You can freely build on How Jarvik's Artificial Heart Uses Electric Motors to Pump Blood

What this patent covers

This patent describes a system that converts electricity into hydraulic pressure to move blood through an artificial heart or assist device. It uses a reversible brushless DC motor connected to a hydraulic pump impeller. By spinning the motor in one direction, the system pushes hydraulic fluid to cause the heart's blood chamber to contract (systole). By reversing the motor's direction, it draws fluid back to allow the chamber to refill (diastole). This setup allows for a compact, integrated design that can be implanted to support or replace a failing human heart.

What is now free to use

All 0 claims of US 4173796 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 pneumatic (air-driven) artificial hearts that rely on external air compressors.

• Does not cover continuous-flow blood pumps that lack a reversible motor-driven hydraulic cycle.

• Does not cover biological or tissue-engineered heart replacements.

• Does not cover external blood pumps that remain outside the patient's body.

Who is building on this today

The technology laid the groundwork for modern companies like Abbott (which acquired Thoratec) and Medtronic, who continue to develop advanced ventricular assist devices. While the specific Jarvik-7 design is historical, the principles of miniaturized, implantable hydraulic and rotary blood pumps remain the standard for cardiac support.

Products built on expired version of this technology

How to cite this patent in your documentation

University of Utah. US Patent 4173796. Total artificial hearts and cardiac assist devices powered and controlled by reversible electrohydraulic energy converters. Granted 1979, expired 1997. 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.