners and the integrity of the entire process depend on the candor of counsel

and applicants to disclose, if known, material adverse information. The duty of candor is

codified at 37 C.F.R. 1.56. At the relevant time, it stated as follows (emphasis added): 

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§ 1.56. Duty to disclose information material to patentability.

(a) A patent by its very nature is affected with a public interest. 

The public interest is best served, and the most effective patent

examination occurs when, at the time an application is being

examined, the Office is aware of and evaluates the teachings of all

information material to patentability. Each individual associated

with the filing and prosecution of a patent application has a duty of

candor and good faith in dealing with the Office, which includes a

duty to disclose to the Office all information known to that

individual to be material to patentability as defined in this section. 

The duty to disclose information exists with respect to each

pending claim until the claim is cancelled or withdrawn from

consideration, or the application becomes abandoned. 

* * *

However, no patent will be granted on an application in connection

with which fraud on the Office was practiced or attempted or the

duty of disclosure was violated through bad faith or intentional

misconduct. The Office encourages applicants to carefully

examine: 

(1) prior art cited in search reports of a foreign patent

office in a counterpart application, and 

(2) the closest information over which individuals

associated with the filing or prosecution of a patent

application believe any pending claim patentably defines,

to make sure that any material information contained

therein is disclosed to the Office. 

(b) Under this section, information is material to patentability

when it is not cumulative to information already of record or being

made of record in the application, and 

(1) It establishes, by itself or in combination with other

information, a prima facie case of unpatentability of a

claim; or 

(2) It refutes, or is inconsistent with, a position the

applicant takes in: 

(i) Opposing an argument of unpatentability relied on

by the Office, or 

(ii) Asserting an argument of patentability. 

A violation of this rule, if proven in district court, can lead to a bar against enforcement

of any claim in the patent. This is the defense of “inequitable conduct.” The Federal Circuit has

recently summarized the elements of proof for inequitable conduct in McKesson Info. Solutions,

Inc. v. Bridge Med., Inc., 487 F.3d 897, 913 (Fed. Cir. 2007): 

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A patent may be rendered unenforceable for inequitable conduct if

an applicant, with intent to mislead or deceive the examiner, fails

to disclose material information or submits materially false

information to the PTO during prosecution. Digital Control,

Inc. v. Charles Mach. Works, 437 F.3d 1309, 1313 (Fed. Cir.

2006). 

* * *

The materiality of information withheld during prosecution may be

judged by the “reasonable examiner” standard. See id. at 1316. 

That is, “[m]ateriality . . . embraces any information that a

reasonable examiner would substantially likely consider important

in deciding whether to allow an application to issue as a patent.” 

Akron Polymer, 148 F.3d at 1382 (citations omitted). Moreover,

“[i]nformation concealed from the PTO may be material even

though it would not invalidate the patent.” Li Second Family, 231 F.3d at 1380. “However, a withheld otherwise material [piece

of information] is not material for the purposes of inequitable

conduct if it is merely cumulative to that information considered

by the examiner.” Digital Control, 437 F.3d at 1319. “As this

court has previously noted, the scope and content of prior art and

what the prior art teaches are questions of fact.” Id. 

“The intent element of the offense is . . . in the main proven by

inferences drawn from facts, with the collection of inferences

permitting a confident judgment that deceit has occurred.” Akron

Polymer, 148 F.3d at 1385. “However, inequitable conduct

requires not intent to withhold, but rather intent to deceive. Intent

to deceive cannot be inferred simply from the decision to withhold

[information] where the reasons given for the withholding are

plausible.” Dayco, 329 F.3d at 1367. In addition, “a finding that

particular conduct amounts to ‘gross negligence’ does not of itself

justify an inference of intent to deceive; the involved conduct,

viewed in light of all the evidence, including evidence indicative

of good faith, must indicate sufficient culpability to require a

finding of intent to deceive.” Kingsdown Med. Consultants, Ltd. v.

Hollister, Inc., 863 F.2d 867, 876 (Fed. Cir. 1988) (en banc in

relevant part). 

“The party asserting inequitable conduct must prove a threshold

level of materiality and intent by clear and convincing evidence.” 

Digital Control, 437 F.3d at 1313. “The court must then determine

whether the questioned conduct amounts to inequitable conduct by

balancing the levels of materiality and intent, ‘with a greater

showing of one factor allowing a lesser showing of the other.’” Id.

(quoting Union Pac. Res. Co. v. Chesapeake Energy Corp., 236 F.3d 684, 693 (Fed. Cir. 2001)). “When, after a trial, the court

has made factual findings as to materiality and deceptive intent,

those factual findings are reviewed for clear error, and the decision

of the ultimate issue of inequitable conduct is reviewed for abuse

of discretion.” Digital Control, 437 F.3d at 1313. 

* * *

ATTORNEY POPE

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This order will consider the required elements first as to Attorney Pope and then as to

Dr. Sanghera. 

MATERIALITY

Contrary to Attorney Pope and Abbott, the submissions made to the EPO were not only

material within the meaning of Rule 56, they were highly material. They were flatly inconsistent

with the main point being made by Attorney Pope and Abbott to Examiner Shay. They centered

on the precise sentence in question, its meaning, and what it taught. Inconsistency is called out

by Rule 56 as a specific indicium of materiality (§ 1.56(b)(2)). 

Contrary to Attorney Pope and Abbott, the EPO submissions were not cumulative. 

While the “optionally but preferably” sentence was, of course, already of record, the supposed

issue was what it taught and even whether it constituted a teaching at all insofar as those skilled

in the art were concerned. On that score, there was nothing already of record (or being made of

record in the PTO) that duplicated the same points made in the EPO appeal or even came close

to duplicating them. Thus, the examiner was led to believe that those skilled in the art would

have had no reasonable expectation of success in trying to implement the guidance of the

sentence in question by deleting a membrane in whole or live blood. The EPO submissions

certainly pointed the other way. 

This is unlike the situation where a reference is already before an examiner who can draw

his or her own conclusions as to what it teaches and is able to discount spin offered by counsel. 

See Innogenetics, N.V. v. Abbott Labs., 512 F.3d 1363, 1379 (Fed. Cir. 2008). Although the key

sentence itself was indeed before Examiner Shay, the inquiry had shifted to a point of extrinsic

evidence. That is, Examiner Shay had acquiesced to Attorney Pope’s request to resort to

extrinsic evidence to show that the sentence would have been understood by skilled artisans

differently than its words suggested. Having received permission to supply extrinsic evidence,

Attorney Pope was duty-bound to present any inconsistent extrinsic information known to him. 

In the arena of extrinsic evidence, the examiner was unable to fend for himself. He had no way

of knowing what, if any, contrary extrinsic information had been left out of the Sanghera

declaration. He was completely dependent on Attorney Pope and Dr. Sanghera to fully disclose

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28 14 The defense presented an experienced patent attorney and former examiner, Thomas Smegal, to

explain why the EPO items were material. Abbott did not present a counter expert. 

33

any extrinsic information, pro and con, known to them on the factual point covered by the

submission. 

Abbott contends that most or all of the key passages in the EPO appeal were, in effect,

dicta that need not have been raised at all by Medisense before the EPO. Put differently,

Medisense could possibly have prevailed in the EPO appeal had it stuck to just one distinction

over D1, namely that D1 specified a different type of filter than did the ’382/’636. It is true that

the D1 needed a diffusion-limiting filter whereas the ’382/’636 referred to a blood-filtering

membrane, which performed a different function. But the hard fact remains that Medisense did

not so limit its appeal. It clearly submitted to the EPO that, in addition, the ’382/’636 needed no

membrane at all, invoking the very “optionally, but preferably” sentence at issue. Regardless of

whether or not Medisense needed to make the second point in its EPO appeal, Medisense did

make the point. Since that point was inconsistent with the PTO submission made later, Abbott

was obligated to disclose it as part of its extrinsic-fact submission. 

In sum, this order finds that the passages quoted above from the EPO submission were

material within the meaning of Rule 56, such that their disclosure to the PTO was obligatory.14 

INTENT

With respect to intent, Attorney Pope read the entire EPO appeal and made a conscious

decision to withhold the contradictory material from the PTO. That is not sufficient to prove the

intent requirement, of course, but there should be no doubt that conscious withholding occurred. 

Intent to deceive must be shown. The Court has carefully considered all of the facts and

circumstances surrounding the decision to withhold. In this regard, Abbott has asserted the

attorney-client privilege. Nonetheless, some direct testimony emerged as to Attorney Pope’s

rationale for non-disclosure. His stated reason was that the EPO information was cumulative,

an argument this order has already solidly rejected. Without a doubt, Attorney Pope knew or

should have known that the withheld information would have been highly material to the

examiner, given the central question of what, if anything, the “optionally, but preferably”

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sentence taught those skilled in the art. There was no other information in the PTO record that

came close to the clear-cut message of the withheld information. 

Despite the insistence by Abbott (and Attorney Pope) during deposition and pretrial that

he would not be presented as a trial witness, the Court allowed Abbott to reverse field and to

present him as a live trial witness. Abbott and Attorney Pope were relieved from this

representation due to the seriousness of the misconduct charge and to give Attorney Pope every

opportunity to explain his conduct. Attorney Pope did not prove to be a convincing trial witness. 

To the contrary, his trial explanation for his withholding was not plausible and he was not

credible. When, for example, Attorney Pope was shown the EPO appeal language quoting the

sentence in question and immediately stating that “[i]t is submitted that this disclosure is

unequivocally clear,” he testified that he had understood the “unequivocally clear”

characterization to refer only to the last six words of the 26-word sentence — that is, to the

concluding phrase “permeable to water and glucose molecules” and not to its other

twenty words. Sadly, this order must find that Attorney Pope had no plausible reason for

consciously withholding the EPO submissions and that he acted with specific intent to deceive

Examiner Shay and the PTO. In making this finding, this Court has taken into account the

demeanor of Attorney Pope during his trial testimony. 

Attorney Pope testified that his motive was to obtain a strong patent. Therefore, he

said he had no motive to conceal and to thus undermine the enforceability of the patent. 

This argument conveniently overlooks the fact that he consciously chose to withhold. 

Counsel who steer a course toward obtaining a strong patent should err on the side of disclosure,

not nondisclosure. And, it must be said, after so many rejections over so many years, it seems

clear that Abbott’s primary goal was to eke out some claim, saving a fight over enforceability

for a later day. 

Attorney Pope also said that patent prosecutors often write specifications broadly so as

to support broad claims, cutting back on their claims as they go along as necessary to avoid the

prior art or as is otherwise necessary. Being aware of this alleged practice, he testified that he,

therefore, read “optionally, but preferably” as an overblown way for a prior patent prosecutor to

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15 Of course, it is true, as Abbott states, that specifications teach and claims claim. SRI Int’l, Inc. v.

Matsushita Elec. Corp., 775 F.2d 1107, 1121 n.14 (Fed. Cir. 1985) (en banc). Still, the specification must

support the claims. 

35

have said “optionally, but always.” This is unconvincing. First, there is no authority for this

secret-code theory. Words are supposed to mean what they say. Otherwise, our

patent-disclosure system would collapse. Second, since the claims of the ’382 covered

membraneless sensors used in blood, as both sides agree, the specification must have been

sufficient to support the membraneless sensors.15

Although Abbott has not advanced the point clearly, the Court has considered the

possibility that Attorney Pope was confused over the difference between live blood and whole

blood. At trial, he stated that he did not appreciate (until recently) that “live blood” referred to

in vivo tests whereas “whole blood” referred to in vitro tests on blood removed from the body. 

Even if he had thought the two were synonymous, the materiality of the EPO statements would

still have been manifest. In some ways, the EPO statements would have been even more

material, for those EPO statements represented that a membrane was merely optional when used

with blood. At all events, even if the sentence and the EPO statements had said that a membrane

was preferred for both live and whole blood, the fact remains that “preferred” does not mean

“required,” which was a point made in the EPO appeal. In sum, this point of possible confusion

offers no excuse. 

BALANCING

Turning to the final step, this order must determine whether the questioned conduct

amounts to inequitable conduct by balancing the levels of materiality and intent, with a greater

showing of one factor allowing a lesser showing of the other, as set forth above. In doing so,

the undersigned is very mindful that patent prosecutors must make judgment calls about what

is and is not material. We must take care to respect their judgments without second-guessing

them and to penalize only clear-cut violations of Rule 56. 

The withheld extrinsic evidence here was richly material. And, intent to deceive,

not just to withhold, was clearly in the mind of Attorney Pope, hard as it is to so conclude

as to a professional. Both showings are strong. The balance is decidedly against Abbott. 

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If concealment of extrinsic information as close to the heart of the prosecution as was involved

here is allowed to pass, then we would in effect be issuing licenses to deceive patent examiners

in virtually all cases. Having searched for any credible explanation for the conduct (and found

none) and having taken into account all possible inferences of good faith (and found none), this

order finds and holds that Attorney Pope and Abbott were guilty of inequitable conduct in

advancing the Sanghera declaration and attorney remarks without also disclosing the inconsistent

EPO submissions as to the meaning of the “optionally, but preferably” sentence. This has been

proven by clear and convincing evidence. 

DR. SANGHERA

The analysis is largely similar for Dr. Sanghera but differs in some ways from that for

Attorney Pope. 

MATERIALITY

For the reasons stated above, the nondisclosed items were material. 

INTENT

Here, the intent analysis diverges somewhat from that for Attorney Pope, although it

reaches the same conclusion. Once Dr. Sanghera disclosed the inconsistent EPO information to

Attorney Pope, he ordinarily would have done all that Rule 56 required. A specific Rule 56

proviso stated that “[i]ndividuals other than the attorney, agent or inventor may comply with

this section by disclosing information to the attorney, agent or inventor.” Dr. Sanghera did so. 

He did disclose the EPO materials based on the very same sentence to Attorney Pope. 

The problem is that he then made direct representations to the PTO — representations

that were materially misleading by omission. He did not have to take this extra step. 

Having done so, he was obligated to avoid intentional deception. His sworn statements to the

PTO about the meaning of the “optionally, but preferably” sentence were known by him to be

inconsistent with his own company’s statements to the EPO — statements he had himself helped

craft. A declarant who makes a materially false and misleading statement under oath to the PTO

cannot escape a charge of inequitable conduct on the theory that he advised the lawyer that the

statement was misleading and why. (In this regard, no claim of good faith reliance on the advice

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16 Contrary to his trial testimony, at his deposition Dr. Sanghera tried to distance himself from the

decision of what was disclosed to the PTO by repeatedly stating that he merely turned over to counsel all

relevant information and let counsel decide what would be disclosed (Sanghera Dep. 60, 62, 360–61). 

37

of counsel was raised by Dr. Sanghera, a step that would have waived any assertion of the

privilege.) In sum, given the fact that Dr. Sanghera made a positive submission to the PTO,

he was himself duty-bound to avoid making an intentionally misleading submission, whether or

not he told Attorney Pope about the inconsistency. 

Although Abbott has not raised it, the Court has, on its own, considered the possibility

that Dr. Sanghera somehow believed that Attorney Pope would disclose the EPO material in

some other way and, thus, there was not a necessity for his declaration to do so. Dr. Sanghera

testified at trial at Abbott’s behest (despite the fact that much trial time was earlier spent on

video excerpts from his deposition). His trial testimony was clear and convincing that he

affirmatively participated in the group discussion not to disclose the EPO submission, i.e., that

he knew all along that no one was going to disclose the EPO submissions (Tr. 757–58, 774,

776–78). As a trial witness, it must be said that Dr. Sanghera was impeached on substantive

points with his prior inconsistent statements and exhibited an unconvincing demeanor (e.g.,

Tr. 764–67, 772–73).16 

At trial, the only explanation Dr. Sanghera gave for his nondisclosure of the EPO

proceedings and the arguments made by Medisense therein was that both he and Attorney Pope

thought that they were all irrelevant (Tr. 777:23–778:10):

Q. It’s your position, is it not, Dr. Sanghera, that you had no

responsibility to disclose to the U.S. Patent and Trademark

Office anything about the European Patent Office

proceedings?

A. It was my responsibility to disclose to the U.S. Patent Office

everything that we deemed as a team, the technical people,

the Abbott counsel, that was relevant to that case for the U.S.

patent office. I don't know if that answers your question, but .

. .

Q. But you didn't disclose the information, correct?

A. We didn't disclose lots of nonrelevant information.

Q. And in particular, you did not disclose the European Patent

Office proceedings to the U.S. Patent Office?

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A. We did not disclose those, no.

As stated, however, the unambiguous and clear-cut statements made to the EPO were clearly

relevant to the only issue before Examiner Shay, namely whether the “optionally, but preferably”

sentence was a teaching and, if so, what it taught. It plainly should have been disclosed to

Examiner Shay for his independent consideration. 

Dr. Sanghera testified that he did think the statements made to the EPO and PTO were

inconsistent. According to Dr. Sanghera, the statements made to the EPO were specifically

directed at distinguishing the D1 reference on the sole issue of whether or not the ’382/’636

patent required a diffusion-limiting membrane — a point not at issue with the ’551 patent. 

As Dr. Sanghera stated (Tr. 777):

The European proceedings revolved around the use of a diffusion

limiting membrane because we were making arguments about

novelty and inventiveness over the La Roche prior art, and we

discussed the first chemistry and the, therefore the lack of a

requirement of a diffusion-limiting membrane. This the U.S. case. 

We were talking about blood separation membranes and filters and

the two are completely separate pieces of technology.

Nonetheless, the statements made to the EPO regarding the ’636 patent plainly went beyond this

point of distinction and submitted that it was “unequivocally clear” that the ’382/’636 needed no

membrane at all for use with blood. Whether or not Medisense needed to make the point to the

EPO, it did make the point. Dr. Sanghera knew the point had been made. His effort at trial to

excise that part of the EPO proceeding and to pretend it never happened was disingenuous. 

Taking into account all possible inferences of good faith, this order concludes that

Dr. Gordon Sanghera had no plausible reason for concealing the inconsistent EPO submissions

and that he consciously made sworn statements to the EPO that were deliberately misleading by

reason of the omission of the inconsistent EPO submissions. His unconvincing trial demeanor

has been a factor in this determination. 

BALANCING

Once again, both materiality and intent have been proven on the strong end of the scale,

so the overall balance is decidedly against Abbott and Dr. Sanghera. And, it should be said that

sworn statements to the PTO ought to be regarded with a reasonable degree of reverence and

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candor rather than as an opportunity to tailor-make convenient extrinsic “facts” to assuage a key

point of concern to the examiner. 

* * *

This Court is well aware that inequitable conduct has become a knee-jerk and often-abused

response by those accused of patent infringement. Judges ought to view such defenses with

skepticism, as has Judge Rader in a recent dissent. See Events Pharma. v. Amphastar, 525 F.3d

1334, 1349 (Fed. Cir. 2008) (Rader, J.). We should insist on every inch of the

clear-and-convincing standard. Here, however, that standard has been met. The present defense

is not an abuse — far from it. If the conduct here proven were blessed, then the duty to provide

inconsistent information under Rule 56 would be a dead letter. 

INVALIDITY CONCLUDED

To complete the obviousness analysis, this order now resumes with the remaining

limitations, i.e., all limitations other than the no-membrane analysis. In brief, this order finds

that the differences between the other limitations and the prior art were paper thin and readily

apparent to skilled artisans at the time of the alleged invention. 

CLAIM 1

Claim 1 is the only independent claim of the ’551 patent. It recited (col. 13:29–17):

1. A single use disposable electrode strip for attachment to the

signal readout circuitry of a sensor to detect a current

representative of the concentration of a compound in a drop of a

whole blood sample comprising:

a) an elongated support having a substantially flat, planar

surface, adapted for releasable attachment to said readout

circuitry;

b) a first conductor extending along said surface and

comprising a conductive element for connection to said

readout circuitry;

c) an active electrode on said strip in electrical contact with

said first conductor and positioned to contact said whole blood

sample;

d) a second conductor extending along said surface

comprising a conductive element for concentration to said

readout circuitry;

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e) a reference counterelectrode in electrical contact with said

second conductor and positioned to contact said whole blood

sample.

wherein said active electrode is configured to be exposed to said

whole blood sample without an intervening membrane or other

whole blood filtering membrane 

and is formed by coating a portion of the first conductor with a

mixture of or layers of an enzyme which catalyzes a redox reaction

with said compound in whole blood and a mediator compound

which transfers electrons from said redox reaction to said first

conductor 

to create a current representative of the concentration of said

compound in said whole blood sample

and wherein said active electrode which is formed on a portion of

said conductor is not in electrical contact with said reference

counterelectrode but these electrodes are so dimensioned and

positioned that they can be simultaneously completely covered by

a single drop of whole blood such that this drop provides an

electrical path between these electrodes to support said current

representative of the concentration of said compound in said whole

blood sample.

These paragraphs are now considered in turn. 

* * * 

A single use disposable electrode strip for attachment to the signal

readout circuitry of a sensor to detect a current representative of

the concentration of a compound in a drop of a whole blood

sample comprising:

a) an elongated support having a substantially flat, planar

surface, adapted for releasable attachment to said readout

circuitry;

U.S. Patent No. 4,225,410 (Pace) taught the use of a disposable-electrode cartridge that

attached to readout circuitry to measure the levels of a target substance in a solution — e.g.,

glucose in blood — by detecting current. The figures below are from the ’410 patent.

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The cartridge 10 shown in Figure 1 (an alternative design is shown in Figure 1a) contained a

matrix of sensors 14. Users would place their finger above the sensor matrix of the circuitry in

cartridge 10 and dispense a drop of blood. The cartridge 10 could then be connected to the

readout device shown in Figure 3 through a socket connection, and the results of the test could

be read out across screen 33. After the test was complete, the user could take out the cartridge

and throw it away. The cartridge was flat and elongated so as to more readily allow the user to

connect and remove it from the readout device. The ’410 patent further described the use of

enzyme electrodes for detection of glucose in blood. 

* * *

b) a first conductor extending along said surface and comprising

a conductive element for connection to said readout circuitry;

This claim limitation merely referred to the actual conductive wires that connect the

electrodes (where the electrochemistry occurs) to the readout circuitry. The wires carried

electricity and simply allowed current to flow to the readout circuitry. Both the ’410 and

’382 patents readily disclosed this limitation. For example, the ’410 specification stated

(col. 7:37–43):

The interconnectors each terminate in an electrical connection

projecting from the end of the chip which is adapted to mate with

a snap-in electrical connector disposed in a slot of [the readout

circuitry]. The connection of the chip overhangs the tray . . . and

includes a slot for keying into connector of [the readout circuitry].

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Likewise, the ’382 patent disclosed conductive wires connecting an electrode to readout circuitry

(col. 8:35). It was elementary that no circuit could be completed without a conductor between

the readout circuitry and the electrode. 

* * *

c) an active electrode on said strip in electrical contact with said

first conductor and positioned to contact said whole blood sample;

The term “an active electrode” has been construed herein to mean “an electrode that

incorporates conductive material, and a mixture of or layers of an enzyme and mediator.” 

The phrase “in electrical contact with said first conductor” was construed to mean “such that

the active electrode is connected or positioned in such a way that electricity can flow between

the active electrode and the first conductor.” As stated above, the active electrode was

essentially where all of the actual electrochemistry occurs in the sensor. A mediator and enzyme

covered the electrode and collectively act to transfer electrons between the glucose molecules in

blood to the active electrode to the conductors. A faster-acting chemistry that generated more

electrons more quickly was, in effect, a principal invention in the ’382 patent. The ’382

specification recited (col. 4:8–12):

In a particularly valuable form of the invention, however, the

electrode comprises a carbon core, a layer of ferrocene or a

ferrocene derivative at a surface thereof and a layer of glucose

oxidase or glucose dehydrogenase at the surface of the ferrocene

layer. 

The ’382 specification, among others, plainly already revealed active electrodes: a conductive

material (i.e., a carbon core), an enzyme (i.e., glucose oxidase), and a mediator (i.e., ferrocene).

* * *

d) a second conductor extending along said surface comprising a

conductive element for concentration to said readout circuitry;

For the same reasons set forth under element (b), this limitation was disclosed in both the

’410 and ’382 patents. 

* * *

e) a reference counterelectrode in electrical contact with said

second conductor and positioned to contact said whole blood

sample;

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At its simplest level, this limitation supplied the completion of the electrical circuit, the

blood itself being the last link in the electrical path. There were no chemicals on the reference

counterelectrode. Judge Jenkins construed the term “a reference counterelectrode in electrical

contact with said second conductor and positioned to contact said whole blood sample” as

follows:

an electrode that (1) is used to complete an electrical circuit with

the active electrode during the glucose measurement; (2) is

positioned or connected in such a way that electricity can flow

between the second conductor and the electrode; (3) has a known

potential relative to a standard; and (4) maintains its potential with

only insignificant variation during the measurement.

The reference counterelectrode must thus meet four separate requirements. The first two

requirements relate to the electrode’s function to “counter” the active electrode and complete

the circuit. The last two requirements relate to the electrode’s function to serve as a “reference”

to the active electrode by maintaining a known potential relative to a standard — e.g., ground. 

The ’551 specification described the reference electrode as a “coating applied to the elongated

support . . . formed by screen printing” and consisting of a silver-silver chloride layer (Ag/AgCl)

(col. 2:6–11 and col 4:57). 

Although both the ’410 and ’382 patents disclosed the use of reference electrodes and

counter electrodes, they only did so in the context of a three-electrode configuration: one

electrode served as the active electrode, one electrode served as the counter, and one electrode

served as the reference. For instance, the ’382 patent stated that the “[active] electrode was

connected to a potentiostat, together with a suitable counter electrode and calomel reference

electrode and placed in a solution containing glucose” (col 8:35–38). Accordingly, in the

’410 and ’382 patents there was no single electrode that served as both the reference and

counter to the active electrode. 

During the earlier stages of prosecution, Medisense argued that the two-electrode

configuration in the ’551 specification was a point of novelty over the prior art. Specifically, in

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an information disclosure statement received by the PTO on June 30, 1988, Medisense

contended (TX 5):

Claim 1 now features a two-electrode strip in which the active

current-measuring electrode is an enzyme deposit on the same strip

that includes a second reference electrode. This two-electrode

strip is far more convenient, and cheaper to make, than the prior art

current-measuring devices. None of those devices discloses a

simple dry two-electrode strip and nothing in those references

would render such a simple strip obvious.

In the subsequent office action signed on October 28, 1988, Examiner Shay rejected this point of

novelty:

ASAH, Kurita, Miyawaki, MITS, Huet et al, Smith et al, a

Fromowitz et al, Takinishi et al, Brown et al, and Higgins et al all

teach various electrode and/or amplifies [sic] configurations.

In fact, two-electrode configurations were common in the prior art. For instance, the

Wingard reference (published in February 1983) disclosed a sensor with a platinum active

electrode (i.e., the electrode coated with the enzyme) connected to a reference counterelectrode. 

As with the ’551 patent, the reference counterelectrode was silver-silver chloride (Ag/AgCl). 

Wingard stated (TX 480):

The basic design of the amperometric glucose oxidase-oxygen

electrode sensor for in vivo glucose determination is essentially

that of Updike and Hick. . . . In the oxygen electrode an external

potential is applied to hold the platinum cathode 0.6-.0.8V more

negative than the silver-silver chloride anode and thus to produce a

current that is related to the concentration of oxygen that reaches

the platinum surface. 

Defendants cited to other prior art references (including an undergraduate textbook) that

contained similar disclosures. At trial, Dr. Turner persuasively testified that a person having

ordinary skill in the art would have been motivated to combine the teachings of two-electrode

systems with the sensors described in the ’382 and ’410 patents. This is not surprising given the

strong overlap between the subject matter of the references.

Abbott argues that defendants have failed to show that the prior art cited aligns with

Judge Jenkins’ claim construction for a reference counterelectrode. Not so. As stated, the

reference counterelectrode must primarily serve two functions: (i) to provide a reference voltage

for the active electrode and (ii) to counter the active electrode and complete the circuit. It is

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17 In three-electrode configurations, no current would pass through the reference electrode. All the

current would be shared between the active electrode and the counter electrode. The reference electrode was

merely used to apply a known potential to bias the circuit. Where the parasitic resistance of the closed circuit or

the current running through the closed circuit was small, however, a two-electrode configuration was more

tolerable because of the small (and unwanted) voltage drop that would result from the parasitic resistance

(i.e., Ohm’s Law, voltage equals the product of current and resistance). The determination of whether a

two-versus-three-electrode system was used therefore centered on whether the system could handle the

decreased accuracy of a two-electrode configuration (TX 316).

45

clear from the language cited above from Wingard that its electrode served as a reference voltage

to the active electrode — “an external potential is applied to hold the platinum cathode 0.6-.0.8V

more negative than the silver-silver chloride anode.” As to the second function, the prerequisite

to serve as a counter electrode was that the same current pass through it and the active electrode. 

The counter electrode (and the blood added by the user) collectively act to close the circuit so

that current can thereby flow. The electrode in the sensor circuit disclosed in Wingard met this

criterion. Current was passed from it to the active electrode to complete the circuit

(“amperometric” as stated in Wingard).17

This order therefore finds that “a reference counterelectrode in electrical contact with said

second conductor and positioned to contact said whole blood sample” was disclosed in Wingard. 

This order further finds that a person having ordinary skill in the art would have had a

motivation to combine Wingard with the teachings of the ’382 and ’410 patents.

* * *

wherein said active electrode is configured to be exposed to said

whole blood sample without an intervening membrane or other

whole blood filtering membrane;

For the reasons set forth above and which will not be reviewed again here, the

no-membrane limitation was taught by the ’382 patent (col. 4:63–66).

* * *

and is formed by coating a portion of the first conductor with a

mixture of or layers of an enzyme which catalyzes a redox reaction

with said compound in whole blood and a mediator compound

which transfers electrons from said redox reaction to said first

conductor;

For the same reasons detailed in the section above relating to the active electrode, this

limitation was disclosed by the prior art — in particular, the ’382 patent.

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* * *

to create a current representative of the concentration of said

compound in said whole blood sample;

The ’382 expressly taught this limitation. It recited (col 8:41–42), “[a] current is produced

which is proportional to the glucose concentration.” This current was then measured and

subsequently extrapolated to yield a measure of the amount of glucose in the target blood

sample.

* * *

and wherein said active electrode which is formed on a portion

of said conductor is not in electrical contact with said reference

counterelectrode but these electrodes are so dimensioned and

positioned that they can be simultaneously completely covered

by a single drop of whole blood such that this drop provides an

electrical path between these electrodes to support said current

representative of the concentration of said compound in said

whole blood sample.

This limitation required that the active electrode and reference counter electrode be

positioned in such a manner so that a single drop of blood could cover both. The two electrodes,

however, could not be in electrical contact with one another. As described above, the ’410

patent disclosed a disposable cartridge comprising a matrix of sensors. The user would prick

their finger and place a drop of blood over the cartridge. In so doing, the sensors in the matrix

would be covered by the user’s single drop of blood.

In addition, one of the preferred embodiments disclosed in the ’382 patent was a needle

electrode that could be used for tests within the body — i.e., in vivo. This embodiment was as

follows:

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The user could prick themselves with the needle 16. Blood would then enter through the side

windows 18 and come into contact with the electrodes in the device. In this way, current was

generated and could subsequently be measured. In the same fashion, because the needle

electrode was so small, the user could have easily applied a drop of blood to the side windows 18

outside of the body instead of placing the needle in the body. Dr. Turner testified that if a drop

of blood were applied in this manner, the device would still function properly. Abbott has

offered no evidence to the contrary.

CLAIM 2

Claim 2 stated: “The electrode strip of claim 1 wherein the compound is glucose and the

enzyme is glucose oxidase or glucose dehydrogenase” (col. 14:18–20). As previously discussed,

there were multiple references and teachings in the ’382 patent to testing glucose levels in blood

using a glucose oxidase or glucose dehydrogenase enzyme (col. 1:66–68) (“The enzyme is

therefore preferably a glucose oxidase, or possibly a glucose dehydrogenase, for example a

bacterial glucose dehydrogenase.”)

CLAIM 3

Claim 3 stated: “The electrode strip of claim 1 wherein said conductive elements of the

first and second conductors for connection to the readout circuitry are positioned toward one end

of said elongated support and said active electrode and reference counterelectrode are positioned

remote from said end” (col. 14:21–25). Claim 3 required that the active electrode and reference

counterelectrode both be positioned on the opposite end of the strip from the portion of the

conductors that connect to the readout circuitry. As illustrated in Figure 1a of the ’410 patent

(shown above), the sensors 14 were placed on one end of the cartridge while the electrical

connections 27 for the readout circuitry were at the other end. The ’410 patent thus disclosed

this limitation.

CLAIM 4

Claim 4 stated: “The electrode strip of claim 1 wherein said conductive elements of said

first and second conductors are configured to allow reasonable attachment with a socket on a

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read out meter which carries said signal readout circuitry” (col. 14:26–29). For the same reasons

set forth above, the ’410 patent disclosed this further limitation to claim 1 (col. 7:37–43).

* * *

Under 35 U.S.C. 103, a patent may not be obtained if the differences between the claimed

invention and the prior art would have been “obvious” at the time the invention was made to a

person having ordinary skill in the art to which the patent is directed. The Supreme Court

recently addressed the issue of obviousness in KSR Int’l Co. v. Teleflex Inc., 127 S.Ct. 1727

(2007). There, the Supreme Court reversed the Federal Circuit’s rejection of summary judgment

of obviousness. In so doing, the Supreme Court emphasized that the obviousness inquiry is

pragmatic and flexible: “A person of ordinary skill is also a person of ordinary creativity, not an

automaton.” Id. at 1742. The Supreme Court further stressed that if a person having ordinary

skill in the art would have been able to implement a predictable variation of the prior art to yield

the claimed invention, Section 103 would likely bar patentability. As the Supreme Court stated

in KSR Int’l Co., 127 S.Ct. at 1740–41.:

Often, it will be necessary for a court to look to interrelated

teachings of multiple patents; the effects of demands known to the

design community or present in the marketplace; and the

background knowledge possessed by a person having ordinary

skill in the art, all in order to determine whether there was an

apparent reason to combine the known elements in the fashion

claimed by the patent at issue.

Where there is “a design need or market pressure” to solve a particular problem and there are

only a discrete number of predictable solutions that led to the anticipated success of the patent,

“[the patent] is likely the product not of innovation but of ordinary skill and common sense.” 

Id. at 1742.

Under this practical approach, this order finds all asserted claims of the ’551 patent to

be obvious in light of the prior art. All but one limitation was disclosed expressly by the

’382 and/or ’441 patents. The remaining limitation, implementing a two-electrode configuration,

was well known prior to the ’551 patent’s priority date. Each reference relied on above to show

obviousness was expressly aimed at the specific subject matter covered by the ’551 patent —

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18 See Ecolochem, Inc. v. Southern California Edison Co., 227 F.3d 1361, 1379–80 (Fed. Cir. 2000);

Monarch Knitting Mach. Corp. v. Sulzer Morat GmbH, 139 F.3d 877, 885 (Fed. Cir. 1998); Advanced Display

Sys. v. Kent State Univ., 212 F.3d 1272, 1285–85 (Fed. Cir. 1988); Interconnect Planning Corp. v. Feil, 774

F.2d 1132, 1144 (Fed. Cir. 1985); EWP Corp. v. Reliance Universal, Inc., 755 F.2d 898, 907 (Fed. Cir. 1985). 

49

i.e., construction of electrochemical sensors that could be used to measure glucose levels in

blood. One skilled in the art would therefore have readily thought to combine these references. 

* * *

The Federal Circuit has held that “secondary considerations, when present, must be

considered in determining obviousness.” Ruiz v. A.B. Chance Co., 234 F.3d 654, 667 (Fed. Cir.

2000); see also Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 1538 (Fed. Cir. 1983)

(“evidence of secondary consideration may often be the most probative and cogent evidence in

the record. It may often establish that an invention appearing to have been obvious in light of

the prior art was not. It is to be considered as part of all the evidence, not just when the

decisionmaker remains in doubt after reviewing the art”). Originally, three factors were

regarded as secondary considerations: commercial success, long-felt but unsolved needs, and

failure of others. Graham v. John Deere Co. of Kansas City, 383 U.S. 1, 17 (1966). Since then,

several additional factors have been taken into account by the Federal Circuit, including: 

copying by others, praise of the invention, unexpected results, disbelief of experts, general

skepticism of those in the art, commercial acquiescence, and simultaneous development.18 

Evidence of secondary considerations, however, only has probative value where there is

“a nexus between the merits of the claimed invention and the secondary consideration.” 

Ashland Oil, Inc. v. Delta Resins & Refractories, Inc., 776 F.2d 281, 306 n.42 (Fed. Cir. 1985). 

The burden of proof as to this connection or nexus resides with the patentee. Demaco Corp. v.

F. Von Langsdorff Licensing Ltd., 851 F.2d 1387, 1392 (Fed. Cir. 1988).

Here, Abbott has primarily offered three grounds to support its showing of secondary

considerations: (i) the commercial success of the Medisense-Abbott-Exactech product;

(ii) a long-felt need for the Exactech product; and (iii) an alleged attempt to design around the

’551 patent by a competitor. 

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Steven Scott, the former project manager for Abbott’s Exactech, testified that over

one billion test strips were sold over the lifetime of the Exactech product. He further testified

that at the time the Exactech was released in September 1987, no other competitor had an

electrochemical strip on the market. According to Abbott, before the Exactech product was

released, diabetic patients had to use colormetric test strips that were far less convenient because

they required the user to follow precise instructions that could easily be botched to produce

inaccurate results.

This order assumes all of Abbott’s representations regarding the Exactech product were

true. Nonetheless, Abbott has failed to show that the success of the Exactech product was

attributable to the ’551 patent. Significantly, the Exactech product was released in

September 1987 — two years after the ’382 patent issued and over seven years before the

’551 application was filed. Both Dr. Sanghera and Scott testified that Medisense marked the

Exactech product packaging with the ’382 patent before and after the ’551 patent issued. 

Abbott’s expert, Dr. Jay Johnson, admitted that the Exactech product was covered by claim 1 of

the ’382 patent (Tr. 552:15–18):

Q: But all these limitations that you see in the Claim 1 of the

Higgins ’382 patent are met by the Exactech strip. We just

walked through them.

A. Yes. 

Dr. Sanghera acknowledged on multiple occasions the novelty behind the invention of the

’382 patent — an invention for which Abbott received the full term of a patent. Nothing on the

record demonstrates that the purported novelty behind the ’551 patent contributed to the success

of the Exactech product. Abbott has therefore failed to show the requisite nexus between the

claims of the ’551 patent and the Exactech product. The record instead demonstrates that the

success of the Exactech product was more attributable to the fast-working chemistry disclosed in

the ’382 patent. 

Abbott next proffers the testimony of James McCann (Genetics International’s former

founder) to support its showing of secondary considerations. McCann is currently employed at

Cambridge Sensors Ltd., a company also engaged in the manufacture of glucose sensors. At his

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deposition, McCann testified that Cambridge Sensors redesigned one of its sensors in an attempt

to design around the ’551 patent by placing a mesh layer on the active electrode and moving the

enzyme above the mesh layer. He stated (McCann Dep. 140–41):

Q. Was that version created in an effort to design around the

’551 patent?

A. Yes.

* * *

Q. Okay you made that redesign in an effort to avoid the claims

of the ’551?

A. Yes.

It is not clear exactly how much weight McCann’s testimony should be given. Both parties have

been unable to cite to any decision where such evidence was considered or discounted when

assessing secondary considerations. Cambridge Sensor’s design-around efforts could show

nothing more than its desire to avoid the threat of litigation, meaning it would shed little light on

the validity or novelty of the ’551 patent. On the other hand, the redesign may be relevant to

show that the industry regarded the ’551 patent as likely valid and enforceable. In any case,

however, this evidence by itself is not enough to tip the scales. Given the absence of other

factors weighing in favor of secondary considerations, it would be a far leap to preclude a

finding of obviousness based on such scant evidence. 

* * *

Many inventions seem obvious after the fact but that, of course, is not the test for

invalidity: 

It is difficult but necessary that the decision maker forget what he

or she has been taught at trial about the claimed invention and cast

the mind back to the time the invention was made (often as here

many years), to occupy the mind of one skilled in the art who is

presented only with the references, and who is normally guided by

the then-accepted wisdom in the art. 

W.L. Gore & Associates, Inc. v. Garlock, Inc., 721 F.2d 1540, 1553 (Fed. Cir. 1983). 

A patent is presumed valid, and the burden of establishing invalidity as to any claim of a

patent rests upon the party asserting such invalidity. 35 U.S.C. 282. Invalidity must be proven

by clear and convincing evidence. Although not susceptible to precise definition, “clear and

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convincing” evidence has been described as evidence which produces in the mind of the trier of

fact “an abiding conviction that the truth of [the] factual contentions are “highly probable.” 

Builder, Inc. v. Kason Indus., Inc., 849 F.2d 1461, 1463 (Fed. Cir. 1988). 

Viewing the prior art in whole, one skilled in the art would have deemed the ’551 patent as

a necessary and logical result of the teachings already a part of the public domain. The main

claim elements at issue in trial were the deletion of the membrane and the implementation of a

two-electrode system. On the former element, the ’382 patent expressly disclosed that a

membrane was optional but preferred on live blood. It was not required. On the latter element,

two-electrode configurations were common and even disclosed in an undergraduate

electrochemistry textbook. The remaining elements of claims 1–4 were not novel either; they

were readily taught by the prior art. Those in the field would have appreciated that combining

these elements was a predictable variation on the prior art. 

WRITTEN DESCRIPTION

Pursuant to 35 U.S.C. 112 ¶ 1, a patent specification is required to “contain a written

description of the invention, and of the manner and process of making and using it, in such full,

clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or

with which it is most nearly connected, to make and use the same.” The written-description

requirement and its corollary, the new-matter prohibition of 35 U.S.C. 132, serve to ensure that

the patent applicant was in full possession of the claimed subject matter at the time the original

application was filed. “To satisfy the written description requirement the disclosure of the prior

application must convey with reasonable clarity to those skilled in the art that, as of the filing

date sought, [the inventor] was in possession of the invention.” PowerOasis, Inc. v. T-Mobile

USA, Inc., 522 F.3d 1299, 1306 (Fed. Cir. 2008) (emphasis in original). Any disclosure relied on

must be actual or inherent. In order for a disclosure to be inherent, “the missing descriptive

matter must necessarily be present in the [original] application’s specification such that one

skilled in the art would recognize such disclosure.” Tronzo v. Bioment, Inc., 156 F.3d 1154,

1159 (Fed. Cir. 1998). 

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Defendants contend that the ’551 specification fails to comport with the written-description

requirement. In particular, defendants argue there was no adequate written description in the

’551 specification to support the claim limitation “without an intervening membrane or other

whole blood filtering membrane.” It is true that the no-membrane idea was not expressly called

out in the specification and, indeed, was at most lurking in its penumbra. Nonetheless, the

relevant inquiry is whether those skilled in the art would have thought the inventors were in

possession of an electrochemical sensor without a membrane for use in whole blood as of

May 1983. Contrary to the defense, this order finds that those skilled in the art would have

recognized such disclosure in the ’551 specification. Plaintiff’s Expert Johnson gave a detailed

description of an embodiment disclosed in the ’551 specification describing a membraneless

sensor that could be used in whole blood (col. 8:27–52). On direct examination, defense

Expert Turner admitted that the ’551 disclosed a glucose sensor without a membrane that could

be used in blood (Tr. 249):

Q. Did you find anything in the ’551 patent that specially

adapted that sensor disclosed? And we’ve looked at Claim

1, but claims 1 through 4, is there anything in those claims

that shows that these sensors are specially adapted for use

with blood?

A. No. The ’551 describes the same structures and approach,

effectively, as here. So the ’551 could be used with and

without a membrane; the ’382 could be used with and

without a membrane.

Accordingly, this order finds that the ’551 specification adequately disclosed the contested

limitation. 

That said, it is certainly true that the ’382 specification had already announced a

description of a glucose sensor without a membrane for use in blood that was as good or better. 

After all, the ’382 specification expressly recited, “[o]ptionally, but preferably when being used

on live blood, a protective membrane surrounds both the enzyme and the mediator layers . . .”

(col. 4:63–65). The only affirmative passage in the ’551 specification on this specific point

stated (col. 6:66–7:2):

Although the enzyme electrode should be in electrical contact

with the liquid, it may be found valuable to exclude the sensor

from interfering contact with larger molecules or tissue fluid

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components. This can be done by a covering or surrounding

membrane, depending on the electrode geometry.

As such, while the ’551 patent adequately disclosed the membraneless limitation, it only did so

after such disclosure in the ’382 patent.

CONCLUSION

For the foregoing reasons, claims 1–4 are invalid as obvious and U.S. Patent No. 5,820,551

is unenforceable by reason of inequitable conduct in procuring its allowance. This order

concludes all proceedings in the district court on the merits of the ’551 claims. Before a

Rule 54(b) judgment is entered, counsel shall advise the Court whether any further proceedings

are needed. Please do so by NOON ON JULY 2, 2008.

IT IS SO ORDERED.

Dated: June 24, 2008. 

WILLIAM ALSUP

UNITED STATES DISTRICT JUDGE

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