Ibormeith IP, LLC was is the assignee of US Patent Number 6,313,749, which is directed towards monitoring conditions affecting a vehicle driver’s sleepiness and warning the driver before the drive falls asleep. The monitor in the ‘749 patent takes into account multiple factors associated with sleepiness including the driver’s circadian rhythm, attributes of the road the driver is driving on, cabin temperature, length of drive, etc. Claim 1 of the ‘749 patent is reproduced below:
1. A sleepiness monitor for a vehicle driver, or machine operator, comprising:
a sensor for sensing a driver or operator control input;
a memory for storing an operational model that includes a physiological reference model of driver or operator circadian rhythm pattern(s) and a vehicle or machine operating model or algorithm;
computational means for weighting the operational model according to time of day in relation to the driver or operator circadian rhythm pattern(s) and for deriving, from the weighted model, driver or operator sleepiness condition and producing an output determined thereby; and
a warning indicator triggered by the computational means output, to provide a warning indicator of driver or operator sleepiness. (Emphasis Added)
At issue, Ibormeith sued Mercedes for infringing several of the claims of the ‘749 patent. In response, Mercedes argued that the means-plus-function “computational means” limitation in the claims was indefinite. The district court concluded that the specification of Ibormeith’s patent did not disclose a “structure for performing the functions claimed in the computational means limitations.” The district court concluded that the specification only disclosed an algorithm for weighting the operational model according to factors, but did not disclose the steps necessary to actually perform the suggested algorithm.
On appeal, the court of appeals reasoned that although the ‘794 patent included several tables with factors that may be related to driver drowsiness, there is no disclosure in the ‘794 patent that includes a concrete relationship between the various factors that are used to compute an outcome to warn of driver drowsiness. The court further reasoned that at best the tables and figures provide raw information that a person of ordinarily in the art could use to design their own method of weighting. However, the court held that a description of an algorithm that places no limitations on how values are calculated, combined, or weighted I insufficient to make the bounds of the claim understandable.
AUSTIN PATENT ATTORNEY TAKE-A-WAYS:
- 1. When drafting an application with a set of variables/equations, try to include in the body of the application an explanation of what is happening in simple English.
- 2. I like to use “thresholds” to correlate different variables together. I am not sure if this would have won the day in this case. But if there was a threshold that was set to X amount, the X amount could be used to show at least somehow of what the variable weights should be.
- 3. I try to limit the amount of equations in a patent, unless the equations/actual calculation of how you are doing something is the novel feature in your invention. In this case, if the patent attorney’s drafted the application based on the high level features and provided a description of what is being measured, I believe this patent application would have been held to be definite.