Patent Publication Number: US-2013246089-A1

Title: Method for display and navigation to clinical events

Description:
The present application relates to medical monitoring and clinical data display devices for monitoring the physiological condition of a patient. It finds particular application in improving the display and navigation to events of interest containing patient information on a patient monitoring device, central station monitor, single or multi-patient dashboard display device and will be described with particular reference thereto. 
     Presently, a limited amount of physiological data is capable of being displayed on a patient monitoring device. When an alarm is triggered or an event is detected due to a measured change in the physiological condition of a patient or clinical event, data relating to the alarm or event is displayed. To better diagnose a current physiological state of the patient, the clinician views patient data leading up to and during the alarm or event from a variety of sensors. Monitors typically display current data and store past data. One way to display past data is in the format of an electronic strip chart. That is, data, such as that from an electrocardiogram (ECG) or other physiologic waveform, is displayed along a time line that can be extended back minutes, hours, or even days. With an average heart rate of about 70 beats per minute, scanning this number of heartbeats for events or alarms can be time consuming. Moreover, the occurrence of an alarm or event typically supersedes the display of other physiological data and events that occurred prior to or simultaneously with the alarm. 
     The present application provides a new and improved method of display and navigation of patient information on a patient monitoring device, which overcomes the above-referenced problems and others. 
     In accordance with one aspect, a device for generating visual renderings of medical events and alarms is provided. The device includes a display controller and a display on which visual renderings are displayed. The display controller is programmed to receive data of a selected patient from a data store. The data includes physiological information indicative of physiological status along a time line and segments along the time line corresponding to events and/or alarms. The display controller is programmed to create an event object for each event/alarm segment, including a bar extending along the time line. The display controller is also programmed to label each event object using at least one of color coding, height coding, color intensity coding, and character coding. Finally, the display controller is programmed to control the display in order to display the labeled bar and the physiological data. 
     In accordance with another aspect, a medical monitoring system is provided. The system includes a control processor and a plurality of medical sensors, which sense the physiological status of a patient. The control processor is programmed to compare the physiological status from the medical sensors with at least one of an event and alarm criteria to detect when along a time line each event and/or alarm occurs. The control processor is also programmed to store physiological information indicative of the physiological status, as well as the history related to the history of the event including event creation, event annunciation, user or system response to the annunciation, and event conclusion, along the time line and segments of the time line corresponding to the occurrence of the event and/or alarm in a data store. 
     In accordance with another aspect, a method for generating visual renderings of medical events and alarms is provided. The method includes receiving data of a selected patient, which includes physiological information indicative of physiological status along a time line and segments along the time line corresponding to events and/or alarms. An event object is created for each event/alarm segment including a bar extending along the time line. Each event object is labeled using at least one of color coding, height coding, color intensity coding, and character coding. The labeled event objects are displayed on a display. 
     In accordance with another aspect, a method of grouping events is provided. The method includes collecting alarms and events from at least one other medical device or clinical system and presenting alarms and events of similar cause, body system, or event context, grouped together under a single hierarchical representation. 
     One advantage resides in a hierarchal display of patient event data, allowing multiple physiological parameters and associated events and alarms to be displayed over an extended time range. 
     Another advantage resides in the improved navigation of patient data to locate and evaluate clinical events. 
     Another advantage resides in the concurrent display of system information (e.g. alarm state, confidence level of an event, etc.) and physiological events. 
     Another advantage resides in the improved disclosure to the user as “why”, “where”, “who” and “how” the event or alarm was addressed or acknowledged and responded to, in the system. 
     Still further advantages of the present invention will be appreciated to those of ordinary skill in the art upon reading and understand the following detailed description. 
    
    
     
       The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. 
         FIG. 1  is a diagrammatic illustration of a patient monitoring device in accordance with the present application. 
         FIG. 2  is a diagrammatic illustration of event attributes in relation to physiological data. 
         FIG. 3  is one embodiment of a display of a patient monitoring device with hierarchal grouping of patient events. 
         FIG. 4  is another embodiment of a display of a patient monitoring device where the alarm state is represented through the event object height. 
         FIG. 5  is another embodiment of a display of a patient monitoring device where the alarm state is represented with a darker line in the event object. 
         FIG. 6  is another embodiment of a display of a patient monitoring device where the confidence level of the event is represented by the height of a vertical bar and a unique terminator mark presents additional information. 
         FIG. 7  is a flow chart diagram of the display of patient events on a display of a patient monitoring device. 
     
    
    
     With reference to  FIG. 1 , a patient (not shown) is monitored by various medical monitoring devices or sensors, or clinical information systems  10  that measure physiological parameters of the patient and generate physiological or clinical data indicative thereof. These medical monitoring devices or clinical information  10  may include ECG sensors, IV fluid pumps, blood pressure sensors, SpO2 sensors, pulse sensors, thermometers, respiratory sensors, gas sensors, therapy administration events and clinical order or administration transactions, and the like. Of course, other medical monitoring devices  10  can be associated with a patient, and not all of the above-mentioned medical monitoring devices  10  need be associated with a patient at any given time. It should be appreciated that while five medical or clinical devices  10  are illustrated, fewer or more medical monitoring devices are contemplated. As used herein, medical monitoring devices  10  signify data sources indicating patient health, laboratory results, patient treatment (e.g., administration of medication), or the like. Electronics for receiving signals from the medical monitoring devices  10  and for optionally performing signal processing on such signals are embodied in the illustrated embodiment as a patient monitoring device  12 . The patient monitoring device  12  is frequently located near the patient, e.g. a bedside monitor, or centrally located in a nurse&#39;s station, or the like. The invention may also be practiced in data views available remote from the bedside and care unit via remote access to the system over the hospital LAN, intranet, or internet. It should also be appreciated that the medical monitoring devices  10  and the patient monitoring device  12  could also be embodied into a single device. The patient monitoring device  12 , for example, may be a monitor that travels with the patient, such as the transmitter of an ambulatory patient worn monitoring system, or the like. 
     The medical monitoring devices  10  may be powered by battery, external AC power, or a combination of both. The physiological data can be communicated continuously or periodically. For a given patient, some data may be communicated continuously, such as EGG, and other data, such as blood pressure, periodically. The medical monitoring devices  10  transmit the generated physiological data via a body coupled network, Zigbee, Bluetooth, wired network, wireless network, or the like to a controller  14  of the patient monitoring device  12 . The patient monitoring device  12  serves as a gathering point for the physiological data associated with the events and alarms measured by the medical monitoring devices  10 , and provides storage for the monitored data, as well as relevant time and clinical context to the application, in a data store  16  or other onboard or remote electronic memory. The data store  16  contains both per-patient entries and, based on the application, system wide events. 
     The controller  14  receives the generated physiological data from the medical monitoring devices  10 . Additionally the controller  14  receives data from the alarm and event sources  10 , related to how the system or user acknowledged the alarm or event which is also saved in the data store  16 . The controller  14  includes an event detector  20 , such as a processor, algorithm or unit which compares the data with event criteria from an event criteria memory unit  22 . Events are physiological data variations in excess of selected criteria. When an event is detected, an event marking unit  24  marks the beginning or onset time and end or resolution time of each event as well as how the event was acknowledged , by whom and where. The data and the event markings are stored together in the data store  16 . An alarm detector  26  such as an algorithm or unit, compares the data with alarm criteria from an alarm criteria memory unit  28 . If an alarm condition is detected an alarm marking unit or algorithm  30  marks a beginning or annunciation time which is stored in the data store  16  in conjunction with the data, as well as how the alarm was acknowledged, by whom and where. The detection of the alarm condition also triggers an alarm  32 , such as an auditory and/or visual alarm. A clinician through a user interface  34  acknowledges the alarm which causes an alarm reset unit  36  to control the alarm marker  30  to mark the alarm acknowledgment time in the stored data and resets the alarm  32 . The controller  14 , in one embodiment, includes one or more processors programmed to perform the above described operations. In another embodiment, the controller  14  includes a plurality of processors or units, each designed to function as described above. 
     A display controller  40  which may be part of the controller  14  is controlled by the user interface  34  to retrieve the stored physiological data the event onset times, the annunciation times, the acknowledgement times, and the resolution times from the data store  16  and format the retrieved information for display on a display  42  in a manner which facilitates easy identification and analysis of events and alarms. Rather than storing the data on the monitor  12 , the data can be stored in a remote memory  16 ′. A work station  44  can include a display controller  40 ′ and a display  42 ′. Display  42 ′ may be embodied in remote applications away from the bedside and care unit and via remote access to the system over the hospital LAN, intranet or internet. Several embodiments of suitable display formats which the display controller  40  is programmed or controlled to generate are illustrated in conjunction with  FIGS. 2-6  below. 
     Each event contains event attributes describing the event type (single physiologic parameter, multiple physiologic conditions, system conditions, etc.), event onset time, annunciation time, acknowledgement time, and resolution time. The event onset time is the time identified when the event is first detected by the event detector  20 . The annunciation time is the time when the alarm detector  26  announces the presence of the alarm level to the alarm  32  and causes the alarm  32  to become active (not turned off). The acknowledgement time is the time when the event is acknowledged either by the clinician, or the host system. The resolution time is the time when the event is no longer active. 
     With reference to  FIG. 2 , a diagrammatic representation  50  of the relationship between event attributes and physiological data  52  is shown. The physiological data  52  is shown with system states  54 ,  56 ,  58 ,  60 . A change in the physiological data  52  is identified by the event detector  20  and signaled as the onset time  64 . Following detection of the onset of the physiological event, the alarm is signaled as the annunciation time  66 . The alarm continues as long as the alarm control  56  is set to on, or until the system receives acknowledgement by the user or another stimulus, signaled as the acknowledgement time  68 . The end of the physiological event is identified by the event detector  20  and signaled as the resolution time  70  and is independent from acknowledgment activity. An event duration  72  is a time range beginning with detection of the event at the onset time  64  and concluding with the detection of the end of the event at the resolution time  70 . The alarm duration  74  is the time range beginning with the annunciation time  66  and concluding with acknowledgement of the alarm at the acknowledgement time  68 . 
     As previously mentioned, the display controller  40  controls the display  42  to retrieve and display the events received and stored by the various medical monitoring devices and clinical systems  10 . With reference to  FIG. 3 , the display object is rendered with rows of events collapsed to show the highest level data view  80 . In the case where the subgroups contain multiple events, the expanded rows  82 ,  84  are rendered to represent the event which exists below the higher level grouping  80 . This representation, in one embodiment, is based on color intensity to show over lapping events, each event attribute being a different color. In  FIG. 3 , color transparency is used to show overlapping events. Event objects are overlaid to symbolize the occurrence of events in the timeline. Event onset time  64  of the top row “Asystole” condition is depicted by “A”, annunciation time  66  is depicted by “B”, acknowledgement time  68  is depicted by “C”, and resolution time  70  is depicted by “D”. Overlaid events can be expanded such that each event is rendered in a separate row  82 ,  84  over the same time range or collapsed into a high level data view  80 , 86 , in which multiple events are rendered as a single collapsed row. An “Asystole” bar  80  is expanded into the sub group “Asystole Events”  82  and “*** Asystole Alarms”  84 . A collapsed “Yellow Arrhythmia Alarms”  86  is also shown. In the case where the sub groups  82 ,  84  contain multiple events, the collapsed rows are rendered to represent the event which exists below the higher level grouping. “Asystole”  80  is rendered with rows of events collapsed  82 ,  84  to show the highest level data view  80 . 
     Each object rendered on the display spans the same time range. Each event segment is rendered as an object in a row on the display  20 , in the assigned color and color intensity, over the range of time that the event segment occurred. 
     Event segments that overlap in time are rendered by changing the color intensity, color transparency, or a combination thereof of the overlapping portion. In the preferred embodiment, color intensity is changed to show overlapping events, each event segment being a different color as well. Other embodiments include the use of color transparency or event row height to show overlapping events. In the Yellow Arrhythmia Alarms, two overlapping events/alarms  90 ,  92  are both visible due to the use of color transparencies. An underlying event/alarm can be seen through the overlapping event/alarm as an area of greater color intensity. 
     With reference to  FIG. 4  an event object  100  prior to the alarm object  74  is displayed with reduced in height compared to the rest of the Asystole event object  72 , indicating that the sourcing parameter for the alarm object  74  was at reduced confidence between point “A” and point “B”. In prior provisional patent application US 61/152,979, a system to derive a level of confidence with an event or alarm based on signal quality of the related input signals, is proposed. This indicates to the user why the alarm did not announce at the onset time  64  when it was detected by the arrhythmia detection algorithm. It should be noted that in the figure the confidence in the event is rendered to be constant over time but can be a variable function over time. 
     In  FIG. 5 , the event object  100  prior to the alarm object  74  is rendered with a darker line  102  to represent that the alarm for this event is paused. This information indicates why the alarm did not announce at the beginning of the event (“A”), but rather announced later when the alarm was turned on (B). 
     With reference to  FIG. 6 , a unique commencement mark  110  at the beginning  64  of the event indicate a self terminating event (condition corrected itself), such as a latched alarm, from a user acknowledged alarm, and what acknowledgement was detected (pause alarms, acknowledge alarms, change limits, etc.). The unique terminator mark  110  at the end  68  also provides a target for the user to obtain access to annotations created by event. The height of a confidence bar  112  can also indicate a relative confidence on the validity of the event from such a level of confidence system. A unique mark can alternatively be utilized to indicate an event with low confidence. A family of marks can be used to indicate a variety of useful information. 
     In operation, one or more physiological parameters of a patient are monitored and displayed in real time on a monitor display. When a clinician wants to review the physiological parameters leading up to the current time, the clinician moves back through the data. In one embodiment, the clinician scrolls backward through the data. The color or other graphical depiction of the events and the alarms helps the clinician to find the pertinent time periods. Hovering a tool tip over a selected time range, in one embodiment, causes the graphical event and alarm depictions to be displayed for the highlighted time period. Clicking sets the time focus to the selected time and causes all events in the selected time focus to be displayed. Clicking can also be used to expand and collapse the various event and alarm bars in the selected time focus. 
       FIG. 7  illustrates operation of the display controller  40  or  40 ′ of the patient monitoring or clinical information system device  12  or  44 . In a step  122 , the device  12  receives physiological or clinical data and compares the data with event criteria. In a step  124 , an event object is created to graphically represent each detected event. In a step  126 , each event object is labeled with the color assigned to that event segment type. In a step  128 , the event object width (length) is set to represent the time range the event segment spans. In a step  130 , each event attribute is checked to see if it overlaps with another event attribute in time. If an event attribute overlaps in time with another event attribute  132 , then the color intensity or color transparency of the overlapping portion of the event object is changed to represent that the event segments overlap. In a step  134 , the overlapping and non-overlapping event objects are rendered along the timeline spanning the correct time range. Optionally, in a step  136 , the object height is changed to represent the alarm enablement state, signal quality, or other system properties. Optionally, in a step  138 , a confidence bar is rendered on the object to represent the confidence level of the event having occurred and not being due to a system error. Optionally, in a step  140 , a unique terminator mark is rendered at the beginning or end of an object to signify or present event segments with additional information. 
     The invention has been described with reference to the preferred embodiments. Modifications and alterations may occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be constructed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.