Litigation summary

Based on the previous analysis of US Patent 10,959,649, this section details the patent's prosecution history, outlining the interactions between the inventor's representative and the USPTO examiner that led to the patent's grant.

Prosecution History Analysis

The prosecution history, or "file wrapper," for US Patent 10,959,649 (filed under application number 14/608,571) reveals a negotiation process with the USPTO focused on distinguishing the invention from existing technologies. The key patentable feature that emerged was the specific method of using a "verified" stride length to iteratively calibrate "estimated" stride lengths across different step-rate ranges.

Initial Filing and Claims (January 29, 2015)

The application was filed with a set of claims broadly directed at a method and apparatus for determining stride length. The originally filed independent claims were broader than those ultimately granted. They focused on the general concept of:

1. Receiving user-specific information.
2. Determining a step rate.
3. Calculating an "estimated" stride length based on the user information and step rate.
4. Calculating a "verified" stride length when location data (e.g., GPS) was available.
5. Using the historical data (estimated or verified) for future calculations when GPS is unavailable.

Non-Final Rejection (September 1, 2017)

The USPTO examiner issued a Non-Final Rejection, primarily under 35 U.S.C. § 103 for obviousness. The examiner contended that the invention as claimed would have been obvious to a person of ordinary skill in the art based on a combination of prior art references.

The key prior art cited was:

• US 2008/0133139 A1 ("Vock et al."): This reference taught a system for determining stride length using an accelerometer to measure step frequency and a database that correlates step frequency with stride length. Vock et al. also disclosed using GPS to measure distance and calculate an average stride length.
• US 2014/0278211 A1 ("Yuen et al."): This reference disclosed a fitness monitoring device that determines a user's stride length based on user characteristics like height and gender. It also described using GPS to track distance and calibrate activity metrics.

The examiner argued that it would have been obvious to combine the teachings of Vock et al. and Yuen et al. Vock provided the core concept of correlating step rate with stride length and using GPS for verification. Yuen provided the idea of using personal user data (height, sex) to create an initial estimate. The examiner concluded that combining these known elements to create the claimed system was a predictable and obvious step.

Applicant's Response and Claim Amendments (December 1, 2017)

In response to the rejection, the applicant's representative filed an amendment that significantly narrowed the claims and presented arguments to distinguish the invention from the cited prior art.

The most critical amendment was made to what would become the independent claims (1 and 13). The applicant added the specific limitation that the verified stride length associated with a first step rate is used to adjust the estimated stride length associated with other, different step rates.

In the "Remarks" section of the response, the applicant argued that neither Vock et al. nor Yuen et al., alone or combined, taught or suggested this crucial calibration step.

• They argued that Vock et al. might verify a stride length for a specific activity or step rate but did not disclose using that single verification to then go back and adjust a whole database of estimated stride lengths for other step rates. For example, Vock did not teach using a verified stride length from a 120 steps/minute run to then adjust the estimated stride length for an 80 steps/minute walk.
• This iterative and cross-relational calibration was presented as the core novelty. It solved the problem of inaccuracy when a user moves at various speeds, especially when GPS is off, by creating a smarter, self-correcting model of the user's personal gait.

Notice of Allowance (November 27, 2020)

After further examination and a subsequent amendment refining the claim language, the USPTO issued a Notice of Allowance. The Examiner's Reasons for Allowance explicitly acknowledged the patentability of the amended claims. The examiner stated that the prior art did not teach the specific limitation of "inferring that estimated stride lengths for the user at other step rates or step rate ranges may also be shorter/longer" and "incrementally increasing or decreasing" the estimated stride lengths at those other step rates based on the comparison between a verified and estimated stride length at a specific, measured step rate (as recited in the amended Claim 1).

This indicates that the patent was granted precisely because of the addition of the specific, detailed calibration process where a single verified data point is used to refine a whole set of estimated data points for different conditions. This limitation was deemed non-obvious and a specific improvement over the prior art.