You can freely build on Using Nuclear Magnetic Resonance to Detect Cancer in Tissue

What this patent covers

This patent details a way to detect cancer by looking at the behavior of atomic nuclei within a tissue sample. It involves placing the tissue in a special machine (a nuclear induction apparatus) that uses magnetic fields. First, the nuclei are energized to a higher energy state using magnetic radiation. Then, the machine measures how long it takes for these energized nuclei to return to their normal state. This measurement, called relaxation time (specifically spin-lattice and spin-spin relaxation times), is different for normal and cancerous tissues. By comparing these measured times to known standards for healthy and cancerous tissue, doctors can determine if cancer is present and how aggressive it might be. For example, claim 2 mentions using water protons as the indicator nuclei, and claim 3 describes actuating two magnetic energy sources to achieve this.

What is now free to use

All 1 claims of US 3789832 are in the public domain. Specifically:

The 1 dependent claim 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.

• Detecting cancer using methods other than measuring NMR relaxation times.

• Methods that do not involve comparing measurements to established standards for normal and cancerous tissue.

• Detecting cancer in non-mammalian tissue (though the principles might be similar).

• Using nuclei other than those exhibiting deviant behavior in cancerous tissue as the primary indicator.

Who is building on this today

The principles laid out in this patent are fundamental to virtually all modern MRI and MRS technology. Major medical imaging companies like Siemens Healthineers, GE Healthcare, and Philips Healthcare build upon this foundational work in their MRI scanner development. Research institutions continue to refine MRS techniques for more precise cancer diagnosis and characterization.

Products built on expired version of this technology

How to cite this patent in your documentation

Individual. US Patent 3789832. Apparatus and method for detecting cancer in tissue. Granted 1974, expired 1992. 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.