{
  "patent_number": "US 4173796",
  "country": "US",
  "title": "How Jarvik's Artificial Heart Uses Electric Motors to Pump Blood",
  "original_title": "Total artificial hearts and cardiac assist devices powered and controlled by reversible electrohydraulic energy converters",
  "summary": "A 1977 invention by Robert Jarvik that uses a reversible electric motor to power a hydraulic pump, enabling artificial hearts to mimic the natural pumping action of a human heart.",
  "what_it_does": "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_it_does_not_cover": [
    "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."
  ],
  "filed": "1977-12-09",
  "granted": "1979-11-13",
  "expires": "1997-12-09",
  "status": "expired",
  "holder": "University of Utah",
  "holder_url": "https://patentbrief.org/company/university-of-utah",
  "inventors": [
    {
      "name": "Robert K. Jarvik",
      "url": "https://patentbrief.org/inventor/robert-k-jarvik"
    }
  ],
  "times_cited": 68,
  "tags": [
    "biotech",
    "mechanical",
    "semiconductors"
  ],
  "abstract": "Total artificial hearts and circulatory assist devices, including left ventricular assist devices. The invention relates to electrohydraulic energy converter systems, whereby electric energy from a power source, which may be a battery or other source, is converted into hydraulic power capable of actuating diaphragm, sack, axi-symmetric or other types of blood pumps.",
  "url": "https://patentbrief.org/patent/us/4173796/jarvik-artificial-heart",
  "markdown_url": "https://patentbrief.org/patent/us/4173796/jarvik-artificial-heart/md",
  "google_patents_url": "https://patents.google.com/patent/US4173796",
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}