Abstract: A system is provided for taking an electrocardiogram of a subject. The system includes a wireless communications system; a first device which is disposable on a first limb of the subject, said first device containing a first tangible, non-transient memory device and a first sensor which measures a first electrophysiological signal of the user; a second device which is disposable on a second limb of the subject, said second device containing a second sensor which measures a second electrophysiological signal of the user and which is in communication with said first device via said wireless communications system; and a software program which is resident in said first memory device and which produces an electrocardiogram from the first and second electrophysiological signals measured by the first and second sensors.

Abstract: A light source is provided which comprises an LED array containing a plurality of LEDs, and a lens array containing a plurality of lenslets. The lens array is aligned with the LED array such that one lenslet is disposed over each LED, wherein each of said plurality of lenslets comprises at least first and second sublenslets having first and second respective optical centers, and wherein at least one of said first and second optical centers deviates from the geometric center of the lenslet.

Abstract: An infrared detector (301) is provided which comprises a pyroelectric detector (303) having first and second sensing elements (345), an aperture stop (311), and a Fresnel lens array (305). The detector may be used as a passive infrared sensor unit for detecting intrusion into large openings.

Abstract: An infrared detector (301) is provided which comprises a pyroelectric detector (303) having first and second sensing elements (345), an aperture stop (311), and a Fresnel lens array (305). The detector may be used as a passive infrared sensor unit for detecting intrusion into large openings.

Abstract: An infrared detector (301) is provided which comprises a pyroelectric detector (303) having first and second sensing elements (345), an aperture stop (311), and a Fresnel lens array (305). The detector may be used as a passive infrared sensor unit for detecting intrusion into large openings.

Abstract: A light source is provided which comprises an LED array containing a plurality of LEDs, and a lens array containing a plurality of lenslets. The lens array is aligned with the LED array such that one lenslet is disposed over each LED, wherein each of said plurality of lenslets comprises at least first and second sublenslets having first and second respective optical centers, and wherein at least one of said first and second optical centers deviates from the geometric center of the lenslet.

Abstract: An infrared detector (301) is provided which comprises a pyroelectric detector (303) having first and second sensing elements (345), an aperture stop (311), and a Fresnel lens array (305). The detector may be used as a passive infrared sensor unit for detecting intrusion into large openings.

Abstract: An infrared imaging device is provided which comprises first and second plastic Fresnel lenses that are in optical communication with each other. Each of the first and second lenses have a first major surface which is convex and a second major surface which comprises a Fresnel surface. The first lens is adapted to mimic a meniscus asphere correct for conjugates of infinity and for the focal length of said first lens, and the second lens is adapted to mimic a meniscus asphere and is further adapted to act as a field flattener.

Abstract: An infrared imaging device is provided which comprises first and second plastic Fresnel lenses that are in optical communication with each other. Each of the first and second lenses have a first major surface which is convex and a second major surface which comprises a Fresnel surface. The first lens is adapted to mimic a meniscus asphere correct for conjugates of infinity and for the focal length of said first lens, and the second lens is adapted to mimic a meniscus asphere and is further adapted to act as a field flattener.

Abstract: An infrared imaging device is provided which comprises first and second plastic Fresnel lenses that are in optical communication with each other. Each of the first and second lenses have a first major surface which is convex and a second major surface which comprises a Fresnel surface. The first lens is adapted to mimic a meniscus asphere correct for conjugates of infinity and for the focal length of said first lens, and the second lens is adapted to mimic a meniscus asphere and is further adapted to act as a field flattener.

Abstract: A passive infrared motion detector that creates a detection pattern with non-diverging insensitive zones. The sensing elements are of alternating polarity and each has a width w. An optical collection system directs infrared radiation onto the sensing elements. The sensing elements are separated by a distance equal to an integer multiple of width w, with the integer being at least two. The optical centers of the optical collection system are separated by an integer multiple of width w, with the integer being at least two. The arrangement of the optical centers and the sensing elements results in a detection pattern with non-diverging insensitive zones, with the insensitive zones having a negligible width.

Abstract: A Fresnel lens formed of an infrared transmitting material has a grooved surface. The grooves all extend to the same depth, and the distances between successive grooves vary across the lens. In a circular lens, the grooves are concentric, and the distances between grooves nearer the center are longer than the distances between the grooves nearer the circumference. A substantial portion of the grooves have an aspherical surface.