Medical ventilator system
First Claim
1. A ventilator system for providing artificial ventilation to a patient, comprising:
- means for providing a pressure regulated source of respiratory gas;
flow control means for controlling the rate of flow of said respiratory gas in accordance with a predetermined flow rate-versus-time function, the flow control means receiving the gas from said source and being in fluid communication with the patient for transmitting the gas to the patient;
exhalation valve means in fluid communication with the patient and with the flow control means for providing an outlet to the ambient for the proximal gases of the patient, said proximal gases including respiratory gas made available for breathing of the patient and gases exhaled by the patient, the exhalation valve means receiving an input pressure signal and being adapted for closing said outlet to the ambient when the input pressure signal exceeds the pressure of the proximal gases;
pressure control means operatively connected with the exhalation valve means for providing said input pressure signal in accordance with a predetermined pressure-versus-time function, the pressure control means including venturi jet means receiving gas under substantially constant pressure, an outlet port for a stream of gas flowing in the venturi jet means to the ambient, a static port in fluid communication with said stream of gas to provide the input pressure signal, and means for regulating the flow rate of said stream of gas whereby the input pressure signal is regulated, the means for regulating including motor actuated means for interfering with the flow of the stream of gas in accordance with electric input signals received by the motor actuated means;
pressure transducer means for sensing the instantaneous pressure of the proximal gases, and for generating electric signals indicative of said instantaneous pressure of the proximal gases, andcomputer means for receiving the electric signals from the pressure transducer means, for providing the predetermined pressure-versus-time function, for comparing the value required by said function to the instantaneous pressure of the proximal gases sensed by the pressure transducer means, and for generating and sending a corrective electric signal to the motor actuated means to regulate the flow of the stream of gas to adjust the input pressure signal to a value required by the predetermined pressure-versus-time function.
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Accused Products
Abstract
A volume ventilator is disclosed which has a balloon valve type exhalation valve for permitting release of gases to the ambient environment during the exhalation period of artificial ventilation or spontaneous breathing, or when there is excess proximal pressure in the ventilator system. A pressure transducer continuously senses the proximal pressure in the ventilator system and sends to a microcomputer controller and associated circuitry of the ventilator system a signal indicative of the instantaneous proximal pressure. The pressure in the balloon, which is the pilot pressure of the exhalation valve, is regulated through a jet venturi type pressure controller which is connected to a source of pressurized gas. The gas flows through the jet venturi, wherein its flow rate is regulated by a ball valve moving against a suitable valve seat. The ball valve is controlled by a stepper motor through a cam follower. The stepper motor is controlled through electronic signals generated in the computer control in response to the difference between the instantaneously sensed proximal pressure, and the pilot pressure required to be present in the balloon in accordance with an algorithm or preselected pilot pressure-versus-time function. Accurate servo control of the flow of respiratory gas to the patient is accomplished by a flow control subsystem which incorporates a flow control valve controlled by a second stepper motor. The flow of the respiratory gas is monitored, downstream of the flow control valve, by a flow transducer. The flow transducer sends to the microcomputer controller a signal indicative of the instantaneous flow rate of the respiratory gas. The microcomputer controller compares the instantaneous flow rate to a flow rate value required by an algorithm or preselected flow rate-versus-time function stored in its memory. The microcomputer controller then sends a signal to the second stepper motor to adjust the flow control valve to provide the flow rate instantaneously required by the preselected function or algorithm.
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Citations
34 Claims
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1. A ventilator system for providing artificial ventilation to a patient, comprising:
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means for providing a pressure regulated source of respiratory gas; flow control means for controlling the rate of flow of said respiratory gas in accordance with a predetermined flow rate-versus-time function, the flow control means receiving the gas from said source and being in fluid communication with the patient for transmitting the gas to the patient; exhalation valve means in fluid communication with the patient and with the flow control means for providing an outlet to the ambient for the proximal gases of the patient, said proximal gases including respiratory gas made available for breathing of the patient and gases exhaled by the patient, the exhalation valve means receiving an input pressure signal and being adapted for closing said outlet to the ambient when the input pressure signal exceeds the pressure of the proximal gases; pressure control means operatively connected with the exhalation valve means for providing said input pressure signal in accordance with a predetermined pressure-versus-time function, the pressure control means including venturi jet means receiving gas under substantially constant pressure, an outlet port for a stream of gas flowing in the venturi jet means to the ambient, a static port in fluid communication with said stream of gas to provide the input pressure signal, and means for regulating the flow rate of said stream of gas whereby the input pressure signal is regulated, the means for regulating including motor actuated means for interfering with the flow of the stream of gas in accordance with electric input signals received by the motor actuated means; pressure transducer means for sensing the instantaneous pressure of the proximal gases, and for generating electric signals indicative of said instantaneous pressure of the proximal gases, and computer means for receiving the electric signals from the pressure transducer means, for providing the predetermined pressure-versus-time function, for comparing the value required by said function to the instantaneous pressure of the proximal gases sensed by the pressure transducer means, and for generating and sending a corrective electric signal to the motor actuated means to regulate the flow of the stream of gas to adjust the input pressure signal to a value required by the predetermined pressure-versus-time function. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A ventilator system for providing artificial ventilation to a patient, comprising:
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means for providing a pressure regulated source of respiratory gas; flow control means for controlling the flow rate of the respiratory gas in accordance with a predetermined flow rate-versus-time function, the flow control means including adjustable valve means through which the respiratory gas flows to the patient and a stepper motor having a rotatable shaft, an asymmetrical cam mounted to the shaft, and a cam follower mounted for linear movement in relation to the valve means and operating the valve means to control the flow rate, the stepper motor being responsive to a first electric signal; flow rate sensing and transducing means disposed downstream of the flow control means and in fluid communication therewith for sensing the flow rate of the respiratory gases and for generating a second electric signal indicative of the instantaneous flow rate of the respiratory gases; exhalation valve means being in fluid communication with the patient and with the flow control means for providing an outlet to the ambient for the proximal gases of the patient, said proximal gases including respiratory gas made available for breathing of the patient and gases exhaled by the patient, the exhalation valve means receiving an input pressure signal and being adapted for closing said outlet to the ambient when the input pressure signal exceeds the pressure of the proximal gases; pressure control means operatively connected with the exhalation valve for providing said input pressure signal in accordance with a predetermined pressure-versus-time function, and computer means for receiving the second electric signal from the flow rate sensing and transducing means, for storing the predetermined flow rate-versus-time function, for comparing the value required by said function to the second electric signal generated by the flow rate sensing and transducing means, and for generating and sending the first electric signal, responsive to the second electric signal, to the stepper motor to regulate the valve means to adjust the flow rate to an instantaneous value required by the predetermined flow rate-versus-time function. - View Dependent Claims (18, 19, 20, 21, 22, 23)
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24. In a ventilator system for providing artificial ventilation to a patient including a pressure regulated source of respiratory gas;
- flow control means for controlling the flow of the respiratory gas in accordance with a predetermined flow rate-versus-time function;
exhalation valve means in fluid communication with the flow of the respiratory gas and the patient for providing an outlet to the ambient for proximal gases of the patient, said proximal gases including the respiratory gas and the gases exhaled by the patient, and mixtures thereof, the exhalation valve means including means for receiving a pilot pressure and being adapted for closing the outlet to the ambient when the pilot pressure exceeds the instantaneous pressure of the proximal gases;
pressure control means operatively connected with the exhalation valve means for providing the pilot pressure in accordance with a predetermined pressure-versus-time function;
pressure transducer means for sensing the instantaneous pressure of the proximal gases and for generating a first electric signal indicative of said instantaneous pressure of the proximal gases, and computer means for receiving the first electric signal, for providing the predetermined pressure-versus-time function, for comparing the value required by the predetermined pressure-versus-time function to the instantaneous pressure of the proximal gases as indicated by the first electric signal, and for generating and sending a corrective second electric signal to the pressure control means to regulate the pilot pressure generated by the pressure control means, the improvement comprising;means for providing a source of pressurized gas in addition to the respiratory gases provided for the patient; venturi jet means included in the pressure control means for receiving the pressurized gas and having an outlet port to the ambient whereby a stream of gas flows through the venturi jet means, the venturi jet means further including a static pressure port wherefrom the pilot pressure for the exhalation valve means is tapped, and adjustable valve means included in the venturi jet means for regulating the stream of gas to the ambient whereby the pilot pressure is regulated, the adjustable valve means being controlled by the corrective electric signal generated by the computer means. - View Dependent Claims (25, 26, 27, 28, 29)
- flow control means for controlling the flow of the respiratory gas in accordance with a predetermined flow rate-versus-time function;
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30. In a ventilator system for providing artificial ventilation to a patient including a pressure regulated source of respiratory gas;
- flow control means for controlling the flow of the respiratory gas to the patient in accordance with a predetermined flow rate-versus-time function;
flow sensing and transducer means for measuring the flow rate of the respiratory gas downstream of the flow control means and for generating a first electric signal indicative of said flow rate;
exhalation valve means in fluid communication with the flow of the respiratory gas and with the patient for providing an outlet to the ambient to proximal gases of the patient;
pressure control means operatively connected with the exhalation valve means for controlling the exhalation valve means to maintain the proximal pressure in accordance with a predetermined pressure-versus-time function; and
computer means for receiving the first electric signal, for providing the predetermined flow rate-versus-time function, for comparing the value required by the predetermined flow rate-versus-time function to the instantaneous flow rate as indicated by the first electric signal, and for generating and sending a corrective second electric signal to the flow control means to regulate the flow control means, the improvement comprising;a stepper motor included in the flow control means and having a rotatable shaft, an asymmetric cam mounted to the rotatable shaft and a cam follower operatively mounted to follow the cam in a substantially linear motion, the stepper motor being controlled by the corrective second electric signal, and an adjustable flow control valve included in the flow control means and having an orifice interfacing with a valve body which is connected to the cam follower, whereby the stepper motor controls the flow rate. - View Dependent Claims (31, 32, 33, 34)
- flow control means for controlling the flow of the respiratory gas to the patient in accordance with a predetermined flow rate-versus-time function;
Specification