Abstract: A hand-held pachymeter includes an ultrasonic probe capable of emitting ultrasonic pulses and capable of receiving echo signals of the ultrasonic pulses. The echo signals may include an echo signal from an anterior portion of a cornea of an eye and an echo signal from a posterior portion of the cornea. The hand-held pachymeter also includes a hand-held computing device and an expansion module that interfaces the probe to the hand-held computing device. The expansion module includes circuitry to produce digitized signals that correspond to the echo signals, and a memory which stores computer instructions to determine a thickness of the cornea based on the digitized signals. The computer instructions are executed by the hand-held computing device.

Abstract: A mechanism for transferring movement between two reciprocating bodies, such as pistons or displacers (10, 11) comprises a crank or eccentric (12) and may be included in a Stirling or Vuilleumier engine. The crank or eccentric is connected to a connecting member (13) by means of a bearing or pivot (D). The connecting member (13) is connected to one (10) of the pistons or displacers via a second pivot (X) and to one arm (16) of a lever (15) by means of a third pivot (A). The pivots (A, D, X) of the connecting member (13) defines the vertices of a triangle. The other arm (17) of the lever (15) is pivotally connected to the other piston or displacer (11).The arms (16, 17) of the lever (15) may define an angle therebetween, and this angle may be selected so as to obtain a desired angle between the directions of the movements of the pistons, for example an angle of 90.degree..

Abstract: The invention relates to a pumping system for supplying fluid at a variable delivery rate in accordance with demand. The system includes one pump having a variable delivery rate and one or more auxiliary pumps arranged in parallel therewith, each having a fixed delivery rate. The variable delivery pump operates over a predetermined control range between minimum and maximum rates. Each fixed delivery rate pump has on and off operating modes with the on mode delivery rate being at the maximum delivery rate of the variable delivery pump. A control unit for operating the pumps matches the pump delivery with the demand. The control unit functions to set the variable delivery pump at its minimum delivery rate when operation of the fixed delivery pump is initiated during upward demand control and for setting it at its maximum delivery rate when operation of the fixed delivery pump is terminated during downward demand control.