Invalidity dossier
US 4441500
Added 9/23/2026, 4:31:51 PM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
US 4,441,500 — EKG Electrode: Overview
Title: EKG Electrode
Patent number: US 4,441,500 A
Inventors: Robert W. Sessions, Jerome Jeslis, Richard A. Rodzen
Original assignee: Ferris Manufacturing Co. (current assignee listed: Ferris Pharmaceuticals Inc)
Priority date: 1980-04-17 (claimed from application US06/141,057, patent US4353373A)
Filing date: 1981-03-25 (application US06/247,560)
Publication/grant date: 1984-04-10
Legal status: Expired – Lifetime (anticipated expiration 2001-04-10)
Purpose. The patent addresses two problems in prior EKG electrodes: short shelf life (moisture escaping from the jel-impregnated foam because the seal near the electrical contact was inadequate) and the limited number of circular electrodes that could be used at once on a person with a small chest.
Plain-language scope. The disclosure covers an electrode and its packaging. In one form, a rectangular adhesive foam pad carries a jel-impregnated circular foam disk, with a metal electrical connector passing through the pad. The pad's adhesive side sticks to a thin plastic (polyethylene, or MYLAR which is preferred for moisture retention) base liner having a hole through which the jelled disk extends; a plastic cap (polyethylene or MYLAR) is sealed over the disk to extend shelf life from weeks to months. Two parallel strips of electrodes may be packaged on one base layer, which can be folded in half for compact storage. A method is described: starting from a multi-layer preform with a holed polyethylene sheet, adhering rectangular foam pads centered on the holes, temporarily attaching a holed protective liner, punching a hole through each pad, applying a metal snap electrode, adding and jel-impregnating a foam disk, removing the liner, and sealing a plastic cap over each disk. A second aspect describes a circular electrode with a woven or spun plastic fabric lower layer removably adhered to a circular polystyrene base liner, a two-part eyelet and stud electrode, and a release liner.
Source: https://patents.google.com/patent/US4441500/en
Not established by this excerpt: the full claim language and exact claim scope; the complete specification and drawings (FIGS. 1–15 are only described, not shown); any litigation, ownership transfers beyond the assignment entries listed, validity, or prior-art analysis beyond the two patents mentioned (US 3,805,769 and US 4,034,854).
Generated 10/1/2026, 9:44:23 PM
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Litigation summary
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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