This invention is directed to a method to improve the performance of stepper motor driven systems.Stepper motors are ubiquitous in modern office equipment and other machinery, yet little is published regarding their optimal use in open loop systems.Accurate control of a stepper motor is limited by the ability of the control system to approximate the actual motor and subsequently provide the correct instructions for achieving the actual desired movement with little or no error.Moving the motor to a specific position within a specified time period is difficult due to variations between motors

Terahertz (THz) waves occupy a segment of the electromagnetic spectrum between the infrared and microwave bands. As such, they can be used for imaging and sensing in ways that are not possible with conventional technologies such as X-ray and microwave. Because THz radiation transmits through almost anything that is not metal or liquid, the waves can see through most materials that might be used to conceal explosives or other materials, such as packaging, corrugated cardboard, clothing, shoes, backpacks, and book bags. They are also safer than X-rays and microwaves for human tissue.

Many times following orthopedic surgery or injury to lower extremeties patients are advised to gradually bear weight on their limb. Since patients do not want to cause further damage or pain to the injury they put little to no weight on the area. The application is necessary, however, for proper recovery. This invention is a mechanical device that indicates to the patient when a first level of weight is applied. So, this encourages them to step firmly enough to reach this level without fear that they are going to hurt themselves or cause pain.