Abstract: An improved optical rotation detector for detecting optically active molecular compounds in a sample solution using: a laser diode with the beam passing through an optical fiber or lens to improve its quality, a reference oscillator at frequency f, a first polarizer, a specially constructed flow cell to minimize mechanical birefringence and leaking in the cell's optical windows, a second polarizer, and an improved detection scheme. The detection scheme includes a first and second photodetector for sensing first and second signals, where the first signal is light passed through the second polarizer and the second signal is light reflected off the second polarizer. A compensator circuit low pass filters the signals, inverts one signal and sums it with the other, and then notch filters off the undesired components to produce a compensated signal. The compensated signal then drives a lock-in amplifier which is driven by the reference oscillator to sense the amplitude modulated f frequency signal.

Abstract: The instant invention is a shielded monopolar electrosurgical instrument for use in laparoscopic and the like surgical procedures. The instrument consists of a rigid outer metallic shield which operates as a conductive coaxial shield and is connected to a patient return electrode of an electrosurgical generator. The use of a coaxial shield coupled to the patient return electrode on the outer surface of the instrument eliminates the need for an outer insulative coating. The shield houses a conductive wire positioned through the center of the shield which is coupled to the active lead from the electrosurgical generator. Between the wire and the shield is placed an insulating sleeve. The tip of the instrument is interchangeable and the instrument may be used in conjunction with a form fitting handle providing the surgeon with finger holes in order to apply pressure to the instrument for operation of grasping items when such a tip is employed.