PTAB

IPR2017-02012

Fitbit Inc v. Blackbird Tech LLC

Log In

1. Case Identification

2. Patent Overview

  • Title: Pedometer with Actual Stride Length Calculation
  • Brief Description: The ’212 patent discloses a pedometer system designed to improve distance calculation accuracy. It comprises components like a strap, step counter, and heart rate monitor, and uses a data processor to calculate distance by multiplying the step count by a stride length that varies according to the user's stride rate, determined from a plurality of user-specific calibrations.

3. Grounds for Unpatentability

Ground 1: Claims 2 and 5 are anticipated by Amano

  • Prior Art Relied Upon: Amano (Patent 6,241,684).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Amano, which discloses an "exercise workout support device," teaches every limitation of claims 2 and 5. Amano discloses a wrist-mounted device with a "body motion detector" (step counter), a "pulse wave detector" (heart rate monitor), and a CPU (data processor), all attached via a "wrist band" (strap). Crucially, Amano teaches calculating distance traveled by multiplying the number of steps by a stride length that varies with the stride rate (termed "pitch"). Amano determines the variable stride length by using a user-generated calibration table that stores "stride correction coefficients" corresponding to different stride rates, thereby meeting the key data processing limitations of the challenged claims.
    • Key Aspects: Petitioner argued that while Amano’s device is primarily shown as wrist-mounted, it explicitly states the device can be incorporated into any object worn on the body, such as a band, anticipating the broader claim scope.

Ground 2: Claims 2 and 5 are obvious over Amano

  • Prior Art Relied Upon: Amano (Patent 6,241,684).
  • Core Argument for this Ground:
    • Prior Art Mapping: As an alternative to anticipation, Petitioner argued that if any single embodiment in Amano does not disclose all limitations, a person of ordinary skill in the art (POSITA) would have found it obvious to combine teachings from Amano's different disclosed embodiments. For instance, if the Board determined that Amano's wrist-mounted device did not meet the "step counter" limitation (per Petitioner's proposed construction requiring chest, waist, or leg mounting), a POSITA would have been motivated to place Amano's device on the user’s chest, waist, or leg, as these were well-known locations for such devices.
    • Motivation to Combine (for §103 grounds): Amano itself taught that its specific structure was not limited to the explained embodiments and that "a variety of modifications" were within the scope of the invention. A POSITA would have been motivated by this disclosure, as well as by common sense and design choice, to combine features such as a "freely detachable" strap (disclosed in one Amano embodiment) with the main device body, or to place the device on different body parts for user convenience and accuracy.
    • Expectation of Success (for §103 grounds): Petitioner contended that combining Amano's disclosed variations, such as making a strap releasable or moving the device to a different body location, involved simple substitutions of known elements that would yield predictable and desirable results.

Ground 3: Claim 6 is obvious over Kato in view of Amano

  • Prior Art Relied Upon: Kato (Patent 5,033,013) and Amano (Patent 6,241,684).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Kato discloses the core hardware of claim 6: a pedometer comprising a detector (step counter), a radio frequency transmitter, and a wireless receiver. Kato's processor also calculates distance using a stride length that varies with stride rate. However, Kato determines stride length from a pre-determined, generic empirical formula based on user height. Amano supplies the missing limitation: "deriv[ing] an actual stride length from a range of stride lengths calculated from a range of corresponding stride rates." Amano teaches using user-specific calibration data to create a more accurate, personalized relationship between stride rate and stride length.
    • Motivation to Combine (for §103 grounds): A POSITA would combine Kato's hardware with Amano's superior data processing method to solve the same problem addressed by both references: improving distance calculation accuracy by accounting for variable stride length. A POSITA would have recognized that replacing Kato's generic formula with Amano's user-specific calibration method was a known technique for improving accuracy and would have been motivated by design incentives to use the increasing computing power of 1990s wearable devices for such personalization.
    • Expectation of Success (for §103 grounds): A POSITA would have had a reasonable expectation of success in integrating Amano’s processing steps into Kato’s device, as both are wearable electronic devices with processors designed for exercise monitoring, and the combination would predictably result in a more accurate pedometer.

4. Key Claim Construction Positions

  • "A Step Counter" (claims 2, 5, and 6): Petitioner proposed the construction "a device mounted to the chest, waist, or leg that counts the number of steps a user takes."
    • This position was based on the ’212 patent’s specification, which Petitioner argued repeatedly disclaimed broader meanings by disparaging the accuracy of wrist-mounted step counters and consistently describing the invention as comprising a chest-, waist-, or leg-mounted counter.
    • Petitioner noted, however, that the challenged claims should be found unpatentable even without this construction, as the prior art also discloses wrist-mounted devices that meet all claim limitations under a broader interpretation.