US20130333703A1 - Ventilator breath display and graphic user interface - Google Patents

Abstract

The invention is directed to a ventilation control system for controlling the ventilation of a patient. The ventilation control system utilizes a user-friendly user interface for the display of patient data and ventilator status. The user interface includes a graphic representation of a breath cycle that displays the breath cycle currently being ventilated, and is also responsive to changes in ventilation settings to assist the user in evaluation the effect of those changes on the ventilator strategy before the changes are implemented.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This application is a continuation of U.S. patent application Ser. No. 11/856,632 filed Sep. 17, 2007; which is a continuation of U.S. patent application Ser. No. 11/366,259 filed Mar. 2, 2006, now U.S. Pat. No. 7,270,126; which is a continuation of U.S. patent application Ser. No. 10/733,794 filed Dec. 10, 2003, now U.S. Pat. No. 7,036,504; which is a continuation of U.S. patent application Ser. No. 09/882,200 filed Jun. 15, 2001, now U.S. Pat. No. 6,675,801; which is a continuation of U.S. patent application Ser. No. 09/253,387 filed Feb. 19, 1999, now U.S. Pat. No. 6,269,812; which is a continuation of U.S. patent application Ser. No. 08/818,807 filed Mar. 14, 1997, now U.S. Pat. No. 5,881,723, the contents of which are hereby incorporated in their entirety by reference.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• This invention relates generally to the field of medical equipment for respiratory therapy and more specifically to the user interface for a ventilator used for monitoring and controlling the breathing of a patient.
• 2. Description of the Related Art
• Modern patient ventilators are designed to ventilate a patient's lungs with breathing gas, and to thereby assist a patient when the patient's ability to breathe on his own is somehow impaired. As research has continued in the field of respiration therapy, a wide range of ventilation strategies have been developed. For example, pressure assisted ventilation is a strategy often available in patient ventilators and includes the supply of pressure assistance when the patient has already begun an inspiratory effort. With such a strategy, it is desirable to immediately increase the pressure after a breath is initiated in order to reach a target airway pressure for the pressure assistance. This rise in pressure in the patient airway which supplies breathing gas to the patient's lungs allows the lungs to be filled with less work of breathing by the patent. Conventional pressure assisted ventilator systems typically implement a gas flow control strategy of stabilizing pressure support after a target pressure is reached to limit patient airway pressure. Such a strategy also can include programmed reductions in the patient airway pressure after set periods of the respiratory cycle in order to prepare for initiation of the next patient breath.
• As patient ventilator systems and their various components, including sensors and control systems, have become more sophisticated, and more understanding is gained about the physiology of breathing and the infirmities and damage which form the requirements for respiratory therapy, the number of variables to be controlled and the timing and interrelationships between the parameters have begun to confront the caregiver with a daunting number of alternative therapeutic alternatives and ventilator settings. Also, in such a complex environment, the interface between the ventilator and the caregiver has often not been adaptable to the capabilities of the operator, thus running the chance of either limiting the choices available to a sophisticated user or allowing a relatively less sophisticated user to chose poorly from the alternatives presented. Thus, it would be beneficial if a ventilator interface guided the user through the setup or therapy modification process, illustrating the relationship between changes, preventing incorrect or dangerous settings and sounding alarms or other audible indications of invalid settings when something is about to done that exceeds limits, but also allowing the advanced and sophisticated user to gain access to the full range of ventilator capabilities through an interface which both presents the various parameters and allows the visualization of their relationships.
• Clinical treatment of a ventilated patient often requires that the breathing characteristics of the patient be monitored to detect changes in the breathing patterns of the patient. Many modern ventilators allow the visualization of patient breathing patterns and ventilator function and the caregiver adjusts the settings of the ventilator to fine tune the respiratory strategy being performed to assist the patient's breathing. However, these systems have been, up until now, relatively difficult to use by the unsophisticated user unless a limited number of options are selected. For example, in one prior art system, only a single respiratory parameter may be altered at a time. Moreover, the various respiratory parameters must often be entered into the ventilator controller in a prescribed order, or, where no order is prescribed, certain orders of entry should be avoided, otherwise the intermediate state of the machine before entry of the remaining parameters may not be appropriate for the patient. This inflexible approach to ventilator setup requires additional time and training if the user is to quickly and efficiently use the ventilator in a critical care environment.
• Previous systems have also been deficient in that it is often difficult to determine the underlying fault that has caused an alarms to be sounded, and what controls or settings should be adjusted to cure the problem causing the alarm. For example, prior alarm systems have consisted of nothing more than a blinking display or light with an alarm to alert the user that a problem existed. Similarly, many prior art systems provided only limited assistance to a user or technician in setting the parameters to be used during treatment. For example, if a technician attempted to enter a setting that was inappropriate for the patient because of body size or for some other reason, the only alarm provided may have been an auditory indication that the value was not permitted, but no useful information was provided to assist the technician in entering an appropriate setting.
• One problem consistently presented by prior art ventilator control systems has been that the user interface has offered relatively little to guide and inform the user during the setup and use of the ventilator. Prior systems typically utilized a single visual display of the operating parameters of the ventilator and sensed patient parameters. Alternatively, prior systems may have numerous fixed numeric displays, certain of which may not be applicable during all ventilation therapies. Even when more than one display has been provided, users typically received limited feedback, if any, from the control system indicating the effect that changing one particular setting had on the overall respiratory strategy. If a parameter was to be adjusted, the display would change to display that particular parameter upon actuation of the appropriate controls, and allow entry of a value for that parameter. However, the user was provided with no visual cue as to how the change in the parameter value would effect the overall ventilation strategy, and thus had no assistance in determining whether the value entered for the parameter was appropriate for the patient.
• What has been needed and heretofore unavailable in patient ventilators is a user friendly graphic interface that provides for simultaneous monitoring and adjustment of the various parameters comprising a respiratory strategy. Such an interface would also preferably guide sophisticated users in implementing ventilation therapies, provide guidance on the relationships between parameters as they are adjusted, allow rapid return to safe operation in the event that an undesirable strategy was inadvertently entered, provide alarms that are easily understood and corrected and present all of the relevant information in an easily understood and graphic interface. The present invention fulfills these and other needs.
SUMMARY OF THE INVENTION
• Briefly, and in general terms, the present invention is directed to a graphic user interface system for controlling a computer controlled ventilator to provide respiratory therapy to a patient. In a broad aspect of the invention, the invention includes a digital processor, a touch sensitive display screen and entry means cooperating to provide a user-friendly graphic interface for use in setting up and carrying out a wide variety of respiratory therapies. The processor controls the displaying of a plurality of screens, including user selectable graphic on-screen buttons for setting the values of various ventilator operating parameters for controlling the ventilator. Depending on the on-screen button touched, the processor causes different graphics to be displayed on the screens, provides graphic representations of the effect on the overall respiratory strategy caused by changes to the settings, and may also provide displays of patient data, alarm conditions; and other information.
• In one preferred embodiment of the invention, the system includes the use of a digitally encoded knob for altering selected and displayed values of ventilation parameters, with the acceptable values indicated and unacceptable values alarmed and/or limited to prevent harm to the patient. The digital encoded rotation of the knob may be analyzed by the processor and a magnification factor applied to the knob output to increase the speed with which displayed values are altered. The magnification factor may also be used in the event of an overshoot condition to assist a user in recovering from the overshoot.
• In another preferred embodiment of the invention, the processor may detect the connection of a patient to the ventilator when the ventilator is powered-up. The processor may then, in response to such a detection, start up the ventilator using a predetermined set of ventilator control settings deemed to be safe for the widest possible variety of patients.
• In a further preferred embodiment of the invention, the processor may only display ventilator control settings appropriate for a selected mode of ventilation. The ranges of values of the appropriate settings, or bounds of the ventilation, may be limited by the processor in response to the selected mode of ventilation such that only those values determined to be appropriate are displayed, thus limiting the opportunity to select incorrect settings. Additionally, the processor may be responsive to specific values entered for certain of the ventilator settings to adjust the ranges of values allowed for ventilator settings dependent on the certain settings. Further, the processor may be programmed to require that a so called “ideal body weight” be entered before beginning ventilation of a patient, and then only ranges of values for settings that would be appropriate for ventilation of a patient with that ideal body weight are displayed.
• In another presently preferred embodiment of the invention, the graphic user interface system includes at least two touch sensitive screen displays, a plurality of manual parameter controls, including at least one control knob that is activated upon selection of a parameter to be controlled and displayed on the screen, and a microprocessor controller which controls the logic and arrangement of the screen displays and the interface with the ventilator. The system of the invention includes protocols programmed into the microprocessor for entry of parameters within ranges predetermined to be appropriate for the patient parameters entered, alarms and other audible indications of invalid entry associated with entries outside of the acceptable ranges of parameters or inappropriate operation such as startup with a patient connected to the ventilator, and the ability to lock selected parameters while allowing for user variation of other parameters.
• In another presently preferred embodiment of the invention, the user is provided a graphic interface in which the user is allowed to view and adjust a variety of alarm limits and is able to vary the levels at which the alarms are set off, within limits that are preset by the programming of the microprocessor as representative of values that are not to be exceeded, either as a function of ideal body weight or general parameters for all patients. The resultant setting of a filtered set of alarms may then be used by the user to avoid the setting of parameters that are likely to result in patient distress or other problems with the therapy, while still allowing the sophisticated user to configure a therapy that is customized for the particular patient.
• In one presently preferred embodiment, the invention also allows the user an “undo” option in which a previously successful setting is reestablished after the user realizes that a series of proposed changes are likely to unworkable for the patient.
• In yet another presently preferred embodiment of the invention, the user is provided with alarm indicators indicating the severity of a particular alarm. Alarm messages are also displayed in a selected screen area of the graphic user interface to assist the user in alarm recognition and understanding. Each alarm message may comprise an identifying message identifying the alarm being indicated, an analysis message providing information about the condition that caused the alarm to be indicated, and a remedy message suggesting steps that may be taken by the user to correct the alarm condition.
• In a further currently preferred embodiment of the invention, the processor allows the user to configure the graphic user interface to provide a display of the current and/or proposed breath parameters and a graphic representation of the breath timing controlled by those parameters. Such a display allows the visualization of relationships between breath parameters, and, while parameters are being changed, provides the user with a visual representation of the effect of the proposed changes on the ventilation strategy while simultaneously allowing the user to view current settings, thus allowing the user to simultaneously view “where they are now” and “where they are going to be.”
• From the above, it may be seen that the present invention represents a quantum leap forward in the user interface available for patient ventilation. While assisting the sophisticated user in both visualizing the ventilation strategy and performance of the patient on the ventilator, it also guides and controls the less sophisticated user in setup and understanding of the relationships between ventilator settings. The invention provides these benefits while enforcing fail-safe functioning in the event of a variety of inadvertent or erroneous settings or circumstances.
• These and other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
• In the drawings, where like reference numerals indicate like or similar components, elements and features across the several figures:
• FIG. 1 is a schematic diagram of showing a patient receiving respiratory therapy from a ventilator system comprising a graphic user interface and a respirator constituting one embodiment of the present invention;
• FIG. 2 is a schematic diagram, primarily in block form, of the various subsystems of the graphic user interface shown inFIG. 1;
• FIG. 3 is frontal plan view showing external details of graphic user interface ofFIG. 1;
• FIG. 4 is a schematic diagram, primarily in block form of the sequence of display screens typically displayed by the graphic user interface ofFIG. 3;
• FIG. 5 is an illustration of a ventilator startup screen displayed upon startup of the graphic user interface ofFIG. 3;
• FIG. 6 is an illustration of a main controls setup screen used to set the main control settings of the ventilator ofFIG. 3;
• FIG. 7 is a schematic diagram, primarily in block form, illustrating how the adjustment of certain settings affects the applicability of other settings used to control the ventilator ofFIG. 3;
• FIG. 8 is an illustration of a proposed vent settings screen including a breath diagram;
• FIGS. 9A,9B, and9C are illustrations depicting the display of the breath diagram ofFIG. 8 dependent upon the values of the parameters represented by the breath diagram;
• FIG. 10 is an illustration of an alarm setup screen including graphical representations of various alarms settings, acceptable alarm setting parameter ranges, and current patient data;
• FIG. 11 is an illustration of the upper display screen ofFIG. 3;
• FIG. 12 is an illustration of a “More Alarms” display screen displayed within the information area of the display screen ofFIG. 11;
• FIG. 13 is an illustration of a “Waveforms” display screen displayed within the information area of the display screen ofFIG. 11;
• FIG. 14 is an illustration of an “Apnea Ventilation In Progress” display screen displayed within the information area of the display screen ofFIG. 11; and
• FIG. 15 is an illustration of an “Apnea Settings” display screen displayed within the information area of the lower display screen ofFIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• The present invention provides a sophisticated graphic user interface and ventilator breath display capability that allows great flexibility in the setup of the ventilator and visualization of the effect that proposed changes to the ventilator setup may have on the ventilation strategy. More particularly, the invention provides a graphic representation of a breath cycle that allows the user to visually evaluate the effect of such changes, and also to select among appropriate parameters a parameter to “lock” and hold constant while other parameters are changed.
• The drawings will now be described in more detail, wherein like referenced numerals refer to like or corresponding elements among the several drawings.
• FIG. 1 shows apatient1 receiving respiratory therapy from a ventilator system having agraphic user interface20 connected to and controlling a breath delivery unit, orrespirator22. The patient is connected to therespirator22 by a patient circuit comprising aninspiratory line2, andexpiratory line4, and apatient connection tube6, all connected by a patient connector (not shown) of a type well-known in the art. Therespirator22 includes a processor orcontroller60 which controls the real-time operation of therespirator22.
• FIG. 2 depicts thegraphic user interface20 ofFIG. 1 in more detail. Generally, thegraphic user interface20 comprisesuser inputs25, aprocessor30 andmemory35 comprising read only memory, random access memory or both. Thememory30 may be used to store current settings, system status, patient data and ventilatory control software to be executed by the computer. Theprocessor30 may also be connected to a storage device, such as battery protected memory, a hard drive, a floppy drive, a magnetic tape drive or other storage media for storing patient data and associated ventilator operating parameters. Theprocessor30 accepts input received from theuser inputs25 to control therespirator22. Theventilation control system20 may also includestatus indicators45, a display for displaying patient data and ventilator settings and an audio generator for providing audible indications of the status of theventilator system10.
• Thememory35 and amemory65 associated with therespirator processor60 may be non-volatile random access memory (NVRAM) for storing important, persistent variables and configuration settings, such as current breath mode setup. Typically, during normal operation of theventilation control system20, such an NVRAM functions similarly to a typical random access memory. If, however, a low-voltage condition is detected, such as may occur during a brown-out or at the beginning of a power failure, the NVRAM automatically stores its data into non-volatile storage.
• Thegraphic user interface20 includes aninterface32 for providing control signals from theprocessor30 to therespirator processor60 of therespirator22, and also for receiving signals fromsensors27 associated with therespirator22 indicative of patient condition and the status of therespirator22. Theprocessor30 of thegraphic user interface20 may also receive input representative of various clinical parameters indicating clinical condition of thepatient1 and the status of the respiratory therapy from thesensors27 in therespirator22. The interface may include, for example, an ethernet connection of a RS-232 serial interface. Acable34 having an appropriate number of conductors is used to connect therespirator22 to an appropriate connector (not shown) of theinterface32.
• A preferred embodiment of thedisplay50 incorporating a user interface is illustrated inFIG. 3. Generally, thedisplay50 comprises anupper display60 and alower display70,dedicated keys80,82,84,86,88,90,92,94,96,98,100,102,104 andknob106. As will be described in more detail below, additional user inputs are dynamically provided by on-screen buttons that are drawn on the upper andlower displays60 and70. Typically, each dedicated key or on-screen button includes, within the outline of the button, either a graphic icon or text identifying the purpose of the button to the user. These graphic icons or text enhance the ease of use of what would otherwise be a confusing array of user inputs. Moreover, the use of graphic icons or text to identify the function of dynamically generated on-screen buttons provides for virtually unlimited opportunities to add functions to thegraphic user interface20 by upgrading the programming of theprocessor30 as new functions are desired by the users of the system. Additionally, the use of graphic icons overcomes the potential problem of identifying the functions of a button where language comprehension may be a problem, such as the use of the ventilator in a country where English is not readily understood.
• Referring again toFIG. 3, key80 is identified with a graphic design in the form of a stylized padlock. Actuation of key80 by an operator locks the keys and buttons of thegraphic user interface20 to prevent inadvertent altering of the settings of the system.Keys82 and84 control the contrast and brightness of thedisplays60,70.Key86 bears a stylized graphic design representative of a speaker emitting sound, and a graphic indicative of a volume control. Thus, key86 is easily identifiable as a control for altering the loudness of audible alarm signals provided by thegraphic user interface20.Key92 bears a “?” and actuation ofkey92 activates a help system to assist a user in operating thegraphic user interface20.
• Keys94,96,98 and100 control various aspects of the ventilator, and are used by an operator to override the automatic settings of thegraphic user interface20. When key94 is pressed, theprocessor30 of thegraphic user interface20 provides a signal over the 32 to the processor in therespirator22 instructing the respirator processor to ventilate the patient with 100% oxygen for two minutes. The processor in therespirator22 also starts a timer and causes the value of the time at any given instant to be written to a memory associated with the respirator processor. When the value in the respirator memory is equal to two (2) minutes, indicating that the 100% oxygen gas mixture has been provided to the patient for two (2) minutes, the respirator processor controls therespirator22 to stop the flow of the 100% oxygen to the patient. If the user presses key94 during the two (2) minute duration of the 100% oxygen ventilation, the value of the time stored in the memory is reset to “0” and timing continues for an additional two minutes. Typically, the respirator processor may be programmed to respond to any number of actuations ofkey94 without prompting the user for validation or before sounding and displaying an alarm. Alternatively, the respirator processor may be programmed to respond to only a limited number of actuation of key94 before sending a signal through theinterface32 to theprocessor30 of thegraphic user interface20 requesting theprocessor30 to provide a visual prompt on thedisplay50 and/or to control theaudio generator55 to sound an audible alarm indicating that an allowed number of actuations ofkey94 has been exceeded.
• When key96 is pressed during an exhalation, theprocessor30 controls the ventilator to immediately provide an inspiration. Actuation of key98 results in an extension of the expiration phase. Similarly, actuation ofkey100 results in a lengthening of the inspiration phase.
• Key102 is labeled with the text “Clear” and actuation ofkey102 causes proposed changes to the value of a currently selected setting, to be discussed in more detail below, to be cleared.Key104 is labeled with the text “Accept.” When key104 is touched, any proposed changes to the ventilator settings are confirmed, and become the current ventilator settings.
• Knob106 is used to adjust the value of an individual setting selected by pressing eitherkeys82,84 and86 or certain on-screen buttons.Knob106 is mounted on a shaft whose rotation is digitally detected by a rotary encoder/decoder, such that theprocessor30 receives signals indicating not only the magnitude of the rotation ofknob106, but also the speed and rate of acceleration and deceleration of the rotation ofknob106. These signals are interpreted by theprocessor30 to display allowable values for the selected setting. In one embodiment of the present invention, theprocessor30 is responsive to the signals indicative of the speed of rotation ofknob106 to calculate a velocity based magnification factor dependent on how fast and how long the user turned the knob that is applied by theprocessor30 to adjust the increment of the values displayed. Theprocessor30 uses this magnifying factor to increment the displayed values in larger increments whenknob106 is rotated rapidly, and incrementing the displayed values in smaller increments whenknob106 is rotated slowly.
• A common problem using rotating knobs where a magnification factor is applied in this manner is that there is inevitable “overshoot” of the desired value. Following an overshoot the user must reverse the direction of rotation of the knob. This reduces the speed of rotation of the knob to zero, and eliminates the magnification. Elimination of the magnification, however, results in more rotation and time to recover from the overshoot. One novel aspect of the present invention is that theprocessor30 does not reduce the magnification factor to zero when the knob is counter rotated, as described above. Rather, theprocessor30 applies a magnification factor to the counter rotation to reduce the amount of rotation of theknob106 necessary to recover from the overshoot. The processor sets a time-based limit on how quickly the magnification factor is allowed to decrease, thus ensuring that some magnification remains during overshoot recovery.
• Additionally, theprocessor30 may provide signals to theaudio generator55 to cause theaudio generator55 to provide an audible indication of the rotation ofknob106. For example, theaudio generator55 may generate a “click” for a predetermined amount of rotation of theknob106 or to signify that an on-screen button or dedicated key has been actuated. Theaudio generator55 may also provide an audio signal to the user if the maximum or minimum value of the range of values for the selected setting has been reached, indicating that further rotation of theknob106 will not cause any larger or smaller values to be displayed.
• Referring again toFIG. 3, the display area of theventilation control system20 comprises anupper display60 and alower display70. Theupper display60 is divided into four non-overlapping areas. These areas are “vital patient data”area110, an “alarm message”area120, an “information area”130 and a “controls”area140.Area130 is a multipurpose area that maybe used to display, for example only, screens depicting current alarms, an alarm history log, real-time waveforms, measured patient data that is not otherwise displayed in the vitalpatient data area110, quick reference information, a log of diagnostic codes, operational time for system components, a ventilator test summary, the current ventilator software hardware configuration, a log of the results from running a short self test, apnea ventilation settings and safety ventilation settings.
• Similarly, thelower display70 is divided into five non-overlapping areas. These areas are a “main settings”area150, an “information area”160, a “controls”area170, a “symbol definition”area180 and a “prompt”area190. Examples of information displayed inarea160 include, but are not limited to screens displayed during ventilator startup and ventilator setup, apnea setup, alarm setup, new patient setup, communications setup, date/time setup, miscellaneous setting not otherwise shown in themain settings area150 and breath timing graphs.
• It will be understood that the labeling of the four non-overlapping areas of theupper display60 and the labeling of the five non-overlapping areas of thelower display70 are not critical to the present invention, but are for convenience only. Thus, the areas could have other labels, depending on the information desired to be conveyed.
• The display area also includes an alarm display area generally indicated byreference numeral108. Thealarm display area108 includes a highurgency alarm indicator110, a mediumalarm urgency indicator112 and a lowurgency alarm indicator114. Thealarm urgency indicators110,112 and114 may be light emitting diodes or any other means of providing a visual indication of an alarm. Additional indicators (not shown) may also be included below the alarm indicators.
• Low urgency alarms are used to inform the user that there has been some change in the status of the patient-ventilator system. During a low urgency alarm, the lowurgency alarm indicator114 lights, an audible alarm having a tone indicating that a low urgency alarm event has occurred, and an alarm message is displayed in thealarm message area120 of theupper screen60. During a medium urgency alarm, the medium urgency alarm indicator lights, a medium urgency audible alarm is sounded, and an alarm message is displayed in thealarm message area120 of theupper screen60. Because medium urgency alarms typically require prompt attention to correct the cause of the alarm, the medium urgency indicator may flash, and the audible alarm may sound repeatedly with a distinctive tone.
• High urgency alarms require immediate attention to ensure patient safety. During a high urgency alarm, thehigh urgency indicator110, which may be colored red, flashes, a distinctive audible alarm is sounded and an alarm message is displayed in thealarm message area120 of theupper screen60.
• Referring now toFIG. 4, the overall hierarchical structure of the user interface comprising the keys, on-screen buttons and upper and lower display screens will be described. When the user of the ventilator turns on the power to thegraphic user interface20 andrespirator22 by actuating a power switch typically located on the respirator22 (not shown), theprocessor30 begins to power itself up by initiating a power on self test (POST). If the user actuates a test button, also typically mounted on the respirator22 (not shown) during the time when the POST is running, the ventilator will start up in a SERVICE mode. If the test button is not actuated, the ventilator will start up in a VENTILATOR mode.
• When the graphic user interface starts up in the VENTILATOR mode, thelower display70 of thegraphic user interface20 displays theventilator startup screen200 depicted inFIG. 5. When theventilator startup screen200 is displayed, themain settings area150 of the lower display has two subareas; theupper subarea152 displays the main ventilator mode settings, while thelower subarea154 displays the values of the ventilator settings appropriate to the main ventilator mode settings that were in use prior to powering down thegraphic user interface20 andrespirator22.
• Thecontrol area170 on thelower screen70 typically contains one or more on-screen buttons (seeFIG. 8), but is blank on theventilator startup screen200, as illustrated inFIG. 5. This illustrates the dynamic nature of the various screens that are presented to the user to assist the user in selecting ventilator settings appropriate to a given respiratory strategy. At this stage of the startup process, no settings other than those illustrated are presented to the user so that the user may not inadvertently enter an inappropriate ventilator setting. Other novel features of the display of the present invention further assisting the user will be described below.
• A message instructing the user as to what action to take next is displayed in theprompt area190. As indicated by the message displayed in the prompt area, it is important that the ventilator be setup before attaching the ventilator to a patient.
• As is illustrated by display depicted inFIG. 5, on-screen buttons such asbuttons225,230 and240 that are active and may be touched by the user to initiate activity are displayed so that the on-screen buttons appear to have a raised, three dimensional appearance. In contrast, on-screen buttons whose actuation is not appropriate on a particular screen are displayed having a flat, non-three dimensional appearance, as, for example, the on-screen buttons displayed insubarea154 of themain settings area150.
• Theinformation area160 of theventilator startup screen200 provides the user with three on-screen buttons to choose from to initiate the next step in completing the setup of thegraphic user interface20. The user may touch the SAME PATIENT on-screen button225 followed by the off-screen ACCEPT key10.4 to set up the ventilator with the settings displayed in themain settings area150. If no previous patient settings are stored in thememory35, the SAME PATIENT on-screen button will not be displayed. Alternatively, if the ventilator is being used to provide respiratory therapy to a patient different from the previously treated patient, the user may actuate the NEW PATIENT on-screen button230. Actuation of the NEW PATIENT on-screen button230 will result in the display of a new patient setup screen. The user may also choose to perform a short self test (SST) of the ventilator and thegraphic user interface20 by touching the SST on-screen button240. The SST on-screen button240 will not be displayed if the ventilator is already connected to a patient.
• Theupper display60 and thelower display70 incorporate touch sensitive screen elements, such as, for example only and not by way of limitation, infrared touch screen elements, to allow for actuation of on-screen buttons, such as on-screen buttons205,210,215,220,225,230 and240. The touch screen elements and theprocessor30 operate in coordination to provide visual cues to the user as to the status of the on-screen buttons. For example, as described previously, the on-screen buttons are displayed in such a manner as to appear to be three-dimensional. When one of the on-screen buttons is actuated by the user touching the display screen with a finger, a pencil or other instrument, the touch screen elements detect the application of the finger, pencil or other instrument and provide the processor3D with signals from which the screen location where the touch occurred may be determined. Theprocessor30 compares the determined location of the touch with the locations of the various buttons displayed on the current screen stored in thememory35 to determine the button, and thus the action to be taken, associated with the location of the touch. The processor then changes the display of the touched on-screen button to make the button appear to be depressed. The processor may also alter the display of the text incorporated into the three-dimensional on-screen button. For example, the SAME PATIENT text displayed on the on-screen button225 normally appears as white letters on a dark or gray button when the button is in an untouched stated. When thebutton225 is touched, theprocessor30 may cause SAME PATIENT to be displayed as black letters on a white button. Additionally, theprompt area190 may change to a white background with black letters to draw the user's attention to theprompt area190 when a message is displayed in theprompt area190.
• Typically, the action initiated by touching an on-screen button is obtained when the user lifts the finger, pencil or other instrument from the surface of the display screen. However, the processor may also be responsive to a user sliding the finger, pencil or other instrument off the on-screen button and onto the remaining surface of the display screen to reset the on-screen button in its un-actuated state and to take no further action. Thus, the action initiated by the touching of the on-screen button may only be obtained when the finger, pencil or other instrument is lifted from the portion of the display screen that is displaying the on-screen button. This feature allows the user to abandon a button touch without activating the function associated with the button in the case where the button was touched inadvertently or in error.
• When the NEW PATIENT on-screen button230 is touched, theprocessor30 responds by displaying a new patient setup screen (not shown) and purges any previously entered settings from thememory35. The new patient setup screen includes an IBW onscreen button for displaying and altering the value for the ideal body weight (IBW) of the patient. The new patient setup screen also includes a CONTINUE on-screen button; however, the CONTINUE button is not displayed until the IBW button is touched to ensure that the user adjusts the IBW to a suitable value. The CONTINUE button is displayed immediately after the IBW button is touched. Thus, if the value for IBW currently stored in thememory35 is acceptable, the IBW does not need to be adjusted, and the CONTINUE button may be touched to accept the current value of the IBW.
• When the IBW on-screen button is touched, the value for IBW currently stored in thememory35 of thegraphic user interface20 may be adjusted by the user by rotating theknob106 to either increase or decrease the displayed value until the value for the IBW desired by the user is displayed. The user may then touch the CONTINUE button to store the new value for IBW in thememory35. When the CONTINUE button is touched, theprocessor30 responds by causing a vent setup screen to be displayed. Because the vent setup screen is being displayed in response to the completion of the new patient setup screen, the vent setup screen is displayed in a new patient mode, and is labeled accordingly.
• Theprocessor30 is responsive to the entered value for the patients' IBW to determine the initial values and ranges, or bounds, of the values of the various ventilator settings that are appropriate for use with a patient having that IBW. For example, the range of appropriate values for the various ventilator settings differ between adults and children. The processor will display only values that fall within the appropriate range of values for selection by the user during setup dependent upon the IBW, and will not accept values for settings that fall outside of the determined range: If the user attempts to enter a value outside of the appropriate range for that patient's IBW, theprocessor30 may provide an audible indication of an attempt to enter an out of range value and/or a prompt to the user that the value is inappropriate.
• Referring now toFIGS. 6-8, the layout and functions of the vent setup screen will now be described. Traditionally, setting up a ventilator required a user to navigate through a number of confusing and complicated displays. A novel aspect of the present invention is the simplification of ventilator setup by hierarchically categorizing the ventilator controls and settings to minimize the number of choices available to a user on anyone screen. The vent setup sequence used to configure the ventilator comprises two display phases. These two phases have been designed to simplify setup of the ventilator by grouping ventilator settings in logically arranged groups. Further, the settings entered during the first phase determine the settings presented to the user during the second phase. In this manner, only those ventilator parameters that are appropriate for the mode settings entered during the first phase are displayed. Additionally, the ranges of values, or bounds, of the displayed settings may be further limited as appropriate depending on the proposed ventilator mode and settings. Moreover, since some ventilator parameters may be dependent on the values selected for certain other ventilator parameters, the ranges of values for the dependent ventilator parameters may be limited in accordance with the settings of those independent ventilator parameters. In this manner, the user is presented only with those settings that are appropriate depending on settings already entered by the user. Such a hierarchical sequencing and presentation are useful in preventing the inadvertent entry of inappropriate ventilator settings.
• Once a value for IBW has been entered, the subsequent phases of the New Patient Setup process are similar to the “Vent Setup” sequence of screens which may be accessed at any time during normal ventilation by touching button321 (FIG. 8). For example, in the first phase of New Patient Setup, a screen is displayed entitled “New Patient Setup” instead of “Current Vent Setup” and is preceded by a screen presenting the proposed setting for IBW. Similarly, in the second phase, the title of the screen is “New Patient Settings” instead of “Current Vent Settings.” Accordingly, the following discussion address the “Vent Setup” sequence.
• When the vent setup screen is first activated, or following the IBW screen utilized during the new patient setup procedure described above, the Main Controls phase depicted inFIG. 6 is displayed. In the Main Controls phase, onlybuttons302,304 and306, representing the main control settings, are visible in theinformation area160 of thelower display screen70. As shown inFIG. 8, however, the values for the currently selected main controls continue to be displayed inarea152, and the currently selected settings are display inarea154 of themain settings area150 of thelower screen70. The values displayed inareas152 and154 remain visible at all times during ventilation setup; thus it may be assumed that they are displayed unless specific reference is made to the display of different information inareas152 and154. When the main controls screen is being displayed during the “New Patient Setup” sequence, the on-screen buttons inarea154 of themain settings area150 are displayed with a flat, non-three dimensional appearance, indicating that they cannot be actuated. During normal ventilation however, the on-screen buttons inarea154 may always be actuated by the user; thus they are displayed with a raised, three-dimensional appearance during normal ventilation.
• As depicted inFIG. 7, the present invention decomposes the traditional mode setting into a simple mode plus separate “mandatory type” and “spontaneous type” settings. There are three modes: “A/C”, or assist/control mode; “SIMV” or synchronous intermittent mandatory ventilation; and “SPONT”, for spontaneous respiration. Dependent on the mode and type selected, theprocessor30 will display only those settings appropriate to that mode and mandatory type. For example, if the user selects “A/C” mode and “PC” mandatory type, theprocessor30 will display on-screen buttons for changing ventilator settings related to pressure control of the ventilation. Similarly, selecting “SPONT” mode and “PS” spontaneous type results in the display of on-screen buttons for changing ventilator settings related to pressure support.
• Referring again toFIG. 6,Button302 is labeled with “Mode”;Button306 is labeled with “Mandatory Type”; andButton306 is labeled with “Trigger Type.” Each of thebuttons302,304 and306 also display the setting currently selected for each of the main control settings. For example,button302 displays “A/C” indicating that assist/control mode is selected. Alternatively, where SIMV or SPONT modes are currently selected,button302 will display either SIMV or SPONT as appropriate. When either SIMV or SPONT modes are currently selected, a fourth button, button308 (not shown) labeled with “Spontaneous Type” may also be displayed. Further, when the mode is set to SPONT, a message may be displayed belowbutton304 indicating that the value displayed onbutton304, “Mandatory Type,” applies to manual inspiration only.
• As with others of the buttons used to make changes to the values of various operational parameters used by theprocessor30 to control the respiratory therapy of a patient, the main control settings on the current vent setup screen are set by touching the desired one of the displayedbuttons302,304,306 or308 (not shown), and then rotatingknob106 until the desired value is displayed. When the desired value for the setting is displayed, the user may provisionally accept and store that value in thememory35 by touching the continuebutton310. Alternatively, if more than one main control setting needs to be changed by the user, the user may defer touching the continuebutton310, and may instead select among the other buttons to change the values of a different main control settings. The user may, if so desired, change the values of each of the main control settings. When the user has changed all of the desired main control settings, the changed values for each of the main control settings may be provisionally accepted, pending completion of the second phase of the ventilator setup procedure, and stored in thememory35 simultaneously by touching the continuebutton310. Thus, the values for the main control settings may be accepted and stored in a batch, rather than one setting at a time. This is advantageous in that entry of multiple settings is easier and less time consuming. Batch entry is also useful in that all of the proposed values for the main control settings are displayed, and may be checked for entry errors by the user before being committed storage in thememory35.
• When the continuebutton310 is touched, the first phase of ventilator setup is complete and the second phase begins. In the second phase of ventilator setup, theprocessor30 displays a proposed vent settings screen320 to prompt the user to complete the vent settings phase of the setup procedure, as depicted inFIG. 8. The proposed vent settings screen is displayed in theinformation area160 of the lower display70 (FIG. 3). This screen includes adisplay326 of the main control settings set in the first phase described above, and anarea328 where a plurality of buttons are displayed. The buttons displayed in thearea328 are for setting the values for particular ventilation parameters that are appropriate to the main control setting. Thus, the buttons displayed inarea328 are dependent upon the values selected for the main control settings in the first phase of the ventilator setup. This display of only those buttons whose settings are appropriate to their associated main control settings simplifies the display, thus aiding the user in setting up the ventilator and preventing inadvertent errors due to user confusion.
• As with the main settings screen displayed during the first phase of the vent setup procedure, the user may select a parameter to change by touching one of the on-screen buttons, such as the “P₁” on-screen button352. When the user touchesbutton352, the button appears to be depressed, and may change color and text contrast as described above. The user then adjusts the value of the setting by turning knob106 (FIG. 3) until the desired value is displayed on thebutton352. If the user is satisfied with the value entered forbutton352, and the other displayed values, the user may touch the PROCEEDbutton356, followed by the ACCEPT key104 (FIG. 3) to complete the vent setup procedure. Alternatively, the user may touch another one of the on-screen buttons, such as the “f” on-screen button350. Whenbutton350 is touched,button352 “pops” up, indicating thatbutton352 is no longer selected, andbutton350 appears to become depressed. An audible indication that the button is touched, such as a “click” may also be provided. In this manner, the values for all of the settings displayed may be changed one after another if desired, or only certain of the settings may be changed, as desired by the user. The user then may configure the ventilator to operate in accordance with all of the changed settings at once in a batch fashion by touching the PROCEED on-screen button356, followed by pressing the off-screen ACCEPT key104.
• FIG. 8 further illustrates additional aspects of the graphical features provided by theuser interface20 that assist the user in setting up and operating the ventilator. As depicted inFIG. 8, themain settings area152 displays the currently active main settings. These settings are easily compared with the main settings entered during the first phase of setup that are now displayed on the proposed vent settings screen inarea160. For example, as illustrated inFIG. 8, the ventilator is currently setup to ventilate in the SIMV mode, and the user has provisionally changed the mode to A/C, as indicated in thedisplay326. Another aspect of the invention is the visual prompt provided to a user that a particular setting has been changed. This aspect is illustrated by the change in the font used to display the value of the setting for “P₁” where the value “15.0” is displayed in italics, indicating that this value has been changed, compared to the normal font used to display the value “16” for “f”, indicating that this value has not been changed.
• If any of the main settings were changed during the first phase of the vent setup procedure were changed, the PROCEED on-screen button356 is displayed on the proposed vent settings screen320. Similarly, if none of the main settings were changed, the PROCEED on-screen button is not displayed until one of the settings displayed during the second phase of the vent setup procedure is changed. If the user is satisfied with the values for the settings that have been entered, the user may touch the PROCEED on-screen button356. The user may then complete configuration of the ventilator settings, replacing the current vent settings with the proposed settings, by pressing the off-screen ACCEPT key104. The off-screen placement of the ACCEPT key104 ensures that no inadvertent changes are made to the ventilator settings.
• If theprocessor30 determines that the vent setup screen has been activated within a predetermined short period of time, for example, within 45 minutes of the most recent time the vent setup screen was used to change values of the ventilator settings, theprocessor30 may display a PREVIOUS SETUP button on the main settings screen300 (FIG. 6). Theprocessor30 removes this button from the screen if any changes are made using the screen. If the user touches the PREVIOUS SETUP button (not shown) on the main30 settings screen, a screen similar to the second phase display depicted in area160 (FIG. 8) is displayed, showing values for the settings as they were immediately prior to the last setting change made using the vent setup screen. The on-screen settings buttons are all displayed in the flat, non-three dimensional state, indicating that they cannot be adjusted. A prompt message is displayed inarea190 explaining that accepting the displayed values will result in the entire previous setup being restored, including old alarm and apnea settings. The previous setup may be re-instated by the user by touching the PROCEEDbutton356, followed by pressing the ACCEPT key104. This feature of the present invention allows a user to quickly restore the ventilator to the settings state it was in prior to a major setup change in the event that the altered ventilation strategy is not successful. A time lime is placed on the availability of the previous settings to avoid the possibility of re-imposing the settings when the patient's condition may have changed substantially. Individual changes to settings may be made to settings in the period following a major settings change without invalidating the settings stored for the previous setup. However, batch changes, that is, the changing of more than a single setting at a time, results in the stored previous settings being replaced with the most recent set of settings. This provides the user with the ability to fine tune the settings made during the major change without losing the ability to “UNDO” all of the major changes and return to the previous settings.
• Referring again toFIG. 8, the proposed vent settings screen320 also includes a graphical representation, or breath diagram330, of the breath cycle that will be provided to the patient based on the settings entered by touching the buttons displayed inarea328 and adjusting the resulting displayed values using theknob106, as described above. The breath diagram330 includes atime line332 that is displayed for scale purposes only, aninspiration bar334 indicating the portion of the total breath duration during which inspiration will take place, anexpiration bar336 indicating the portion of the total breath duration during which expiration will take place, an inspiration/expiration ratio display338 and a totalbreath time display346. Besides the graphical representation of the duration of the inspiration and expiration portions of the total breath cycle, text representing the selected value for the durations may be displayed in therespective bars334 and336. For example, the inspiration phase of the breath is set to require 1.0 seconds and the expiration phase is set to require 2.75 seconds. The colors or shading of theinspiration bar334 and theexpiration bar336 are preferably different to facilitate a user distinguishing between them. For example, theinspiration bar334 may be shaded dark with white text, indicating that the breath timing parameter is “locked”, while theexpiration bar336 may have grey shading and black text. It will be understood that this color scheme is only one example of a variety of color schemes that may be used to enhance the graphical representation of the breath cycle to provide a readily comprehensible display of either the current status of the ventilation or to assist a user in evaluating the effects of proposed changes to the ventilator settings.
• Lock on-screen buttons340,342 and344 are displayed above thetime line332 and display the lock status of the settings for theinspiration bar334, the inspiration/expiration ratio338 and theexpiration bar336 respectively. The user may change the lock status of the settings by selecting and touching one of thelock icons340,342,344. For example,lock button340 displays a graphical representation of a closed, or locked, padlock, whilelock buttons342 and344 display graphical representations of open, or unlocked, padlocks. Touchinglock button340 will result in the lock button changing to the open, or unlocked state. Similarly, touchinglock buttons342 or344 will result in the touched lock button changing to the closed, or locked, state. The effect of the “locked” setting is that the setting will not be automatically changed in accordance with a subsequent change in the breath rate parameter, while both of the settings for the “unlocked” parameters, here, the expiration time and the ration of inspiration to expiration, will be changed.
• The display of the lock buttons is dependent upon the selected main control settings. For example, in the representative example depicted inFIG. 8, main control setting Mandatory Type is set to “PC”, thus causing the lock buttons to appear; if the Mandatory Type is set to “VC”, the lock buttons would not be displayed. When the Mandatory Type is “PC”, only of the three “breath timing” settings, T₁, T_Eor LE is displayed. T₁is set by touching the on-screen button labeled T₁, and adjusting theknob106 until a desired value is displayed. The value will be displayed both on the on-screen button T₁, and in theinspiration bar334 of the breath diagram330. Because the value for T₁, is locked, as evidenced by theclosed lock button340, and the dark shading of theinspiration bar334, changes to the breath rate do not result in a change to the inspiration time; only the expiration time, inspiration/expiration ratio and the total breath time change. If another time parameter, such as T_Ewas locked, changes to the rate would not affect T_Ebut T₁and the inspiration/expiration time ratio would change.
• The above described relationship is apparent fromFIGS. 9A-C. InFIG. 9B, the breath rate has been reduced; thus, the total breath time is increased, as indicated by the value intotal time display344b. Since the value for the inspiration time was locked, the relative length of the inspiration bar334bdid not change, while the relative length of the expiration bar336bincreased. A novel aspect of the present invention evident from the display depicted inFIG. 9B is the change in the location of the totalbreath time display344b. InFIG. 9A, the total breath time display344ais located below thetime line332a. InFIG. 9B, the expiration bar336bhas grown larger because of the increased breath time to the extent that the totalbreath time display344bhas approached the end of thetime line332b. Theprocessor30 maintains the location of each of the graphical features of the displays in thememory35, and constantly assesses whether the display of a graphical feature, such as the breath diagram330, on-screen buttons or text may possibly collide or overlap. In the case depicted inFIG. 9B, theprocessor30 determined that the totalbreath time display344bwould be displayed sufficiently close to the end of thetime line332bthat the totalbreath time display344bwould interfere with the display of the numerical scale of thetime line332b. Accordingly, the processor caused the totalbreath time display344bto be displayed above thetime line332bto avoid such interference. It will be understood that the use of the totalbreath time display344bis for purposes of example only. Any of the text or numeric values displayed in conjunction with the breath timing diagram330 may be displayed as necessary to prevent interference with other graphical elements.
• Theprocessor30 is also responsive to the values of the setting to change the scale of thetime line332 when appropriate. As depicted inFIG. 9C, the total breath duration344chas been increased again, and is now greater than the previous scale of thetime line332c. Accordingly, theprocessor30 has caused thetime line332cto be displayed with a larger scale. As the scale of thetime line332cenlarges, the relative lengths of the inspiration and expiration bars334,336 also change. As was described above, if the relative length of the inspiration bar334cbecomes too small to allow the display of the value of the inspiration time setting within the bar as depicted, the processor may cause the value to be displayed either above, below or to the left of thetime line332cin the vicinity of the inspiration bar334c.
• One advantage of a preferred embodiment of the invention is that the main control settings are displayed on both the vent setup screen and in the main setting area of the 152 of thelower display150. Thus a user may adjust the main settings using either screen. However, it is particularly advantageous to make adjustments to the main control settings using the vent setup screen because only one main setting at a time may be changed in themain settings area152, while multiple changes may be made in the vent setup screen and then accepted by the user and stored in thememory35 of thegraphic user interface20 by the user as a batch.
• Referring now toFIG. 10, the alarm setup screen will be described. Touching the “Alarms” button215 (FIG. 5) on thelower screen70 causes theprocessor30 to display thealarm setup screen400. Thealarm setup screen400 displays graphical representations for those user-adjustable alarms that are appropriate given the values selected for the main control settings. Thus, a user may be presented only with alarm settings required by the ventilation strategy already entered and stored in thememory35 of thegraphic user interface20. This facilitates setup and prevents errors or omissions due to information overload given the relatively small size of theinformation display area160 on thelower screen70 of thegraphic user interface20.
• Ease of use is further enhanced in that eachgraphical representation410a,410b,410c,410dand410eof an alarm includes alabel415 identifying the patient data parameter associated with the alarm and adisplay420 of its current value. The value for the alarm setting associated with particular patient data parameter setting is displayed on anonscreen button425. To further enhance the usefulness and comprehensibility of thegraphical representations410a,410b,410c,410dand410e, theprocessor30 causes the alarm on-screen button425 to be displayed at a location along the graphical line that is proportional to the value of the setting with respect to total length of the graphical line.
• The user may adjust the setting of each of the displayed alarm settings by touching a selected alarm on-screen button, such asalarm button425, and then rotating the knob106 (FIG. 3) until the desired alarm setting is displayed on thealarm button425. As the value for the alarm setting is changed by rotating theknob106, the processor changes the position of thealarm button425 along the graphical line, providing a visual display of the change to the user. The position of the displayedpatient data parameter420 is similarly adjusted.
• Certain alarm settings may also be turned off so that no alarm sounds for selected control settings. One possible display of an alarm in the off state is shown by the location and display of the alarm on-screen button425b.
• Some patient data parameters may require the setting of both upper and lower alarm limit values defining a range of acceptable values beyond which a user desires an alarm to be given, as is depicted by thegraphical representation410c. Alternatively, as depicted by thegraphical representation410d, a lower limit alarm may be turned off by the user, while setting an upper limit alarm to a selected value. Similarly, the upper limit alarm may be turned off while a value for a lower limit alarm is set. When all of the alarms are set, the user may store the values for one, or all of the alarm settings in a batch manner by touching the PROCEEDbutton430 followed by pressing the off-screen ACCEPT key104.
• Referring now toFIG. 11, one exemplary layout of theupper display screen60 of thegraphic user interface20 will now be described. As described above, theupper display screen60 includes fournon-overlapping areas110,120,130 and140. Generally, theupper display screen60 provides a user with information regarding the state of the current ventilation therapy. Vital patient information is displayed in the vitalpatient information area110. The information displayed inarea110 is always displayed when ventilation is in progress, even while thelower display screen70 is being used to modify the settings controlling the ventilation. One novel aspect of the present invention is the display of the current breath type and breath phase in thebreath type area525 shown located in the upper left corner of the vitalpatient data area110. In addition to the “CONTROL” breath type displayed, the ASSIST OR SPONT breath types may be displayed in accordance with the values for the main settings set as described above. The breath phase, that is, inspiration or expiration, is indicated by alternately reversing the display of the breath type in thebreath type area525. For example, the text displayed in thebreath type area525 may be displayed as black letters on a white background during the inspiration phase, and as white letters on a black background during the expiration phase.
• It is not unusual during the course of a ventilation treatment session for values of monitored parameters to exceed the limits set for the various alarms that may be active during the session. Theprocessor30 receives signals from the sensors27 (FIG. 2) for a variety of monitored parameters through theinterface32 and compares the values of those inputs to the values associated with the alarm settings stored in thememory35. When the processor determines that the value of an input violates the value or values for the limit or limits for a particular alarm setting associated with that input stored in thememory35, theprocessor30 may cause an audible alarm to be sounded, and displays a text prompt identifying the monitored parameter, the cause of the alarm and a proposed course of action to correct the out of limit condition in thealarm messages area120. If an event occurs that is potentially harmful to the patient, theprocessor30 may also control the ventilator to abort delivery of the current breath until a user may intervene and correct the condition causing the alarm.
• Many alarm conditions, however, may exist that do not require immediate correction, but are useful to evaluate the course of the respiratory treatment. Accordingly, all alarms are accumulated in an “Alarm Log” that is a chronological listing of all alarms that have occurred and which may be reviewed inarea130 of the upper screen130 (FIG. 3) at any time during or after respiratory treatment. If, for some reason, the alarm log contains records of alarm conditions than may be conveniently stored for latter viewing, theprocessor30 may cause the oldest alarm records to be deleted, and thus they will not be available for viewing.
• If multiple alarm conditions occur during the course of treatment, the number of alarm messages may exceed the display area available in the alarmmessage display area120. Theprocessor30 may display those alarms having the highest priority in thedisplay area120, scrolling alarms having a lower priority off the screen. The user may review alarms having a lower priority by touching the “More Alarms”button510 displayed in thecontrols area140. The scrolled alarm messages are displayed in theinformation area130 of theupper screen60. When the “More Alarms”button510 is touched, theupper screen60 is temporarily re-arrange to mergeareas130 and120 into a combined and larger active alarms display, as depicted inFIG. 12. Touching the “More Alarms”button510 again causes theprocessor30 to redisplay the default screen display depicted in theFIG. 11.
• Each alarm message602 (FIG. 12) includes three messages to assist the user in correcting the cause of the alarm. Abase message604 identifies the alarm. As will be described more fully below, the user may touch the alarm symbol to display a definition of the alarm symbol in thesymbol definition area180 of the lower screen70 (FIG. 3). Ananalysis message606 gives the root cause of the alarm, and may also describe dependent alarms that have arisen due to the initial alarm. Aremedy message608 suggest steps that can be taken by the user to correct the alarm condition.
• As illustrated above, theprocessor30 may be responsive to user commands to display various kinds of information in theinformation area130. For example,FIG. 11 depicts one possible embodiment of theupper screen60 having five on-screen buttons for causing various information and data to be displayed in theinformation area130. Touching “Waveform”button515 causes theprocessor30 to display a graphical plot of the data pertinent to the respiratory therapy being given to the patient. Similarly, touching the “More Data”button530 results in theprocessor30 displaying a screen including a variety of data that may be useful to the user in assessing the status of the patient and the progress of the ventilation therapy. It will be understood that the present invention is not limited to including only the five on-screen buttons depicted inFIG. 11. Because the on-screen buttons are implemented by theprocessor30, with suitable programming theprocessor30 may be enabled to display different or additional on-screen buttons and perform actions in response to their actuation.
• Touching the “Waveform”button515 displays awaveform display screen550 as illustrated byFIG. 13. This display allows for real-time plotting of patient data in the tow plotsareas552 and554. Different plots may be displayed in each of theplot areas552 and554. A plot setup screen (not shown) may be accessed by the user by touching the “Plot Setup”button556. The user may select among plots of pressure versus time, volume versus time, flow versus time and pressure versus volume.
• Thewaveform display screen550 also includes a “Freeze”button558 for freezing any waveform that is currently being plotted in eitherplot area552 or554.
• Touching button558 causes a flashing “Freezing” message to be displayed until the current plot is completed and prevents any changes being made to thewaveform display screen550 by causing the various buttons controlling the scale of the displays, as well asbuttons556 and558 to disappear. The only visible button is an “Unfreeze” button (not shown). When the current plot is complete, plotting stops and the on-screen buttons reappear.
• Other displays may also be accessed by touching the on-screen buttons displayed in thecontrols area140 of theupper screen60. For example, touching the “Alarm Log”button525 causes a screen listing all of the alarm events up to a predetermined maximum number of alarms, including those that have been corrected by the user, that have been sounded during therapy. Touching the “More Screens”button520 causes the display of a set of additional on-screen buttons giving access to additional data not otherwise presented on the main display screens. This feature provides a flexible way to add new features and screens with minimal impact on the overall design of the graphic user interface.
• In some modes of operation, the respirator processor60 (FIG. 2) is responsive to signals received from asensor27 in the ventilator to provide inspiration. In this manner, the inspiration may be provided when the patient begins to draw a breath in, which is sensed by the sensor and results in therespirator processor60 causing the ventilator to provide an inspiration. Therespirator processor60 may be programmed to monitor the rate at which a patient triggers the sensor, and, when that rate falls below a predetermined number of breaths per minute, the value of which may be stored in the memory65 (FIG. 2), therespirator processor60 sends a signal through theinterface32 to theprocessor30 of thegraphic user interface20. In response to this signal, theprocessor30 displays an “Apnea Ventilation In Progress”screen600 inarea130 of theupper display60, as depicted inFIG. 14. A variety of information may be displayed on this screen to inform the user of the status of the patient and the ventilation. For example, the main control settings and the ventilation settings currently active may be displayed along with a message indicating that apnea ventilation is in progress. Simultaneously, therespirator processor60 switches to “Apnea” mode and provides breathing assistance to the patient.
• When therespirator processor60 automatically institutes “Apnea” mode in response to a lack of inspiration by the patient being treated, therespirator processor60 controls the apnea ventilation using values of various settings entered by the user from anapnea setup screen650 that may be displayed in theinformation area160 of thelower screen70 as depicted inFIG. 15 by touching the “Apnea” on-screen button322 on thelower screen70 of thegraphic user interface20. One useful feature of the manner in which the processor controls the displays of the graphic user interface is illustrated inFIG. 15. As is shown, the values for the main control settings and the on-screen buttons for setting the ventilation settings appropriate for those main control settings for the ventilation in process when “Apnea” mode was entered are displayed inareas152 and154 of the lower display screen (FIG. 5). Additionally, the current apnea settings are displayed in theinformation area160, along with on-screen buttons which can be actuated in concert with theknob106 to adjust the apnea settings.
• Referring again toFIG. 5, another novel aspect of the present invention will now be described. Thelower display screen70 includes anarea180 in which theprocessor30 may display a variety of messages to assist the user in setting up the graphic user interface. These messages may be different from, or in addition to prompts displayed by theprocessor30 in theprompt area190 of thelower display screen70. One possible use of thearea180 is to provide a textual definition of a graphic symbol identifying a on-screen button. For example, when a user touches the “Waveform” on-screen button515 on the upper display screen60 (FIG. 11), the text “Waveform” may be displayed by theprocessor30 in thedisplay area180. This feature provides the user with an easily accessible means to determine the functionality of any of the graphically identified on-screen buttons on either the upper or lower display screens60,70 while allowing the elimination of textual information from the displayed on-screen button to simplify the display.
• It is generally an unsafe practice to power-up a ventilator with a patient already attached because the ventilator may attempt to ventilate the patient in a manner which would be harmful to the patient. Therespirator processor60 is responsive to detection of a such a condition to start an “Safety PCV” ventilation mode and to send a signal to theprocessor30 of thegraphic user interface20 to sound an alarm. In this mode, therespirator processor60 controls therespirator22 using a pre-determined set of ventilator setting in pressure-control mode. These pre-determined settings are selected to safely ventilate the widest set of possible patients. Once the new patient, or same patient setup process is completed as described above, the processor terminates the “Safety PCV” mode, and begins ventilating the patient in accordance with the newly entered settings.
• From the above, it will be appreciated that the present invention provides important new capabilities in the display of a graphic representation of a breath cycle for use in evaluating changes to ventilation parameters while using a graphic user interface. While several forms of the invention have been illustrated and described, it will also be apparent that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except by the appended claims.

Claims (1)

We claim:

1. A computer-implemented display for a breathing assistance device, comprising:

a graphical representation of a time scale for indicating data regarding a breath cycle, the breath cycle including an inspiration portion having an inspiration duration and an exhalation portion having an exhalation duration;

an inspiration graphic displayed relative to the time scale, the inspiration graphic comprising a graphical, non-numeric representation of the inspiration duration;

a representation of a calculated measure of the inspiration duration relative to the exhalation duration; and

a numeric representation of the inspiration duration distinct from the calculated measure of the inspiration duration relative to the exhalation duration.

Images