Abstract:
A hyperbaric chamber control system. The system includes a computer and a control valve in communication with the computer, wherein the control valve responds to instructions from the computer to control a supply of gas by producing a control signal, and wherein the control valve is configured to operate independently of the computer when a profile is transferred from the computer to the control valve.

Description:
BACKGROUND 
       [0001]    Hyperbaric chambers are designed to enable a person in the chamber to breathe pure oxygen at a specific pressure for a specific period of time. The chamber is pressurized and ventilated continuously with pure oxygen and the pressure-time profile (i.e., the rate and direction of pressure change and the time held at any particular pressure), as well as the oxygen ventilation rate of any treatment, are controlled by the chamber&#39;s operator. Hyperbaric oxygen administered by a hyperbaric chamber is often used to treat various medical conditions. For example, hyperbaric oxygen may be prescribed for air or gas embolism, decompression sickness, carbon monoxide poisoning, carbon monoxide poisoning complicated by cyanide poisoning, radiation tissue damage, gas gangrene, compromised skin grafts and flaps, crush injuries, compartment syndrome, acute traumatic ischemias, necrotizing soft tissue infections, osteomyelitis, non-healing wounds, exceptional blood loss, intracranial abscesses, thermal burns, and/or any other appropriate condition, as prescribed by an attending physician. 
         [0002]    Hyperbaric chambers are designed to be installed and operated primarily in medical facilities and are intended to be operated by trained medical personnel. Such personnel must manually operate the hyperbaric chamber and monitor the patient being treated. Thus, the personnel must set and monitor the treatment parameters while ensuring that the patient is safe and comfortable. 
       SUMMARY 
       [0003]    In one general aspect, embodiments of the present invention are directed to a hyperbaric chamber control system. The system includes a computer and a control valve in communication with the computer, wherein the control valve responds to instructions from the computer to control a supply of gas by producing a control signal, and wherein the control valve is configured to operate independently of the computer when a profile is transferred from the computer to the control valve. 
         [0004]    Those and other details, objects, and advantages of the present invention will become better understood or apparent from the following description and drawings showing embodiments thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    Various embodiments of the present invention are described herein by way of example in conjunction with the following figures, wherein: 
           [0006]      FIG. 1  illustrates a perspective view of a hyperbaric chamber according to one embodiment of the present invention; 
           [0007]      FIG. 2  illustrates a hyperbaric chamber electronic control system according to one embodiment of the present invention; 
           [0008]      FIGS. 3 and 4  illustrate a diagram of a hyperbaric chamber pneumatic control system and control assembly according to one embodiment of the present invention; 
           [0009]      FIG. 5  illustrates a hyperbaric chamber pneumatic control system according to one embodiment of the present invention; 
           [0010]      FIG. 6 . illustrates a schematic diagram of an electronic controller circuit for a hyperbaric chamber according to one embodiment of the present invention; 
           [0011]      FIG. 7  illustrates a schematic diagram of the hyperbaric chamber control assembly according to one embodiment of the present invention; 
           [0012]      FIG. 8  illustrates a flowchart of an embodiment of a method for manually operating a hyperbaric chamber; 
           [0013]      FIG. 9  illustrates a flowchart of an embodiment of a method for operating a hyperbaric chamber automatically; and 
           [0014]      FIG. 10  illustrates a pressure/time profile according to one embodiment of the present invention. 
       
    
    
     DESCRIPTION 
       [0015]    In general, various embodiments of the present invention are directed to hyperbaric chambers that include electronic control of the pressurization, ventilation and depressurization functions. In various embodiments, predetermined or customized profiles may be used to control chamber pressure and duration by way of electronic, or computer, control of pressurization and depressurization. In various embodiments, the pressure and duration may be controlled manually or automatically in accordance with the profiles. 
         [0016]      FIG. 1  illustrates a perspective view of a hyperbaric chamber  10  according to one embodiment of the present invention. The chamber  10  includes a pressure vessel  12  and a control assembly  14  that are mounted on a chassis  16 . The pressure vessel  12  may include two end heads constructed of, for example, aluminum and a transparent cylinder constructed of, for example, a polymer such as acrylic. A transfer gurney  18  allows for a patient to enter and exit the pressure vessel  12  and a stretcher  20  may be moved into and out of the pressure vessel  12 . In one embodiment, the transfer gurney  18  mates to the pressure vessel  12  and locks into position for safe and efficient patient transfer. A pneumatic control system (not shown in  FIG. 1 ) may be located in or on the chassis  16  or may be located on or mounted to a side of the pressure vessel  12 . A computer  22 , such as a personal computer, may be remotely in communication with the control assembly  14 . In various embodiments, operating profiles (i.e., pressurization and depressurization profiles) may be generated and stored in the computer  22 . The profiles may be transferred to a computer  42  in the control assembly  14  so that the hyperbaric chamber  10  may be operated according to one or more of the transferred profiles. In one embodiment, the on-board computer  42  is the primary computer for controlling the system. 
         [0017]      FIG. 2  illustrates a hyperbaric chamber electronic control system  24  according to one embodiment of the present invention. As used throughout the figures herein, solid lines are generally used to illustrate pneumatic lines (piping, tubing, etc.) and dashed lines are generally used to illustrate electrical lines, wires or buses. A power supply  23  supplies power to the various electronic/electrical components of the system  24 . The system  24  includes the control assembly  14 . The control assembly  14  includes an electrical circuit power button  26 , a reset button  28 , a cycle counter  30 , an emergency stop button  32 , a ventilation rate gauge  33 , ventilation control knob  34 , a start/stop button  36 , a main pneumatic circuit power switch  37 , an automatic/manual selection switch  38 , and a display (e.g., liquid crystal display (LCD)) screen  40 . The main pneumatic power switch  37  activates the pneumatic portion of the control system  24 . The automatic/manual selection switch  38  may be a momentary switch that is used to select the mode of operation of the control system  24  (i.e., manual or automatic). 
         [0018]    The display  40  is in communication with the computer  42 , such as an embedded computer, that includes a memory device  44 , such as a flash drive. In one embodiment, the computer  42  is a computer manufactured by Blue Chip Technology. Input and output devices, such as mouse  46 , keyboard  48  and printer  50  may also be in communication with the control assembly  14 , and ultimately the computer  42 . The computer  42 , in conjunction with the display  40  and input/output devices  46 ,  48 ,  50 , may be used to execute automatic pressurization and depressurization profiles of the pressure vessel  12 . In various embodiments, the profiles are downloaded to the computer  42  and the computer  42  controls a pneumatic control valve  52 , which ultimately controls the amount of gas that enters the pressure vessel  12 . In one embodiment, the control valve  52  is an ER3000 Electronic Pressure Controller manufactured by Tescom Corporation. The pressure of the pressure vessel  12  is displayed on a gauge  54  and supplied to the control valve  52 . The pressure and rate which the operator, in manual mode, sets via controls  56 ,  58  are displayed on gauges  60 ,  62  and supplied to the control valve  52 . 
         [0019]    Supply gas (e.g., Oxygen) is supplied to the system  24  through a volume booster  64  that boosts the volume of the gas for the pressure vessel  12 . The supply gas pressure is displayed on a gauge  66  of the control assembly  14 . An exhaust valve  68  allows for evacuation of the pressure vessel  12 , including when an exhaust bypass control  70  on the control assembly  14  is depressed. The control assembly includes an intercom system  72  that allows the operator of the system  24  to communicate with a person in the pressure vessel  12 . The computer  42  monitors the temperature of the pressure vessel  12  using a temperature sensor  74  and provides a digital or graphical readout of the temperature on the display  40 . An audible buzzer  76  is used to alert the operator when pre-programmed “air-breaks” are required for the patient. 
         [0020]      FIGS. 3 and 4  illustrate a diagram of a hyperbaric chamber pneumatic control system  78  and the control assembly  14  according to one embodiment of the present invention. A chamber door lock cylinder  80  locks the door of the pressure vessel  12  and, unless the door is locked and the main power switch  37  is on, the pressure vessel  12  will not be pressurized by operation of an interlock valve  82 , a volume booster  84 , and a valve  86 . The door lock cylinder  80  is activated when pressure in the pressure vessel  12  is pressurized above a minimum threshold (e.g., ½ psig). In various embodiment, the volume booster  84  is a 1:4 multiplying volume booster and in one embodiment is required for activation of the door lock cylinder  80  at the low pressures required. 
         [0021]    The supply gas (e.g., oxygen) is supplied through a connection  87  and is regulated to, for example, 50 pounds per square inch (PSIG) by a regulator  88  and the pressure is indicated on a gauge  89 . The supply gas passes through a poppet valve  90 , which in one embodiment is a two-way ball valve that is activated by the main power switch  37 . The volume booster  64  acts as the main control valve for the pressure vessel  12  and an orifice pipe  92  provides a differential pressure reference signal that is indicated on the ventilation rate gauge  33 . This ventilation reference is a measure of the total amount of gas passing through the pressure vessel  12 . The supply gas enters the pressure vessel  12  through a pressure supply fitting  93 . A manual override valve  94  is activated when the automatic/manual switch  38  is set to manual operation and a bleed valve  96  ensures that the pressure in the pressure vessel  12  does not increase above a pre-determined maximum pressurization rate when the pressure vessel  12  is being pressurized in manual mode. During manual operation, a control signal pressure is supplied to the control signal input port of the volume booster  64  through the auto/manual select valve  110  connected to the inlet port of the volume booster  64 , An overpressure relief valve  98  ensures that the manual pressure reference signal supplied to the volume booster  64  control signal input port does not exceed a maximum specified operating pressure (e.g., 30 PSIG). 
         [0022]    An equalize valve  100  ensures that the pressure of the pressure vessel  12  is available so that, if the user switches the system from automatic mode to manual mode, the pressure in the pressure vessel  12  will remain the same. As can be seen in  FIGS. 3 and 4 , the pressure vessel  12  is exhausted (i.e., depressurized) from a depressurization connection  99  through an exhaust port  101  if a relief valve (i.e., safety valve)  102 , through a chamber stop valve  103 , is activated, the ventilation control knob  34  is opened (in such a case the venting is regulated by a regulator  104 ), or the exhaust bypass control  70  is depressed (activating valve  106 ). A switch  108  and valve  110  select the output signal from the control valve  52  and pass the output pressure of the control valve  52  to the control signal input port of the volume booster  64  when the system is operating in automatic mode. 
         [0023]      FIG. 5  illustrates the hyperbaric chamber pneumatic control system  78  according to one embodiment of the present invention. The various components of the system  78  are mounted on a mounting panel  112 , which may be mounted, for example, on an end of the pressure vessel  12  or on the chassis  16  of the chamber  10 . 
         [0024]      FIG. 6 . illustrates a schematic diagram of an electronic controller circuit for a hyperbaric chamber according to one embodiment of the present invention.  FIG. 7  illustrates a schematic diagram of the hyperbaric chamber control assembly  14  according to one embodiment of the present invention. Connector assemblies  114 ,  116  connect the various electrical components of the control assembly  14 . 
         [0025]      FIG. 8  illustrates a flowchart of an embodiment of a method for manually operating a hyperbaric chamber. At  800 , the system is started using a startup procedure. For example, the main oxygen supply valve is opened, the pneumatic circuit power switch  37  is turned on, the breathing air supply valve for an air breathing mask, if used, is opened, and the gauge  66  is examined to ensure that the supply pressure is between certain values (e.g., 50 and 90 psig). In one embodiment the electrical circuit momentary power switch  26  is pressed, providing electrical power to the balance of the control system  24 , and then the reset switch  28  is pressed, providing electrical power to the control valve  52 . At  802 , it is determined if the system is operating in manual or automatic mode based on the position of the automatic/manual selection switch  38 . 
         [0026]    If the system is operating in manual mode, at  804  the pressure vessel  12  can be pressurized after the patient is loaded into the pressure vessel  12  and all safety checks are performed. As required for the specific treatment desired, the rate set knob  58  is adjusted to the desired pressurization rate and the set pressure knob  56  is adjusted to the desired treatment pressure. At  806 , the pressure of the pressure vessel  12  is maintained and the patient is monitored. The pressure may be adjusted using the set pressure knob  56 . Also, the pressure vessel  12  may be cooled by increasing the ventilation rate using the ventilation control knob  34 . 
         [0027]    At the conclusion of the patient treatment (or before if desired), the pressure vessel  12  is depressurized at  808 . Depressurization is accomplished by the rate set knob  58  being adjusted to the desired depressurization rate and the set pressure knob  56  being adjusted to zero psig. When the pressure of the pressure vessel reaches a certain threshold (in one embodiment 1 psig), the exhaust bypass button  70  may be depressed, with the pneumatic circuit power switch  37  set to off, to fully depressurize the pressure vessel  12 . At  810 , the patient may be removed when the pressure of the pressure vessel  12  is zero. The system may then be powered down by turning the pneumatic power switch  37  to off, turning the control assembly  14  power switch  26  to off, and closing the oxygen supply valve. 
         [0028]    If it is determined at  802  that the system is not operating in manual mode (i.e., it is operating in automatic mode), a pre-programmed pressurization/depressurization profile is selected by the system operator at  812  via, for example, the display screen  40 . The profiles from which the operator chooses may be stored in the memory device  44  of the computer  42 . In one embodiment, each profile is a graphical representation of a treatment profile and contains parameters such as desired pressures, rates of change and duration of dwells, an example of which is shown in  FIG. 10 . In one embodiment, a profile with certain constraints on the parameters may be created and loaded into the memory  44  of the computer  42 . Upon selection of the desired profile, the selected profile is downloaded into the control valve  52 . At  814 , when the start/stop button  36  is pressed, the system executes the profile by instructing the control valve  52  to pressurize and depressurize the pressure vessel  12  at specific ramp rates according to the selected downloaded profile. When the pressure vessel  12  is depressurized, the patient is removed and the system may be powered down. 
         [0029]      FIG. 9  illustrates a flowchart of an embodiment of a method for operating a hyperbaric chamber automatically. At  900  the desired profile is loaded into the memory device  44  of the computer  42 , and subsequently downloaded into the control valve  52 . At  902  the profile is executed by instructing the control valve  52  to pressurize the pressure vessel  12 . At  904  the process determines whether the profile has been completed. If so, the process ends at  906 . If the profile has not been completed, it is determined if manual mode has been activated by a depression of the automatic/manual selection switch  38 . If manual mode has not been activated, the process determines at  910  whether an error has occurred for which a failsafe mode should be entered. Examples of errors include system power loss, activation of system (controller reset) when chamber  12  pressure is greater than 0 psig, pressure vessel pressure outside a maximum range, signal loss, or rate of change greater or lower than specified. 
         [0030]    If an error has occurred, an error mode is entered at  912 . If no error has occurred, profile execution continues at  902 . If manual mode has been activated as determined at  908 , at  914  profile execution is paused by the computer  42  and manual control is enabled so that the operator may manually control pressure and rate. At  916  it is determined if automatic mode has been reactivated by a depression of the automatic/manual selection switch  38 . If not, manual control is continued at  918 . If automatic mode has been reactivated, the profile is resumed at  920  and the profile is executed at  902 . 
         [0031]    In various embodiments and by way of example, a system may be constructed according to the teachings herein that has the following characteristics and operating parameters: (1) input supply pressure is between 50 and 90 psig; (2) operational temperature is between 50° F. and 100° F.; (3) operational relative humidity between 5% and 95%, non-condensing; (4) operational gas may be 100% oxygen, 100% nitrogen, or atmospheric air; (5) controlled flow capacity may be up to 50 SFCM; (6) output pressure may be controlled from 0 psig to 30 psig; and (7) the rate of pressure change may be controlled between 0 psig and 5 psig. 
         [0032]    While several embodiments of the invention have been described, it should be apparent that various modifications, alterations and adaptations to those embodiments may occur to persons skilled in the art with the attainment of some or all of the advantages of the present invention. It is therefore intended to cover all such modifications, alterations and adaptations without departing from the scope and spirit of the present invention.