The Pulse · Hermetic Packaging & Feedthroughs · 1993-1996

1993: The First Housing

From the album · US 5,535,097 · FIG. 4 A perspective assembly view with the lid half pulled away from the main shell, exposing the connector hardware between them — the connector block, setscrew, spring contact, feedthrough pin, and sealing plug all floating in their positions like a freeze-frame of the device being put together.

The origin pointT1 · from the patentUS5535097A

Filed November 23, 1993 — the earliest patent in the corpus, with David A. Ruben first on the inventor list. The subject could not be more foundational: the pacemaker's body itself — the hermetic housing, and the connector module that joins it to the lead running into the heart.

A Medtronic pacemaker of 1993 — the very year of the first filing in this corpus — kept now under museum glass. The housing patents begin with an object exactly like this one: a machine designed to be closed once, and trusted. Medtronic Micro-Minix pacemaker (1993), Science Museum, London — The wub, CC BY-SA 4.0, via Wikimedia Commons.

The problemT1 · from the patentUS5535097A

The background section is a compact history of pacemaker construction: discrete components potted in epoxy; then sealed metal cans. By the early '90s the standard was a "clam shell" — two halves butt-welded around the electronics, requiring weld-ring protection and separate plastic cups to position components. Many parts, many steps, many chances for error.

The principleT1 · from the patentUS5535097A

Redesign the enclosure so the parts locate themselves. Claim 1: a first enclosure portion with a planar lower interior surface and a stepped second interior surface; battery and circuit mounted adhesively; connections made by wire bonding (chip-industry technique, not hand-soldered wires); the feedthrough passing through the stepped surface; a second portion completing the hermetic seal. (The molded resilient shroud forming the connector module is the abstract's summary — in the claims it is claim 3's connector module "mounted to said circumferential edge surface.") Claimed result: "fewer components and fewer manufacturing steps," lower cost, and a "smooth, rounded contour" kinder to the tissue pocket it lives in.

Plain-English registerT3 · interpretationconfidence: high

Instead of building a box and then engineering trays to hold everything, shape the box's interior so each part has one obvious seat — then close the lid once. Fewer pieces, fewer welds, fewer ways to fail.

Set-piece · light tracing the seam

The last act of every housing design is the same: a pulsed laser walks the seam between lid and can, each spot of light remelting half of the pulse before it, until the chain of small suns becomes one continuous hermetic weld. Close the lid once; make the closing perfect.

Measured influenceT1 · from the patentUS5535097A

Google Patents lists 100 citing patents — among the most-cited work in the corpus (only the accelerometer line's members rank higher) — meaning a hundred later inventions found this design foundational enough to cite as prior art.

The sealed machine itself: an explanted Medtronic can, its laser weld line running the rim, the lead still coiled around it like a signature. This is what "fewer components and fewer manufacturing steps" looks like when it comes back out of a body, intact. Explanted Medtronic Micro Minix pacemaker with pacing electrode — Kuroczynski, CC BY-SA 4.0, via Wikimedia Commons.

Why it matters to the storyT3 · interpretationconfidence: high

Every theme of the next three decades is already present in this one 1993 filing: hermeticity as the prime constraint, manufacturability as a design input, borrowing microelectronics techniques into medical devices, and volume efficiency as mercy on the patient. The corpus doesn't wander — it deepens. This is the seed.

Set-piece note (for Presentation)T3 · interpretation

The natural opener for the whole site: the 1993 patent's line drawing of the housing assembling itself piece by piece — battery seating into its step, bond-wires arcing, lid closing — then the finished can slowly morphs through the decades into the miniaturized modern forms. Career in one shot.

From the family album

Plate I · US 5,535,097 · FIGS. 1-3 Three plain outline views of the finished pacemaker can — front, back, and razor-thin edge-on — establishing its rounded D shape, the connector bore at the top corner, and the feedthrough spot on the rim.

Plate II · US 5,535,097 · FIG. 5 The open main shell viewed from above with the lid removed, showing the stepped interior ledge along the top edge where the feedthrough and connector parts seat themselves — the self-locating geometry at the heart of the claim.

Plate III · US 5,535,097 · FIG. 6 A perspective of the closed housing from the connector end, showing the molded shroud, the lead-receiving bore and its slotted aperture, and the section line for the later cross-section cuts.

Plate IV · US 5,535,097 · FIG. 7 A flat side view of the can with hidden lines revealing the internal plumbing along the top edge — the wire path running from the feedthrough over to the connector block and setscrew — plus the big battery cavity filling the body.