Respirator with a breathing circuit

• US 6,422,237 B1
• Filed: 12/27/1999
• Issued: 07/23/2002
• Est. Priority Date: 05/18/1999
• Status: Expired due to Fees

• Current Assignee: Drager Medizintechnik GmbH
• Original Assignee: Drager Medizintechnik GmbH
• Inventors: Witt, Matthias, Manigel, Jürgen, Bunke, Claus, Engel, Dieter
• Primary Examiner(s): Weiss, John G.
• Assistant Examiner(s): MITCHELL, TEENA KAY
• Application Number:
  US09/472,566
• Time in Patent Office: 939 Days
• Field of Search: 128/200.24, 128/203.12, 128/203.13, 128/203.14, 128/203.25, 128/204.18, 128/204.21, 128/204.23, 128/204.24, 128/204.28, 128/205.13, 128/205.14, 128/205.17, 128/205.28, 128/207.14, 128/207.16, 128/205.11
• US Class Current: 128/204.21
• CPC Class Codes: A61H 2201/018 By limiting the applied torque or force
• CPC Class Codes: A61H 2201/107 Respiratory gas
• CPC Class Codes: A61H 2201/5007 computer controlled
• CPC Class Codes: A61H 2201/5089 Gas sensors, e.g. for oxygen or CO2
• CPC Class Codes: A61H 2230/40 Respiratory characteristics
• CPC Class Codes: A61H 31/00 Artificial respiration or heart stimulation, e.g. heart massage artificial respiration by treatment with gas or air, e.g. mouth-to-mouth respiration A61M16/00; applying electric currents by contact electrodes for stimulation, e.g. heart pace-makers A61N1/36 ; teaching or training models, demonstration models for medical purposes G09B23/288
• CPC Class Codes: A61M 16/01 specially adapted for anaesthetising A61M16/104, A61M16/18 take precedence
• CPC Class Codes: A61M 16/22 Carbon dioxide-absorbing devices ; Other means for removing carbon dioxidecartridges with absorbing substances for respiratory apparatus A62B19/00
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2016/0042 in the expiratory circuit

Abstract

An improved respirator with a breathing circuit (100) and a corresponding process for operating the respirator are provided. Defined breathing gas volumes can be delivered to the patient and the current operating state can be reliably monitored despite a strong breathing gas volume flow being delivered in the breathing circuit (100). A gas delivery element (1) designed as a rotary compressor is connected on the inlet side to a reversible breathing gas reservoir (7) and on the outlet side to a patient connection piece (9) for inspiration via a first gas volume flow sensor (2) with a first nonreturn valve (11). A second gas volume flow sensor (5) is located in the connection line between the patient connection piece (9) and the patient being inspirated. The patient connection piece (9) is connected for expiration to a second nonreturn valve (10) via a third gas volume flow sensor (3) and to the reversible breathing gas reservoir (7) via a controllable shut-off valve (4). At least one measuring and control device (14, 15) is connected to the gas volume flow sensors (2, 5, 3), it receives their measured signals and sends control signals to the gas delivery element (1) and to the controllable shut-off valve (4).

Claims

1. A respirator comprising:

a breathing circuit with an inlet branch and an outlet branch;

a reversible breathing gas reservoir;

a first gas volume flow sensor;

a patient connection piece;

a first nonreturn valve;

a gas delivery element including a rotary compressor, said gas delivery element being connected on an inlet branch to said reversible breathing gas reservoir and being connected on an outlet branch to said patient connection piece for inspiration via said first gas volume flow sensor with said first nonreturn valve;

a second nonreturn valve;

a controllable shut-off valve connected to said outlet branch providing an open state allowing flow through said outlet branch and a shut state stopping flow through said outlet branch;

a connection line between said patient connection piece and a patient being respirated;

a second gas volume flow sensor located in said connection line between said patient connection piece and the patient being respirated;

a third gas volume flow sensor;

said patient connection piece being connected for expiration to said second nonreturn valve via said third gas volume flow sensor and to said reversible breathing gas reservoir via said controllable shut-off valve; and

a measuring and control unit connected to said gas volume flow sensors receiving measured signals and sending control signals to said gas delivery element to control a speed of said gas delivery element and to said controllable shut-off valve to control the open and shut state of said controllable shut-off valve.

2. The respirator in accordance with claim 1, further comprising:

a fresh gas and anesthesia gas metering device with a fresh gas reservoir and a CO₂ absorber arranged between said gas delivery element and said reversible breathing gas reservoir.

3. The respirator in accordance with claim 1, further comprising:

measuring transducers for measuring temperature and/or pressure, said measuring transducers being arranged in said outlet branch of said breathing circuit between said gas delivery element and said patient connection piece, said measuring transducers being connected to said measuring and control unit with said measuring transducers generating measuring signals which are sent to said measuring and control unit.

4. The respirator in accordance with claim 1, further comprising an evaluating unit associated with said control unit and a suction site located close to said patient in said connection line between said patient connection piece and said patient to take gas samples, said gas samples being evaluated in said evaluating unit to determine the content of gas in said connection line between said patient connection piece and said patient.

5. The respirator in accordance with claim 4, further comprising an additional suction site provided in said outlet branch of said breathing circuit to take outlet branch gas samples, said outlet branch gas samples being evaluated in said evaluating unit to determine the content of gas in said outlet branch.

6. The respirator in accordance with claim 1, wherein said gas delivery element is a radial compressor, which is driven by means of a d.c. electric motor.

7. The respirator in accordance with claim 2, wherein said reversible breathing gas reservoir and said CO₂ absorber are an integral component.

8. A process for operating a respirator, the process comprising the steps of:

providing a breathing circuit with a patient connection piece and a connection line between said patient connection piece and a patient being respirated;

providing a reversible breathing gas reservoir;

providing a first gas volume flow sensor, a second gas volume flow sensor located in said connection line between said patient connection piece and said patient being respirated and a third gas volume flow sensor;

providing a first nonreturn valve, a second nonreturn valve and a controllable shut-off valve;

providing a gas delivery element including a rotary compressor;

connecting an intake of said gas delivery element to said reversible breathing gas reservoir and connecting a discharge of said gas delivery element to said patient connection piece, for inspiration via said first gas volume flow sensor and said first nonreturn valve;

connecting said patient connection piece for expiration to said second nonreturn valve via said third gas volume flow sensor and to said reversible breathing gas reservoir via said controllable shut-off valve;

receiving measurement signals from said gas volume flow sensors at a measuring and control device and sending control signals from said control device to said gas delivery element to control a speed of operation of said gas delivery element and sending control signals from said control device to said controllable shut-off valve to control the open and shut status of said controllable shut-off valve;

triggering the beginning of each phase of inspiration and/or expiration either in a time-controlled manner or by a measured signal brought about by inspiration or expiration by the patient detected at said second gas volume flow sensor;

closing said controllable shut-off valve during each phase of inspiration, with said gas delivery element activated, so that said gas delivery element delivers breathing gas from said reversible breathing gas reservoir;

controlling a speed of rotation of said gas delivery element during each phase of inspiration as a function of said measured signals of said first gas volume flow sensor;

reducing the speed of rotation of said gas delivery element during each phase of expiration to a lower value or to zero;

opening said controllable shut-off valve during each phase of expiration;

measuring an exhaled gas volume flow with said second gas volume flow sensor during each phase of expiration;

controlling the speed of rotation of said gas delivery element as a function of measured signals of said first gas volume flow sensor during each phase of expiration; and

determining a gas volume flow to said patient from a difference of said measured signals of said first and said third gas volume flow sensors during opening and closing of said controllable shut-off valve at a beginning and at an end of each phase of inspiration, and controlling the speed of rotation of said gas delivery element during inspiration as a function of this difference.

9. The process in accordance with claim 8, wherein the speed of rotation of said gas delivery element is controlled as a function of a pressure actually measured in said breathing circuit and said gas volume flow actually measured in said breathing circuit.

10. The process in accordance with claim 8, wherein a measured signal is sent to said measuring and control device by means of said second gas volume flow sensor at a beginning of said inspiration by the patient, so that said controllable shut-off valve is closed via said measuring and control device and said gas delivery element is activated by increasing the speed of rotation of said gas delivery element.

11. The process in accordance with claim 10, wherein at the end of the inspiration, said measuring and control device first reduces the speed of rotation of said gas delivery element and opens said controllable shut-off valve based on the measured signal received from said first gas volume flow sensor or from said second gas volume flow sensor.

12. A process for operating a respirator, the process comprising the steps of:

providing a breathing circuit with a patient connection piece and a connection line between said patient connection piece and a patient being respirated;

providing a reversible breathing gas reservoir;

providing a first gas volume flow sensor, a second gas volume flow sensor located in said connection line between said patient connection piece and a patient being respirated and a third gas volume flow sensor;

providing a first nonreturn valve, a second nonreturn valve and a controllable shut-off valve;

providing a gas delivery element including a rotary compressor;

connecting an intake of said gas delivery element to said reversible breathing gas reservoir and connecting a discharge of said gas delivery element to said patient connection piece for inspiration via said first gas volume flow sensor and said first nonreturn valve;

connecting said patient connection piece for expiration to said second nonreturn valve via said third gas volume flow sensor and to said reversible breathing gas reservoir via said controllable shut-off valve;

receiving measured signals from said gas volume flow sensors at a measuring and control device and sending control signals to said gas delivery element and to said controllable shut-off valve;

triggering the beginning of each phase of inspiration and/or expiration either in a time-controlled manner or by a measured signal brought about by patient inspiration or expiration detected at said second gas volume flow sensor;

during each phase of inspiration, controlling said controllable shut-off valve with said third gas volume flow sensor such that a gas volume flow is maintained in the respirator and controlling the speed of rotation of said gas delivery element as a function of the pressure detected in the respirator only; and

during each phase of expiration, reducing a speed of rotation of said gas delivery element to a lower value or to zero, opening said controllable shut-off valve, measuring exhaled gas volume flow with said second gas volume flow sensor, and controlling the speed of rotation of said gas delivery element as a function of measured signals of said first gas volume flow sensor.

13. A process for operating a respirator, the process comprising the steps of:

providing a breathing circuit with a patient connection piece and a connection line between said patient connection piece and a patient being respirated;

providing a reversible breathing gas reservoir;

providing a first gas volume flow sensor, a second gas volume flow sensor located in said connection line between said patient connection piece and said patient being respirated and a third gas volume flow sensor;

providing a first nonreturn valve, a second nonreturn valve and a controllable shut-off valve;

providing a gas delivery element including a rotary compressor;

connecting said gas delivery element, being on an inlet branch to said reversible breathing gas reservoir and on an outlet branch to said patient connection piece for inspiration via said first gas volume flow sensor with said first nonreturn valve;

connecting said patient connection piece for expiration to said second nonreturn valve via said third gas volume flow sensor and to said reversible breathing gas reservoir via said controllable shut-off valve;

receiving measured signals from said gas volume flow sensors at a measuring and control device and sending control signals to said gas delivery element and to said controllable shut-off valve;

triggering the beginning of each phase of inspiration and/or expiration either in a time-controlled manner or by a measured signal brought about by inspiration or expiration at said second gas volume flow sensor;

reducing a speed of rotation of said gas delivery element during each phase of expiration to a lower value or to zero, opening said controllable shut-off valve, and measuring said exhaled gas volume flow with said second gas volume flow sensor, and controlling the speed of rotation of said gas delivery element as a function of measured signals of said first gas volume flow sensor;

providing a first mode of operation including closing said controllable shut-off valve during each phase of inspiration, with said gas delivery element activated, so that said gas delivery element delivers breathing gas from said reversible breathing gas reservoir, and said speed of rotation of said gas delivery element is controlled as a function of said measured signals of said first gas volume flow sensor and determining a gas volume flow to said patient from a difference of said measured signals of said first and said third gas volume flow sensors during a switching phases of said controllable shut-off valve at a beginning and at an end of each phase of inspiration, and controlling a speed of rotation of said gas delivery element as a function of this difference; and

providing a second mode of operation including controlling said controllable shut-off valve during each phase of inspiration with said third gas volume flow sensor such that a gas volume flow is maintained in the respirator and the speed of rotation of said gas delivery element is only controlled as a function of the pressure detected in the respirator during each phase of inspiration.

14. A process for operating a respirator in accordance with claim 13, further comprising the steps of:

providing a switching means associated with said respirator for switching between said first mode of operation and said second mode of operation; and

switching between said first mode of operation and said second mode of operation.