Portable field anesthesia machine and control therefore

• US 20060196505A1
• Filed: 10/14/2005
• Published: 09/07/2006
• Est. Priority Date: 03/02/2005
• Status: Active Grant

• Current Assignee: John I. Izuchukwu
• Original Assignee: John I. Izuchukwu
• Inventors: Izuchukwu, John I.
• Granted Patent: US 7,438,072 B2
• Time in Patent Office: Days
• US Class Current: 128/203.15
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/01 specially adapted for anaesthetising A61M16/104, A61M16/18 take precedence
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/101 using an oxygen concentrator
• CPC Class Codes: A61M 16/1015 using a gas flush valve, e.g. oxygen flush valve
• CPC Class Codes: A61M 16/104 specially adapted for anaesthetics A61M16/18 takes precedence
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 16/18 Vaporising devices for anaesthetic preparations
• 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 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2016/1035 the anaesthetic agent concentration
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2202/0283 Nitrous oxide (N2O)
• CPC Class Codes: A61M 2205/3358 Measuring barometric pressure, e.g. for compensation
• CPC Class Codes: A61M 2205/3372 Temperature compensation
• CPC Class Codes: A61M 2205/3389 Continuous level detection A61M2205/3393 takes precedence
• CPC Class Codes: A61M 2205/3584 using modem, internet or bluetooth
• CPC Class Codes: A61M 2205/3673 thermo-electric, e.g. Peltier effect, thermocouples, semi-conductors
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/52 : with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2205/584 : having a color code
• CPC Class Codes: A61M 2230/04 : Heartbeat characteristics, e.g. ECG, blood pressure modulation
• CPC Class Codes: A61M 2230/06 : Heartbeat rate only
• CPC Class Codes: A61M 2230/10 : Electroencephalographic signals
• CPC Class Codes: A61M 2230/205 : partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/30 : Blood pressure A61M2230/04 takes precedence
• CPC Class Codes: A61M 2230/42 : Rate
• CPC Class Codes: A61M 2230/432 : partial CO2 pressure (P-CO2)

Abstract

A portable anesthetic machine or device is comprises a chassis having a cradle which removably receives a vaporizer. The device also includes a control panel and a carrying/support member. The control panel and support member are pivotal relative to each other to selectively change the machine from a carrying configuration or position to a use configuration or position. The control panel includes a gas flow path having gas inputs which receive carrier gases from sources of carrier gases, a manifold which combines the gases; a carrier gas outlet and a carrier gas inlet connectable to the vaporizer input and vaporizer outlet, respectively, a common gas port to which a patient cannula can be connected, and flow control devices in the gas flow path to control the flow rate of the carrier gases into the device. A controller is also provided which controls the flow of gas into and around the vaporizer based on vaporizer pressure and temperature, ambient pressure and temperature to maintain a substantially constant concentration of anesthetic agent in the gas stream delivered to the patient without the need to adjust the flow of gases from the gas supply sources.

Claims

1. A portable anesthetic delivery device comprising:

a chassis comprising a cradle which removably receives a vaporizer;

said vaporizer comprising a vaporizer input and a vaporizer outlet;

a panel extending up from said chassis;

said panel comprising a gas flow path, said gas flow path having gas inputs which receive carrier gases from sources of carrier gases, a manifold which combines the gases;

a carrier gas outlet and a carrier gas inlet connectable to the vaporizer input and vaporizer outlet, respectively, a common gas port to which a patient cannula can be connected, and flow control devices in the gas flow path to control the flow rate of the carrier gases into the device;

a support comprising a pair of arms and a member extending between an end of said arms;

at least one of said panel and said support being pivotal relative to other of said panel and support;

whereby, said device is selectively movable between a carrying position in which said support and said panel lie generally in a common plane and a use position in which said panel is angled relative to said support, such that said support in conjunction with said chassis maintain said panel in a generally upright position to facilitate use of the device.

2. The portable anesthetic delivery device of claim 1 including a lock mechanism to maintain the support in a desired position.

3. The portable anesthetic delivery device of claim 1 including external tubing which places said carrier gas outlet in communication with said vaporizer inlet and which places said carrier gas inlet in communication with said vaporizer outlet.

4. The portable anesthetic delivery device of claim 1 wherein said vaporizer inlet and outlet comprise tubes extending from a side surface of said vaporizer;

said carrier gas outlet and said carrier gas inlet comprising ports in said cradle which receive said vaporizer inlet and outlet tubes.

5. The portable anesthetic delivery device of claim 1 comprising a vaporizer lock member which holds said vaporizer in said chassis.

6. The portable anesthetic delivery device of claim 5 wherein said vaporizer lock member comprises said panel;

sand panel including a forward portion and a rear portion;

said forward portion being sized to extend over said vaporizer;

said forward portion being hingedly connected to said rear portion to be movable from an open position in which said vaporizer can be inserted into or removed from said cradle and a closed position in which said vaporizer is held in said cradle.

7. The portable anesthetic delivery device of claim 6 wherein said panel front portion is hingedly connected to said panel rear portion along a top of said panel portions.

8. The portable anesthetic delivery device of claim 5 wherein said chassis comprises a forward portion and a back portion;

one of said chassis forward and back portions being movable relative to the other of said chassis portions;

said chassis portions being movable between an open position in which said vaporizer can be removed from or inserted into said chassis and a closed position in which said vaporizer is secured in said chassis.

9. The portable anesthetic delivery device of claim 8 wherein said chassis comprises a pair of spaced apart clasps;

said clasps each comprising a fixed member and a movable member;

said movable member being pivotally connected to said fixed member;

said clasp members having a surface conforming to the shape of the vaporizer and including a connector to maintain said clasp members in the closed position.

10. The portable anesthetic delivery device of claim 9 wherein said clasp member connector comprises a latch.

11. The portable anesthetic delivery device of claim 1 wherein said flow path comprises a tube which at least partially extends around said vaporizer;

said tube being at least in part transparent or translucent;

said transparent or translucent portion of said tube being visible;

said tube providing a visual indication of the amount of anesthetic agent remaining in said vaporizer.

12. The portable anesthetic delivery device of claim 1 including an anesthetic agent detector;

said anesthetic agent detector comprises a light transmitter operable to pass light of a predetermined wavelength through anesthetic vapor and a light receiver which receives the light passed through the anesthetic vapor;

said receiver producing a signal indicative of the light absorbed by the anesthetic agent.

13. The portable anesthetic delivery device of claim 12 wherein said light transmitter and light receiver of said anesthetic agent detector are located in said anesthetic receiving chamber of said vaporizer.

14. The portable anesthetic delivery device of claim 12 wherein said flow path comprises a tube which at least partially extends around said vaporizer;

said tube being at least in part transparent or translucent;

said light transmitter and light receiver of said anesthetic agent detector being located on opposite sides of said transparent or translucent part of said tube.

15. The portable anesthetic delivery device of claim 1 comprising a plurality of sensors for monitoring various operating parameters of said device;

said operating parameters being selected from the group consisting of oxygen pressure, oxygen flow rate;

nitrous oxide pressure, nitrous oxide flow rate, air pressure, air flow rate, ambient atmospheric pressure, circuit pressure, internal vaporizer temperature, internal vaporizer pressure, gas pressure proximate the common gas port, gas flow rate proximate the common gas port, measure the end-tidal CO₂ concentration in an exhalation branch of a breathing circuit, O₂ concentration in the inhalation branch of a breathing circuit, and combinations thereof.

16. The portable anesthetic delivery device of claim 15 comprising a monitor;

said operating parameters or selected sets of said operating parameters being displayed on said monitor.

17. The portable anesthetic delivery device of claim 16 including connectors adapted to receive inputs from patient monitoring equipment which monitor selected patient parameters;

said patient parameters or selected sets thereof being displayed on said monitor.

18. The portable anesthetic delivery device of claim 15 including a controller;

said gas flow path further including a by-pass line having an inlet on one side of said vaporizer and an outlet on another side of vaporizer such that at least a portion of carrier gas can by-pass said vaporizer;

said flow path further including a by-pass valve which is operable to adjust the ratio of carrier gas which passes through said by-pass line;

said controller controlling the by-pass valve to adjust the amount of carrier gas ratio between the carrier gas which enters the vaporizer and the amount of carrier gas which flows through the by-pass line in order to maintain the partial pressure of the anesthetic agent entrained in the carrier gas at a generally constant value.

19. The portable anesthetic delivery device of claim 18 including a temperature controlling device proximate said vaporizer;

said temperature controlling device being in communication with and being controlled by said controller;

said controller controlling said temperature controlling device in response to a signal received from the internal vaporizer temperature sensor to maintain the internal vaporizer temperature substantially at a desired set point.

20. The portable anesthetic delivery device of claim 19 wherein said temperature controlling device is a thermoelectric heat pump.

21. The portable anesthetic delivery device of claim 19 wherein said controller controls said temperature control device in response to the ambient atmospheric pressure and the internal vaporizer pressure in addition to the internal vaporizer temperature.

22. An anesthetic delivery device comprising:

a vaporizer having an inlet and an outlet;

a gas flow path comprising gas inlets connectable to sources of air, oxygen and nitrous oxide;

a manifold in which said air, oxygen and nitrous oxide are combined to form a carrier gas;

a vaporizer;

a first carrier gas line extending from said manifold to said vaporizer inlet;

a second carrier gas line extending from said vaporizer outlet to a common gas port;

a by-pass line being connected at a first end to said carrier gas first line and at a second end to said carrier gas second line;

a by-pass valve operable to adjust the amount of carrier gas which passes through said by-pass line; and

sensors for monitoring various operating parameters of said device;

said operating parameters being selected from the group consisting of oxygen pressure, oxygen flow rate;

nitrous oxide pressure, nitrous oxide flow rate, air pressure, air flow rate, ambient atmospheric pressure, circuit pressure, internal vaporizer temperature, internal vaporizer pressure, gas pressure proximate the common gas port, gas flow rate proximate the common gas port, measure the end-tidal CO₂ concentration in an exhalation branch of a breathing circuit, O₂ concentration in the inhalation branch of a breathing circuit, and combinations thereof;

a controller;

said controller receiving signals from said sensors indicative of the parameter being monitored and said controller being in operatively connected to said by-pass valve;

said controller controlling said by-pass valve in response to the vaporizer pressure and vaporizer temperature to maintain the partial pressure of anesthetic agent in the carrier gas at a substantially constant value.

23. The device of claim 22 wherein the vaporizer comprises inner and outer chambers defining vaporizer gas paths, said vaporizer gas paths comprising a first vaporizer path through said inner chamber to said vaporizer exit, and a second vaporizer gas path through said outer chamber to said vaporizer exit;

said vaporizer further including a regulator which controls the percentage of gas passing through the vaporizer first gas path;

so that the anesthetically saturated gas emanating from the inner chamber combines with the by-pass gas from said vaporizer second flow path.

24. The anesthetic delivery device of claim 22 including a temperature controlling device proximate said vaporizer;

said temperature controlling device being in communication with and being controlled by said controller;

said controller controlling said temperature controlling device in response to a signal received from the internal vaporizer temperature sensor to maintain the internal vaporizer temperature substantially at a desired set point.

25. The portable anesthetic delivery device of claim 24 wherein said temperature controlling device is a thermoelectric heat pump.