The disease scoliosis is a rotational deformity of the spine and ribs, characterized by both lateral curvature and vertebral rotation. Idiopathic genetic scoliosis occurs about seven time more frequently in the female than in the male and accounts for about 80% of all cases of the disease. The deformity first appears in infants, juveniles or adolescents generally, and many school health programs in this country have screening programs for the early detection of the disease. On detection, the patient is referred to a specialist for treatment. Presently, however, over-referral of great numbers of children with very mild curvatures which do not require treatment is causing a large number of unnecessary x-rays and needless lost time and expense. The invention disclosed herein is a simple and convenient device for measuring the clinical deformity in patients with scoliosis which establishes objective criteria for screening and which can significantly reduce the number of over-referrals.

A device is described which accurately and reproducibly identifies points on the circumference of a non-vertical pipe for use as reference marks for pipe inspections. The device comprises a light-permeable disk-shaped chamber having a plurality of pockets spaced about its circumference, a light source transmitting a beam of light through the chamber, and a light-activated switch positioned to detect the light beam. The chamber contains a freely moving ball sized to be retained by the pockets. The device is mounted to revolve about the axis of the pipe. As it revolves the ball moves from one pocket of the chamber to another, interrupting the beam of light and triggering the light-activated switch, thereby indicating that the device has passed to a pre-selected circumferential position on the non-vertical pipe.

An inclination sensor is contemplated which includes case means having a cavity formed in the interior thereof, with this cavity having a longitudinal slope which is generally V-shaped in longitudinal profile, downwardly concave, and having a downwardly facing apex. A movable member is movable longitudinally along the slope within said cavity. A detecting means is operable to detect the inclination of a mounting body to which said case means is attached, in response to longitudinal movement of the movable member along the longitudinal generally V-shaped slope. A restricting means is provided by the apex and is operable to impede movement of the movable member out of the apex only until the case means undergoes a predetermined, longitudinal tilting movement.

A combined earthquake sensor and night light having a base with a bottom portion resting on a support surface subject to vibrations. A top portion of the base is provided with a reflective surface and a centrally mounted lamp. A transparent cylinder is mounted on the base member to suspend a multifaceted spherical crystal above the light source by means of an elastic helical spring to enable the spherical crystal to move in all directions. Vibrations generated by an earthquake are transmitted to the base member causing movement of the crystal giving a visual indication of the vibrations by light reflection and diffractio. In the static mode the unit serves as a decorative lamp.

An inclinometer which is compatible for use with night vision equipment on aircraft and other vehicles. The inclinometer includes a white zirconia sphere movable within a damping liquid of a liquid capsule.