Abstract: A method of determining a focal distance between a principal camera and a target object utilizes first and second video cameras mounted in spaced apart positions relative to a principal camera. A first video image from the first video camera is displayed on a video monitor and a second video image from the second video signal is superimposed onto the first image. First and second controllers are provided for positioning the first and second video images, respectively, on the video monitor. First and second position signals corresponding to positioning of the first and second video images, respectively, are acquired. When the images of a target object in the two video images are aligned, the position signals are used to compute the focal distance from the principal camera to the object.

Abstract: An exercise mat for a person exercising on a floor surface comprises a pad having a top surface, a bottom surface, and a peripheral edge. A cutout is formed in a first portion of the peripheral edge and sized to accommodate the neck of the person. A high-friction non-slip texture or coating may be applied to either the top surface or the bottom surface of the pad, or both. The top surface may further includes a pair of raised shoulder stops. In use, with the bottom surface of the pad resting on the floor surface and with the person's shoulders supported on opposing sides of the cutout proximate the first portion of the peripheral edge, the person's neck may be positioned within the cutout to allow natural flexion curvature of the cervical spine when the person is performing a shoulder stand on the mat.

Abstract: A method of determining a focal distance between a principal camera and a target object utilizes first and second video cameras mounted in spaced apart positions relative to a principal camera. A first video image from the first video camera is displayed on a video monitor and a second video image from the second video signal is superimposed onto the first image. First and second controllers are provided for positioning the first and second video images, respectively, on the video monitor. First and second position signals corresponding to positioning of the first and second video images, respectively, are acquired. When the images of a target object in the two video images are aligned, the position signals are used to compute the focal distance from the principal camera to the object.

Abstract: An exercise mat for a person exercising on a floor surface comprises a pad having a top surface, a bottom surface, and a peripheral edge. A cutout is formed in a first portion of the peripheral edge and sized to accommodate the neck of the person. A high-friction non-slip texture or coating may be applied to either the top surface or the bottom surface of the pad, or both. The top surface may further includes a pair of raised shoulder stops.

Abstract: A gating module for gating an image intensifier tube. The gating module includes a frequency generator generating a base signal having a base frequency. A modulator spread-spectrum modulates the base frequency of the base signal to generate a modulated signal. A gating circuit coupled to the modulator generates a gating signal in response to the modulated signal.

Abstract: A headstand assisting implement for assisting an intended user while the latter performs a headstand includes an implement body defining a ground contacting surface for resting on a ground surface and a substantially opposed cranium contacting surface for contacting the cranium of the intended user. The cranium contacting surface is provided with a cranium receiving concavity configured and sized for substantially fittingly receiving a predetermined portion of the cranium of the intended user so as to ergonomically support the cranium of the intended user when the intended user performs the headstand.

Abstract: A hammer head training target for enhancing the level of training by training realistically and effectively with a life-like target head. The inventive device includes a life-like resilient foam head having an integral oval-shaped handle and a core insert clamshell encasing that traps the handle in place. The head resembles the head of a human being with eye, ear, nose, mouth and temple features. An opening is provided in the back side of the head for access to the handle. The handle is oval in shape and is strategically located at the centroid of the head for optimum angle position for the trainer's hand. The handle is sandwich between the left-hand and the right-hand core insert encasings. The left-hand core insert captivates half of the handle structure. It contains half of the enclosure for protecting the hand during training. The right-hand core insert captivates half of the handle structure. It contains half of the enclosure for protecting the hand during training.