Optics: measuring and testing – Shape or surface configuration
Reexamination Certificate
2001-01-16
2001-12-18
Kim, Robert H. (Department: 2877)
Optics: measuring and testing
Shape or surface configuration
C033S00300A
Reexamination Certificate
active
06331893
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to the field of foot analysis, and more specifically, to the fields of automatically measuring foot dimensions, forces, and movements.
It is well known that shoes and feet come in a variety of sizes and shapes. Consequently, in order to provide a particular consumer with a pair of shoes, a shoe retailer must determine that particular consumer's shoe size. If the consumer is unaware of his or her shoe size, the shoe retailer typically measures the consumer's feet to determine the appropriate shoe size. One of the most commonly used devices for measuring feet for fitting shoes is the Branach device. This manual device includes two levers slidably mounted upon a labeled platform for determining the length and width of a particular foot. Since shoes have traditionally been available in men, women, and children sizes, three different types of Branach devices, corresponding to each of these sizing schemes, have been utilized by shoe retailers. The manual nature of the Branach device, as well as the need for using three different devices for men, women, and children, suggest the need for a system which automatically measures all types of feet for fitting shoes.
Various types of automatic feet measuring devices have been developed in the past. Many of these devices are very expensive and time consuming and often utilize complex mechanical moving components which are subject to ordinary shortcomings of moving mechanical parts. Other devices include one or more light sources located to shine light onto the top or bottom of a foot to cast planar outlines of the foot onto light sensitive sensors which are monitored to produce foot length and width measurements. Although length and width measurements are useful and relatively easily obtained from such systems, additional desirable measurements which are difficult or impossible to obtain from such prior systems include, among others, foot height, foot volume, foot shape, and force distribution throughout the foot in a normal stance.
In addition to analyzing feet for fitting shoes, it has also been well known to analyze feet for various medical reasons. Force plates of various designs have previously been used to monitor changes of center of pressure and postural sway for various medical purposes, such as evaluating the effects of age, various neurological disorders (e.g. Parkinson's disease, Epilepsy), drug/alcohol/chemical abuse and use, and various injuries, such as limb, back or traumatic brain injuries, as well as evaluating the need and effect of various surgeries (such as determining how weight is being shifted before and after knee or hip surgery) and vocational rehabilitation. The center of pressure and postural sway objective information is known to be very useful in diagnosing and treating a large variety of medical problems. In addition, static analysis of center of pressure and postural sway has also been linked to predicting falls and a patient's ability to walk without injury. Unfortunately, many of the prior devices are expensive, difficult to use, and often provide little readily useful information. Another medical reason for analyzing feet relates to the processes of prescribing or selecting an orthotic, such as an insole. Such processes are often very subjective, expensive, time-consuming and inaccurate. While it is understood that a primary purpose of a foot sole/insole combination is to distribute forces applied to the foot, such a result is rarely reached without great effort.
There is a need, therefore, in the industry for a method and an apparatus for analyzing feet for these and other related, and unrelated, purposes.
SUMMARY OF THE INVENTION
Briefly described, the present invention, includes a preferred apparatus and a variety of preferred methods for analyzing feet. In one preferred embodiment, a method is provided for measuring feet for fitting shoes. An apparatus for accomplishing the inventive method includes a housing which houses a controller and a monitor and defines left and right foot wells for receiving left and right feet, respectively. The floor of each foot well includes a pressure pad assembly which includes a matrix of pressure sensor contacts covered by a variably resistive pressure pad to form a matrix of pressure sensors. Each pressure sensor is independently addressable and includes two contacts separated by an insulated gap which is selectively bridged by the pressure pad to effect an independently measurable, pressure-related resistance across the insulated gap.
A digital signal processor (DSP) is electrically positioned between the controller and the pressure sensors and controls operation of the pressure sensors. During operation, a reference voltage is driven onto one row at a time addressed through an analog multiplexer array. The resulting current flowing from one column addressed through a second analog multiplexer array is converted into an amplified analog voltage. Subsequently, the analog voltage is converted into a resulting digital representation. The DSP then references a table to convert the digital representation into pounds and thereafter transfers the raw pound data, one row at a time, to the controller through a first-in-first-out (FIFO) memory resource. The DSP also conditions each row of pound data for display on the monitor. A smoothing method and an auto-normalization method are also employed to provide more accurate and visually appealing monitor output screens.
Located around the inner perimeter of each foot well are optical sensors, consisting of infrared (IR) light emitting diodes (LED's) and corresponding phototransistors, which are utilized to measure the length, width, and heights of a foot. A microprocessor is electrically positioned between the controller and the optical sensors and controls operation of the optical sensors by addressing and driving the sensors through programmable array logic circuits (PAL's) and multiplexer arrays. According to the preferred method, one LED in each foot well is supplied a modulated current while a corresponding phototransistor is checked for receipt of the modulated signals.
Before a foot is placed in a foot well, the optical sensors operate in a scan mode which only checks every fifth LED/phototransistor pair. When a foot is placed in a foot well, thus blocking one of the optical sensors, the optical sensors enter into a tracking mode where the outer limits of the width, length, and height are tracked, thus saving time over repeatedly checking every optical sensor.
According to one preferred method of the present invention, when the foot wells are empty, the controller displays on the monitor a slide show of user defined screens. When the optical sensors detect a foot and enter into the tracking mode, the controller reads data created by the DSP and IR microprocessor, calculates additional data, and displays the resulting data on the monitor. The pressure sensors and optical sensors are utilized to determine in a normal stance, among others, foot length, foot width, shoe size, foot volume, foot shape, force distribution, pronation, arch type, and recommended last type. The IR measurements begin with the leg and ankle and continue around the foot. Such determinations, along with intended use information obtained from the customer, are compared to a database of available shoes to determine recommended best fits for each customer. Such data can also be stored or transferred to an external system for storage with reference to each particular customer.
According to another preferred method of the present invention, the programming of the apparatus of the preferred embodiment is altered to calculate and display center of pressure information for postural sway analysis. In addition to displaying an initial pressure distribution screen similar to that of the first preferred method, the apparatus of this second preferred embodiment uniquely displays a center of pressure screen showing a center of pressure grid for each foot relative to an ou
Brown Algie C.
Dabbs James M.
Welty Carl T.
Williams David M.
Williams Henry G.
Coursey R. Stevan
Footmark, Inc.
Kim Robert H.
Stafira Michael P.
Troutman Sanders LLP
LandOfFree
Foot analyzer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Foot analyzer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Foot analyzer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2592401