You can freely build on How the First Heart-Lung Machine Oxygenated Blood
This patent expired in 1973. Every claim — 0 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
JEFFERSON MEDICAL COLLEGE
Patent granted
1955
Expired
1973
Forward citations
4
What this patent covers
This device creates a thin, continuous film of blood inside a rotating cylinder to expose it to oxygen. By spinning the outer shell, centrifugal force spreads the blood into a wide, thin layer, which maximizes the surface area for gas exchange. A stationary inner cylinder helps direct a counter-current flow of oxygen upward while the blood flows downward, mimicking the natural gas exchange process in human lungs. A vertical jet assembly allows doctors to precisely control where the blood is introduced into this rotating system.
What is now free to use
All 0 claims of US 2702035 are in the public domain. Specifically:
The 0 dependent claims add narrowing limitations and are also free.
What is NOT covered
Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.
Does not cover membrane-based oxygenators that use synthetic materials instead of direct gas-to-blood contact.
Does not cover systems that oxygenate blood through bubbling or foam-based methods.
Does not cover the pump mechanisms or the surgical procedures themselves, only the specific oxygenating chamber assembly.
Who is building on this today
Modern manufacturers like Getinge (Maquet) and Medtronic continue to refine extracorporeal life support systems, though they have largely moved away from the rotating film design toward hollow-fiber membrane oxygenators.
Products built on expired version of this technology
Early heart-lung bypass machines used in the 1950s
Experimental extracorporeal circulation circuits
How to cite this patent in your documentation
JEFFERSON MEDICAL COLLEGE. US Patent 2702035. Oxygenating unit for extracorporeal circulation devices. Granted 1955, expired 1973. Now in the public domain.
Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.
PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.