Medical apparatus for monitoring body liquid discharge

Abstract

A medical apparatus for automatically measuring and displaying the quantity of a liquid discharged by a patient during a defined real time interval. The apparatus is comprised of a reusable housing and a disposable plastic container adapted to be removably received in a cavity in the housing. A transducer is mounted in the floor of the cavity to engage the container and transmit sonic pulses through the container wall into a liquid pool in the container. A molded silicon rubber cap is fitted over the transducer to assure good acoustic coupling between the transducer and the container without requiring the use of an intermediate gel substance. The container is configured such that when it is received in the housing cavity, it is oriented to cause liquid entering an inlet port in the top portion to pool over the flat section of the container bottom wall. The apparatus includes an electronic measurement subsystem for measuring both the volume of liquid in the container and the passage of real time and for digitally displaying the volume of liquid accumulated within a defined real time interval. The measurement subsystem periodically samples the liquid level in the container by energizing the transducer to transmit an ultrasonic pulse. The pulse travels through the container wall and the liquid pool and is reflected off the surface of the pool. The reflected pulse then again passes through the liquid pool and is received by the transducer. The measurement unit determines the travel or 'flight' time duration between pulse transmission and pulse receipt.