Obviousness

Obviousness Analysis of US Patent 11,806,120 under 35 U.S.C. § 103

This analysis identifies combinations of prior art references that would render the independent claims (1, 9, and 17) of US Patent 11,806,120 obvious to a person having ordinary skill in the art (PHOSITA) at the time of the invention. The motivation for combining these references stems from recognized problems in existing fitness monitoring and the desire to improve accuracy, personalization, and power efficiency in wearable health devices.

The core distinguishing features of US 11,806,120, as identified in the prior art summary, are:

1. Variable Sampling Rate: Modifying the heart rate sampling rate based on a comparison of a previous heart rate measurement to the user's heart rate range (the difference between maximum and resting heart rate).
2. Specific Weighting Method: Determining an expected heart rate level based on motion information and then weighting the actual heart rate values based on both the motion information and a comparison of the heart rate values with this expected heart rate level.

Combination 1: US20140073486A1 (Bobo Analytics) + WO2013166341A1 (Aliphcom - PPG accuracy) + General Knowledge in Wearable Sensing and Power Management

Grounds for Obviousness

A PHOSITA, seeking to improve the accuracy and utility of health risk indicators derived from wearable devices, would have been motivated to combine the teachings of these references.

1. Obtaining Heart Rate and Motion Information (Claim Elements Covered by US20140073486A1):
US20140073486A1 ("Systems, devices and methods for continuous heart rate monitoring and interpretation") explicitly teaches a system that collects both heart rate values and motion information from a user over a monitoring period to provide metrics about physical activity and fitness levels. This forms the foundational step of the claimed invention.

2. Variable Sampling Rate Based on Heart Rate Range (Claim Element Covered by General Knowledge in combination with US20140073486A1 and US5243992A):
The concept of a variable sampling rate is not new. US5243992A ("Pulse rate sensor system") describes a pulse rate sensor that can adjust its mode of measurement, demonstrating the general principle of adaptive sensing. In the context of continuous monitoring by battery-powered wearable devices (such as those described in US20140073486A1), a PHOSITA would be well-motivated to implement variable sampling rates to optimize battery life while maintaining data quality during relevant periods. The background of US11806120 itself states that "Sampling rate could be variable. This can help to achieve a suitable balance between data accuracy and (battery) power consumption." [Description]

Furthermore, using an individual's heart rate range (maximum heart rate minus resting heart rate) as the basis for adjusting the sampling rate would be an obvious design choice for a PHOSITA. The heart rate range is a standard physiological parameter indicating a user's potential for exertion. A PHOSITA would understand that increased sampling is beneficial when the heart rate indicates activity (e.g., above a certain percentage of the heart rate range) and decreased sampling is acceptable during periods of rest or low activity. This personalized adjustment improves efficiency over static thresholds and is a logical application of physiological knowledge to optimize continuous monitoring in a device like that taught by US20140073486A1.

3. Determining an Expected Heart Rate Level Based on Motion Information (Claim Element Covered by WO2013166341A1 in combination with US20140073486A1):
WO2013166341A1 ("Physiological characteristic detection based on reflected components of light") teaches the use of motion data from an accelerometer to filter noise and motion artifacts from heart rate signals. This demonstrates a clear understanding in the prior art that motion information is highly correlated with and can be used to interpret heart rate data. A PHOSITA, building on the combined heart rate and motion sensing from US20140073486A1 and the principle of using motion to inform heart rate interpretation from WO2013166341A1, would be motivated to go beyond mere noise filtering.

The problem recognized by the inventors of US11806120—that a high heart rate might be due to emotional stress rather than physical exertion when motion is low—would further motivate a PHOSITA to refine activity assessment. [Description] To address this, it would be obvious to a PHOSITA to use the motion information to establish an "expected heart rate level" that corresponds to the detected physical movement. This expected level serves as a physiological benchmark, a logical extension of using motion data to contextualize heart rate readings.

4. Weighting Heart Rate Values Based on Motion and Comparison to Expected Heart Rate (Claim Element Covered by WO2013166341A1 in combination with US20140073486A1):
Having established an expected heart rate level from motion (as motivated above), a PHOSITA would then be motivated to adjust the contribution of actual heart rate values to an aggregate activity score based on how they compare to this expected level. If, for instance, a user's measured heart rate is significantly higher than the expected heart rate for their detected motion (e.g., indicating stress rather than exercise), a PHOSITA would logically apply a reduced weighting to those heart rate values when calculating a "health-predictive activity score" that specifically targets physical exertion. This directly solves the problem of inaccurate activity estimation highlighted in the background of US11806120, by ensuring the aggregate heartbeat value more accurately reflects true physical activity. The patent explicitly describes this adjustment, for example, "reducing the weighting applied to heart rate values determined to be greater than a predetermined threshold higher than predetermined expected heart rate values associated with the data indicating movement of the user..." [Description].

5. Determining a Health-Predictive Activity Score (Claim Element Covered by US20140073486A1):
Both US20140073486A1 and US20120316456A1 teach deriving meaningful metrics about physical activity and overall health from collected heart rate and motion data. The concept of a "health-predictive activity score" based on an aggregate measure of activity is a direct outcome of such systems. Statistically linking such scores to health outcomes like peak oxygen uptake is a known practice in health informatics, as noted in the detailed description of US11806120. [Description]

Conclusion on Obviousness

The independent claims of US Patent 11,806,120 would be obvious when considering the combination of:

• US20140073486A1 (Bobo Analytics): For the fundamental collection of heart rate and motion data to assess activity and health.
• WO2013166341A1 (Aliphcom - PPG accuracy): For establishing the principle of using motion data to inform and interpret heart rate readings.
• General knowledge of power management and physiological parameters in wearable devices (possibly aided by US5243992A): For implementing a variable sampling rate that is tailored to a user's individual heart rate range for efficiency and accuracy.

A PHOSITA would be motivated to combine these references to create a more accurate, personalized, and power-efficient system for determining health risk indicators from activity, directly addressing the shortcomings of prior art systems that either misinterpret activity levels or consume excessive power. The specific adjustments to sampling rate and heart rate weighting are logical and straightforward refinements to existing monitoring techniques, driven by a clear need in the art.