US 6,301,964 · Granted 2001-10-16
The Shoe Sensor Patent That Turned Feet Into Motion Detectors
Imagine putting tiny motion sensors in your shoe that measure every twist, turn, and acceleration of your foot as you move. This patent describes how to mount accelerometers (devices that sense movement and direction) on a shoe's sole to track exactly how fast you're walking, which way your foot is rotating, and how your body accelerates with each step.
The plain-English version
What it protects
The claim covers a motion-sensing system mounted directly on or in a shoe that uses at least two perpendicular accelerometers (and optionally a third) to measure linear acceleration in multiple directions and rotational acceleration of the foot. What's protected here is the specific arrangement of these sensors on the shoe's sole plane, plus the method of combining their readings to calculate actual movement variables like velocity, position changes, and gait speed—not just raw acceleration data, but interpreted kinematic quantities.
Why it matters
This patent sits at the intersection of biomechanics and wearable sensors, enabling direct measurement of human movement from the ground up. Rather than relying on external motion-capture cameras or mathematical models, the shoe itself becomes the measurement instrument. This kind of embedded sensing opened doors for gait analysis in physical therapy, athletic performance tracking, and rehabilitation monitoring—areas where understanding exactly how someone's body moves can guide treatment or training decisions.
Real-world use
A physical therapist analyzing a patient's walking pattern after knee surgery could use shoe sensors like these to measure whether the patient's gait is improving week by week, revealing subtle changes that the naked eye might miss.
Original USPTO abstract
A device comprised of at least a pair of accelerometers and a tilt sensor mounted in fixed relation to a datum plane defining surface (sole of a shoe) may be used for extracting kinematic variables including linear and rotational acceleration, velocity and position. These variables may be resolved into a selected direction thereby permitting both relative and absolute kinematic quantities to be determined. The acceleration is determined using a small cluster of two mutually perpendicular accelerometers mounted on a shoe. Angular orientation of the foot may be determined by double integration of the foot's angular acceleration (which requires a third accelerometer substantially parallel to one of the two orthogonal accelerometers). The two orthogonal accelerations are then resolved into a net horizontal acceleration or other selected direction which may be integrated to find the foot velocity in the selected direction. The average of the foot velocity corresponds to the subject's gait speed.
Patent details
- Publication number
- US 6,301,964
- Filing date
- 1999-07-06
- Grant date
- 2001-10-16
- Assignee
- Dyhastream Innovations Inc.
- Inventor(s)
- FYFE KENNETH R., ROONEY JAMES K., FYFE KIPLING W.
- CPC class
- G01P1/127
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