Abstract: An aspiration control system includes a motor and vacuum pump which are controlled by a system controller, in accordance with input commands to provide a precise, continuously variable vacuum or negative pressure within a vacuum chamber and surgical handpiece. The resulting vacuum is proportional to the control signal sent from the system controller to the motor. A transducer samples the vacuum output and produces a signal fed system controller. The signal is compared with a variable input signal set by a potentiometer or other signal source activated by the input commands so that the transducer signal tracks the voltage source signal. Therefore, the vacuum output of the vacuum pump and motor relates directly and predictably to the input commands. In one embodiment the motor is a brushless DC motor.

Abstract: A portable, hand-held tympanometer that has the capability of performing the tympanometry and of displaying and storing the test results all within the hand-held instrument. A separate unit that is not in any way attached to the tympanometer during the testing is provided to print the test results and to recharge the tympanometer battery. The tympanometer has a body portion and a head portion to which a speculum is attached, the speculum being adapted to engage the canal of the ear being examined in sealed relation thereto. A speaker in the speculum transmits acoustic signals into the ear canal and a microphone in the speculum receives the signals that are reflected back through the canal by the tympanic membrane. A pressure transducer is located in the head portion of the tympanometer, and a miniature pump located in the body portion operates to introduce a range of pressures into the ear canal while the acoustic signals are being transmitted and received.