Invalidity dossier
US 5362420
Low impedance pressure sensitive adhesive composition and biomedical electrodes using same
Current assignee: 3M Co
Added 9/23/2026, 4:43:50 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview: US 5,362,420
Title: Low impedance pressure sensitive adhesive composition and biomedical electrodes using same
Patent Number: US 5,362,420 A
Inventors: Steven K. Itoh, Timothy M. Dietz, Rosa Uy
Original Assignee: Minnesota Mining and Manufacturing Co. (current assignee listed as 3M Co)
Key Dates:
- Priority date: 1991-11-15
- Filing date: 1993-12-21
- Publication/grant date: 1994-11-08
- Anticipated expiration: 2011-11-15 (status: Expired – Lifetime)
Purpose:
The invention relates to low impedance, ionically-conductive, hydrophilic pressure-sensitive adhesive (PSA) compositions and their use in biomedical electrodes. The patent explains that biomedical electrodes typically include a conductor connected to equipment and a conductive medium adhered to mammalian skin. Because such electrodes transmit electrical signals to and from skin, good conductivity with minimal electrical impedance is required during diagnostic, therapeutic, or electrosurgical procedures. Low impedance is especially important for defibrillation electrodes (to help ensure an effective circuit during life-saving measures) and for dispersive electrodes (where higher impedance at one contact area can raise current density elsewhere).
Plain-Language Scope:
The patent concerns water- and humectant-plasticized PSA hydrogels used as the conductive medium in biomedical electrodes. These hydrogels are described as one-phase compositions that are both hypoallergenic pressure-sensitive adhesives and ionically-conductive media. The excerpt describes the hydrogel's dependence on water/moisture content for formation and for conductivity via interaction with an electrolyte, and discusses prior approaches such as the two-phase adhesive of U.S. Pat. No. 4,588,762 (Mruk et al.) and an interpenetrating polymer network composition in European Patent Publication 0 085 327 (Cahalan et al.).
What the Excerpt Does Not Establish:
The supplied text is a partial excerpt. It does not include the full claims, the complete written description, detailed composition ranges, working examples, or the full discussion of prior art. Specific numerical impedance values and formulation details are not shown.
Generated 10/1/2026, 9:44:15 PM
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Litigation summary
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PTAB challenges
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Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
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Obviousness
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Extensions
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Derivative works
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