Patent Publication Number: US-2010114206-A1

Title: Patient Interface Device and Therapy Delivery System

Description:
TECHNICAL FIELD 
     This disclosure relates generally to medical devices and more particularly to a system and method for diagnosing a medical condition, alerting a patient that a therapy is impending, and allowing the patient to override or modify the impending therapy. 
     BACKGROUND 
     Historically, an implantable, subcutaneous or external medical device may be used to monitor physiological parameters in a patient to ensure that they fall within certain acceptable values or ranges. Such medical devices have further been capable of delivering therapy to a patient, where the device may be configured to automatically deliver the therapy in response to the monitored physiological parameters reaching certain values or ranges. 
     SUMMARY 
     A method and system are provided for determining that therapy should be delivered to a patient by a medical device in response to sensed physiological parameters, alerting the patient that the therapy is impending, and allowing the patient to override or modify the impending therapy. In one or more embodiments, the method involves sensing a physiological parameter within a patient; determining whether the sensed physiological parameter qualifies for a therapy to be delivered to the patient based on a therapy criteria; alerting the patient that the therapy is impending if the sensed physiological parameter qualifies for therapy; determining whether a therapy modification indication is received that satisfies a modification criteria; and modifying delivery of the therapy to the patient for a predetermined period of time if the therapy modification indication is received and the modification criteria are satisfied. In one or more embodiments, the method may include notifying a remote recipient of the receipt of the therapy modification indication, wherein such notification includes information relating to the sensed physiological parameter. In one or more embodiments, the method may include adjusting the therapy criteria in response to the receipt of the therapy modification indication; and after the predetermined period of time passes, resuming the sensing of the physiological parameter within the patient and the therapy determination using the adjusted therapy criteria. The therapy criteria adjustment may include increasing a specificity of therapy criteria for determining whether the sensed parameter qualifies for therapy to be delivered to the patient based on the therapy criteria. The modification criteria may include whether the therapy to be delivered comprises a high voltage pulse to be applied to at least a portion of the patient&#39;s heart, whether a predetermined amount of therapy has already been delivered to the patient, or whether certain desired actions have been performed on a patient activator device for causing initiation of the therapy modification indication. In one or more embodiments, the method may be performed in response to an indication from the patient that the patient is experiencing a condition that qualifies for the therapy. 
     The system for diagnosing a medical condition, alerting a patient that a therapy is impending, and allowing the patient to override or modify the impending therapy may include an implantable medical device (“IMD”) and a patient interface device. In one or more embodiments, the IMD may comprise a sensor configured to sense a physiological parameter within a patient, a controller configured to determine whether the sensed physiological parameter qualifies for a therapy to be delivered to the patient based on a therapy criteria, a therapy module configured to deliver the therapy, and a telemetry module configured to send an alert when the therapy is impending. In one or more embodiments, the patient interface device may comprise a transceiver configured to receive the alert, an output device configured to notify the patient when the therapy is impending, an input device configured to receive a therapy modification indication from the patient, wherein the transceiver is further configured to send the therapy modification indication to the IMD. In one or more embodiments, the implantable medical device may be configured to modify delivery of the therapy to the patient for a predetermined period of time if the therapy modification indication is received and satisfies a modification criteria. In one or more embodiments, the implantable medical device may deliver a predetermined amount of therapy to the patient prior to allowing therapy to be modified by the therapy modification indication. 
     In one or more embodiments, the implantable medical device may include means for sensing a parameter within a patient; means for determining whether the sensed parameter qualifies for a therapy to be delivered to the patient based on a therapy criteria; means for alerting the patient that the therapy is impending if the sensed parameter qualifies for therapy; means for determining whether a therapy modification indication is received that satisfies a modification criteria; and means for modifying delivery of the therapy to the patient for a predetermined period of time if the therapy modification indication is received and the modification criteria are satisfied. In one or more embodiments, the implantable medical device may also include means for notifying a remote recipient of the receipt of the therapy modification indication, wherein such notification includes information relating to the sensed parameter; means for adjusting the therapy criteria in response to the receipt of the therapy modification indication; means for resuming the sensing of the parameter within the patient and the therapy determination using the adjusted therapy criteria after the predetermined period of time passes; or means for delivering a predetermined amount of therapy to the patient prior to allowing therapy to be modified by the therapy modification indication. In one or more embodiments, the modification criteria may include whether the therapy to be delivered comprises a high voltage pulse to be applied to at least a portion of the patient&#39;s heart or whether certain desired actions have been performed on a patient activator device for causing initiation of the therapy modification indication. 
     In one or more embodiments, the patient interface device may apply a unique identifier to the therapy modification indication to ensure that therapy modification indications are only received from a desired patient interface device. In one or more embodiments, the unique identifier may correspond to the associated implantable medical device. In one or more embodiments, the input device of the patient interface device may be configured to cause the therapy modification indication to be sent to the IMD only if a predetermined input is entered or a certain action is taken by the patient. In one or more embodiments, the input device may comprise a plurality of buttons and the predetermined input may require pressing each button in any sequence, in a predetermined sequence, or simultaneously. In one or more embodiments, the input device may comprise at least one button and the predetermined input may require continually pressing the at least one button until therapy is no longer impending. 
    
    
     
       DRAWINGS 
       The above-mentioned features and objects of the present disclosure will become more apparent with reference to the following description taken in conjunction with the accompanying drawings wherein like reference numerals denote like elements and in which: 
         FIG. 1  illustrates components of the system including an implantable medical device in accordance with one or more embodiments of the present disclosure. 
         FIG. 2  is a schematic block diagram illustrating the various system components configured to operate in accordance with one or more embodiments of the present disclosure. 
         FIG. 3  is an operational flow diagram illustrating a process for allowing a patient to override or modify an automatically initiated therapy in accordance with one or more embodiments of the present disclosure. 
         FIG. 4  is an operational flow diagram illustrating a process for allowing a patient to override or modify an automatically initiated therapy in accordance with one or more embodiments of the present disclosure. 
         FIG. 5  is a block diagram illustrating the various system components including an implantable medical device and a patient interface device in accordance with one or more embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description of embodiments of the present disclosure, reference is made to the accompanying drawings in which like references indicate similar elements, and in which is shown by way of illustration specific embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present disclosure, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical, functional, and other changes may be made without departing from the scope of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present disclosure is defined only by the appended claims. As used in the present disclosure, the term “or” shall be understood to be defined as a logical disjunction and shall not indicate an exclusive disjunction unless expressly indicated as such or notated as “xor.” 
     A method and system for diagnosing a medical condition, alerting a patient that a therapy is impending, and allowing the patient to override or modify the impending therapy are provided. In one or more embodiments, the system includes an implantable medical device (“IMD”)  10  and a patient interface device  40 , as illustrated in the block schematic illustration of  FIG. 1 .  FIG. 1  is a simplified schematic view of components of the system including an implantable medical device in accordance with one or more embodiments of the present disclosure. In one or more embodiments, IMD  10  may comprise a hermetically sealed enclosure  14  and connector module  16  for coupling IMD  10  to electrical leads and other physiological sensors arranged within body  12 , such as pacing and sensing leads  18  connected to portions of heart  20  for delivery of pacing pulses to heart  20  of patient  12  and sensing at least one physiological parameter within heart  20 . While IMD  10  is depicted in a pacemaker device configuration in  FIG. 1 , it is understood that IMD  10  may comprise any type of implanted, subcutaneous or external medial device. IMD  10  may collect and process data from one or more sensors for deriving parameters used in computing a probability that a medical condition is occurring in patient  12  in which IMD  10  is implanted. Patient interface device  40  may be capable of being arranged with respect to IMD  10  such that the various components are capable of communicating with each other. 
     In one or more embodiments, IMD  10  may be a device that is implanted within patient  12 , as illustrated in  FIG. 1 . IMD  10  may be configured to sense a physiological parameter within patient  12 . IMD  10  may be configured to deliver therapy to patient  12  based on the sensed physiological parameter. IMD  10  may be configured to alert patient  12  that delivery of therapy is impending prior to actual delivery of the therapy. 
     In one or more embodiments, IMD  10  may communicate with patient interface device  40 . IMD  10  may send an alert to patient interface device  40  when therapy is impending. Patient  12  may operate patient interface device  40  to send a therapy modification indication to IMD  10 . The therapy modification indication may override or modify the impending therapy and cause IMD  10  to modify the therapy for at least a predetermined period of time. In one or more embodiments, modification to a therapy may include overriding the therapy, delaying the therapy, modifying the way in which the therapy is delivered, modifying the amount of therapy delivered, exchanging the impending therapy for another therapy, or any other desired modification to the therapy that is impending. Patient interface device  40  may be readily accessible by patient  12 . Patient interface device  40  may comprise an in-home monitoring device, a personal computer, a handheld or wearable device (e.g., a wristwatch), or any other device capable of receiving an input from patient  12  and communicating with other components of the system. Patient interface device  40  may be portable, carryable, wearable or located within the patient&#39;s home to allow patient  12  to receive alerts from IMD  10  or send therapy modification indications to IMD  10 . 
     In one or more embodiments, patient interface device  40  may comprise a wearable watch that communicates wirelessly with IMD  10  implanted within patient  12 , as illustrated in  FIG. 2 . In one or more embodiments, the system includes IMD  10 , patient interface device  40 , and remote recipient  50 , as illustrated in the block schematic illustration of  FIG. 2 . In one or more embodiments, patient interface device  40  may communicate with at least one remote recipient  50 . Patient interface device  40  may send data including at least a portion of: the operation history of patient interface device  40 , the operation history of IMD  10 , physiological parameters sensed by IMD  10 , patient input provided to patient interface device  40 , therapy delivered to patient  12 , diagnostic procedures executed, or indications of a need for service to IMD  10  or patient interface device  40 . Remote recipient  50  may be capable of analyzing the data received and returning a response comprising at least one of a confirmation signal, instructions for patient  12 , and commands to be sent to IMD  10 . In one or more embodiments, remote recipient  50  may be any device outside patient interface device  40  configured to receive the data from patient interface device  40 . In one or more embodiments, remote recipient  50  may be a physician, a clinician, a portable device, a personal computer, or a facility where others may receive and analyze the data, as illustrated in  FIG. 2 . In one or more embodiments, the system may include an in-home monitoring device, such as the Medtronic CareLink® Network monitor, that collects information from IMDs implanted in patients and communicates such information to remote clinicians through the Internet, phone lines or wireless networks. CareLink is a registered trademark of Medtronic, Inc. of Minneapolis, Minn. 
     With reference to  FIG. 3 , an operational flow diagram is provided illustrating a process for allowing patient  12  to override or modify a therapy to be delivered by IMD  10  in accordance with one or more embodiments of the present disclosure. Initially, in operation  100 , IMD  10  may sense one or more physiological parameters within patient  12 . In one or more embodiments, physiological parameters may include cardiac activity, electrocardiograms, heart rate, pressure, and other metrics corresponding to events, activity, and conditions within patient  12 . 
     In one or more embodiments, physiological parameters may include cardiac signals or events sensed by one or more sensors. In one or more embodiments, physiological parameters may include a set of separate measurements taken at different points in time or a waveform produced by a constant measurement across time. For example, such separate or constant measurements could be applied to algorithm-based analysis to detect whether the patient is experiencing a condition that qualifies for therapy. 
     In one or more embodiments, physiological parameters may include cardiac signals sensed by a plurality of sensors forming at least one sensing vector. The plurality of sensors may be located at different locations within patient  12 . For example, a single sensing vector may be formed by a mathematical combination of measurements taken by each of the plurality of sensors. Such sensing vectors may aid in the estimation of physiological parameters. 
     In one or more embodiments, in operation  102 , IMD  10  may determine whether a sensed physiological parameter satisfies one or more therapy criteria corresponding to whether the sensed physiological parameter qualifies for therapy. In one or more embodiments, therapy criteria may include a threshold determination of whether a sensed physiological parameter qualifies for therapy. In one or more embodiments, therapy criteria may include a lower limit, an upper limit, or a range within which a sensed physiological parameter may fall. In one or more embodiments, therapy criteria is an operational setting of IMD  10  that may be predetermined. In one or more embodiments, therapy criteria is an operational setting of IMD  10  that may be adjusted, as discussed further herein. 
     In one or more embodiments, therapy criteria may include detection of a condition that qualifies for therapy based on algorithm-based analysis of at least one sensed physiological parameter. For example, IMD  10  may apply a detection algorithm for combining or otherwise analyzing sensed cardiac events or electrogram (EGM) waveforms in order to detect whether a medical condition qualifying for therapy is present (e.g., ventricular fibrillation, myocardial infarction, heart failure, tachycardia, etc.). In one or more embodiments, IMD  10  may apply algorithms for selecting an appropriate therapy. 
     In one or more embodiments, if the sensed physiological parameter does not satisfy the therapy criteria, then IMD  10  may determine that the physiological parameter does not qualify for therapy and IMD  10  may resume physical parameter monitoring. In one or more embodiments, IMD  10  may immediately execute operation  100  after operation  102 . In one or more embodiments, IMD  10  may wait for a predetermined period of time before executing operation  100  after operation  102 . 
     In one or more embodiments, if the sensed physiological parameter does satisfy the therapy criteria, IMD  10  may alert patient  12 , in operation  104 , that the sensed physiological parameter qualifies for therapy and that therapy is impending. For example, in the situation where IMD  10  is an implantable cardioverter-defibrillator, the impending therapy may include a desired pulse to be delivered to the patient&#39;s heart. In one or more embodiments, IMD  10  transmits a signal to patient interface device  40 , causing patient interface device  40  to notify patient  12  that therapy (e.g., a pulse) is impending. This provides patient  12  with an opportunity to modify therapy if patient  12  believes the therapy is unnecessary or undesired at that time. 
     In one or more embodiments, in operation  106 , IMD  10  may determine whether patient  12  has provided a therapy modification indication. If patient  12  does not provide a therapy modification indication, then IMD  10  may proceed to operation  108 , wherein IMD  10  may deliver therapy corresponding to the therapy criteria that has been satisfied. In one or more embodiments, patient  12  may communicate with IMD  10  by operating patient interface device  40 . In one or more embodiments, patient interface device  40  may notify patient  12  of the results of the delivery of therapy. 
     In one or more embodiments, if patient  12  does provide a therapy modification indication, then in operation  110 , IMD  10  may determine whether the therapy modification indication satisfies a modification criteria. Modification criteria of one or more embodiments are discussed below. If the therapy modification indication does not satisfy the modification criteria, then IMD  10  may proceed to operation  108 , wherein IMD  10  may deliver therapy corresponding to the therapy criteria that has been satisfied. If the therapy modification indication does satisfy the modification criteria, then IMD  10  may proceed to operation  112 , wherein it may modify therapy for a predetermined amount of time. In one or more embodiments, patient interface device  40  may notify patient  12  of the results of the modification of therapy. 
     In one or more embodiments, IMD  10  may wait for a predetermined period of time before delivering therapy, thereby providing the patient  12  with an opportunity to provide a therapy modification indication in response to the alert that therapy is impending. For example, if patient  12  has not provided a therapy modification indication before expiration of the predetermined period of time, then IMD  10  may deliver the therapy as planned in operation  108 . 
     In one or more embodiments, the modification criteria verified in operation  110  may include whether a predetermined amount of therapy has been delivered to patient  12 . In one or more embodiments the modification criteria may include whether a predetermined amount of therapy within a predetermined period of time has been delivered to patient  12 . In one or more embodiments, the modification criteria may include whether a predetermined amount of therapy has been delivered for one or more of a predetermined number of sensed physiological parameters that qualify for therapy. For example, IMD  10  may deliver at least a minimal degree of therapy after a sensed physiological parameter is determined to qualify for therapy without allowing therapy to be modified, even if a therapy modification indication has been provided. After such minimal therapy is provided, patient  12  may be given an opportunity to override or modify any additional therapy to be subsequently provided. In one or more embodiments, the initial minimal therapy may be sensed or felt by patient  12  and may serve as the alert that is provided to patient  12  that additional therapy is impending. 
     In one or more embodiments, the modification criteria verified in operation  110  may include whether a predetermined amount of time has elapsed since the first sensed physiological parameter qualifying for therapy was sensed. In one or more embodiments, the modification criteria may include whether a predetermined number of sensed physiological parameters that qualify for therapy have been sensed. In one or more embodiments, the modification criteria may include whether a predetermined number of sensed physiological parameters that qualify for therapy have been sensed within a predetermined period of time. In one or more embodiments, the modification criteria may include whether a therapy modification indication was provided within a predetermined period of time. 
     In one or more embodiments, the modification criteria may include whether a sensed physiological parameter qualifies for a first type of therapy. In one or more embodiments, the first type of therapy may include a low energy therapy (e.g., pulse or shock that will not be painful to patient  12 ) such that there is no need to override or modify the low energy therapy. The sensed physiological parameter may, however, qualify for a different, second type of therapy, such as a high energy therapy (e.g., a high energy pulse, shock, or defibrillation that can be painful for patient  12 ). Patient  12  may need or desire to modify such second type of therapy if such painful therapy is not required. For example, a sensed physiological parameter that qualifies for high energy defibrillation therapy may not be necessary if patient  12  is not suffering from a medical condition that requires defibrillation (e.g., a life-threatening arrhythmia), and such a physiological parameter would satisfy the modification criteria. Furthermore, in this example, a sensed physiological parameter that qualifies for low energy pacemaking therapy or Cardiac Resynchronization Therapy (e.g., Bradycardia) may not satisfy the modification criteria, and such a low energy therapy may be delivered in operation  108  regardless of the patient&#39;s desire to modify such therapy. 
     In one or more embodiments, the modification criteria may include whether an activity within patient  12  qualifies to modify at least one therapy. In one or more embodiments, a modification criteria corresponding to an activity within patient  12  that is known to potentially interfere with delivery of a therapy, when satisfied, may cause a modification to any of the therapies. Such therapies could include any therapy deliverable by IMD  10 , including high energy therapy, such as defibrillation, and low energy therapy, such as pacing for bradycardia, antitachycardia pacing (ATP) for tachycardias, or Cardiac Resynchronization Therapy. For example, where Cardiac Resynchronization Therapy offers a plurality of pacing vectors, and an activity (e.g., Phrenic Nerve Stimulation) is known to potentially interfere with the operation of one of the pacing vectors, the therapy may be modified such that only the pacing vectors that are not affected by any interference deliver therapy. 
     In one or more embodiments, the modification criteria may include whether a therapy modification indication received by IMD  10  from patient interface device  40  is valid, In one or more embodiments, the modification criteria may include whether the patient&#39;s condition has not significantly worsened in the time intervening between the detection of a potential need for therapy and the current time. In one or more embodiments, the modification criteria may include whether the therapy to be administered to the patient would be expected to be painful because it involves delivery of a high energy pulse to the heart. 
     In one or more embodiments, the modification criteria may include any combination of the modification criteria disclosed herein. 
     In one or more embodiments, in operation  114 , patient interface device  40  may send data to remote recipient  50 . The data sent may include at least a portion of: the operation history of patient interface device  40 , the operation history of IMD  10 , physiological parameters sensed by IMD  10 , patient input provided to patient interface device  40 , therapy delivered to patient  12 , diagnostic procedures executed, or indications of a need for service to IMD  10  or patient interface device  40 . 
     In one or more embodiments, in operation  116 , IMD  10  may adjust one or more operational settings based upon the activity that occurred in previous operations. Operational settings that IMD  10  may adjust may include, but are not limited to: the manner in which physiological parameters are sensed, the manner in which events or conditions within patient  12  are detected (e.g. modify a detection algorithm and/or revert back to the initial therapy criteria), one or more therapy criteria, one or more modification criteria, a period of time for waiting to sense a physiological parameter, a period of time for waiting for a therapy modification indication, a type of therapy to be delivered, a remote recipient  50  to be alerted, a period of time for which modification of therapy applies, and/or any setting that affects the operation of IMD  10  and/or patient interface device  40 . 
     In one or more embodiments, where sensed physiological parameters include a sensing vector based on cardiac signals sensed by a plurality of sensors, IMD  10  may adjust an operational setting corresponding to the formation of the sensing vector. For example, IMD  10  may alter which of the sensors contributes to the formation of the sensing vector or in what way the sensors contribute to the formation of the sensing vector (e.g., what weight each sensor will be given in a computation of an average value). In one or more embodiments, IMD  10  may adjust the formation of a sensing vector in response to a therapy modification indication from patient  12 . For example, where IMD  10  senses a physiological parameter that satisfies a therapy criteria and patient  12  modifies therapy by responding to an alert, IMD  10  may adjust which sensors contribute to the sensing vector in order to achieve a more accurate measurement of a physiological parameter. For example, sensors involved in a therapy that is modified by patient  12  may be excluded from or given less weight in subsequent formulations of a sensing vector. In one or more embodiments, IMD  10  may perform diagnostic procedures to determine whether a given sensor is providing accurate measurements and thereby determine whether, or to what degree, the sensor should contribute to a sensing vector. In one or more embodiments, IMD  10  may communicate with a calibration device to determine which of various formations of sensing vectors provides the most accurate measurements. Such calibration devices may include patient interface device  40 , remote recipient  50 , or any other device that provides an accurate calibration standard and with which IMD  10  may communicate. For example, maintenance of IMD  10  by a medical professional may include calibration of a sensing vector. In one or more embodiments, IMD  10  may be manually configured to select a certain formation of a sensing vector according to known advantages. For example, where activity within patient  12  or imposed upon patient  12  is known by a medical professional to potentially interfere with the operation of certain sensors, a formation of a sensing vector that excludes or limits the contribution of such certain sensors may be selected. 
     In one or more embodiments, where IMD  10  senses a physiological parameter that satisfies a therapy criteria and patient  12  modifies therapy by responding to an alert, IMD  10  may adjust one or more operational settings, such as a therapy criteria, to reflect that the sensed physiological parameter does not qualify for therapy. For example, IMD  10  may increase the specificity applied when determining whether a sensed physiological parameter qualifies for therapy to be delivered to the patient based on a therapy criteria. In one or more embodiments, where IMD  10  senses a physiological parameter that satisfies a therapy criteria and patient  12  overrides therapy by responding to an alert, IMD  10  may adjust the period of time for waiting to sense a physiological parameter to reflect that sensing may be suspended for a longer period of time. In one or more embodiments, IMD  10  may perform diagnostic procedures to confirm the sensed physiological parameter. In one or more embodiments, IMD  10  may adjust one or more operational settings corresponding to a possible faulty operation of IMD  10 . Where IMD  10  senses a physiological parameter that satisfies a therapy criteria and patient  12  overrides therapy by responding to an alert, IMD  10  may adjust one or more operational settings corresponding to diagnostic operations that are performed by IMD  10 . For example, IMD  10  may perform diagnostic procedures to detect for possible malfunction of components of IMD  10 , such as components relating to sensing a physiological parameter, or to detect interference from external influences, such as lead noise detection. Where faulty operation of IMD  10  is detected, IMD  10  may notify patient  12  or remote recipient  50  of a need for service via patient interface device  40 . In one or more embodiments, an adjustment to one or more operational settings may be temporary, such that IMD  10  reverts to default physiological parameter sensing procedures after a predetermined period of time. In one or more embodiments, an adjustment to one or more operational settings may be fixed until a subsequent adjustment is made during a subsequent execution of operation  116 . 
     In one or more embodiments, patient  12  may cause an adjustment to one or more operational settings prior to execution of operation  100  where IMD  10  may sense a physiological parameter within patient  12 . In one or more embodiments, patient  12  may indicate to IMD  10  that patient  12  will be engaged in activity that justifies an adjustment to a therapy criteria. For example, patient  12  may indicate to IMD  10  that patient  12  will be exercising for a set duration of time, causing IMD  10  to adjust a therapy criteria to reflect that a sensed physiological parameter may be induced by exercise. In one or more embodiments, patient  12  may indicate, prior to operation  100 , that sensing or delivery of therapy should be modified, such that patient  12  may modify or avoid therapy in situations where the patient&#39;s activities could provide misleading information regarding the sensed physiological parameters or during which therapy would be undesirable. In one or more embodiments, patient  12  may indicate to IMD  10  that patient  12  is experiencing an event or condition that qualifies for therapy by providing such indication through patient interface device  40 . For example, where patient  12  is experiencing an event, such as pain or discomfort, that IMD  10  has not yet sensed, patient  12  may cause IMD  10  to adjust one or more operational settings, such as a period of time for waiting to sense a physiological parameter, such that IMD  10  may more promptly or accurately determine whether therapy should be delivered. In one or more embodiments, patient  12  may not adjust one or more operational settings until after a physiological parameter that qualifies for therapy has been sensed. 
     In one or more embodiments, the order in which the operations are executed as shown in  FIG. 3  may vary. With reference to  FIG. 4 , the modification criteria verified in operation  110  may be applied after operation  102  where the determination of whether therapy should be applied is performed and before operation  104  where patient  12  is alerted of such impending therapy. For example, where a modification criteria is not satisfied, patient  12  may not be alerted and may not have an opportunity to override or modify the therapy that corresponds to the physiological parameter that satisfied the therapy criteria. For example, one aspect of the modification criteria applied in operation  110  may be that the impending therapy is known to be likely to cause pain or discomfort to the patient, and therefore, should not be delivered to the patient via operation  108  without first alerting the patient and providing the patient with an opportunity to provide a therapy modification indication. 
     In one or more embodiments, the modification criteria verified in operation  110  is alternatively applied after operation  104  where patient  12  is alerted of the impending therapy and before operation  106 . In one or more embodiments, operations  112 ,  114 , and  116  may be executed either substantially simultaneously or in any sequence. In one or more embodiments, one or more of operations  112 ,  114 , and  116  may not be required to be executed and can be omitted. In one or more embodiments, any one of operations  112 ,  114 ,  116 , or  100  may be performed before therapy is delivered in operation  108 . 
     With reference to  FIG. 5 , a block diagram is provided illustrating the various system components including IMD  10  and patient interface device  40  in accordance with one or more embodiments of the present disclosure. IMD  10  is shown as including at least one sensor  22 , controller  24 , memory  26 , battery  28 , telemetry module  30 , therapy module  32 , and other components as appropriate to produce the desired functionalities of the device. 
     In one or more embodiments, sensor  22  may be configured to sense a physiological parameter within patient  12 . IMD  10  may obtain data from physiological signals via electrodes and/or sensors  22  deployed on leads  18  and/or other sources. Sensors  22  may monitor electrical, mechanical, chemical, or optical information that contains physiological data of the patient and can utilize any source of physiological signals used for physiological events, parameters, or conditions. For example, sensor  22  may comprise a heart sensor, such as the MDT Reveal® system, commercially available from Medtronic of Minneapolis, that is capable of sensing cardiac activity, electrocardiograms, heart rate, pressure, or the like. Reveal is a registered trademark of Medtronic, Inc. of Minneapolis, Minn. In one or more embodiments, data obtained by sensor  22  may be provided to controller  24 , which suitably analyzes the data, stores appropriate data in memory  26 , or provides a response or report as appropriate. 
     In one or more embodiments, controller  24  may be configured to determine whether a sensed physiological parameter satisfies a therapy criteria. Controller  24  may be implemented with any type of microprocessor, digital signal processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other integrated or discrete logic circuitry programmed or otherwise configured to provide functionality as described herein. Controller  24  executes instructions stored in memory  26  to provide functionality as described herein. Instructions provided to controller  24  may be executed in any manner, using any data structures, architecture, programming language and/or other techniques. Memory  26  is any storage medium capable of maintaining digital data and instructions provided to controller  24  such as a static or dynamic random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), flash memory, or any other electronic, magnetic, optical or other storage medium. 
     In one or more embodiments, communication between IMD  10  and patient interface device  40  can occur via telemetry, such as a long-distance telemetry system through the telemetry module  30 . Telemetry module  30  may comprise any unit capable of facilitating wireless data transfer between IMD  10  and patient interface device  40 , where patient interface device  40  may comprise an external medical device, a programming device, a remote telemetry station, a physician-activated device, a patient-activated device, a mobile handheld unit (e.g., mobile phone, PDA, etc.), a personal computer, an in-home monitoring device, a patient-wearable device, a display device or any other type of device capable of sending and receiving signals to and from IMD  10 . Telemetry module  30  and patient interface device  40  may be respectively coupled to antennas  32  and  34  for facilitating wireless data transfer. Telemetry module  30  may be configured to perform any type of wireless communication. For example, telemetry module  30  may send and receive radio frequency (RF) signals, infrared (IR) frequency signals, or other electromagnetic signals. In the case of electromagnetic signals, antennas  32  and  34  may comprise coils for transmitting and receiving signals when positioned adjacent to one another. Any of a variety of modulation techniques may be used to modulate data on a respective electromagnetic carrier wave. Alternatively, telemetry module  30  may use sound waves for communicating data, or may use the patient&#39;s tissue as the transmission medium for communicating with a programmer positioned on the patients skin. Telemetry module  30  may facilitate wireless data transfer between IMD  10  and patient interface device  40 . Other types of wired communications may also occur when IMD  10  is alternatively configured as an external medical device or contains wired communication channels that extend from within patient  12  to points outside of patient  12 . 
     In one or more embodiments, therapy module  32  may be configured to deliver at least one type of therapy to patient  12 . For example, therapy module  32  may produce a stimulus to the heart tissue of patient  12  (e.g., defibrillation stimulus, pacing stimulus, pacing rate adjustment, pacing characteristic adjustment, and/or pulse adjustment stimulus). In one or more embodiments, therapy module  32  may include a pacemaker, which may utilize electrical impulses to regulate the beating of the heart to treat bradycardia (a slow, irregular, or interrupted heartbeat). In one or more embodiments, therapy module  32  may include a biventricular pacemaker, also known as a cardiac resynchronization device, which may help selected chambers of the heart to beat in a more coordinated fashion, so that blood pumps more efficiently to the body. In one or more embodiments, therapy module  32  may include an implantable cardioverter defibrillator, which may provide burst pacing pulses or a defibrillation shock to the heart when the heart is beating too fast or goes into fibrillation. 
     With further reference to  FIG. 5 , patient interface device  40  is shown as including transceiver  200 , output device  204 , processor  206 , memory  208 , input device  210 , input/output port  212 , and other components as appropriate to produce the desired functionalities of the device. 
     In one or more embodiments, patient interface device  40  may include antenna  34 , coil or wired input for communicating data and other signals between patient interface device  40  and IMD  10 . Data may be received from IMD  10  through antenna  34 , which is connected to transceiver  200  that may serve to receive and transmit communication signals through antenna  34 . The demodulated signals may be applied in parallel or serial digital format to input/output (I/O) port  212 , where they in turn may be applied to an output device  204  or provided to processor  206  or memory  208 . In one or more embodiments, output device  204  may include a screen or types of interface devices capable of communicating information to the patient (e.g., an audio speaker device, a tactile vibrating device, or other output device). In one or more embodiments, output device  204  may be configured to alert patient  12  that therapy from IMD  10  is impending. 
     In one or more embodiments, patient interface device  40  may include an input device  210  that allows data, commands or selections to be input into patient interface device  40  by a patient, physician or clinician. For example, the patient may use input device  210  to enter a command to override or modify the therapy from IMD  10 . Input device  210  may include, but is not limited to, at least one of the following: a keyboard, keypad, track ball, mouse, touch-sensitive displays, push buttons, magnetic readers, RF readers, tablets, styluses, microphones, voice recognizers, handwriting recognizers and any other device that allows a patient, physician or clinician to input data to external device. In one or more embodiments, patient interface device  40  will only send a therapy modification indication to IMD  10  when a predetermined input is provided by patient  12  into input device  210 . For example, in one or more embodiments, input device  210  may comprise a plurality of buttons, wherein patient  12  must press each one of the plurality of buttons in any sequence to cause an therapy modification indication to be sent to IMD  10 . In one or more embodiments, input device  210  may comprise a plurality of buttons, wherein patient  12  must press a predetermined sequence of buttons to cause an therapy modification indication to be sent to IMD  10 . In one or more embodiments, input device  210  may comprise a plurality of buttons, wherein patient  12  must press multiple buttons simultaneously to cause an therapy modification indication to be sent to IMD  10 . In one or more embodiments, input device  210  may comprise at least one button, wherein patient  12  must continually press the at least one button as long as therapy from IMD  10  is impending to cause an therapy modification indication to be sent to IMD  10 . 
     In one or more embodiments, a signal containing data may be sent from patient interface device  40  to IMD  10 . In one or more embodiments, patient interface device  40  may generate a signal with transceiver  200  to be received wirelessly by telemetry module  30  of IMD  10 . In one of more embodiments, a given patient interface device  40  may be configured to be associated with a given IMD  10 , such that the given patient interface device  40  may only communicate with the given IMD  10 . For example, patient interface device  40  and IMD  10  may apply unique identifiers to signals sent that cause only an associated device to recognize and respond to the signals. In one or more embodiments, the unique identifier may correspond to a serial number of each associated device. For example, patient interface device  40  may apply the serial number of an associated IMD  10  to a signal to ensure that only the associated IMD  10  may respond to the signal. In one or more embodiments, a signal may employ an encryption/decryption scheme, wherein the signal is encrypted such that only an associated device is capable of decryption to interpret and respond to the signal. In one or more embodiments, a signal may contain data comprising the unique identifier and a command, such that the associated device may determine whether it is the intended recipient of the signal by reading the unique identifier and respond accordingly. 
     Processor  206  of patient interface device  40  may include any type of microprocessor, digital signal processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other integrated or discrete logic circuitry programmed or otherwise configured to control operating of patient interface device  40  and provide functionality as described herein. In one or more embodiments, processor  206  executes instructions stored in memory  208  to provide functionality as described herein. In one or more embodiments, instructions may be stored in memory  208  for operating a patient override program that allows patient  12  to override or modify the delivery of therapy by IMD  10 . In one or more embodiments, data may be recorded in memory  208  for later transmission during communication with remote recipient  50 . Such data may include at least a portion of: the operation history of patient interface device  40 , the operation history of IMD  10 , physiological parameters sensed by IMD  10 , patient input provided to patient interface device  40 , therapy delivered to patient  12 , diagnostic procedures executed, or indications of a need for service to IMD  10  or patient interface device  40 . Processor  206  may control operation of output device  204  and may be responsive to commands received from input device  210 . Memory  208  is suitable for storing data received from IMD  10  or other sources, input device  210 , processor  206  or other data or commands otherwise received by patient activator device  40 . Patient interface device  40  may further include an input/output port  212  for connecting patient interface device  40  to other devices, communication networks, phone lines, wireless devices, etc. When data received from IMD  10  through the telemetry uplink is to be transmitted to a remote recipient  50  for further analysis, such information and data may be transmitted through input/output port  212  to a connected network or through transceiver  200  or to a wirelessly connected device. 
     While the system and method have been described in terms of what are presently considered to be specific embodiments, the disclosure need not be limited to the disclosed embodiments. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures. The present disclosure includes any and all embodiments of the following claims.