Liquid level monitoring apparatus

Abstract

Apparatus for monitoring the drop of the level of the liquid in a plastic bag that is used during the intravenous administration of a solution includes a housing in which switch means having an integral, spring actuated contact means is mounted with the switch means being electrically connected to alarm means for generating a signal when the condition of the switch means changes in response to the reduction of the contents of the bag to a predetermined volume. A first arm is pivotally mounted so that a portion of the first arm engages a first surface of the bag. First spring means are employed for normally biasing the first arm in a direction towards the first surface of the bag. A second arm includes a portion that is in opposition to the bag engaging portion of the first arm so that the bag may be positioned therebetween and compressed thereby. The second arm also includes means for actuating the switch means. There is also provided a third, angularly adjustable arm together with a second spring that extends between the third arm and the second arm. When the contents of the plastic bag is reduced to the predetermined volume after the initiation of the administration of the solution the total force that will be exerted on the bag is represented by the sum of the forces exerted by the spring that actuates the switch means contacts and the second spring means. The total force that is required to change the condition of the switch means can be varied by angularly displacing the second arm.

Dependencies are inferred from the claim text.