Addressing the question of indefiniteness of a claim limitation cast as a means for performing a specific function, subject to requirements of 35 USC § 112(f), the U.S. Court of Appeals for the Federal Circuit upheld summary judgment of indefiniteness, finding that certain algorithms disclosed in the specification did not adequately define the structure for performing the claimed functions. Ibormeith IP, LLC v. Mercedes-Benz USA, LLC, Case No. 13-1007 (Fed. Cir., Oct. 22, 2013) (Taranto, J.).

Ibormeith patented a device for monitoring conditions affecting a vehicle driver’s sleepiness and issuing of a warning to the driver before the driving is unduly impaired. The device may take into account multiple factors including natural body-clock (circadian) rhythm, the magnitude and number of corrective steering actions the driver is taking, the cabin temperature, the monotony of the road, and how long the driver has been driving.  The factors are weighted according to contributory importance, and combined in a computational decision algorithm, to provide the warning. Both independent claims of the patent recite a monitor comprising a sensor, a memory  and a “computational means” for weighing specified factors, deriving driver’s sleepiness condition and either providing a warning indication or producing an output for a warning indicator.

Ibormeith sued Mercedes for patent infringement for using a feature called Attention Assist in its vehicles.  To comply with § 112(f) (or the pre-America Invents Act § 112, sixth paragraph) as here triggered by the computational means limitation, a patent specification is required to disclose a specific structure for preforming functions claimed in the limitation.  The absence of such disclosure renders the claim indefinite, because there is insufficient definition of something which is incorporated into the claim by virtue of § 112(f).  At the district court, Ibormeith argued that the required structure was provided by algorithms disclosed in the specification.  The district court had concluded that the disclosure was inadequate because there was no algorithm or steps disclosed for weighing the factors according to their relative importance, deriving driver’s sleepiness condition, or providing an output or a warning indication.  After the district court granted Mercedes’s motion for summary judgment of invalidity based on the computational means limitation of the claims being indefinite, Ibormeith appealed.

The Federal Circuit reiterated that “for a claim to be definite, a recited algorithm . . . must be sufficiently defined to render the bounds of the claim—declared by section 112(f) to cover the particular structure and its equivalents—understandable by the implementer,” and (like the district court) concluded that the disclosed algorithm in this case did not adequately define the structure.  Ibormeith argued for a broader reading of the disclosure of algorithms in the specification so as to cover the accused device within claim scope, which the Federal Circuit adopted and deemed as a binding admission. The Court then found that the broad reading could not avoid invalidity because it left the disclosure without a defined and understandable algorithm as there was no indication which factors were to be used in what combination, and with what relative weights to determine driver drowsiness and arrive at warning threshold.

Practice Note:  Other limitations of the claims recited structures rather than the means-plus-function language. If the practitioner had avoided using the term “computational means,” and instead recited a computational device, there would be no presumption that the claim element was to be construed under § 112(f).  Even given the minimal support for such a device in the specification, the outcome might have been different. 

 Ibormeith IP, LLC v. Mercedes-Benz USA, LLC