How the First Heart-Lung Machine Oxygenated Blood
A 1955 invention that allowed surgeons to oxygenate a patient's blood outside the body, enabling the first successful open-heart surgeries.
Original patent title: “Oxygenating unit for extracorporeal circulation devices”
A 1955 invention that allowed surgeons to oxygenate a patient's blood outside the body, enabling the first successful open-heart surgeries. Granted to JEFFERSON MEDICAL COLLEGE in 1955 with 2 claims and 4 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
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.
The gap
What does this patent NOT cover?
- 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.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The invention uses a rotating cylinder to turn gravity and centrifugal force into a tool for spreading blood into a precise, thin film, solving the problem of how to oxygenate blood quickly without damaging the delicate blood cells.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Early heart-lung bypass machines used in the 1950s
Experimental extracorporeal circulation circuits
Why it matters
The bigger picture
This patent represents the core technology behind the heart-lung machine developed by Dr. John Gibbon. It was the critical breakthrough that allowed surgeons to stop a patient's heart and lungs during surgery without causing brain damage from oxygen deprivation. It effectively launched the field of modern cardiac surgery.
Filed
February 27, 1953
Granted
February 15, 1955
Market context
Who's building on this
Companies in this space
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.
Market impact
This patent provided the technical foundation for the first generation of cardiopulmonary bypass machines. It enabled the transition of heart surgery from a theoretical possibility to a routine life-saving procedure, fundamentally changing the standard of care in hospitals worldwide.
Claim 1 — Plain English
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.
The clever bit
The invention uses a rotating cylinder to turn gravity and centrifugal force into a tool for spreading blood into a precise, thin film, solving the problem of how to oxygenate blood quickly without damaging the delicate blood cells.
What it does not cover
- 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.
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Early stage
Citation count
14/40
Early citations
Claim breadth
1/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
20/20
Major company or institution
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$5K – $15K
Midpoint $10K · expired or expiring · industry ×1.6
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
2 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Gibbon, J. J. H., Malmros, G. V. A., & Barber, J. E. A. (1955). How the First Heart-Lung Machine Oxygenated Blood (U.S. Patent No. 2,702,035). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/2702035/heart-lung-machine-gibbon
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How the First Heart-Lung Machine Oxygenated Blood cover?
A 1955 invention that allowed surgeons to oxygenate a patient's blood outside the body, enabling the first successful open-heart surgeries.
Who owns patent US 2702035?
JEFFERSON MEDICAL COLLEGE owns this patent, granted in 1955.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 2702035 cited by?
This patent has been cited by 4 later patents that build on its ideas.
What problem does this patent solve?
This patent represents the core technology behind the heart-lung machine developed by Dr. John Gibbon. It was the critical breakthrough that allowed surgeons to stop a patient's heart and lungs during surgery without causing brain damage from oxygen deprivation. It effectively launched the field of modern cardiac surgery.
What does this patent NOT cover?
Does not cover membrane-based oxygenators that use synthetic materials instead of direct gas-to-blood contact.
Patent monitoring