Abstract: The present invention comprises a method and apparatus for monitoring neuromuscular blockage, and more specifically contemplates the quantitative measurement of movement of the skin of a patient overlying an electrically simulated skeletal muscle as an indicia of such blockage. The preferred embodiment of the apparatus of the present invention includes a piezoelectric film affixed over the patient's skin, the film generating an electric current in proportion to the magnitude of skin movement.

Abstract: The present invention comprises a safety inflation apparatus for preventing full inflation of a catheter balloon in a small body cavity of lesser internal diameter than that of the fully-inflated catheter balloon. The present invention includes a safety reservoir which inflates to absorb excess fluid volume from a catheter inflation device (such as a syringe) when the catheter balloon comes into contact with the wall of the small cavity, thereby preventing damage to the cavity wall and injury to the patient. In one embodiment of the invention, sensors and associated electronic displays are employed to provide an indication of the operating state of the system as the catheter balloon is inflated.

Abstract: An anesthetic system and a transportation ventilation system include a breathing circuit which is isolatable from ventilator machines and anesthesia machines. The breathing circuit is connectable to the patient and includes a respiration bag within an actuator bag which is translucent and inelastic. The ventilation machine supplies signals so that the respiration bag collapses and expands within the actuator bag through a multi-port valve structure.

Abstract: The invention is directed to a method for simulating and demonstrating the gas exchange during ventilation wherein the breathing gas is influenced with respect to its constituents by changing the portion of at least one breathing gas component metered to the carrier gas. The method permits simulation of physiological functions occurring during anesthesia such as the uptake and release of anesthetic agents. For this purpose, an anesthetic agent is admixed to the breathing gas and this anesthetic gas mixture is conducted through a reservoir filled with organic oil to simulate the anesthetic agent uptake and release by the human or animal body.

Abstract: The concentration of multiple polyatomic gases are determined almost simultaneously by Raman scattering. The gas sample is placed in a sampling cell located in the resonance cavity of a laser and a polarized laser beam having sufficient intensity to produce detectable signals of Raman scattered light is passed through the cell. The scattered light is captured and redirected by means of a reflection mirror located parallel to the axis of the laser beam adjacent to and outside of the cell. Signals of both inelastic Raman scattered light and elastic laser scattered light are collected by a collection lens means opposite the reflection mirror and outside the gas cell. The collection lens is also parallel to the axis of the laser beam.

Abstract: Metabolic gas monitoring apparatus and methods for measuring the metabolic rate in patients. The apparatus includes separate inlets for a calibration gas, inspired gas, and expired gas, and means for alternately introducing each gaseous sample into a thermoelectric cooler. The cooler is configured with relatively narrow passageways so as to contain a minimal amount of gaseous volume therein and thus provides for a more dynamic response time and for more accurate measurements. The apparatus further includes a carbon dioxide sensor and an oxygen sensor for measuring the concentration of carbon dioxide and oxygen, respectively, in the gaseous samples, and a microprocessor for comparing the measured concentrations of carbon dioxide and oxygen in the inspired gas and expired gas and for calculating the metabolic rate. Preferably, the oxygen sensor has a zirconium oxide differential electrode and a substantially equal pressure is maintained in a sample chamber and a reference chamber of the oxygen sensor.

Abstract: A closed loop system for controlled infusion of fluids, medication or diagnostic substances into a patient based on real time measurement of urine output. Proper urine flow techniques and a self compensating drop count apparatus provide accurate representation as to cumulative number of drops and flow rate, with drop volume variations being compensated by a control algorithm which corrects computer parameters reflecting drop volume to correspond with urine volume measured. This real time urine flow rate is compared with a preset, desired flow rate to develop an error signal which is processed by a computer. Such processing includes modification by a PID control algorithm which governs infusion of fluids into the patient to effect the proper fluid resuscitation, medication or diagnostic treatment.

Abstract: A dynamic method and apparatus for determining the rate of expiration of a selected fluid constituent expired by a living subject during respiration. The apparatus includes a fluid path system which conducts the expired air to a first fluid detector which produces a first signal operable as a function of concentration for the selected fluid constituent. The signal registered by the detector is used for later comparison with a second signal which provides the basis for determining the expiration rate of fluid constituent originally present in the expired air. To make this determination, the fluid constituent is removed from the expired air, with the expired air being advanced to a mixing chamber where a second detection means senses the fluid concentration.

Abstract: An oxygen consumption monitor system suitable for use in measuring oxygen uptake in neonates wherein the system includes a check valve system in combination with a high flow, positive-end-expiratory-pressure respirator for supplying a high volume, controlled flow of oxygen through a flow circuit which includes (1) a primary flow line for carrying most of the oxygen supply through a respirator circuit maintained at a positive pressure, and (2) a secondary outlet communicating from said primary flow line through the check valve combination to permit inspiration of oxygen from the respirator circuit and expiration to a separate chamber for measurement of oxygen consumption. Minimal deadspace is developed in the check valve combination to insure fresh oxygen supply with each inspiration by the neonate. The use of opposing oneway valves at inlet and outlet locations of the valve combination permits use of a single opening for coupling to an endotrachael tube.

Abstract: A device for continuously monitoring oxygen consumption and anesthesia gas uptake of surgical patients, having servo-controlled replenishment mechanisms to automatically maintain preset levels of oxygen and anesthesia gas for inhalation. A closed, recirculating delivery circuit is utilized to adminster an appropriate volume of oxygen and anesthesia gas to a surgical patient. An oxygen sensor monitors decreases in oxygen concentration within the recirculatory system and triggers restoration to the preset concentration by means of feedback comparator circuitry. With the oxygen held at the desired level, any volume changes in the system are caused by uptake of anesthesia gas, which is monitored by detecting variations in the expansion of a respirator bellows. The desired amount of anesthesia gas is preset and maintained by a potentiometric monitoring device which produces a voltage proportional to the peak expansion of the bellows.