Abstract:
Disclosed are systems and methods which provide a relatively small, preferably easily transportable, interpretive biotelemetric monitor, such as may utilize platforms developed for use as personal digital assistants, adapted for use by non-health care personnel. A preferred embodiment biotelemetric monitor comprises a self-contained EKG monitor providing ICU cardiac monitoring with accurate real-time diagnostic heart rhythm analysis directly to the wearer. Preferred embodiment biotelemetric monitors implement multiple interactive screens to guide a user through a series of screens to help understand the monitored conditions. Moreover, the biotelemetric monitor may operate to analyze and interpret the monitored data to thereby present information with respect to the probable implications of the monitored condition and/or make recommendations which may be useful to the patient at that time. Preferably, communications functionality is included to facilitate communication between the biotelemetric monitor and a host system.

Description:
TECHNICAL FIELD OF THE INVENTION 
   The invention relates generally to biotelemetry and, more particularly, to monitoring, displaying, analyzing, and recording biotelemetric data. 
   BACKGROUND OF THE INVENTION 
   Various devices have been developed to observe, monitor, and/or record biotelemetry data for use in diagnosis and treatment of an individual. For example, electrocardiograms (EKGs) have been developed to monitor the electrical activity associated with a beating heart. By attaching electrical transducers to an individual at particular locations, an EKG may be utilized to provide graphical traces of heart activity. These graphical traces may include specific relevant portions, such as a P wave, QRS complex, T wave, U wave, P-R segment, S-T segment, PR interval, and QT interval, each useful in providing particular diagnostic information. 
   However, such EKGs have typically been very expensive and complex devices. For example, in order to provide all the information described above, EKGs have typically employed 12 leads, where leads are various combinations of signal paths associated with transducer electrodes placed upon the body. 
   Three of these leads, usually designated as leads I, II and III, are bipolar (i.e., they detect a change in electric potential between two points) and detect an electrical potential change in the frontal plane. Specifically, lead I is between a right arm electrode and a left arm electrode, the left arm electrode being positive. Lead II is between the right arm electrode and a left leg electrode, the left leg electrode being positive. Lead III is between the left arm electrode and the left leg electrode, the left leg electrode again being positive. The same three electrodes providing leads I, II and III discussed above are also typically used to form three unipolar leads, known as the augmented leads. These three augmented leads are referred to as aVR (right arm), aVL (left arm) and aVF (left leg), and also record a change in electric potential in the frontal plane. These augmented leads are unipolar in that they measure the electric potential at one point with respect to a null point (one which does not register any significant variation in electric potential during contraction of the heart). This null point is typically obtained for each lead by adding the potential from the other two leads. Additionally, six unipolar leads, each in a different position on the chest and monitoring electrical variations that occur directly under the electrode, record the electric potential changes in the heart in a cross sectional plane. 
   Properly placing this number of leads is often difficult, requiring the assistance of a trained professional. Additionally, equipment for monitoring all 12 leads and providing output of information with respect thereto typically must be complex. Moreover, the information provided by such prior art 12 lead EKGs typically requires reading by a trained professional in order to provide useful diagnostic information. 
   In addition to the complexity generally associated with the use of 12 leads, typical EKGs have additional functionality associated therewith, such as may be useful to professionals utilizing the EKG. For example, EKGs typically are adapted to monitor additional biotelemetry attributes, such as oxygen saturation. EKGs also generally include added functionality, such as including a cardiac defibrillator, a graph printer, and the like. 
   As can be readily appreciated from the above, prior art EKGs are typically provided in a relatively large, complex, and expensive form factor. Although not objectionable in a typical health care provider setting, such as a clinic or hospital, such EKGs are typically not widely available due to such size, complexity, and/or expense related considerations. For example, because of their size and expense, cardiac patients typically do not have availability of EKG machines in their home or office for monitoring and diagnostic purposes. Accordingly, a cardiac patient, or any individual who suspects a heart related anomaly, must typically present himself at a hospital emergency room, or other health care provider facility, in order to have access to an EKG machine for monitoring and diagnosis. Moreover, even if a typical prior art EKG machine were available to such a patient, such as in the patient&#39;s home or office, the use of such a device by the patient would be of limited usefulness as the information presented by the EKG would still require interpretation by a trained professional. 
   Accordingly, a vast amount of time and money are needlessly wasted each year in association with the limited availability of such biotelemetric machines. For example, patients with cardiac type symptoms, such as tightness in the chest, shortness of breath, light headedness, etcetera, must wait in a crowded hospital emergency room or clinic to be placed upon an EKG machine for monitoring and pay the services of a physician and for the use of the EKG machine only to discover that a benign condition, such as a gastrointestinal anomaly, was the cause. 
   Some attempts have been made to address problems associated with such limited availability of such biotelemetric machines, resulting in such devices as the Holter monitor and various forms of event recorders. However, these devices are themselves not without disadvantages. 
   The Holter monitor, for example, was initially developed as a 75 pound backpack to be worn by a patient to record the EKG of the wearer and transmit the signal to a host system. Since its introduction, the device has been greatly reduced in size, providing a more portable form factor, allowing for more freedom of movement with respect to its wearer. However, the use of a typical Holter monitor does not provide its wearer with information, but rather digitally records the EKG information for downloading and analysis by a trained professional at a later time. 
   Similarly, typical event recorders available today do not provide information to a user, but rather simply record an event for later analysis by a trained professional. For example, EKG recording by an event recorder may be initiated as the patient experiences particular symptoms in order to record the EKG coincident with the symptoms. This recorded information may be downloaded for analysis by a trained professional, possibly with notes by the patient as to the particular symptoms experienced at that time, at a later time. 
   Accordingly, a need exists in the art for acquisition, presentation, and/or analysis of biotelemetry data in real-time to a patient. A further need exists in the art for machines providing such biotelemetry data to be portable and relatively inexpensive to facilitate their deployment and widespread use by ambulatory patients. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention is directed to systems and methods which provide a relatively small, preferably easily transportable, interpretive biotelemetric monitor adapted for use by non-health care personnel. A preferred embodiment of the present invention comprises a self-contained EKG monitor providing ICU cardiac monitoring with accurate real-time diagnostic heart rhythm analysis directly to the wearer. 
   Preferred embodiment EKG monitors of the present invention comprise a small, portable, user-friendly, microprocessor controlled unit using multiple interactive screens, such as may implement touch screen technology, to guide a user through a series of screens to help the patient understand the monitored conditions. For example, an EKG monitor of the present invention may monitor various electrodes coupled to the user to present the user with information as to the user&#39;s current rhythm. Moreover, the microprocessor, and associated instruction set of the present invention, may operate to analyze and interpret the monitored data, perhaps utilizing a historical database of data monitored from the user and/or known comparative data, to thereby present information with respect to the probable implications of the monitored condition and/or make recommendations which may be useful to the patient at that time. 
   Preferably, biotelemetric information is provided by the EKG monitor in a hierarchy of screens. For example, a highest level screen might be a monitor screen presenting information with respect to currently monitored attributes. This screen may include interpretive information, such as a general status indicator of “normal,” “arrhythmia,” etcetera, with respect to the monitored condition. Alarms are also preferably provided to alert the user of potentially serious conditions. 
   Screens further down in the hierarchy preferably provide additional detail or information. These screens are preferably navigated by a user and/or displayed upon particular events. For example, an alarm may be triggered with respect to a particular monitored attribute and presented on a high level monitor screen, such as next to a graphical representation of the monitored attribute for which the alarm has been triggered. The user may then be able to select the alarm to display a screen presenting more detailed information with respect to the condition. This screen, or perhaps screens below this screen in the hierarchy, may provide instruction to the user, such as to seek professional care immediately or to take particular action to mitigate risk of permanent injury. 
   Preferred embodiment EKG monitors of the present invention record monitored biotelemetric data, such as to a historical database. Accordingly, this information may be utilized in determining a user&#39;s condition, such as for comparison to a current condition to detect changes, to analyze trends, or even to provide to a health care provider for professional analysis. 
   Embodiments of EKG monitors according to the present invention provide functionality in addition to the aforementioned monitoring, displaying, analyzing, and recording of biotelemetric data. For example, an EKG monitor of the present invention may include communications functionality to facilitate communication between the EKG monitor and a host system, such as a computer, computer network, or telephony device of a health care professional. Such communications may utilize wired and/or wireless links. For example, a preferred embodiment EKG monitor of the present invention may be coupled to a telephone line or network link periodically to download biotelemetric data to and/or receive operational instructions or information from a computer system of the user&#39;s physician. Additionally or alternatively, an EKG monitor of the present invention may include wireless communication capability, such as that compatible with cellular type personal communication services, in order to transmit data periodically and/or real-time, such as to notify emergency personnel of a life threatening condition being monitored. 
   A most preferred embodiment EKG monitor of the present invention is provided in a relatively small form factor to facilitate transportability. For example, an EKG monitor of the present invention may be developed upon a relatively small, and substantially rugged, processor based platform which includes a suitably sized display screen and operates upon battery power. Such platforms have been developed for use as personal digital assistants (PDAs) and have advanced such that processing power, memory capacity, display screen size and resolution, and battery life of this technology may be leveraged in providing an EKG monitor of the present invention. For example, the “pocket PC” variety of PDA, such as may use the INTEL STRONGARM processor under control of the MICROSOFT WINDOWS CE operating system, may be adapted to provide an EKG monitor of the present invention. However, other processing platforms may be utilized according to the present invention, such as those of the PALM series of PDAs using the PALM OS. 
   Accordingly, it should be appreciated that a technical advantage of the present invention is that acquisition, presentation, and/or analysis of biotelemetry data is provided for in real-time to a patient. A further technical advantage of the present invention is that preferred embodiments provide a biotelemetric device which is portable and relatively inexpensive, thereby facilitating deployment and widespread use by ambulatory patients. 
   The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: 
       FIG. 1A  shows a biotelemetry monitoring device according to a preferred embodiment of the present invention; 
       FIG. 1B  shows a functional block diagram of an embodiment of the biotelemetry monitoring device of  FIG. 1 ; 
       FIG. 2  shows a display screen hierarchy of a biotelemetry monitoring device according to a preferred embodiment of the present invention; 
       FIG. 3  shows a block diagram of a display screen of an embodiment of the present invention; 
       FIG. 4  shows pseudo code for populating a display screen such as that of  FIG. 3  with information according to a preferred embodiment of the present invention; and 
       FIGS. 5A–5C  show a biotelemetry monitoring device according to an alternative embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1A  shows a preferred embodiment biotelemetric monitoring device of the present invention as EKG monitor  100 . EKG monitor  100  of the illustrated embodiment comprises case  101 , which preferably presents a relatively small form factor to facilitate transportability. Case  101  is preferably rugged and water resistant. For example, case  101  may be sealed and pressurized with an inert gas, such as nitrogen, to thereby prevent infiltration by dust or water particles. Components of EKG monitor  100  are preferably disposed within case  101  in such a way as to be shock resistant. For example, resilient material, such as rubber, may be utilized at attachment points between case  101  and other components of EKG monitor  100 . Case  100  of the preferred embodiment is further adapted to provide desired functionality, such as storage of wire leads and/or electrodes therein, providing couplers for accommodating belt clips and the like, providing a cover or covers to protect or hide various portions of the monitor, such as interface jacks and/or the display screen, and/or the like. 
   EKG monitor  100  of the illustrated embodiment further comprises display  110 , which preferably presents a relatively large display screen suitable for displaying both graphical and textual information. For example, display  110  may comprise a liquid crystal display (LCD) as is well known in the art. Display  110  may be a monochromatic screen, to reduce costs associated therewith, or may be color. A back or side light may be included with display  110 , to facilitate reading of information therefrom. However, any such light is preferably controllable to conserve energy and, therefore, prolong battery life for use of EKG monitor  100 . Display  110  may incorporate touch screen technology, as is in wide spread use in personal digital assistants (PDAs), to facilitate user input. Of course, other user input devices, such as keyboards, thumb wheels, joysticks, buttons (whether software or hardware and whether programmable or fixed function), trackballs, pointing devices, styluses, and the like, may be used in addition to or in the alternative to the aforementioned touch screen for accepting user input, if desired. 
   EKG monitor  100  of the preferred embodiment is adapted to interface for accepting information, signals, input, etcetera from a number of sources. For example, as mentioned above, EKG monitor  100  is preferably adapted to interface with a user to accept input therefrom. Accordingly, EKG monitor  100  of the illustrated embodiment includes various forms of user interface buttons. 
   A first form of user interface button is shown as software buttons  131 – 134  and  141 – 144 . These software buttons may present programmable button images upon display  110  for selection by a user, such as by touching the corresponding portion of the screen or operating a pointing device to select a desired button. The software buttons may preferably be positioned at any desired location of display  110  and may present information therein or associated therewith, such as to identify the function of the button or present an alarm condition for which the button provides a link to additional relevant information. 
   A second form of user interface button is shown as hardware buttons  151  and  152 . For example, hardware button  151  may provide for powering EKG monitor  100  on and off. Hardware button  152  may provide an always available event record button to allow a user to initiate event recording when experiencing particular symptoms, irrespective of the status of display  110  and, therefore, the software buttons displayed thereon. For example, hardware button  152  may operate in cooperation with memory  12  to identify a portion of monitored biotelemetry data stored therein for association with the occurrence of an event as indicated by manipulation of button  152 . Such cooperation may be useful in providing several minutes of data surrounding the activation of an event record button for analysis of pre and post symptomatic intervals. 
   It should be appreciated that the preferred embodiment hardware buttons, like the software buttons described above, may present information therein or associated therewith. For example, hardware button  151  may have a light emitting diode (LED) disposed therein to indicate a powered on state of EKG monitor  100 . Further information, such as the status of the battery, may be indicated by a change in color or a flashing pattern of this LED, for example. 
   Further interfacing of EKG monitor  100  is preferably provided by interface ports disposed thereon. For example, EKG monitor  100  of the illustrated embodiment includes power interface  161 , such as may be used to interface with an external power supply for receiving operating power and/or recharging an internal battery. EKG monitor  100  of the illustrated embodiment further includes biotelemetric probe interface port  162 , such as may be utilized to interface with one or more electrodes or other probes configured to obtain biotelemetry data. Interface port  163  of the illustrated embodiment provides a data interface, such as may be utilized to couple EKG monitor  100  to a host computer system, a network, the Internet, a telephone system, a printer, a facsimile machine, and/or the like. 
   Although not readily apparent in the illustration of  FIG. 1A , EKG monitor  100  of the preferred embodiment may include one or more additional or other interfaces for use according to the present invention. For example, EKG monitor  100  may include a wireless interface, such as a radio frequency (RF) or infra-red (IR) interface, to allow data communication without EKG monitor  100  being tethered to a host system. Wireless interfaces utilized according to the present invention are not limited to those used in establishing data communication, but may include, for example, wireless interfaces providing various functional features such as position determinations as are available with global positioning sensor (GPS) technology. Such interfaces are represented in the block diagram of EKG monitor  100  shown in  FIG. 1B . 
   Directing attention to  FIG. 1B , a functional block diagram of a preferred embodiment of EKG monitor  100  is shown. The block diagram of  FIG. 1B  includes three primary functional blocks of EKG monitor  100 , those being central processing unit (CPU)  11 , memory  12 , and interface  13 , each of which is provided power by battery  14 . 
   CPU  11  may be any processor configured to operate under control of an instruction set defining operation as described herein, such as a processor from the INTEL PENTIUM family of processors or the MOTOROLA POWERPC family of processors. However, a most preferred embodiment of the present invention leverages portable processor platforms and technology already developed and, therefore, utilizes a processor from the INTEL STRONGARM family of processors developed for use in portable devices. 
   Memory  12  may be comprised of random access memory (RAM), read only memory (ROM), flash memory, magnetic and/or optic storage media, and/or the like. Memory  12  preferably provides storage of an instruction set (e.g., operating system  12 - 1 , monitor application  12 - 4 , and interface control  12 - 5 ) defining operation as described herein as well as user data (e.g., historical database  12 - 2 ) and/or other data (e.g., comparative database  12 - 3 , configuration information  12 - 6 , and reference database  12 - 7 ) useful therewith. For example, memory  12  may provide streaming and/or loop storage of monitored biotelemetry data. 
   Interface  13  may be comprised of any number of input and output devices and/or ports as well as components ancillary thereto. For example, interface  13  may provide biotelemetry input  13 - 1  (such as may correspond to biotelemetric probe interface  162  of  FIG. 1A ), network interface  13 - 2  (such as may correspond to interface port  163  of  FIG. 1A ), wireless interface  13 - 3 , display interface  13 - 4  (such as may correspond to display  110  of  FIG. 1A ), user input interface  13 - 5  (such as may correspond to software buttons  131 – 134  and  141 – 144 , hardware buttons  151  and  152 , and/or a touch screen aspect of display  110  of  FIG. 1A ), and power interface  13 - 6  (such as may correspond to power interface  161  of  FIG. 1A ). 
   Battery  14  is preferably a rechargeable power source, such as a nickel-cadmium or lithium-ion power cell well known in the art. Accordingly, battery  14  may be relied upon to provide operational power to EKG monitor  100  when carried by the user. 
   EKG monitor  100  of the preferred embodiment provides interfacing for a plurality of biotelemetric probes, such as electrodes useful in monitoring electronic signals generated from the operation of heart muscles. Additional or alternative biotelemetric probes useful according to the present invention may include provide information with respect to oxygen saturation, blood pressure, respiration, muscle tension, muscle movement, ocular movement, electroencephalogram, and/or the like. 
   An EKG monitor of a most preferred embodiment provides a 3 lead capability. Preferably the monitor may be adjusted to read any 3 of 6 standard limb leads through 3 separate wire interfaces of the monitor. For example, the wire interfaces may be coupled to electrodes disposed at each wrist and the left ankle, and the user may choose between monitoring the I, II, and III bipolar leads or the aVR, aVL, and aVF unipolar augmented leads (it being appreciated that the leads may be placed on the wrists and ankles with the electrodes behaving as if they were at the shoulders and groin because the limbs serve as electrical conductors to these points). Alternatively, the 3 leads of the preferred embodiment may be any 3 of the 6 unipolar chest leads, or any other combination of leads chosen by the user. 
   Although discussed above with respect to wireline interfacing of various leads utilized to monitor biotelemetry according to the present invention, it should be appreciated that the present invention is not limited to the use of such wireline tethers. For example, wireless probes, such as may utilize a radio frequency (RF) protocol such as BLUETOOTH or IEEE 802.11 or a light frequency such as an infrared (IR) protocol, may be utilized according to the present invention. In such an embodiment EKG monitor  100  may easily be transported in a purse, satchel, or backpack of the user or, perhaps, even left stationary while the user remains within an operational area of the particular probes utilized. 
   Preferably, biotelemetric information is provided by EKG monitor  100  in a hierarchy of screens. A highest level screen may present high level information with respect to operation of EKG monitor  100 , such as to show the biotelemetric data being monitored, provide operational control of the monitor, and/or provide user interfacing to facilitate intuitive navigation of the screens of the hierarchy. Lower level screens may present more detailed information, perhaps making recommendations to a user with respect to a monitored condition, provide particular selected categories of information, and/or provide user interfacing to facilitate intuitive navigation of the screens of the hierarchy. For example, a user may navigate from a first screen presenting high level data and/or a broad overview of monitored data, following the hierarchy, to arrive at secondary screens giving the basic interpretation, perhaps including definitions, and from there further information may be accessed as far as symptoms, causes, recommendations, course of action, need for medical attention, etcetera. 
   Similarly, one or more screens of the preferred embodiment hierarchy may be utilized to solicit information from a user. For example, a user may activate an event recorder button to cause EKG monitor  100  to identify, and perhaps isolate, monitored information for a period of time, preferably pre and post activation of the button, for analysis. This operation may be accompanied by a screen or series of screens soliciting symptom information from the user to be associated with the recorded event, such as for use in analysis or diagnosis. For example, a symptom “wizard” process may be activated to intelligently query the user, preferably interacting to present appropriate questions responsive to input by the user and/or monitored biotelemetric information. 
   An illustrative embodiment of a screen hierarchy is represented in  FIG. 2 , wherein highest level screen  170  of  FIG. 1A  is linked to various lower level screens providing more detailed information and/or selected operational functions. Accordingly, various buttons operational with respect to screen  170  may present particular associated lower level screens when operated. For example, operation of software buttons  131 – 134 , which in the preferred embodiment are associated with alarms, may result in EKG monitor  100  displaying a corresponding one of alarm information screens  231 - 1  through  234 - 1 . Similarly, operation of software buttons  142 – 143 , which in the preferred embodiment are associated with control/navigation, may result in EKG monitor  100  displaying a corresponding one of operation screens  243 - 1  and  244 - 1 . 
   It should be appreciated that the screen hierarchy may include any number of levels of screens. For example, each of lower level screens  231 - 1  through  234 - 1  and  243 - 1  have still lower level screens associated therewith, shown here as screens  231 - 2  through  234 - 2 . Moreover, there may be any number of lower level screens associated with any particular higher level screen. For example, in the illustrated embodiment operation screen  243 - 1 , providing configuration options according to the preferred embodiment, has a plurality of lower level screens, configuration screens  243 - 2  and  243 - 3 , associated therewith. In contrast, operation screen  244 - 1 , providing user condition diagnostic information according to the preferred embodiment, has no lower level screens uniquely associated therewith. 
   According to the preferred embodiment, one or more screens are not strictly restricted to hierarchical access and/or may not be uniquely associated with a particular higher level screen. Accordingly, screens presenting general interest information and/or information or functions desired to be readily available, may be available throughout the hierarchy, or portions thereof. For example, glossary screen  201  of the illustrated embodiment, such as may present definitions of terms used with respect to EKG monitor  100 , and/or reference information  202 , such as may provide instruction and/or general information, may be available from a number of the screens of the preferred embodiment hierarchy. Although such screens may be available from a number of screens in the hierarchy, they may be operable to provide information associated with a particular screen from which they were accessed. For example, glossary screen  201  may provide a definition of a particular word selected upon any screen of the hierarchy from which it has been activated. Similarly, reference information screen  202  may provide context sensitive help and/or general information associated with the context of a particular screen from which it is accessed, if desired. 
   The highest level screen of the aforementioned hierarchy might be a monitor screen presenting information with respect to currently monitored attributes, as represented by monitor screen  170  of  FIG. 1A . Such a screen may provide information with respect to the monitored biotelemetric data, such as graphical representations of lead I (trace  111 ), lead II (trace  112 ), and augmented lead aVR (trace  113 ) and/or alpha numeric representations of monitored attributes (data  122 ), such as may include the heart rate, the PR interval, the QRS complex, QTc, the QRS axis, the ST segment changes, and/or the like. 
   This screen may include interpretive information, such as a general status indicator provided by status indicator  121 , with respect to the monitored condition. The rhythm interpretation provided by status indicator  121  may display the current rhythm being monitored, whether a normal sinus rhythm or an abnormal rhythm, either atrial or ventricular rhythm, and may have detailed interpretation/diagnostic information associated therewith, such as presented upon the same screen or available in a subsequent screen. In use, a monitor application of EKG monitor  100  may learn the user&#39;s normal resting rhythm, even if it is an abnormal rhythm, and recognize when the rhythm changes. Such an analysis of the monitored data may be of particular importance to cardiac patients that frequently go in and out of abnormal rhythms. For example, it would be particularly useful to recognize when a user goes into an abnormal rhythm and alert the user in order to correlate the abnormal rhythm with symptoms, such as for providing an accurate treatment. 
   One such abnormal rhythm that is encountered by a number of individuals is atrial fibrillation. It is not uncommon for an individual to frequently go in and out of atrial fibrillation. The preferred embodiment EKG monitor  100  with regular use will preferably learn the user&#39;s basic rhythm and would alert the user to changes, such as the onset of atrial fibrillation as well as a return to normal sinus rhythm. It should be realized that atrial fibrillation is of particular importance because of the potential for strokes, particularly when the individual returns to a normal sinus rhythm from atrial fibrillation. 
   Similarly, the ST segment may be monitored for ST segment changes to warn of potential problems with the cardiac circulation. This type of monitored data interpretation may be utilized to warn a user in real-time that he is exceeding his cardiac function capability. Similarly, ST measurement information may be used according to the present invention to provide EKG stress test analysis during physical activity. Accordingly, monitor screen  170  may provide information regarding the monitored condition which has been interpreted to a useful conclusion or aggregation. Moreover, such interpretive information may be utilized to apprise a professional of the condition for further analysis and interpretation. 
   Alarms are also preferably provided according to the present invention to alert the user and/or others of potentially serious, or other noteworthy, conditions. Preferably, one or more of the monitored attributes and/or the interpretive results have an alarm indicator associated therewith. If an attribute of such biotelemetric data is outside the range of normal, or other window or threshold established according to the present invention, the alarm will alert the user and/or a professional, such as by sounding a tone, flashing an indicator, establishing a communication link with an external host and/or the like. 
   For example, the embodiment of EKG monitor  100  illustrated in  FIG. 1A  includes alarm buttons  131 – 134  corresponding to data  122 , trace  111 , trace  112 , and trace  113  respectively. As mentioned above, alarm buttons  131 – 134  of the preferred embodiment are software buttons, such as may not only present information with respect to an alarm condition (or lack thereof), but may also provide a user interface, such as to facilitate presenting further information with respect to a particular alarm condition when an alarm button is operated by a user. For example, if data  122  includes a particularly high heart rate for the user of EKG monitor  100 , such as may be determined through entry of a high heart rate threshold in a user configuration database and/or as may be determined by historical analysis of data monitored by EKG monitor  100 , alarm button  131  would preferably display information with respect to the heart rate being particularly high and prompt the user to go into further screens for more information, definitions, possible causes, possible symptoms, diagnostics, and/or recommendations. 
   Accordingly, when an alarm condition is detected by EKG monitor  100  in any of data  122 , trace  111 , trace  112 , trace  113 , and/or any other monitored attribute (whether currently displayed or not), a corresponding one of alarm buttons  131 – 134  may preferably change color, flash, or otherwise operate to attract attention, and present information therein, or associated therewith, to indicate the particular condition resulting in alarm. The user may operate the particular one of alarm buttons  131 – 134  indicating an alarm condition and have displayed a lower level screen with respect to the alarm condition, such as alarm information screens  231 - 1  through  234 - 1  and/or detail/recommendation screens  231 - 2  through  234 - 2 . This further information may explain the alarm condition, provide interpretation of the monitored biotelemetric data, provide a recommended course of action, and/or the like. Of course, rather than awaiting a user to operate a button to display a lower level screen with respect to a particular alarm condition, embodiments of the present invention may operate to automatically display a lower level screen upon one or more alarm conditions, if desired. 
   In addition to the aforementioned changing of the particular alarm button and presenting of information to indicate the particular condition causing alarm, EKG monitor  100  of the preferred embodiment provides further sensory stimulation to alert the user of the alarm. For example, a tone may be sounded simultaneously with the changing of the alarm button through a speaker, piezoelectric device, or other auditory mechanism (all not shown). Additionally or alternatively, the use of digitally synthesized speech may be used, such as to announce the alarm in a particular language, if desired. Additional or alternative means of notifying a user of an alarm condition useful according to the present invention may include vibration of EKG monitor  100  or some portion thereof to stimulate the user&#39;s sense of touch, flashing of a light output by EKG monitor  100  to stimulate the user&#39;s sense of sight, and/or the like. 
   It should be appreciated that notification of an alarm condition is not limited to local stimulus. For example, if a particular alarm condition is of a very serious nature, EKG monitor  100  may establish a communication link with a health care professional and/or rescue personnel in order to summon aid for a user perhaps unable to summon aid for himself. Such a link may utilize the aforementioned wireless communication, perhaps in association with position determining technology such as GPS circuitry of an embodiment of EKG monitor  100 . 
   The use of one or more such means of notification may preferably be selected by a user, such as by using configuration screens  243 - 1  through  243 - 3  of the preferred embodiment. For example, a user may select to have a wireless communication link established for particularly serious alarm conditions in order to minimize the risk of being unable to summon help upon the onset of such a condition. Additionally or alternatively, the user may select to have speech notice, perhaps in a language selected specifically to be likely to be understood by bystanders, in order to increase the likelihood of obtaining assistance when needed, such as when traveling abroad. 
   It should be appreciated that the preferred embodiment monitor screen  170  may provide navigation/control functionality in addition to that associated with the aforementioned alarm buttons. For example, software buttons  141 – 144  may provide various navigational and/or control functions according to the present invention. 
   Software button  141  of the preferred embodiment may provide a first aid function to allow a user to alert rescue personnel quickly when distressing symptoms are experienced. Accordingly, it should be appreciated that the preferred embodiment screen hierarchy of  FIG. 2  does not show a lower level screen associated with first aid button  141 . The preferred embodiment initiates a wireless link with a health care professional or rescue personnel upon operation of this button. Of course, a lower level screen may be associated with operation of this button, such as to show the status of the summon for help. Additionally or alternatively, lower level screens may be accessed to provide instructions as to what first aid measures should be applied, such as through EKG monitor  100  referencing monitored conditions and interpreting those conditions to present a recommended course of first aid treatment. For example, first aid button  141  may provide basic first aid information, including CPR etcetera, for assisting the user or others in an emergency. 
   Software button  142  of the preferred embodiment may provide help or other reference information to a user. For example, help button  142  of the preferred embodiment may access reference information screen  202  of  FIG. 2  to allow a user to navigate an on-line operation manual with respect to EKG monitor  100 . Additionally or alternatively, reference button  142  may access reference information screen  202  of  FIG. 2  to allow a user to browse an electronic reference volume providing general information with respect to conditions to be monitored by EKG monitor  100  etcetera. 
   Software button  143  of the preferred embodiment may provides navigation with respect to operational aspects of EKG monitor  100 . For example, configuration button  143  of the preferred embodiment may provide access to configuration/settings screen  243 - 1 , perhaps displaying presently selected configurable settings of EKG monitor  100 , and/or configuration screens  243 - 2  and  243 - 3 , perhaps allowing selection of particular configurable aspects of EKG monitor  100 . 
   Software button  144  of the preferred embodiment may provide data interpretation and/or diagnosis of a condition to a user. For example, diagnostic button  144  of the preferred embodiment may cause EKG monitor  100  to give an interpretation of the EKG tracings with definitions, recommended courses of action, and/or the like. 
   The preferred embodiment of screen  170  provides for navigation of screens using intuitive links, not necessarily represented by buttons as described above. For example, the three leads displayed upon screen  170  might be paused, for example, and a user may be able to select any the complexes displayed to go to a secondary screen to give a description of that particular complex or an abnormality represented thereby. 
   Although not actually a part of monitor screen  170  of the preferred embodiment, it should be appreciated that hardware button  151  provides an event record button to allow a user to initiate event recording when experiencing particular symptoms and thereby freeze the monitored data displayed upon monitor screen  170 . Accordingly, the preferred embodiment of EKG monitor  100  can store data and/or traces, similar to an event recorder, when a user experiences symptoms, such as lightheadedness, or feels palpitations etcetera. This recorded information may be retrieved later, such as by a data download to a host system, by hard copy output, by viewing of EKG monitor  100  by a trained professional, by facsimile transmission, and/or the like, for further professional diagnostic interpretation. 
   Additionally or alternatively, freezing of such data may be utilized to implement interpretation of the monitored data by EKG monitor  100 . Accordingly, operation of a event record button according to the present invention may trigger data interpretation, such as may be displayed upon a lower level screen and/or recorded for later analysis by a trained professional. It should be appreciated that frequently symptoms occur with or without palpitations and it is difficult to correlate the abnormal rhythms with symptoms and, accordingly, the preferred embodiment event recording and interpretation function of EKG monitor  100  may be utilized to assist in making a correlation. For example, if there is an actual arrhythmia or rhythm problem that is causing any particular symptom, EKG monitor  100  would preferably be able to correlate the two with the event recorder. 
   It should be appreciated that, although described above with reference to a preferred embodiment highest level monitor screen, one or more of the above screen attributes may be present in various other ones of the screens of the preferred embodiment hierarchy. For example, monitored data, whether data  122 , trace  111 , trace  112 , trace  113 , or some portion thereof, may be displayed upon a lower level screen, such as an alarm information screen accessed by an alarm button corresponding to the particular monitored data. Similarly, one or more of the aforementioned software buttons may be present in various ones of the lower level screens. For example, first aid button  141  may be present in all, or substantially all, screens to ensure quick availability thereof. 
   Of course, any or all of the above described attributes may be changed from screen to screen according to the present invention. For example, the information provided in a lower level screen, although corresponding to information presented in a higher level screen, may be formatted differently, may present greater or lesser detail with respect thereto, etcetera. Similarly, the various software buttons available upon various screens in the hierarchy may provide different functionality, be disposed in different locations, be different in number, etcetera. 
   Even where a same attribute is presented from screen to screen, that attribute may be changed in some way. For example, although hardware button  152  will be present in association with each of the screens of the hierarchy, the functionality of this or other buttons may change according to the context of a particular screen then displayed. 
   It should be appreciated that the preferred embodiment of the present invention may provide information, data, control, navigation, operation, and/or the like in addition to or in the alternative to that described above. For example, navigation buttons may be provided to allow scrolling and/or paging through information of a screen where that information is unable to be conveniently displayed upon the physical dimensions of display  110 . 
   Any or all of the aforementioned buttons may be implemented in hardware and/or software such that a menu hierarchy may be developed where a few navigation buttons are used to either display software buttons for choices and/or use programmable buttons for different functions depending on the level of the hierarchy. 
   It should be appreciated that a screen of the preferred embodiment hierarchy accessed at any particular time depends upon such things as a selection by the user, the status of various ones of the monitored biotelemetric data, a screen currently displayed, and/or the like. Accordingly, a particular screen from which monitor screen  170  of the preferred embodiment may proceed may vary depending upon a number of factors. 
   Directing attention to  FIG. 3 , an example of a lower level screen format, such as may be accessed by operation of alarm buttons  131 – 134  of monitor screen  170 , is shown. Additionally or alternatively, lower level screens such as screen  370  of  FIG. 3  may be accessed by various navigation techniques, such as selecting information displayed upon a higher level screen. For example, high level heart rate information may be displayed upon highest level screen  170  which when selected displays a lower level screen presenting detailed information, definitions, current status, analysis of monitored attributes, instructions, and/or the like with respect to the high level information selected. 
   Accordingly, the lower level screen format of  FIG. 3 , presenting screen  370 , includes various informational areas, areas  301 – 307 , in which information appropriate to the circumstances in which the screen was accessed may be displayed. For example, area  301  may present identification of the particular monitored biotelemetric data for which the remainder the information of screen  370  is associated. Area  302  may present a current status determined from the monitored biotelemetric data. Areas  303 – 306  may present further detailed information, such as definitions, symptoms, causes, and recommendations, and/or links to screens providing further detail with respect thereto. Area  307  may present various navigational aids, such as buttons to control scrolling of data, browsing of higher level and/or lower level screens, and/or the like. 
   Pseudo code for populating the areas of screen  370  according to a preferred embodiment of the present invention is provided in  FIG. 4 . For example,  FIG. 4  presents information with respect to the monitored biotelemetric data “heart rate” as may be accessible by selecting heart rate data of data  122  and/or by selecting alarm button  131  when a heart rate alarm is indicated. 
   According to the illustrated embodiment “Heart Rate”  401  would be associated with identification area  301  of  FIG. 3  for display upon screen  370 . Similarly, variables MONITORED DATA  402 A, STATUS  402 B, INFO  403 , SYMPTOMS  404 , CAUSES  405 , and RECOMMENDATION  406  would be set as provided in  FIG. 4  and each be associated with a corresponding one of areas  302 – 306  of  FIG. 3 . It should be appreciated that information provided in each such area by the pseudo code of  FIG. 4  may include specific information relating to a monitored condition, see e.g. MONITORED DATA  402 A, STATUS  402 B and RECOMMENDATION  406 . Additionally or alternatively, information provided in the areas by the pseudo code of  FIG. 4  may include a constant text entry, see e.g., INFO  403 , which may or may not include a “jump” or “link” to other information, e.g., “pulse” of INFO  403  may provide a link to a glossary providing further information. The pseudo code of  FIG. 4  may additionally or alternatively provide pointers to relevant information to be displayed, see e.g., SYMPTOMS  404  and CAUSES  405 , perhaps displaying an excerpt from a reference database of EKG monitor  100  and/or providing “jumps” or “links” to facilitate the display of more detail with respect thereto. Likewise, the pseudo code of  FIG. 4  may additionally or alternatively provide calls to common routines or “toolboxes,” see e.g., toolbox call  407  associated with area  307 , to simplify the implementation of reoccurring functions, such as screen hierarchy navigation tools. 
   Any or all of the above presented information may provide for associated input by the user. For example, the aforementioned “jumps” or “links” may provide for selection by a user to indicate a desire to jump to the associated information. Similarly, the information of screen  307  may provide for substantive input, such as by allowing a user to input symptoms currently experienced, such as by selecting one or more systems presented by symptoms  404  and/or by inputting a symptom narrative. 
   It should be appreciated that the pseudo code of  FIG. 4  is not limited to populating the areas of screen  370  of  FIG. 3 . Accordingly, various functions may be performed to provide desired functionality associated with the particular screen displayed. For example, function  408  may provide correlation of one measure of heart rate with another measure of pulse in order to interpret the data for a determination as to whether fibrillation is occurring. Similarly, function  409  may provide correlation of the monitored heart rate with symptoms indicated for storage in a historical database of EKG monitor  100 , for interpretation by EKG monitor  100 , and/or for analysis by a trained professional. Such correlation, or other functions provided by the present invention, may be utilized in providing information to the user, such as correlation of heart rate with symptoms by function  409  for establishing a value of variable RECOMMENDATION  406  to be displayed to user in area  306 . 
   It should be appreciated that the present invention may operate to provide a number of different analyses using a various biotelemetric information and/or other parameters. For example, a PR interval of greater than 0.20 second may be determined to indicate a 1° atrio-ventricular block, which if not present before may be correlated to ischemia, a new medication, or other available data. QRS greater than 0.12 second may be determined to indicate intra-ventricular conduction delay, such as right bundle branch block or left bundle branch block, which if not present before may be correlated to ischemia, structural heart disease, etcetera. Any pause in electrical activity greater than 2 seconds may be determined to be a significant event which indicates a pacemaker is needed and may be correlated with symptoms on an event recorder for further analysis. QT interval prolongation may be determined to be indicative of ischemia or may be correlated to the use of a new medication and may provide early warning of risk of death due to prolonged QT syndrome. ST segment changes greater than 2 mm may be determined to indicate ischemia if present in 2 or more leads. Isolated premature ventricular contractions in alternating patterns with normal QRS may be determined to indicate a condition known as Bigeminy/Trigeminy. Atrio-ventricular heart block of 1° may be determined from prolonged PR, of 2° may be determined from Type I (Wenkebach) or Type II AV nodal blocks, of 3° may be determined from complete articular/ventricular dissociation with very slow pulse indicates a pacemaker is needed. Articular tachycarda may be determined from a narrow QRS complex. Ventricular tachycardia may be determined from wide QRS complex. 
   Accordingly, preferred embodiments of the present invention correlate symptoms, such as chest pain/shortness of breath, sweating/cold and clammy/weakness, pain in jaw/neck/shoulder/arm, dizziness/light headed/faintness, palpitation/skipped beats/racing, loss of energy/stamina/fatigue, blue discoloration of the skin/nausea/vomiting, pedal edema, shortness of breath on exertion/shortness of breath when laying prone, and the like, with EKG abnormalities. Additionally or alternatively, preferred embodiments of the present invention correlate EKG findings with other biotelemetric parameters, such as pulse, blood pressure, respiratory rate, oxygen saturation, etcetera. Using such correlation techniques, embodiments of the present invention may be utilized to provide analysis, recommendations, and/or diagnostic information to users. 
   From the above example, it should be appreciated that the information provided on a secondary or lower level screen may include some initial basic information, and that the screen may also present a pathway to further tertiary or yet lower level screens with additional information. For example, any particular secondary screen may have a symptom feature with basic symptoms from which the user could go into a tertiary screen which describes the particular symptoms of that particular feature in more detail. Such tertiary screens may include specific detail, such as symptoms which may correlate with the rhythms being monitored including chest pains, shortage of breath, dizziness, nausea, etcetera, and may also prompt the user to go to additional screens with causes of symptoms, recommendations, and/or potential dangers associated with any abnormalities monitored. 
   It should be appreciated that screen formats in addition to or in the alternative to that of  FIG. 3  may be utilized by various ones of the screens according to the present invention. For example, another lower level or secondary screen may present a primary interpretation of a biotelemetric being monitored, such as to present a primary interpretation of a EKG trace displayed. This screen might provide identification of the biotelemetric for which information is being provided as well as to provide information with respect thereto. Such information in the above EKG trace example may include identification of the rhythm, providing a definition or the meaning of the rhythm, provide potential causes of the rhythm and any symptoms that are usually associated with the rhythm, and/or provide recommendations. Historical information may be provided, such as an indication as to whether the user has ever had that particular rhythm in previous recordings. 
   Additionally or alternatively, basic informational screens may be provided according to the present invention, such as may be accessed from any of the above screens for further information, and/or as may accessed outside of the navigational flow described above. Access to such basic information screens outside of the aforementioned navigational flow may be desirable to provide general information to a user without having to navigate specific screens. Basic informational screens available according to a preferred embodiment of the present invention could include risk factors for heart disease, basic first aid information including CPR for the general user, definitions or glossary screens that would give basic definitions of all the terms and phrases, etcetera. 
   A basic information screen which may be of particular usefulness according to a preferred embodiment of the present invention is one in which the placement of the various probes upon the body is illustrated in order to aid a lay-user in the proper deployment of the probes. Such a screen may include not only a graphical representation of where to place the probes, but may also provide information with respect to when a particular pattern should be selected over another of the available patterns. In situations where various probe deployment patterns are possible, as described above with respect to the 12 EKG lead positions, such a screen may not only illustrate the proper placement of the probes, but may also operate to configure the monitor for use with a particular selected probe deployment pattern. 
   In addition to the aforementioned screens presenting substantive information with respect to biotelemetry, there may be additional screens utilized according to the present invention, such as a legal screen providing limitations on the use of the device as well as disclaimers. For example, on a legal disclaimer screen, an important feature may be to clearly warn the user that the device does not provide an absolute diagnostic tool capable of replacing consultation with a trained professional. 
   Preferred embodiments of the present invention provide a portable unit which is affordable enough to facilitate large scale deployment. Accordingly, preferred embodiments may be provided using the aforementioned existing PDA platforms. Such embodiments may include software defining operation as described herein operable upon a particular host PDA platform. Interfaces or other components may be provided for use according to the present invention by coupling expansion circuitry to existing PDA interfaces, such as a CF FLASH slot or other such interface. For example, an expansion “sleeve” may be developed to include all or some of the interface functionality of interface  13  shown in  FIG. 1B  which interfaces with the expansion port of the IPAQ SERIES 3600 POCKET PC available from Compaq Computer Corporation to thereby provide a portable unit of the present invention. 
   However, preferred embodiments of the present invention, although utilizing circuitry and other components of such an existing platform, provide a solution in which the form factor of the device is unique to the present application, such as to provide a sufficiently ruggadized case enclosing all components thereof. Moreover, the form factor of the present invention is not limited to that represented in the illustrated embodiment of  FIG. 1A . For example, embodiments of the present invention may provide a device, such as may include the features and functions described above or portions thereof, in a form factor configured for a particular use. Directing attention to  FIG. 5  an alternative embodiment biotelemetry monitor according to the present invention is shown as EKG monitor  500 . 
   EKG monitor  500  of the illustrated embodiment provides a portable unipolar chest lead monitor. Preferably, unipolar lead  562  is provided integrally with monitor  510  to facilitate placing of EKG monitor  500  upon one of the aforementioned unipolar chest lead locations for displaying a corresponding trace upon monitor  510 , much like a physician would place a stethoscope upon a patient. The EKG monitor may preferably be used and/or moved to any of the six chest lead positions to give the EKG display of each lead. Preferably, screens would be available to show the current rhythm associated with the particular lead being monitored. EKG monitor  500  may provide additional processing as discussed above, such as to record monitored biotelemetric data, to interpret data, to provide information, etcetera. 
   EKG monitor  500  may preferably stand alone as an independent unit to give the rhythm of anyone of the six chest lead positions. Additionally or alternatively, EKG monitor  500  may provide a probe which may be interfaced with another system, such as to provide a lead of EKG monitor  100  described above, or to provide an enhanced stethoscope probe, etcetera. For example, EKG monitor  500  may be attached to a stethoscope to enable a physician to simultaneously listen to the heart sound and view the unipolar chest leads EKG trace. Accordingly, it should be appreciated that EKG monitor  500  may include biotelemetric transducers in addition to or in the alternative to a unipolar electrodes, such as a diaphragm for receiving sound energy. 
   Although preferred embodiments of the present invention have been discussed above with respect to electrocardiogram monitoring, the present invention is not so limited. Embodiments of the present invention may provide biotelemetry monitoring and data analysis for a variety of uses. For example, an alternative embodiment of the present invention provides a low cost, portable, and interpretive polygraph device, such as may be used in the field by law enforcement officers. 
   Moreover, preferred embodiments of the present invention may provide biotelemetry monitors adapted or adaptable for a plurality of uses. For example, the aforementioned processor platform may be provided with an application program defining operation as an EKG monitor of the present invention and an application program defining operation as an interpretive polygraph device of the present invention. Particular biometric probes may be coupled to the biotelemetry monitor depending upon the current use to which the device is to be put. 
   Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.