The Software IP Report

Fed. Cir.: Inertial Tracking System Is Patent-Eligible

By Charles Bieneman

Categories: Patent Eligibility, Software Patents, The Software IP Report

Reversing a lower court judgment on the pleadings of invalidity, the Federal Circuit held that claims of U.S. Patent No. 6,474,159, directed to a motion-tracking system, were patent-eligible under 35 U.S.C. § 101 and the Mayo / Alice test.  Thales Visionix, Inc. v. U.S., 2015-5150 (Fed. Cir. March 8, 2016) (Opinion by Judge Moore, joined by Judges Wallach and Stoll) (precedential).

The independent claims of the ’159 patent recite:

1. A system for tracking the motion of an object relative to a moving reference frame, comprising:

a first inertial sensor mounted on the tracked object;

a second inertial sensor mounted on the moving reference frame; and

an element adapted to receive signals from said first and second inertial sensors and configured to determine an orientation of the object relative to the moving reference frame based on the signals received from the first and second inertial sensors.


22. A method comprising determining an orientation of an object relative to a moving reference frame based on signals from two inertial sensors mounted respectively on the object and on the moving reference frame.

The lower court had “found the claims (1) are directed to the abstract idea of using laws of nature governing motion to track two objects, and (2) provide no inventive concept beyond the abstract idea.”

The Federal Circuit thought that “[f]or the purpose of evaluating patent eligibility, the ’159 patent claims are nearly indistinguishable from the claims at issue in” Diamond v. Diehr, 450 U.S. 175 (1981) (claims directed to use of known formula for curing rubber were patent-eligible).  Here, recited “navigation equations” were dependent on a “particular arrangement of sensors.”  Diehr’s claims analogously “required the temperature measurement ‘at a location closely adjacent to the mold cavity in the press during molding.’”

Thus, the ’159 patent claims

are not merely directed to the abstract idea of using “mathematical equations for determining the relative position of a moving object to a moving reference frame,” as the Claims Court found. Thales, 122 Fed. Cl. at 252. Rather, the claims are directed to systems and methods that use inertial sensors in a non-conventional manner to reduce errors in measuring the relative position and orientation of a moving object on a moving reference frame.

Accordingly, the claims passed step 1 (the abstract idea prong) of the Mayo/Alice test, and the court did not need to consider step 2 (whether the claims recited a significant additional innovation).


This case gives ammunition if you want to argue that claims are patent-eligible because, even if they recite a conventional set of hardware, they recite an unconventional arrangement, and/or an unconventional use, of that hardware.