DCT
3:12-cv-00636
Taidoc Technology Corp v. Diagnostic Devices Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: TaiDoc Technology Corporation (Republic of China)
- Defendant: OK Biotech Co. Ltd. (Republic of China); Diagnostic Devices, Inc. (North Carolina); Prodigy Diabetes Care, LLC (North Carolina)
- Plaintiff’s Counsel: Ryder, Lu, Mazzeo & Konieczny LLC
- Case Identification: 3:12-cv-00636, W.D.N.C., 05/04/2012
- Venue Allegations: Venue is alleged based on Defendants having transacted business within the Western District of North Carolina.
- Core Dispute: Plaintiff alleges that Defendant’s blood glucose monitoring systems and associated disposable test strips infringe two patents related to biosensing meter technology and electrochemical strip construction.
- Technical Context: The technology concerns electrochemical biosensors for in-home patient monitoring of biological analytes, such as blood glucose, which constitutes a significant market for diabetes management.
- Key Procedural History: Subsequent to the filing of this complaint, both patents-in-suit underwent ex parte reexamination proceedings at the USPTO. U.S. Patent No. 7,316,766 had key claims amended, with a reexamination certificate issuing in 2013. U.S. Patent No. 7,514,040 was subject to two separate reexaminations; the first resulted in amended claims in 2013, but the second, concluding in 2016, resulted in the cancellation of all claims of the patent. The cancellation of all claims of the '040 Patent raises a threshold question about the viability of any infringement cause of action based upon it.
Case Timeline
| Date | Event |
|---|---|
| 2005-02-14 | '040 Patent Priority Date |
| 2005-05-27 | '766 Patent Priority Date |
| 2008-01-08 | '766 Patent Issue Date |
| 2009-04-07 | '040 Patent Issue Date |
| 2012-05-04 | Complaint Filing Date |
| 2013-02-27 | '040 Patent Reexamination Certificate (C1) Issued |
| 2013-06-24 | '766 Patent Reexamination Certificate (C1) Issued |
| 2016-08-16 | '040 Patent Reexamination Certificate (C2) Issued (All Claims Cancelled) |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,514,040 - "Intelligent Biosensing Meter," issued April 7, 2009
The Invention Explained
- Problem Addressed: The patent describes drawbacks of prior art biosensing meters. Some required a specific "code card" to be inserted for each new batch of test strips to calibrate the meter, which was described as expensive and administratively burdensome. Other meters with fixed internal parameters could not be updated for new strip technologies, rendering the meter obsolete. ('040 Patent, col. 1:30 - col. 2:54).
- The Patented Solution: The invention is a "hybrid" biosensing meter that contains an internal memory ("parameter storing unit") with pre-loaded parameters for various test strips. It also features a single slot capable of receiving either a test strip for measurement or a "code card" containing new parameters not already stored in the meter's memory. The meter can distinguish between different inserted items (e.g., test strip vs. code card) through their unique circuit designs, allowing it to update its capabilities or perform a test through the same physical interface. ('040 Patent, Abstract; col. 5:11-19).
- Technical Importance: This design aimed to reduce the manufacturing cost and user complexity associated with constant code card use, while preserving the flexibility to support future, improved test strip batches over the operational life of the meter. ('040 Patent, col. 2:10-14).
Key Claims at a Glance
- The complaint does not specify which claims are asserted. This analysis focuses on independent Claim 1, as amended by the first ex parte reexamination certificate (US 7,514,040 C1), which was in force during a portion of this litigation's pendency.
- The essential elements of amended Claim 1 include:
- a parameter storing unit comprising a plurality of parameters that a sample strip detection needed;
- at least one slot for receiving a sample strip comprising a reaction well and a plurality of electrodes;
- wherein the sample strip has a short circuit formed between two selected electrodes thereof for switching on the biosensing meter;
- at least one button for choosing different parameters stored in the parameter storing unit;
- a memory unit for storing results; and
- a microprocessor for reading parameters to control the measurement of an analyte.
U.S. Patent No. 7,316,766 - "Electrochemical Biosensor Strip," issued January 8, 2008
The Invention Explained
- Problem Addressed: The patent identifies an issue where the test reagent in a biosensor strip does not adhere well to the underlying substrate, which is often made of a hydrophobic material like PET plastic. This can cause the reagent to spread unevenly or flake off during manufacturing, leading to inconsistent and inaccurate test results. ('766 Patent, col. 1:50-60).
- The Patented Solution: The invention introduces a "hydrophilic layer" applied to the strip's base before the test reagent is applied. Critically, this layer is patterned to be "excluded from the electrode system" or to cover only a small fraction (e.g., 0% to 50%) of the electrode area that corresponds to the test reagent. This structure is intended to improve the reagent's adhesion and uniform distribution on the strip without the hydrophilic material interfering with the electrical signal transmission between the electrodes. ('766 Patent, Abstract; col.2:1-8; Fig. 2).
- Technical Importance: The invention sought to improve the manufacturing consistency, stability, and accuracy of disposable electrochemical test strips by solving a materials science challenge at the interface of the substrate, the reagent, and the electrodes. ('766 Patent, col. 2:4-8).
Key Claims at a Glance
- The complaint does not specify which claims are asserted. This analysis focuses on independent Claim 1, as amended by the ex parte reexamination certificate (US 7,316,766 C1).
- The essential elements of amended Claim 1 include:
- a base;
- an electrode system laid on the base, with a portion exposed for connection to a meter and a predetermined portion exposed for applying a test reagent;
- a cover cooperating with the base to form a cavity for drawing fluid; and
- a hydrophilic layer laid under the test reagent, which is laid on an area of the base excluded from the electrode system and also laid on "about 50% to 0% of the area of the predetermined portion of the electrode system...exposed for applying the test reagent."
III. The Accused Instrumentality
Product Identification
The PRODIGY AutoCode Blood Glucose Monitoring System and the PRODIGY Voice Blood Glucose Monitoring System, including the disposable test strips used with these systems (Compl. ¶¶10, 15).
Functionality and Market Context
The complaint alleges the accused products are "blood glucose meters embodying the patented invention" (Compl. ¶¶10, 15). The "AutoCode" trade name suggests a functionality related to automatic calibration or parameter selection, which is a central theme of the '040 Patent. The "Voice" system presumably adds audible outputs for user guidance or results. The complaint does not provide further technical details on the operation of the meters or the material composition of the associated test strips.
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
'040 Patent Infringement Allegations
| Claim Element (from Independent Claim 1, as amended) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a parameter storing unit comprising a plurality of parameters that a sample strip detection needed | The complaint alleges the accused meters embody the patented invention, which would require an internal memory for storing test strip calibration parameters. | ¶10 | col. 2:60-62 |
| at least one slot for receiving a sample strip | The accused meters are alleged to be blood glucose monitoring systems, which by their nature require a slot to receive a disposable test strip. | ¶10 | col. 2:64-65 |
| wherein the sample strip has a short circuit formed between two selected electrodes thereof for switching on the biosensing meter | The complaint does not provide sufficient detail for analysis of this element. | ¶10 | col. 5:58-62 |
| at least one button for choosing different parameters stored in the parameter storing unit | The complaint does not provide sufficient detail for analysis of this element. | ¶10 | col. 2:62-64 |
| a microprocessor for reading the parameters from the parameter storing unit or the memory unit for controlling operational procedures to measure an analyte | The complaint alleges the accused products are functional blood glucose meters, which would require a microprocessor to control the test cycle and calculate a result. | ¶10 | col. 3:5-11 |
- Identified Points of Contention:
- Scope Questions: A central question would be whether the "AutoCode" feature of the accused meters meets the "button for choosing different parameters" limitation. The analysis would explore whether an automated selection process, even if initiated by a general-purpose button, constitutes "choosing" in the manner claimed.
- Technical Questions: An evidentiary question is whether the accused system uses the specific claimed mechanism for activation—a "short circuit formed between two selected electrodes" on the strip—to switch on the meter upon strip insertion.
'766 Patent Infringement Allegations
| Claim Element (from Independent Claim 1, as amended) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a base | The complaint alleges infringement by test strips, which necessarily include a substrate or base. | ¶15 | col. 3:4-6 |
| an electrode system laid on the base | The complaint does not provide sufficient detail for analysis of this element. | ¶15 | col. 3:4-10 |
| a cover cooperating with the base to form a cavity for drawing an analyte-containing fluid | The complaint does not provide sufficient detail for analysis of this element. | ¶3:1-3, ¶4:60-63 | |
| a hydrophilic layer laid under the test reagent and laid on an area of the base excluded from the electrode system... and also laid on about 50% to 0% of the area of the... electrode system... exposed for applying the test reagent | The complaint does not provide sufficient detail regarding the material layers or chemical composition of the accused test strips to analyze this element. | ¶15 | col. 4:1-8, col. 5:10-18 |
- Identified Points of Contention:
- Technical Questions: The infringement analysis for the '766 patent hinges entirely on the physical and chemical composition of the accused test strips. A dispositive question is whether the strips contain a distinct "hydrophilic layer" with the specific, patterned placement relative to the electrodes as required by the claim. Answering this would likely require expert testimony and materials analysis, such as scanning electron microscopy or spectroscopy.
V. Key Claim Terms for Construction
- For the '040 Patent:
- The Term: "button for choosing different parameters"
- Context and Importance: This term is critical because the accused product is marketed as "AutoCode," suggesting an automated parameter selection process. The outcome of the case could depend on whether an automatic function, possibly initiated by a general-purpose button, is equivalent to a user actively "choosing" from a list of parameters with a button.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states the button "is utilized for choosing different parameters" ('040 Patent, col. 2:62-64), which a party could argue is a broad statement of purpose that does not preclude an automated process triggered by the button.
- Evidence for a Narrower Interpretation: The patent describes a scenario where "users can operate the button (17) to choose the right parameter" ('040 Patent, col. 4:47-49), which suggests a more direct, manual selection by the user, potentially supporting a narrower definition that excludes fully automated selection.
- For the '766 Patent:
- The Term: "a hydrophilic layer"
- Context and Importance: The existence, composition, and structure of this layer is the core of the invention. Its construction is central to determining infringement, as it defines what material or coating qualifies and whether it must be a distinct layer separate from the base substrate and the test reagent.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification discloses that the layer "is composed of hydrophilic substances," listing examples like "methylcellulose (MC), carboxymethyl cellulose (CMC)," and surfactants, which may support a functional definition based on the material's properties rather than its method of application. ('766 Patent, col. 3:24-34).
- Evidence for a Narrower Interpretation: The figures and description repeatedly show the hydrophilic layer (60) as a discrete structural element situated between the base (10) and the test reagent (62). ('766 Patent, Fig. 2; col. 4:63-65). This could support a narrower construction requiring a distinct, separately applied layer.
VI. Other Allegations
- Indirect Infringement: The complaint makes conclusory allegations of "inducement and/or contributory infringement" for both patents but does not plead specific supporting facts, such as identifying instructions in user manuals that would direct users to perform infringing acts. (Compl. ¶¶10, 15; Prayer for Relief ¶¶ A, B).
- Willful Infringement: The complaint alleges that Defendants "have knowledge" of the patents and that their infringement "is and continues to be willful and deliberate." (Compl. ¶¶12, 17). The complaint does not state the basis for this alleged knowledge, such as a pre-suit notice letter.
VII. Analyst’s Conclusion: Key Questions for the Case
- A dispositive issue for the '040 patent is procedural and potentially fatal: given that all claims of the '040 patent were cancelled by the USPTO in a 2016 ex parte reexamination, what, if any, legal basis for infringement liability remains for the period preceding the final cancellation?
- For the '766 patent, the case will likely turn on a key evidentiary question of physical structure: do the accused test strips in fact incorporate a distinct "hydrophilic layer" that is selectively patterned to cover between 0% and 50% of the active electrode area, as required by the amended claims?
- A central question of claim construction for the '040 patent (prior to its cancellation) would have been one of functional scope: can a meter’s "AutoCode" feature, which may automatically select test parameters upon strip insertion, be found to meet the claim limitation of a "button for choosing" those parameters?