Abstract: A polygraph for detecting and displaying the beat by beat changes in the relative rate of increase of the blood pressure of the heart. Electronic circuitry for measuring the derivative of the blood pressure pulse, and displaying it on either a separate channel or by adding it to the top of the blood pressure pulse waveform from which it was derived is disclosed.

Abstract: Apparatus for detecting and displaying on a polygraph record chart any change in either the sensitivity or balance control of each polygraph electronic module. The apparatus includes a detector in the form of a differentiator for detecting a change in voltage on the wiper of the sensitivity or balance potentiometer that produces a signal indicative of the voltage change, and a display operatively connected to the detector for displaying a signal indicative of the adjustment of the potentiometer. The record chart display includes circuitry having a monostable multivibrator configured as a non-retriggerable one shot device responsive to the voltage change signal from the detector to provide a single pulse driving signal to a pen driving motor. The circuitry also includes a rectifier circuit in the form of comparators responsive to the voltage change signal for producing a positive trigger signal to the one shot device.

Abstract: An apparatus permitting non-invasive electrical monitoring of the volume of flow of a fluid at relatively low pressures and flow rates. The apparatus comprises an analog flow gage having a housing with an inner flow chamber of upwardly increasing cross sectional area and a ball indicator received in the chamber. The flow chamber is in the shape of a cylinder with a plurality of longitudinal slits extending outwardly from the cylinder and equally radially spaced apart. Each of the slits has a wedge shaped tapered portion which accounts for the increasing cross sectional area of the chamber. The flow rate inside the chamber is directly linearly related to the amount of upward displacement of the ball indicator along the length of the tapered portions.

Abstract: A rectilinear pen movement apparatus is provided which is responsive to an electrical signal representing a measurement of galvanic skin resistance in order to provide a record of galvanic skin resistance on a chart recording medium. There is provided a support frame and a drive motor mounted to the frame. The drive motor has an output means which rotates on a first axis in response to an input signal representing an electrical measurement of galvanic skin resistance. An input shaft connected to a potentiometer senses the rotation of the output means and provides negative feedback. The input shaft also serves as a step up movement for rotating a swing disc on a second axis parallel to the first axis. A recording pen is supported for rotation about the second axis by a support shaft which is rigidly attached to the swing disc. The support shaft rotates on a third axis parallel to the first and second axis so that the tip of the recording pen moves rectilinearly in response to rotation of the output means.