Liquid ventilator with venturi-inducing patient connector

• US 5,492,109 A
• Filed: 11/03/1993
• Issued: 02/20/1996
• Est. Priority Date: 11/03/1993
• Status: Expired due to Fees

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Hirschl, Ronald B., Merz, Scott I., Montoya, Jean P.
• Primary Examiner(s): Asher, Kimberly L.
• Application Number:
  US08/147,057
• Time in Patent Office: 839 Days
• Field of Search: 128/913, 128/201.21, 128/204.18, 128/207.14, 128/911, 128/912, 128/204.25
• US Class Current: 128/201.21
• CPC Class Codes: A61M 1/32 Oxygenators without membranes
• CPC Class Codes: A61M 16/0054 Liquid ventilation
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 2202/0476 Oxygenated solutions
• CPC Class Codes: Y10S 128/913 Breathable liquids

Abstract

An involuntary respiratory apparatus for perfusing and entraining a breathable liquid from the lungs of a patient. The system includes a number of components which are interconnected by a conduit so as to form a substantially closed loop, single path circuit. The various components include a reservoir, a pump, an oxygenator, a heat exchanger, an endotracheal tube, a Y-connector, a valve and a controller. To simulate inspiration, the controller closes the valve, which is located downstream of the Y-connector, thereby forcing the liquid into the lungs of the patient. After a tidal volume of liquid has been perfused into the patient'"'"'s lungs, the controller opens the valve. The Y-connector is shaped such that the flow of liquid through its inspiratory limb will cause the liquid in the patient'"'"'s lungs to be entrained into the flow out of the Y-connector. In this manner, the Y-connector operates as an ejector pump and allows the apparatus to continuously perfuse the liquid through the single path circuit.

Claims

1. An involuntary respiratory apparatus for introducing and removing liquid from the lungs of a patient, said apparatus comprising:

a reservoir adapted for containing a liquid therein, said reservoir having an inlet opening to receive said liquid thereinto and an outlet opening for dispensing said liquid therefrom;

a substantially closed loop conduit means for transporting said liquid therethrough, said conduit means being coupled to said outlet opening for receiving said liquid from said reservoir and also being coupled to said inlet opening for discharging said liquid from said conduit means into said reservoir;

pump means for continuously perfusing said liquid through said conduit means;

oxygenation means for oxygenating said liquid;

temperature control means for maintaining the temperature of said liquid within a predetermined range of temperatures;

one endotracheal tube generally coupled to said conduit means and enabling said liquid to be both introduced into and withdrawn from said lungs of said patient through said one endotracheal tube; and

inspiration and expiration means for causing the introduction of a predetermined volume of said liquid through said endotracheal tube into said lungs generally simulating inspiration by said patient and subsequently withdrawing a predetermined volume of said liquid from said lungs through said endotracheal tube generally simulating expiration by said patient, whereby said patient involuntarily respires as said liquid is introduced and withdrawn from said lungs, said inspiration and expiration means including a Y-connector having an inspiratory limb connected to said conduit means in an upstream direction, an expiratory limb connected to said conduit means in a downstream direction and an endotracheal limb connected to said endotracheal tube, said inspiration and expiration means further including means for selectively occluding and unoccluding said conduit means downstream of said Y-connector, and said inspiratory limb having a diameter sufficiently smaller than a diameter of said expiratory limb to form a venturi when said conduit means is unoccluded downstream of said Y-connector as liquid flows into said Y-connector through said inspiratory limb and from said Y-connector through said expiratory limb to draw liquid from said endotracheal tube and the lungs of the patient into said Y-connector, and when said conduit means is occluded, liquid pumped through said inspiratory limb into said Y-connector is directed out of said Y-connector through said endotracheal tube and into the lungs of the patient whereby alternating occlusion and unocclusion of said conduit means produces simulated inspiration and expiration of the patient.

2. The involuntary respiratory apparatus set forth in claim 1 wherein said conduit means forms a single path substantially closed loop.

3. The involuntary respiratory apparatus set forth in claim 1 wherein said conduit means is a tube interconnecting said reservoir, said pump means, said oxygenating means, said temperature control means, said endotracheal tube and said inspiration and expiration means.

4. The involuntary respiratory apparatus set forth in claim 1 wherein said reservoir, said pump means, said oxygenating means, said temperature control means, said endotracheal tube and said inspiration and expiration means are interconnected in series.

5. The involuntary respiratory apparatus set forth in claim 1 wherein said conduit means successively interconnects said reservoir to said pump means, said pump means to said oxygenating means, said oxygenating means to said temperature control means, said temperature control means to said inspiration and expiration means, and said inspiration and expiration to said reservoir.

6. The involuntary respiratory apparatus set forth in claim 1 wherein said means for selectively occluding and unoccluding said conduit means includes a valve and control means, said control means for causing said valve to occlude said conduit means causing said liquid to be introduced into said lungs of said patient.

7. The involuntary respiratory apparatus set forth in claim 6 wherein said valve is a pinch valve.

8. The involuntary respiratory apparatus set forth in claim 1 wherein said pump means is a peristaltic pump.

9. The involuntary respiratory apparatus set forth in claim 1 wherein said inspiratory limb has a diameter which is less than the diameter of said endotracheal limb.