PTAB

IPR2017-02023

TomTom Intl BV v. Blackbird Tech LLC

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1. Case Identification

2. Patent Overview

  • Title: Pedometer
  • Brief Description: The 6,434,212 patent discloses a pedometer with improved accuracy for calculating distance. The system calculates a user's actual stride length based on their current stride rate, using a mathematical function derived from a plurality of calibration runs performed at different speeds over a known distance.

3. Grounds for Unpatentability

Ground 1: Claims 1-8 are obvious over Jimenez in view of Levi

  • Prior Art Relied Upon: Jimenez (Patent 4,367,752) and Levi (Patent 5,583,776).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Jimenez disclosed the basic physical components of the challenged claims, including an exercise monitoring device with a strap, a step counter, a heart rate monitor, and a data processor. However, Jimenez’s processor calculated distance using a single, constant stride length, a known source of inaccuracy. Levi addressed this precise deficiency in prior art pedometers by teaching a "Dynamic Step Size Algorithm." Levi disclosed calculating a variable stride length based on the user's step frequency (stride rate) by using a calibration curve derived from measurements at different speeds to create a linear model. This directly corresponds to the core limitation in the ’212 patent's independent claims requiring a stride length that varies according to the rate at which steps are counted.
    • Motivation to Combine: A POSITA would combine the teachings of Jimenez and Levi to create a single device that both monitors heart rate and more accurately calculates distance traveled. It was well known that effective aerobic exercise required monitoring heart rate within a target zone, and it was also well known that stride length varied with speed. Therefore, a POSITA would be motivated to improve the functionality of Jimenez’s integrated device by incorporating Levi’s more accurate, dynamic distance calculation method to overcome the known limitations of fixed-stride-length pedometers.
    • Expectation of Success: A POSITA would have a reasonable expectation of success in combining these references. The combination involved implementing a known software improvement (Levi's algorithm) on a known hardware platform (Jimenez's device), which was a predictable and common engineering task. The result would be an improved pedometer with enhanced accuracy, a predictable outcome of the combination.

Ground 2: Claims 1-8 are obvious over Jimenez in view of Ebeling

  • Prior Art Relied Upon: Jimenez (Patent 4,367,752) and Ebeling (Patent 6,145,389).
  • Core Argument for this Ground:
    • Prior Art Mapping: As in the first ground, Petitioner asserted that Jimenez provided the foundational hardware combination. The argument then substituted Ebeling for Levi as the source for the dynamic stride length calculation. Ebeling, like Levi, explicitly sought to solve the inaccuracy of pedometers that use a preset average stride length. Ebeling taught using the frequency of steps (stride duration) to determine a variable stride length. Its method involved performing "several sessions" of calibration at various walking and running speeds to collect data for a "multiple linear regression" analysis. This process generated coefficients for a formula that calculated stride length based on stride duration, directly teaching the key data processing limitation of the challenged claims.
    • Motivation to Combine: The motivation was identical to that in Ground 1. A POSITA would be motivated to enhance the basic exercise monitor of Jimenez by incorporating the more accurate distance calculation method taught by Ebeling. This would satisfy the market need for a single device that could accurately track both physiological data (heart rate) and performance data (distance traveled), overcoming the known inaccuracies of prior art devices.
    • Expectation of Success: The expectation of success was high and based on the same reasoning as Ground 1. Combining Ebeling's known method for improving pedometer accuracy with Jimenez's hardware platform was a straightforward application of known technologies to achieve a predictable improvement in device functionality.

4. Key Claim Construction Positions

  • Petitioner stated that for the purposes of the IPR, it would adopt the claim constructions proposed by the Patent Owner in related district court litigation. This strategy was intended to demonstrate that the challenged claims were obvious even under the Patent Owner's own interpretations.
  • Key constructions adopted by Petitioner included:
    • "step counter": "a device that collects data to generate a step count."
    • "stride rate": "number of steps over a time period."
    • The phrase "from a range of stride lengths calculated from a range of corresponding stride rates" (and similar phrases in other claims) was construed to mean that the correspondence between stride length and stride rate is generated from "two or more calibrations." Petitioner argued that both Levi's calibration curve and Ebeling's multiple calibration sessions met this limitation.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-8 of the 6,434,212 patent as unpatentable under 35 U.S.C. §103.