WO1993008858A1 - Gated programmable ventilator - Google Patents

Gated programmable ventilator Download PDF

Info

Publication number
WO1993008858A1
WO1993008858A1 PCT/US1992/009132 US9209132W WO9308858A1 WO 1993008858 A1 WO1993008858 A1 WO 1993008858A1 US 9209132 W US9209132 W US 9209132W WO 9308858 A1 WO9308858 A1 WO 9308858A1
Authority
WO
WIPO (PCT)
Prior art keywords
flow rate
signal
ventilator
fluid
control signal
Prior art date
Application number
PCT/US1992/009132
Other languages
French (fr)
Inventor
Eric A. Hoffman
C. William Hanson, Iii
Charles F. Ward, Iii
Original Assignee
The Trustees Of The University Of Pennsylvania
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by The Trustees Of The University Of Pennsylvania filed Critical The Trustees Of The University Of Pennsylvania
Publication of WO1993008858A1 publication Critical patent/WO1993008858A1/en

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/0003Accessories therefor, e.g. sensors, vibrators, negative pressure
    • A61M16/0009Accessories therefor, e.g. sensors, vibrators, negative pressure with sub-atmospheric pressure, e.g. during expiration
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/021Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes operated by electrical means
    • A61M16/022Control means therefor
    • A61M16/024Control means therefor including calculation means, e.g. using a processor
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/10Location thereof with respect to the patient's body
    • A61M60/122Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body
    • A61M60/165Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body implantable in, on, or around the heart
    • A61M60/191Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body implantable in, on, or around the heart mechanically acting upon the outside of the patient's native heart, e.g. compressive structures placed around the heart
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/20Type thereof
    • A61M60/289Devices for mechanical circulatory actuation assisting the residual heart function by means mechanically acting upon the patient's native heart or blood vessel structure, e.g. direct cardiac compression [DCC] devices
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/50Details relating to control
    • A61M60/508Electronic control means, e.g. for feedback regulation
    • A61M60/515Regulation using real-time patient data
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/50Details relating to control
    • A61M60/585User interfaces
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/0003Accessories therefor, e.g. sensors, vibrators, negative pressure
    • A61M2016/003Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter
    • A61M2016/0033Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter electrical
    • A61M2016/0036Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter electrical in the breathing tube and used in both inspiratory and expiratory phase
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2230/00Measuring parameters of the user
    • A61M2230/04Heartbeat characteristics, e.g. ECG, blood pressure modulation

Definitions

  • the present invention relates generally to the field of cardio-pulmonary physiology and particularly to methods and apparatus for augmenting cardiac output.
  • a recurrent problem in the medical and surgical intensive care field is the patient with coextensive respiratory and cardiac failure. Patients exhibiting this condition are typically treated through the use of positive pressure ventilation techniques, such as standard volume cycled ventilation, inotropic infusions and not infrequently with mechanical cardiac assist devices such as the intra-aortic balloon pump (IABP) or the ventricular assist device (VAD) .
  • positive pressure ventilation techniques such as standard volume cycled ventilation, inotropic infusions and not infrequently with mechanical cardiac assist devices such as the intra-aortic balloon pump (IABP) or the ventricular assist device (VAD) .
  • IABP intra-aortic balloon pump
  • VAD ventricular assist device
  • inotropic infusions have inherent risks and benefits. While they may improve perfusion, i.e. the movement of fluids, through cardiac and cerebral circulation systems, there may be detrimental effects to perfusion in pulmonary and splanchnic circulation systems.
  • IABP provides cardiac assistance based on the principal of cardiac cycle-specific changes in the volume and pressure of the proximal aorta through the use of an intra-aortic balloon.
  • cardiac afterload is decreased during systole, i.e. ejection of fluid from the heart, by deflating the balloon.
  • Cardiac afterload is that parameter indicative of volume and pressure of the proximal aorta.
  • Deflation of the balloon enhances so-called stroke volume - forward blood flow.
  • Cardiac afterload is increased during diastole, i.e. filling of the heart, by inflating the balloon, thereby enhancing coronary perfusion.
  • cardiac cycle-specific non- invasive changes in intra-thoracic pressure are used to effectuate changes on ventricular preload and afterload and by direct mechanical action on the myocardium to improve cardiac performance.
  • Studies relating to changes in intra-thoracic pressure have been carried out. See M.R. Pinsky et al. , Determinants of cardiac augmentation by elevations in intrathoracic pressure. Journal of Applied Physiology, Vol. 58 (4) r PS. 1189-1198 (1985) and M.R. Pinsky et al. , Hemodynamic*> effects of cardiac cycle-specific increases in intrathoracic pressure. Journal of Applied Physiology, Vol. 60 (2), pps. 604- 612 (19S6) .
  • the objects and advantages of the invention are achieved in a ventilator for ventilating the lungs of a patient.
  • the ventilator is described as including a valve member connected to a fluid source and to the patient.
  • the valve member controls the flow of fluid to the patient in response to a control signal.
  • a programmable controller connected to the valve member, generates the control signal for the valve member.
  • the programmable controller includes a memory in which fluid flow rate information has been stored and a microprocessor. The controller is operative to determine a desired fluid flow rate in relation to the flow rate information and for generating the control signal in relation to the flow rate signal.
  • the valve member includes a plurality of first and second valves, wherein each of the second valves are operative to allow fluid to pass therethrough at flow rates which are multiples of a master flow rate. It is especially preferred for the multiple for each second valve to be equal to the value 2 , where M is an integer from zero to one less than the number of second valves. It is further preferred for the first valve to be a solenoid valve and the second valve to be a needle valve.
  • the memory further has stored therein pressure information it is desireable to include a first monitor for generating a heart signal representative of heart action, a second monitor for generating a flow rate signal representative of the rate of flow of fluid into and out of the lungs and a third monitor for generating a pressure signal representative of the air pressure in the lungs.
  • the controller it is preferred for the controller to be connected to receive the heart signal, the flow rate signal and the pressure signal, and for the control signal to be generated in response to such signals.
  • Fig. 1 is a diagrammatic view of a cardiac augmentation device constructed in accordance with the principles of the present invention
  • Fig. 2 is a more detailed diagram of the ECG gating portion of the invention shown in Fig. 1;
  • Fig. 3 is a more detailed diagram of the valves and sensors shown in Fig. l;
  • Fig. 4 is a more detailed diagram of the manifold shown in Fig. 1. Detailed Description of the Preferred Embodiment
  • FIG. 1 A new and novel cardiac augmentation device is shown in Fig. 1 and generally designated 10.
  • Device 10 is shown to include an ECG monitor 12 for generating a heart signal representative of heart action.
  • monitor 12 includes a plurality of leads
  • the electrical signals provided on such leads are utilized in a known manner to produce an electrocardiogram signal.
  • the heart or electrocardiogram signal is provided to controller 16.
  • Sensors 17 can include any known devices for generating electrical signals representative of flow rate and pressure conditions.
  • sensors 17 would be attached to such a tube in order to monitor pressure and flow rate during inspiration and expiration.
  • Controller 16 monitors the heart signal, the flow rate signal and the pressure signal and generates a control signal
  • control signal 20 in response to the heart signal being representative of a desired point in the pumping cycle and the flow rate and pressure are at desired levels.
  • the control signal is provided to manifold 18.
  • the control signal is representative of a calculated or programed desired air
  • controller 16 It is preferred for controller 16 to incorporate a computer printed circuit board based on the Hitachi 64180 microprocessor.
  • Manifold 18 is connected to a source of pressurized air P and to a vacuum source V. As will be more fully
  • manifold 18 will switch between pressure and vacuum sources depending on whether controller 16 is controlling
  • valves 19 are operative to permit expiration without passing such expired air through manifold 18, i.e. permit expiration without a vacuum assist.
  • controller 16 and manifold 18 constitute the primary components of a respirator, which in the preferred embodiment is of the type designed for attachment to an endotracheal tube.
  • the present invention can be practiced with any known and available respirator design which causes ventilation of the lungs in response to a control or an enabling signal.
  • an enabling signal By applying an enabling signal to a respirator, the respirator is caused to be operative, i.e., to begin inspiration, upon receipt of the enabling signal. It has been found that by gating the respirator, i.e. controlling manifold 18, to a particular point in the pumping cycle and to flow rate and pressure conditions, blood pumped from the heart is assisted by ventilation of the lungs.
  • flow rate and pressure signals generated by sensors 17 at the endotracheal tube site may also be generated by respirator 18 in relation to air flow rates and pressures applied to the patient.
  • respirator 18 The generation of such signals in the respirator would provide an open loop control system rather than the closed loop system depicted in Fig. 1.
  • controller 16 and manifold 18 are the primary components of a CTP-9000 programmable ventilator system manufactured and sold by CWE Inc. of Ardmore, Pennsylvania. Although such ventilator is preferred, any ventilator wherein inspiration can be initiated by means of an enabling or control signal with high frequency response can be utilized. It is especially preferred for the chosen respirator to have the capability of programmable respiratory cycles and to exhibit quick response to programmed variation of respiratory parameters.
  • controller 16 can be hosted by a master controller, preferably a personal computer for communicating pressure and vacuum profiles to the microprocessor. Consequently, the flow rate and pressure of air inspired to and expired from the lungs can be controlled from a personal computer having a serial port. Using such a system.
  • respirator 18 for the present invention by setting flow rate, pressure, inspiration time and expiration time. Upon receipt of the control signal, the programmable respirator will initiate inspiration. In such a system, it is possible and preferred to designate certain function keys on a personal computer to effectuate changes in flow rate or inspiration time. It is also preferred to program respirator 18 to cause inspiration for a fixed time period or to cause inspiration to reach a desired pressure level.
  • the ECG signal generated by monitor 12 includes a QRS portion. A distinct voltage peak is present in this portion. By sensing the voltage of the ECG signal, it is possible to detect the QRS peak and thereby synchronize the generation of a control or enabling signal in relation to the detection of the peak. To this end, one embodiment of the invention envisions the usage of threshold detector 20 as shown in Fig. 2.
  • Detector 20 is depicted as including an operational amplifier, arranged as a comparator, having its negative input connected to a reference voltage and its positive input connected to receive the ECG signal from monitor 12.
  • the reference signal is generated by the connection of variable resistor 24 between a supply voltage V s and ground. It is noted that as the ECG voltage approaches the reference voltage, the output of operational amplifier 22 will change from a logic high to a logic low.
  • the logic high output of operational amplifier 22 is provided by resistor 26 connected to supply voltage V s . When ECG voltage is less than the reference voltage, current passing through 26 is directed to ground through operational amplifier 22. When ECG voltage exceeds the reference voltage, the current passing through resistor 26 is applied to delay circuit 28.
  • delay circuit 28 alternates between a logic high and logic low level depending on the voltage of the ECG signal.
  • delay circuit 28 is of any known design capable of providing a time delay.
  • Delay circuit 28 also includes circuitry for indicating flow rate and pressure. Such circuitry can include threshold detectors identical to detector 20, wherein the reference voltage is selected to detect a given level of pressure or flow rate. It is especially preferred that such time delay be variable. If multiple detectors are included, such time delay can be event based, i.e. the control signal would be delayed until each detector detects desired conditions. In such a situation, the outputs of the detectors could be provided as inputs to an AND gate. If the flow rate and pressure detectors are constructed to provide visual indications of flow rate and pressure to an operator, delay circuit 28 would be constructed to provide a variable timing control, e.g. a variable resistor connected with a capacitor to provide a variable time constant circuit.
  • variable delay By providing a variable delay, one can make whatever fine adjustments are necessary in order to ensure that the enabling signal provided by respirator 18 initiates inspiration sa as to enhance cardiac output. It will be appreciated that there may be some delay in respirator 18 processing the enabling signal and initiating the inspiration cycle. A variable delay could be adjusted to account for such respirator delay.
  • Pressure transducer 30 is connected to the line connecting flow transducer 32 and the endotracheal tube previously mentioned. Transducer 30 generates an electrical signal representative of the air pressure present in -the endotracheal tube and thus in the lungs. Similarly, transducer 32 generates an electrical signal representative of the flow rate of fluid passing to or from the endotracheal tube. Transducers 30 and 32 can be any transducer which will provide an electrical signal of pressure and flow, respectively. Such electrical signals are provided to controller 16. Valves 34 and 36 are provided so that expiration and possibly inspiration can occur without the vacuum or pressure assist provided via manifold 18.
  • valve 34 is closed and valve 36 is open, inspiration and expiration will occur via manifold 18. If valve 36 is closed and valve 34 is open, expiration and inspiration can occur without the assist provided via manifold 18. Although no particular valve is required for purposes of the invention, it is preferred to utilize valves which are electrically actuatable. As shown in Fig. 3, valves 34 and 36 are actuatable in response to signals from controller 16.
  • the capability to program respiratory cycles is achieved through the use of a series of solenoid valves 40, 42, 44 and 46 and needle valves 50, 52, 54 and 56.
  • the actuation signal used to control the solenoid valves is computer generated. It will be appreciated that the solenoid valves require a digital type signal, i.e. ON or OFF. Such a signal is generated by controller 16 generating a digital word which is M bits in length. The word is preferably stored in an M bit latch (not shown) while in use. The signal associated with each bit is provided to a different solenoid valve. The state of each valve, i.e. opened or closed, will depend on the value of the bit provided a given valve. In the preferred embodiment M is equal to 8.
  • Needle valves 50-56 are pre-set such that only a portion or the pressure or vacuum value is permitted to act therethrough.
  • each needle valve is pre-set to permit flow rate or vacuum equal to a multiple of N, where N equals 0.1 liters/minute. Accordingly, if the digital word provided by controller 16 to the solenoid valves is 00000001, only 0.1 liters/minute of either vacuum or pressure will act through manifold 18. By utilizing multiples of N, manifold 18 can permit any pressure or vacuum value to be applied to a patient in 0.1 liters/minute steps, by manipulating the ON/OFF state of the solenoid valves.
  • Valves 60 and 62 serve to control whether pressure or vacuum is applied to the solenoid valves and thereby to the patient. Valves 60 and 62 are also solenoid type valves responsive to an ON/OFF type signal. As shown in Fig. 3, such signals are provided by controller 16. From the above, it will be appreciated that controller 16 can control both inspiration and expiration of the patient in steps as small as 0.1 liters/minute. Accordingly, the intricacy of a pressure or vacuum profile is limited by only the ability to generate digital words, for bit wise provision to solenoid valves 40-46 and by the response time associated with the particular solenoid valves used.
  • the threshold detector be arranged, i.e., the reference voltage be selected, such that the detector detects a particular point during ventricular contraction. It will be noted skilled persons may conclude that initiating inspiration during certain phases may cause air to be trapped in the lungs. However, it has been found that by utilizing the present invention one can balance trapped air and augmented blood flow. In other words, the benefit obtained by augmenting blood low can be made greater than the detriment of having a small amount of air trapped in the lungs. Such a balancing is achieved by monitoring flow rate and pressure. The trapping of too great a volume of air in the lungs will result in significant increases in pressure. By utilizing the present invention to vary the provision of the control signal to the respirator, pressure can be maintained at acceptable levels, thus minimizing the amount of air trapped in the lungs.
  • the respirator is programmable so as to allow for adjustment of total volume, ECG phase delay, peak airway pressure, expiratory time, expiratory negative pressure assist as examples.
  • the cardiac gated ventilation can be tailored for patients with respiratory failure, rib cage abnormalities, variable lung compliance, etc. Programmed for high frequency ventilation, it may be desirable to superimpose inspiration pulses during the ventilation of the lungs. In such a situation, the enabling signal generated by controller 16 would be utilized to initiate such pulses in respirator. Consequently, the present invention is particularly useful as a method for treating coextensive respiratory and cardiac failure. It will be noted that while the present invention is useful for treating coextensive failure, i.e. an extremely failing heart, the present invention is also useful in augmenting blood flow in a normal heart. In other words, the present invention can be used to augment blood flow in a case of respiratory failure.

Abstract

A ventilator for ventilating the lungs of a patient including a valve member connected to a fluid source and to the patient. The valve member controls the flow of fluid to the patient in response to a control signal. A programmable controller, connected to the valve member, generates the control signal for the valve member. The programmable controller includes a memory in which fluid flow rate information has been stored and a microprocessor. The controller is operative to determine a desired fluid flow rate in relation to the flow rate information and for generating the control signal in relation to the flow rate signal. In a preferred embodiment the valve member includes a plurality of first (40, 42, 44, 46) and second (50, 52, 54, 56) valves, wherein each of the second valves (50, 52, 54, 56) are operative to allow fluid to pass therethrough at flow rates which are multiples of a master flow rate.

Description

GATED PROGRAMMABLE VENTILATOR
Field of the Invention
The present invention relates generally to the field of cardio-pulmonary physiology and particularly to methods and apparatus for augmenting cardiac output.
The research disclosed in this patent application was supported in part by National Institutes of Health. The United States government has certain rights in the invention. Background of the Invention A recurrent problem in the medical and surgical intensive care field is the patient with coextensive respiratory and cardiac failure. Patients exhibiting this condition are typically treated through the use of positive pressure ventilation techniques, such as standard volume cycled ventilation, inotropic infusions and not infrequently with mechanical cardiac assist devices such as the intra-aortic balloon pump (IABP) or the ventricular assist device (VAD) .
It will be appreciated that inotropic infusions have inherent risks and benefits. While they may improve perfusion, i.e. the movement of fluids, through cardiac and cerebral circulation systems, there may be detrimental effects to perfusion in pulmonary and splanchnic circulation systems.
Unfortunately, devices such as the IABP or VAD necessitate intravascular placement of a foreign body, i.e. surgical implantation, with the attendant risk of infection or vascular injury. Additionally, IABP provides cardiac assistance based on the principal of cardiac cycle-specific changes in the volume and pressure of the proximal aorta through the use of an intra-aortic balloon. When implementing IABP, cardiac afterload is decreased during systole, i.e. ejection of fluid from the heart, by deflating the balloon. Cardiac afterload is that parameter indicative of volume and pressure of the proximal aorta. Deflation of the balloon enhances so-called stroke volume - forward blood flow. Cardiac afterload is increased during diastole, i.e. filling of the heart, by inflating the balloon, thereby enhancing coronary perfusion.
In the present invention, cardiac cycle-specific non- invasive changes in intra-thoracic pressure are used to effectuate changes on ventricular preload and afterload and by direct mechanical action on the myocardium to improve cardiac performance. Studies relating to changes in intra-thoracic pressure have been carried out. See M.R. Pinsky et al. , Determinants of cardiac augmentation by elevations in intrathoracic pressure. Journal of Applied Physiology, Vol. 58 (4) r PS. 1189-1198 (1985) and M.R. Pinsky et al. , Hemodynamic*> effects of cardiac cycle-specific increases in intrathoracic pressure. Journal of Applied Physiology, Vol. 60 (2), pps. 604- 612 (19S6) . However, such studies on laboratory specimens, particularly mongrel dogs, have found that absent the use of constrictive devices such as thoracoabdominal binding, inspiratory jet pulses from a high frequency jet ventilator had minimal hemodynamic effects as evidenced by small changes in pleural pressure. Furthermore, the authors were only able to demonstrate an effect on the failing heart, not on the normally functioning heart. One of the problems associated with these studies is that the thorax of the subject specimens had to be opened and several monitoring devices implanted. Furthermore, these studies concentrated only on the effect of cardiac gated respiration on the heart. It did not evaluate the effect of this modality on ventilation/perfusion relationships in the lungs.
Unfortunately, the unique interactions between the heart and lungs in the negative-pressure environment of the intact thorax have been difficult to study quantitatively.
Consequently, these unique interactions have been studied only on a limited basis via non-invasive techniques. Developments in recent years to three-dimensional imaging have gone a long way toward providing satisfactory techniques to non-invasively assess intrathoracic organ geometry and function. An ultra-fast X-ray computed tomography (CT) scanner has been produced by Imatron Corporation which is capable of acquiring two (2) slices of the body every 50 ms. By combining such a CT scanner together with equipment to focus the scanner on particular physiologic conditions, non-invasive data relating to precise physiologic conditions can be gathered. When such data is interrogated utilizing new software packages, post analysis of the 4-dimensional data sets can be achieved. One such package is the VIDA™ imaging software developed at the Cardiac Imaging Research Center, Department of Radiology at the Hospital of the University of Pennsylvania. Utilizing such equipment, non-invasive studies of the thorax are possible which may prove beneficial to patients experiencing either cardiac failure alone, respiratory failure alone or a combination of cardiac and respiratory failure. A need exists for apparatus and/or methods for treating cardiac and/or respiratory failure which apparatus and methods are non-invasive in relation to the thorax, whereby cardiac and/or respiratory function are not diminished in the process of augmenting one system or the other. Summary of the Invention
The objects and advantages of the invention are achieved in a ventilator for ventilating the lungs of a patient. The ventilator is described as including a valve member connected to a fluid source and to the patient. The valve member controls the flow of fluid to the patient in response to a control signal. A programmable controller, connected to the valve member, generates the control signal for the valve member. The programmable controller includes a memory in which fluid flow rate information has been stored and a microprocessor. The controller is operative to determine a desired fluid flow rate in relation to the flow rate information and for generating the control signal in relation to the flow rate signal. In a preferred embodiment the valve member includes a plurality of first and second valves, wherein each of the second valves are operative to allow fluid to pass therethrough at flow rates which are multiples of a master flow rate. It is especially preferred for the multiple for each second valve to be equal to the value 2 , where M is an integer from zero to one less than the number of second valves. It is further preferred for the first valve to be a solenoid valve and the second valve to be a needle valve. If the memory further has stored therein pressure information it is desireable to include a first monitor for generating a heart signal representative of heart action, a second monitor for generating a flow rate signal representative of the rate of flow of fluid into and out of the lungs and a third monitor for generating a pressure signal representative of the air pressure in the lungs. In such a situation it is preferred for the controller to be connected to receive the heart signal, the flow rate signal and the pressure signal, and for the control signal to be generated in response to such signals. Brief Description of the Drawings
The present invention will be better understood, and its numerous objects and advantages will become apparent to those skilled in the art by reference to the following detailed description of the invention when taken in conjunction with the following drawings, in which:
Fig. 1 is a diagrammatic view of a cardiac augmentation device constructed in accordance with the principles of the present invention;
Fig. 2 is a more detailed diagram of the ECG gating portion of the invention shown in Fig. 1;
Fig. 3 is a more detailed diagram of the valves and sensors shown in Fig. l; and
Fig. 4 is a more detailed diagram of the manifold shown in Fig. 1. Detailed Description of the Preferred Embodiment
A new and novel cardiac augmentation device is shown in Fig. 1 and generally designated 10. Device 10 is shown to include an ECG monitor 12 for generating a heart signal representative of heart action. As will be appreciated, monitor 12 includes a plurality of leads
14 which are connected at various known locations to a patient.
5 The electrical signals provided on such leads are utilized in a known manner to produce an electrocardiogram signal. The heart or electrocardiogram signal is provided to controller 16.
Signals representative of the air flow rate into the lungs and the pressure of air flowing into or out of the lungs are
10 generated by sensors 17. Sensors 17 can include any known devices for generating electrical signals representative of flow rate and pressure conditions.
It is noted that the present invention is described in relation to the use of an endotracheal tube (not shown)
15 inserted in the patient. In operation, sensors 17 would be attached to such a tube in order to monitor pressure and flow rate during inspiration and expiration.
Controller 16 monitors the heart signal, the flow rate signal and the pressure signal and generates a control signal
20 in response to the heart signal being representative of a desired point in the pumping cycle and the flow rate and pressure are at desired levels. The control signal is provided to manifold 18. In the preferred embodiment the control signal is representative of a calculated or programed desired air
25 pressure for either inspiration or expiration. Such calculations and programming will be described more fully hereinafter. It is preferred for controller 16 to incorporate a computer printed circuit board based on the Hitachi 64180 microprocessor.
30 Manifold 18 is connected to a source of pressurized air P and to a vacuum source V. As will be more fully
-"j described, manifold 18 will switch between pressure and vacuum sources depending on whether controller 16 is controlling
«• inspiration or expiration. The output of manifold 18 is also
35 connected to valves 19. As will be described in relation to Fig. 3, valves 19 are operative to permit expiration without passing such expired air through manifold 18, i.e. permit expiration without a vacuum assist.
It will be appreciated that controller 16 and manifold 18 constitute the primary components of a respirator, which in the preferred embodiment is of the type designed for attachment to an endotracheal tube. The present invention can be practiced with any known and available respirator design which causes ventilation of the lungs in response to a control or an enabling signal. By applying an enabling signal to a respirator, the respirator is caused to be operative, i.e., to begin inspiration, upon receipt of the enabling signal. It has been found that by gating the respirator, i.e. controlling manifold 18, to a particular point in the pumping cycle and to flow rate and pressure conditions, blood pumped from the heart is assisted by ventilation of the lungs.
It is noted that the flow rate and pressure signals generated by sensors 17 at the endotracheal tube site may also be generated by respirator 18 in relation to air flow rates and pressures applied to the patient. The generation of such signals in the respirator would provide an open loop control system rather than the closed loop system depicted in Fig. 1.
In the preferred embodiment, controller 16 and manifold 18 are the primary components of a CTP-9000 programmable ventilator system manufactured and sold by CWE Inc. of Ardmore, Pennsylvania. Although such ventilator is preferred, any ventilator wherein inspiration can be initiated by means of an enabling or control signal with high frequency response can be utilized. It is especially preferred for the chosen respirator to have the capability of programmable respiratory cycles and to exhibit quick response to programmed variation of respiratory parameters. In the preferred embodiment, controller 16 can be hosted by a master controller, preferably a personal computer for communicating pressure and vacuum profiles to the microprocessor. Consequently, the flow rate and pressure of air inspired to and expired from the lungs can be controlled from a personal computer having a serial port. Using such a system. one can program respirator 18 for the present invention by setting flow rate, pressure, inspiration time and expiration time. Upon receipt of the control signal, the programmable respirator will initiate inspiration. In such a system, it is possible and preferred to designate certain function keys on a personal computer to effectuate changes in flow rate or inspiration time. It is also preferred to program respirator 18 to cause inspiration for a fixed time period or to cause inspiration to reach a desired pressure level. It will be understood that the ECG signal generated by monitor 12 includes a QRS portion. A distinct voltage peak is present in this portion. By sensing the voltage of the ECG signal, it is possible to detect the QRS peak and thereby synchronize the generation of a control or enabling signal in relation to the detection of the peak. To this end, one embodiment of the invention envisions the usage of threshold detector 20 as shown in Fig. 2.
Detector 20 is depicted as including an operational amplifier, arranged as a comparator, having its negative input connected to a reference voltage and its positive input connected to receive the ECG signal from monitor 12. The reference signal is generated by the connection of variable resistor 24 between a supply voltage Vs and ground. It is noted that as the ECG voltage approaches the reference voltage, the output of operational amplifier 22 will change from a logic high to a logic low. The logic high output of operational amplifier 22 is provided by resistor 26 connected to supply voltage Vs. When ECG voltage is less than the reference voltage, current passing through 26 is directed to ground through operational amplifier 22. When ECG voltage exceeds the reference voltage, the current passing through resistor 26 is applied to delay circuit 28. In other words, the input to delay circuit 28 alternates between a logic high and logic low level depending on the voltage of the ECG signal. In the preferred embodiment, delay circuit 28 is of any known design capable of providing a time delay. Delay circuit 28 also includes circuitry for indicating flow rate and pressure. Such circuitry can include threshold detectors identical to detector 20, wherein the reference voltage is selected to detect a given level of pressure or flow rate. It is especially preferred that such time delay be variable. If multiple detectors are included, such time delay can be event based, i.e. the control signal would be delayed until each detector detects desired conditions. In such a situation, the outputs of the detectors could be provided as inputs to an AND gate. If the flow rate and pressure detectors are constructed to provide visual indications of flow rate and pressure to an operator, delay circuit 28 would be constructed to provide a variable timing control, e.g. a variable resistor connected with a capacitor to provide a variable time constant circuit.
By providing a variable delay, one can make whatever fine adjustments are necessary in order to ensure that the enabling signal provided by respirator 18 initiates inspiration sa as to enhance cardiac output. It will be appreciated that there may be some delay in respirator 18 processing the enabling signal and initiating the inspiration cycle. A variable delay could be adjusted to account for such respirator delay.
Referring now to Fig. 3, sensors 17 and valves 19 will be described in greater detail. Pressure transducer 30 is connected to the line connecting flow transducer 32 and the endotracheal tube previously mentioned. Transducer 30 generates an electrical signal representative of the air pressure present in -the endotracheal tube and thus in the lungs. Similarly, transducer 32 generates an electrical signal representative of the flow rate of fluid passing to or from the endotracheal tube. Transducers 30 and 32 can be any transducer which will provide an electrical signal of pressure and flow, respectively. Such electrical signals are provided to controller 16. Valves 34 and 36 are provided so that expiration and possibly inspiration can occur without the vacuum or pressure assist provided via manifold 18. As will be appreciated, if valve 34 is closed and valve 36 is open, inspiration and expiration will occur via manifold 18. If valve 36 is closed and valve 34 is open, expiration and inspiration can occur without the assist provided via manifold 18. Although no particular valve is required for purposes of the invention, it is preferred to utilize valves which are electrically actuatable. As shown in Fig. 3, valves 34 and 36 are actuatable in response to signals from controller 16.
In the CTP-9000 the capability to program respiratory cycles is achieved through the use of a series of solenoid valves 40, 42, 44 and 46 and needle valves 50, 52, 54 and 56. The actuation signal used to control the solenoid valves is computer generated. It will be appreciated that the solenoid valves require a digital type signal, i.e. ON or OFF. Such a signal is generated by controller 16 generating a digital word which is M bits in length. The word is preferably stored in an M bit latch (not shown) while in use. The signal associated with each bit is provided to a different solenoid valve. The state of each valve, i.e. opened or closed, will depend on the value of the bit provided a given valve. In the preferred embodiment M is equal to 8.
Needle valves 50-56 are pre-set such that only a portion or the pressure or vacuum value is permitted to act therethrough. In the preferred embodiment each needle valve is pre-set to permit flow rate or vacuum equal to a multiple of N, where N equals 0.1 liters/minute. Accordingly, if the digital word provided by controller 16 to the solenoid valves is 00000001, only 0.1 liters/minute of either vacuum or pressure will act through manifold 18. By utilizing multiples of N, manifold 18 can permit any pressure or vacuum value to be applied to a patient in 0.1 liters/minute steps, by manipulating the ON/OFF state of the solenoid valves.
Valves 60 and 62 serve to control whether pressure or vacuum is applied to the solenoid valves and thereby to the patient. Valves 60 and 62 are also solenoid type valves responsive to an ON/OFF type signal. As shown in Fig. 3, such signals are provided by controller 16. From the above, it will be appreciated that controller 16 can control both inspiration and expiration of the patient in steps as small as 0.1 liters/minute. Accordingly, the intricacy of a pressure or vacuum profile is limited by only the ability to generate digital words, for bit wise provision to solenoid valves 40-46 and by the response time associated with the particular solenoid valves used.
It is particularly preferred to initiate inspiration at the beginning of the contraction of the left ventricle. Since such contraction can be determined from the electrocardiogram signal, it is preferred that the threshold detector be arranged, i.e., the reference voltage be selected, such that the detector detects a particular point during ventricular contraction. It will be noted skilled persons may conclude that initiating inspiration during certain phases may cause air to be trapped in the lungs. However, it has been found that by utilizing the present invention one can balance trapped air and augmented blood flow. In other words, the benefit obtained by augmenting blood low can be made greater than the detriment of having a small amount of air trapped in the lungs. Such a balancing is achieved by monitoring flow rate and pressure. The trapping of too great a volume of air in the lungs will result in significant increases in pressure. By utilizing the present invention to vary the provision of the control signal to the respirator, pressure can be maintained at acceptable levels, thus minimizing the amount of air trapped in the lungs.
In the preferred embodiment, the respirator is programmable so as to allow for adjustment of total volume, ECG phase delay, peak airway pressure, expiratory time, expiratory negative pressure assist as examples. In this regard, the cardiac gated ventilation can be tailored for patients with respiratory failure, rib cage abnormalities, variable lung compliance, etc. Programmed for high frequency ventilation, it may be desirable to superimpose inspiration pulses during the ventilation of the lungs. In such a situation, the enabling signal generated by controller 16 would be utilized to initiate such pulses in respirator. Consequently, the present invention is particularly useful as a method for treating coextensive respiratory and cardiac failure. It will be noted that while the present invention is useful for treating coextensive failure, i.e. an extremely failing heart, the present invention is also useful in augmenting blood flow in a normal heart. In other words, the present invention can be used to augment blood flow in a case of respiratory failure.
While the invention has been described and illustrated with reference to specific embodiments, those skilled in the art will recognize that modification and variations may be made without departing from the principles of the invention as described herein above and set forth in the following claims.

Claims

ClaimsWhat is claimed is:
1. A ventilator for ventilating the lungs of a patient with a fluid from a source of pressurized fluid, comprising: valve means, adaptable for connection to said source and to said patient, for controlling the flow of said fluid therethrough in response to a control signal; and a programmable controller, connected to said valve means, for generating said control signal, said programmable controller comprising a memory in which fluid flow rate information has been stored and a microprocessor connected to said memory, said controller being operative for determining a desired flow rate of said fluid in relation to said flow rate information and for generating said control signal in relation to said flow rate.
2. The ventilator of claim 1, wherein said control signal is a digital word of M bits in length.
3. The ventilator of claim 2, wherein M is equal to 8.
4. The ventilator of claim 1, wherein said memory further has stored therein pressure information, further comprising: a first monitor for generating a heart signal representative of the action of the heart of said patient; a second monitor for generating a flow rate signal representative of the rate of flow of fluid into and out of said lungs; a third monitor for generating a pressure signal representative of the air pressure in said lungs; wherein said controller is connected to receive said heart signal, said flow rate signal and said pressure signal, and wherein said control signal is generated in response to said heart signal, said flow rate signal and said pressure signal.
5. The ventilator of claim 1, wherein said valve means comprises a first valve connected to said source and operative to open and close in response to said control signal and a second valve connected to said first valve and to said patient and operative to allow said fluid to pass therethrough at a fixed flow rate.
6. The ventilator of claim 5, further comprising a plurality of said first and second valves, wherein each of said second valves are operative to allow said fluid to pass therethrough at flow rates which are multiples of a master flow rate.
7. The ventilator of claim 6, wherein each of said multiples are equal to the value 2M, where M is an integer from zero to one less than the number of said second valves.
8. The ventilator of claim 7, wherein said master flow rate equals 0.1 liters/minute.
9. The ventilator of claim 5, wherein said first valve is a solenoid valve and said second valve is a needle valve.
10. The ventilator of claim 1, further comprising a monitor for generating a flow rate signal representative of the fluid flow into said lungs during inspiration, wherein said flow rate information stored in said memory comprises a reference value and wherein said microprocessor compares said flow rate signal to said reference value and adjusts said control signal when said flow rate signal exceeds said reference value.
11. The ventilator of claim 1, wherein said control signal is generated such that inspiration pulses are superimposed during ventilation.
PCT/US1992/009132 1991-11-04 1992-10-28 Gated programmable ventilator WO1993008858A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US07/787,510 US5183038A (en) 1991-11-04 1991-11-04 Gated programmable ventilator
US787,510 1991-11-04

Publications (1)

Publication Number Publication Date
WO1993008858A1 true WO1993008858A1 (en) 1993-05-13

Family

ID=25141729

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1992/009132 WO1993008858A1 (en) 1991-11-04 1992-10-28 Gated programmable ventilator

Country Status (3)

Country Link
US (1) US5183038A (en)
AU (1) AU2910292A (en)
WO (1) WO1993008858A1 (en)

Families Citing this family (49)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5239995A (en) * 1989-09-22 1993-08-31 Respironics, Inc. Sleep apnea treatment apparatus
US5303698A (en) * 1991-08-27 1994-04-19 The Boc Group, Inc. Medical ventilator
US6604523B2 (en) * 1993-11-09 2003-08-12 Cprx Llc Apparatus and methods for enhancing cardiopulmonary blood flow and ventilation
US6932084B2 (en) * 1994-06-03 2005-08-23 Ric Investments, Inc. Method and apparatus for providing positive airway pressure to a patient
US6105575A (en) * 1994-06-03 2000-08-22 Respironics, Inc. Method and apparatus for providing positive airway pressure to a patient
US5596984A (en) * 1994-09-12 1997-01-28 Puritan-Bennett Corporation Lung ventilator safety circuit
US6000396A (en) * 1995-08-17 1999-12-14 University Of Florida Hybrid microprocessor controlled ventilator unit
US5931160A (en) * 1995-12-08 1999-08-03 Cardiopulmonary Corporation Ventilator control system and method
US6158432A (en) 1995-12-08 2000-12-12 Cardiopulmonary Corporation Ventilator control system and method
US6463930B2 (en) 1995-12-08 2002-10-15 James W. Biondi System for automatically weaning a patient from a ventilator, and method thereof
EP1082056B1 (en) * 1998-06-03 2007-11-14 Scott Laboratories, Inc. Apparatus for providing a conscious patient relief from pain and anxiety associated with medical or surgical procedures
WO2000021601A1 (en) 1998-10-09 2000-04-20 The Brigham And Women's Hospital, Inc. Method and apparatus for delivering a measured amount of a gas
US6962155B1 (en) * 1999-07-30 2005-11-08 Universite De Montreal Target drive ventilation gain controller and method
BR9903858B1 (en) * 1999-08-05 2009-05-05 mini mechanical pneumatic pulmonary ventilator.
AU2002350108B2 (en) * 2001-11-01 2008-09-11 Scott Laboratories, Inc. User interface for sedation and analgesia delivery systems and methods
JP2006501899A (en) * 2002-10-03 2006-01-19 スコット・ラボラトリーズ・インコーポレイテッド System and method for providing sensor fusion
WO2004030525A2 (en) * 2002-10-03 2004-04-15 Scott Laboratories, Inc. Systems and methods for providing trend analysis in a sedation and analgesia system
US7189204B2 (en) 2002-12-04 2007-03-13 Cardiac Pacemakers, Inc. Sleep detection using an adjustable threshold
EP3064242A1 (en) 2003-04-28 2016-09-07 Advanced Circulatory Systems Inc. Ventilator and methods for treating head trauma and low blood circulation
US7610094B2 (en) * 2003-09-18 2009-10-27 Cardiac Pacemakers, Inc. Synergistic use of medical devices for detecting medical disorders
US7887493B2 (en) 2003-09-18 2011-02-15 Cardiac Pacemakers, Inc. Implantable device employing movement sensing for detecting sleep-related disorders
US8251061B2 (en) * 2003-09-18 2012-08-28 Cardiac Pacemakers, Inc. Methods and systems for control of gas therapy
US7668591B2 (en) * 2003-09-18 2010-02-23 Cardiac Pacemakers, Inc. Automatic activation of medical processes
US7662101B2 (en) * 2003-09-18 2010-02-16 Cardiac Pacemakers, Inc. Therapy control based on cardiopulmonary status
US7967756B2 (en) * 2003-09-18 2011-06-28 Cardiac Pacemakers, Inc. Respiratory therapy control based on cardiac cycle
US7396333B2 (en) * 2003-08-18 2008-07-08 Cardiac Pacemakers, Inc. Prediction of disordered breathing
US8002553B2 (en) 2003-08-18 2011-08-23 Cardiac Pacemakers, Inc. Sleep quality data collection and evaluation
US7575553B2 (en) * 2003-09-18 2009-08-18 Cardiac Pacemakers, Inc. Methods and systems for assessing pulmonary disease
US8606356B2 (en) 2003-09-18 2013-12-10 Cardiac Pacemakers, Inc. Autonomic arousal detection system and method
EP1670547B1 (en) * 2003-08-18 2008-11-12 Cardiac Pacemakers, Inc. Patient monitoring system
EP1690209A1 (en) * 2003-11-12 2006-08-16 Draeger Medical Systems, Inc. A healthcare processing device and display system
US7680534B2 (en) * 2005-02-28 2010-03-16 Cardiac Pacemakers, Inc. Implantable cardiac device with dyspnea measurement
US20070055115A1 (en) * 2005-09-08 2007-03-08 Jonathan Kwok Characterization of sleep disorders using composite patient data
US8256417B2 (en) 2005-11-23 2012-09-04 Curative (Beijing) Medical Technology Co., Ltd. Method and apparatus for providing positive airway pressure to a patient
US8460223B2 (en) * 2006-03-15 2013-06-11 Hill-Rom Services Pte. Ltd. High frequency chest wall oscillation system
US20080202523A1 (en) * 2007-02-23 2008-08-28 General Electric Company Setting mandatory mechanical ventilation parameters based on patient physiology
US20080230062A1 (en) * 2007-03-23 2008-09-25 General Electric Company Setting expiratory time in mandatory mechanical ventilation based on a deviation from a stable condition of exhaled gas volumes
US8151790B2 (en) 2007-04-19 2012-04-10 Advanced Circulatory Systems, Inc. Volume exchanger valve system and method to increase circulation during CPR
US9352111B2 (en) 2007-04-19 2016-05-31 Advanced Circulatory Systems, Inc. Systems and methods to increase survival with favorable neurological function after cardiac arrest
US8316849B2 (en) * 2007-04-26 2012-11-27 Buxco Electronics, Inc. Integrated ventilator with calibration
GB0712710D0 (en) * 2007-06-29 2007-08-08 Laerdal Medical As Method and instrument to provide ventilation and perfusion
RU2010125146A (en) * 2007-11-19 2011-12-27 Кэафьюжн 2200, Инк. (Us) RESPIRATORY THERAPY SYSTEM WITH ELECTROMECHANICAL DRIVE
CN101467880B (en) * 2007-12-28 2012-06-27 北京谊安医疗系统股份有限公司 Method for improving tidal volume control and detection accuracy by introducing R value for calculation
US8337512B2 (en) * 2008-12-08 2012-12-25 Siemens Aktiengesellschaft Device and workflow for minimally-invasive therapy, in particular needle guidance
US9724266B2 (en) 2010-02-12 2017-08-08 Zoll Medical Corporation Enhanced guided active compression decompression cardiopulmonary resuscitation systems and methods
JP2015500733A (en) 2011-12-19 2015-01-08 レスキューシステムズ インコーポレイテッドResqsystems,Inc. Intrathoracic pressure regulation system and method for treatment
US9811634B2 (en) 2013-04-25 2017-11-07 Zoll Medical Corporation Systems and methods to predict the chances of neurologically intact survival while performing CPR
US20140358047A1 (en) 2013-05-30 2014-12-04 ResQSystems, Inc. End-tidal carbon dioxide and amplitude spectral area as non-invasive markers of coronary perfusion pressure and arterial pressure
US10265495B2 (en) 2013-11-22 2019-04-23 Zoll Medical Corporation Pressure actuated valve systems and methods

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4461293A (en) * 1982-12-03 1984-07-24 Kircaldie, Randall, And Mcnab Respirating gas supply method and apparatus therefor
US4535766A (en) * 1982-02-23 1985-08-20 Dragerwerk Aktiengesellschaft Method and apparatus for monitoring a respirator usable with an endotracheal tube
US4982735A (en) * 1988-03-01 1991-01-08 Sumitomo Bakelite Company Limited Artificial ventilator
US5005570A (en) * 1985-10-02 1991-04-09 Perkins Warren E Method and means for dispensing respirating gases by effecting a known displacement
US5016626A (en) * 1988-05-23 1991-05-21 Instruments And Movements Limited Ventilators for promoting lung function
US5044362A (en) * 1987-02-21 1991-09-03 University Of Manitoba Lung ventilator device
US5107831A (en) * 1989-06-19 1992-04-28 Bear Medical Systems, Inc. Ventilator control system using sensed inspiratory flow rate
US5129390A (en) * 1987-12-18 1992-07-14 Institut Nationale De La Sante Et De La Recherche Medicale Process for regulating an artificial ventilation device and such device

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4535766A (en) * 1982-02-23 1985-08-20 Dragerwerk Aktiengesellschaft Method and apparatus for monitoring a respirator usable with an endotracheal tube
US4461293A (en) * 1982-12-03 1984-07-24 Kircaldie, Randall, And Mcnab Respirating gas supply method and apparatus therefor
US4519387A (en) * 1982-12-03 1985-05-28 Kircaldie, Randall And Mcnab, Trustee Respirating gas supply method and apparatus therefor
US5005570A (en) * 1985-10-02 1991-04-09 Perkins Warren E Method and means for dispensing respirating gases by effecting a known displacement
US5044362A (en) * 1987-02-21 1991-09-03 University Of Manitoba Lung ventilator device
US5129390A (en) * 1987-12-18 1992-07-14 Institut Nationale De La Sante Et De La Recherche Medicale Process for regulating an artificial ventilation device and such device
US4982735A (en) * 1988-03-01 1991-01-08 Sumitomo Bakelite Company Limited Artificial ventilator
US5016626A (en) * 1988-05-23 1991-05-21 Instruments And Movements Limited Ventilators for promoting lung function
US5107831A (en) * 1989-06-19 1992-04-28 Bear Medical Systems, Inc. Ventilator control system using sensed inspiratory flow rate

Also Published As

Publication number Publication date
US5183038A (en) 1993-02-02
AU2910292A (en) 1993-06-07

Similar Documents

Publication Publication Date Title
US5183038A (en) Gated programmable ventilator
US5188098A (en) Method and apparatus for ECG gated ventilation
US20220241578A1 (en) Ventricular assist device control
KR20190045238A (en) Ventricular assist device
US5377671A (en) Cardiac synchronous ventilation
US5413110A (en) Computer gated positive expiratory pressure method
US6669624B2 (en) Temporary heart-assist system
US7229402B2 (en) Minimally invasive ventricular assist technology and method
NL2002225C2 (en) Apparatus and system for monitoring breathing or ventilation, defibrillator device, apparatus and system for monitoring chest compressions, valve apparatus.
DK162257B (en) Control system for controlling a respirator supplying a positive inhalation pressure to a patient
JP2010524578A (en) Volume exchange valve system and method for increasing circulation during CPR
WO1999051285A1 (en) Auxiliary mechanical heart promoting the restoration of heart function
CN110448748A (en) A kind of intra-aortic balloon pump system and its control method
US11769579B2 (en) Facilitating pulmonary and systemic hemodynamics
CN115666707A (en) Controller and method for artificial heart
Kim et al. Application of a phase-locked loop counterpulsation control algorithm to a pneumatic pulsatile VAD

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU CA JP

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
NENP Non-entry into the national phase

Ref country code: CA

122 Ep: pct application non-entry in european phase