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A two-degrees-of-freedom scanned beam imaging system with large dynamic range and dynamic focusing is demonstrated. The laser diode, photo-detector and the optical components are integrated on a moving platform that is made of FR4 (Flame-Retardant 4), a common polymeric substrate used in printed circuit boards. A scan angle of 52 degrees is demonstrated at 60 Hz resonant frequency while the laser is moved 250 um in the out-of-plane direction to achieve dynamic focusing. The laser is scanned by physically rotating the laser diode and the collection optics to achieve high signal-to-noise ratio and good ambient light rejection. The collection optics is engineered such that the collection efficiency decreases when collecting light from close distances to avoid detector saturation. The detection range is extended from contact distance up to 600 mm while the collected power level varies only by a factor of 30 within this long range. Slight modifications will allow increasing the detection range up to one meter. This is the first demonstration of a laser scan engine with such a high degree of integration of electronics, optoelectronics, optics and micromechanics on the same platform.

The purpose of this article is to describe a method for assessing and treating patients with acute cervical joint lock. The assessment method enables the therapist to differentiate between acute cervical joint lock and spondylosis or acute cervical joint sprain. Treatment by mobilization or manipulation or both according to the Maitland approach is described. The contraindications to this type of treatment are described, and the efficacy of the Maitland approach is supported.

Twenty patients were examined in an investigation of the relationships between extension lag at the knee and other measures taken from the injured and uninjured extremity. The results of the study show: 1) there were no significant correlations between extension lag and the depth of squat, the extension force or flexion force, the circumference at the joint line or the circumference 5 and 15 centimeters cephalad to the patella pole, and active or passive knee flexion; 2) that the mean for flexion force was greater than the mean for extension force in the injured extremity, and there was no difference between the means for flexion and extension force in the uninjured extremity; and 3) that the means of the measures for active and passive flexion, flexion force, and circumference measures of the thigh taken from a group of patients who had stiff rotational movements at the tibiofemoral joint.were different from the means of the same measures taken from a group of patients who had normal rotational movements. There is limited evidence to suggest that weakness of the quadriceps muscle may be a factor in extension lag at the knee, but the support for this conclusion is based on comparison between groups of patients and not from the correlations between other variables and extension lag. For future studies, it is recommended that an attempt be made to secure patients with extension lags greater than 3Oin an effort to improve the prospect of detecting any relationships.J Orthop Sports Phys Ther 1982;3(4):178-182.