US20100185251A1 - Method and apparatus for preventing excessive power drain from an implantable device - Google Patents

Abstract

A method and apparatus are provided for controlling interrogation of an implantable device such as a pacemaker, an implantable cardioverter, or a defibrillator utilizing an external device in a home environment. The method controls how frequently a patient can retrieve status information from the implantable device based on a time period elapsed since a last interrogation and a power level of a battery.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This application is a division of U.S. patent application Ser. No. 11/551,661, filed Oct. 20, 2006.
FIELD OF THE INVENTION
• Embodiments of the present invention pertain generally to implantable medical devices, such as cardiac pacemakers and implantable cardioverter defibrillators, and more particularly pertain to methods and apparatus that prevent excessive electrical power drain while exchanging information with devices outside the body.
BACKGROUND OF THE INVENTION
• In the United States, it is estimated that approximately five million people have congestive heart failure (“CHF”). CHF is a life threatening condition that is managed by treating patients with drugs or implantable medical devices such as pacemakers and implantable cardioverter defibrillators (“ICD”). The information obtained through monitoring can be used to diagnose and treat a patient's condition.
• Current ICDs and pacemakers have the ability to non-invasively communicate a patient's physical data and programmable parameters with a device such as an external programmer. The programmer is used to interrogate or program the ICD or pacemaker using a wireless, radio frequency telemetry link. Typically, a physician or medical professional utilizes the programmer, while the patient is in the medical office, to access data stored by the ICD or pacemaker, check and adjust on programmed parameters and the like. The programmer can also be used to instruct the ICD or pacemaker to execute desired functions, such as monitoring, stimulating, and storing diagnostic or other data. Conventional programmers in the marketplace allow numerous different parameters to be programmed. The ability to exchange data via a wireless link also permits the health care provider to reprogram or reconfigure the implantable device as required from time to time due to changes in the patient's condition. Recently, implantable devices have been proposed that allow a patient to operate certain types of home-based programmers to interrogate the implantable device in the privacy of the patient's own home. Heretofore, patients have been able to use the home-based programmers at any time to interrogate the implantable device.
• However, home-based programmers present the opportunity for undue interrogation of the implantable device, and thus excessive drain on a battery of the implantable device. A power supply, typically a specialized battery, is housed within the implantable device to provide the electrical energy required for operation over an extended length of time. One difficulty is the efficient use of electrical energy. The lifetime of the battery depends on the power demands of the implantable device. For instance, implantable devices that require high speed and long range telemetry require greater battery power. ICDs also require a battery to operate at low current drains for long periods of time and simultaneously provide high current pulses. For example, the normal lifetime of a battery may be five years. To provide the longest battery life, it is desirable to reduce the power consumption required for the various functions of the implantable device. Because replacing a battery requires surgery, it is preferable that the battery last as long as possible.
• Most implantable devices are configured to support interrogation by medically trained professionals in a medical office. Most implantable devices do not have the capability of allowing the patient to perform the interrogation at home, and therefore, there is not as great a concern with the drainage of battery power. However, as implantable devices are manufactured to include the feature of allowing a patient to interrogate the implantable device, additional power concerns emerge. Specifically, if a patient does not judiciously interrogate the device, for example if the patient checks the implantable device every few minutes, a heavy power drain on the battery will result. This, in turn, will affect the ability of the implantable device to communicate required patient data as well as affect the operation of the implantable device. Depletion of battery power will potentially lead to early failure of the implantable device and require the battery to be replaced more frequently.
• A need remains for an improved implantable device including electrical circuitry and programmable features to limit the number of interrogations performed by a patient in a home environment in order to extend battery life.
SUMMARY
• In accordance with one embodiment of the present invention, a method is provided for controlling interrogation of an implantable device. The method includes accepting, at the external device, a request for information from an implantable device after verifying a threshold period of time has elapsed since the last request for information.
• In accordance with a further aspect of the invention, an external device, such as a programmer, requests information from an implantable device, which includes a monitoring module, a memory module, and an input/output (“I/O”) module having a telemetry unit. The monitoring module records the last request for information from the patient's external device to the memory module and verifies a threshold period of time has elapsed since the last request for information. The telemetry unit establishes a wireless communication link with the external device and transmits the requested information stored within the memory module based on the amount of time elapsed since the last request for information.
BRIEF DESCRIPTION OF THE DRAWINGS
• In the drawings, which are not necessarily drawn to scale, like numerals describe substantially similar components throughout the several views. Like numerals having different letter suffixes represent different instances of substantially similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.
• FIG. 1 illustrates an implantable device formed in accordance with one embodiment of the present invention that remotely communicates with an external programmer.
• FIG. 2 illustrates a block diagram of an implantable device in communication with an external programmer utilized in accordance with an embodiment of the present invention.
• FIG. 3 illustrates a block diagram of an external device in communication with an implantable device, as shown inFIG. 2, utilized in accordance with an embodiment of the present invention.
• FIG. 4 illustrates a flow chart for a process to control interrogation of an implantable device based on the time lapse since the last interrogation stored in the patient's external device in accordance with an embodiment of the present invention.
• FIG. 5 illustrates a flow chart for a process to control interrogation of an implantable device based on the time lapse since the last interrogation stored in the implantable device in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
• In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the present invention may be practiced. These embodiments, which are also referred to herein as “examples,” are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that the various embodiments of the invention may be combined, or that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. For example, embodiments may be used with a pacemaker, a cardioverter, a defibrillator, and the like. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.
• In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one. In this document, the term “or” is used to refer to a nonexclusive or, unless otherwise indicated.
• FIG. 1 illustrates a programmablecardiac system10 that includes animplantable device12 in communication with a clinician'sexternal device14 and a patient'sexternal device15 via acommunication link16 that is controlled in accordance with an embodiment of the present invention. Theimplantable device12 includes aconnector20 that is joined to a plurality ofleads22. Physiological information is detected over theleads22 that are located with or near aheart24 at either an atrium, a ventricle or both. The physiological information is provided throughleads22 viaconnector20 to theimplantable device12. Theimplantable device12 monitors theheart24 of a patient and detects when the patient is having a post-myocardial infarct, a “silent” myocardial infarct, a myocardial infarct, an ischemia, a heart block, an arrhythmia, a fibrillation, or a congestive heart failure.
• Additionally, theimplantable device12 provides an electrical stimulation through theleads22 based on the physiological information detected. For example, stimulation may be provided when the intrinsic heartbeat is insufficient, when depolarization is not being conducted through theheart24, when the heart rate is too slow to maintain adequate blood from to the body and the like. In addition,implantable device12 detects electrical characteristics ofheart24 subject to a preventative pacing scheme such as bi-ventricular, right ventricular, left ventricular, left atrial, right atrial, and bi-atrial pacing. By monitoring the excitability of cardiac tissue and its response to different pacing schemes, theimplantable device12 is able to provide a physician with information as to the patient's physiological condition, e.g., whether it has improved or is progressing towards cardiac failure.
• A physician can utilize theexternal device14 to access information stored within the implanteddevice12. Theexternal device14 may be implemented as a programmer in accordance with an embodiment of the present invention. Information is accessed from theimplantable device12 after thecommunication link16 is established between theimplantable device12 and theexternal device14.
• Theexternal device14 permits a physician to examine the operation of theimplantable device12. During an office visit, the physician has the ability to review physiological data and programmed parameters of theimplantable device12, as well as to adjust these parameters through theexternal device14 depending on the physiological condition of the patient. Some parameters that a physician may be interested in programming include fibrillation detection rate, tachycardia detection rate, ventricular fibrillation detection rate, ventricular tachycardia detection rate, and the like. Setting a defibrillation detection rate too low may result in an unnecessary defibrillation that is both painful and potentially damaging to the heart. On the other hand, setting a detection rate too high may cause the required electrical shock not to be applied in a timely manner to a fibrillating heart and the patient may die.
• In home-based applications, the patient is limited to certain functions that he/she can access through theexternal device15 while at home. Thus, the patient should be allowed to access a restricted set of information, such as the patient's overall cardiac physiological condition, whether to consult a physician or not, and the status of the implantable device, e.g., battery power condition.
• FIG. 2 illustrates a block diagram of a portion ofimplantable device12. Theimplantable device12 may be a cardiac pacemaker, an implantable cardioverter defibrillator (“ICD”), a defibrillator, or an ICD coupled with a pacemaker implemented in accordance with an embodiment of the present invention. Theimplantable device12 includes aprocessor module30, a data/control bus module32, asensing module34, amonitoring module36, amemory module38, an Input/Output (“I/O”)module40, and abattery42. It is understood that data/control bus module32,sensing module34,monitoring module36 and I/O module40 are conceptual blocks, not necessarily separate hardware and may be implemented in software by theprocessor module30.
• Processor module30 typically includes a microprocessor, a microcomputer, or equivalent control circuitry for processing physiological characteristics of theheart24. Theprocessor module30 may further include RAM or ROM memory, logic and timing circuitry, state machine circuitry, and I/O circuitry. Typically, theprocessor module30 includes the ability to process or monitor data as controlled by a program code stored in a designated block of memory. Data/control bus module32 represents a hardware or software interface between the various functional modules of theimplantable device12.
• Sensing module34 includes asignal conversion module44. Thesensing module34 receives physiology signals from theleads22, such as a depolarization wave as it spreads through the cardiac tissue and measures the timing, direction of propagation, and point of initiation of successive depolarization waves. The depolarization may be a result of an inherent cardiac cycle or in response to a cardiac pacing event, such as pacing the heart utilizing bi-ventricular pacing, right ventricular pacing, left ventricular pacing, left atrial pacing, right atrial pacing or bi-atrial pacing. Thesignal conversion module44 typically includes an analog-to-digital (“ND”) converter (not shown) and receives raw analog signals that are voltages that result from the change in ionic concentrations of sodium and calcium through the cardiac tissue that occur during depolarization. Thesignal conversion module44 converts the raw analog signals to a plurality of digital signals. The digital signals are transferred over the data/control bus module32 and stored in thememory module38.
• Themonitoring module36 analyzes the digital physiology signals from thesignal conversion module44 and identifies desired physiologic characteristics. For example, themonitoring module36 may identify arrhythmias, trends in cardiac behavior, and the like. Themonitoring module36 determines the programmed state of theimplantable device12 and determines the remaining battery power, which is stored asbattery condition48. As previously mentioned theimplantable device12 can be programmed by a physician to operate in a specific mode, e.g., detect ventricular fibrillation and deliver an associated therapy. Themonitoring module36 verifies and records that theimplantable device12 is in the correct programmed state (e.g., not a harmful state) and the amount of time within each state. If themonitoring module36 detects a harmful state, it will report a warning to theexternal device14 or to the patient'sexternal device15 through the I/O module40. Themonitoring module36 also collects timing information that includes a time the data is transmitted, a date the data is transmitted, a number of total interrogations performed, and the date and time of each interrogation request. Themonitoring module36 also monitors operation of theimplantable device12 in connection with receipt and transmission of information and parameters by and from thetelemetry unit52.
• In addition, each time a request to interrogate theimplantable device12 is made by theexternal device15, themonitoring module36 checks on the status of thebattery42 and records thebattery condition48 in thememory module38. As the power of the battery decreases, themonitoring module36 extends the time period required to accept a new interrogation. If the battery power is below a threshold level, themonitoring module36 will prevent further responses to patient'sexternal device15. The battery power level depends on the type and size ofbattery42 utilized by theimplantable device12.Typical batteries42 include zinc-mercury batteries, nickel-cadmium batteries, nuclear batteries, fuel cells, lithium iodine batteries and the like. Themonitoring module36 also checks on the frequency of interrogations. If a specified threshold time period has not lapsed when an interrogation is requested, themonitoring module36 prevents the interrogation from being answered.
• Thememory module38 includes blocks of memory allocated to storeprogrammable parameters46, a communications log47, abattery condition48, andphysiological characteristics50. The blocks of memory may be ROM, PROM, EPROM, EEPROM, RAM, SRAM, DRAM, DDRAM, EDO, SDRAM, Flash, MRAM, FRAM, EEPROM, EAPROM and the like. The communications log47 records data related to past communications to and from theimplantable device12. For example, the communications log47 may include a time at which each incoming transmission is received, a time at which each outgoing transmission was transmitted, a length of each outgoing transmission, a nature or type associated with incoming and outgoing transmissions and an identification of theimplantable device12, as well as an identification of the type of device requesting information, e.g., the physician'sexternal device14 or the patient'sexternal device15. The nature or type of the transmission and length thereof may be of interest to estimate an amount of battery power used in connection with the transmission by theimplantable device12.
• Theprogrammable parameters46 may include a tachycardia detection rate, a fibrillation detection rate, a ventricular tachycardia rate, a ventricular fibrillation detection rate, a bradycardia rate, stability algorithm settings, onset algorithm settings, specific therapies for each cardiac zone, a duration of therapy required for each cardiac zone and the like. Thebattery condition48 may include a low power battery status, a battery internal resistance, a number of charge/discharge cycles, battery age, and a remaining battery charge. Thephysiological characteristics50 may include a series of digitized data signals detected by theleads22 over time and/or a patient's heart rate, an electrical activation pattern of the heart, a strength of contraction of heart muscle, and an amount of fluid in the lungs. Furthermore, thephysiological characteristics50 may also include a possible current condition of the patient, such as a patient's tachycardia rate, a patient's bradycardia rate, a patient's fibrillation rate, and a patient's arrhythmia rate or whether the patient is suffering from a myocardial infarction, a post-myocardial infarction, a “silent” myocardial infarction, an ischemia, an arrhythmia, a heart block, a fibrillation, or a congestive heart failure. Thesephysiological characteristics50 may be transmitted as physiologic information by atelemetry unit52 to the physician'sexternal devices14 or to the patient'sexternal device15.
• Input/Output (“I/O”)module40 includes atelemetry unit52. Thetelemetry unit52 enables theimplantable device12 to download data to the physician'sexternal device14 when a patient is at the physician's office or to the patient'sexternal device15 when the patient is at home via awireless link16. Thetelemetry unit52 interfaces withprocessor module30 andmonitoring module36 to determine whether to perform an interrogation. A patient that does not exercise discretion when making requests for interrogation via theexternal device15 can wear down thebattery42. A low battery condition may be defined as at least 10% of the maximum battery power level, or as a power level that leads to imminent battery power failure. The lifetime of thebattery42 depends on the power demands of theimplantable device12 as well as the frequency of interrogations. For instance, theimplantable device12 may require thebattery42 to operate at low current drains for long periods of time and simultaneously provide high current pulses. To provide the longest battery life, it is desirable to reduce the power consumption required for the various functions of theimplantable device12. By limiting a patient's ability to interrogate theimplantable device12, battery power is conserved.
• FIG. 3 illustrates a block diagram of a patient'sexternal device15 in accordance with an embodiment of this invention. The patient'sexternal device15 includes aprocessor module60, an address/data/control bus module62, a data/memory module64, aprogram memory module66, auser interface module68, atelemetry module70 and abattery72. Address/data/control bus module62, data/memory module64,program memory module66,user interface module68 andtelemetry module70 represent hardware blocks that may partially or totally implemented on the same semiconductor die.
• Processor module60 typically includes a microprocessor, a microcomputer, or equivalent control circuitry for processing a request to interrogate an implantablemedical device12. Theprocessor module60 may further include RAM or ROM memory, logic and timing circuitry, state machine circuitry, and I/O circuitry. Typically, theprocessor module60 includes the ability to process or monitor data as controlled by a program code stored inprogram module66.
• Address/data/control bus module62 represents a hardware interface between the various functional modules of the patient'sexternal device15.
• Thedata memory module64 includes blocks of memory allocated to store physiological information, timing information that includes a time the data is transmitted, a date the data is transmitted, a number of total interrogations performed, and the date and time of each interrogation request, and a battery condition.
• Theprogram memory module66 includes blocks of memory allocated to store a program code that instructsprocessor60 regarding the operation ofexternal device15. For instance, the program code may include instructions on how the user may interface with theexternal device15, what information the user may be allowed to access, and what format messages will be provided to the user (e.g., visual, textual, auditory).
• The blocks of memory may be ROM, PROM, EPROM, EEPROM, RAM, SRAM, DRAM, DDRAM, EDO, SDRAM, Flash, MRAM, FRAM, EEPROM, EAPROM and the like.
• Theuser interface68 accepts commands from the user and displays the requested interrogation information, and thetelemetry module70 interfaces with theimplantable device12 over a wireless link. Further, thetelemetry unit70 is commanded byprocessor module60 to communicate with theimplantable device12. Patient'sexternal device15 also includes abattery72.
• In one embodiment of the present invention, theprocessor module60 monitors each time a request is made by the user utilizingexternal device15 to interrogate the implantablemedical device12. Theprocessing module60checks data memory64 for the last time the user made a request. If a specified threshold time period has not lapsed when an interrogation is requested, theprocessor module60 prevents the interrogation from being performed. If the specified threshold time period has lapsed, theprocessor60 performs an interrogation ofimplantable device15 viatelemetry module70. Theprocessor module60 monitors the receipt and transmission of information and parameters by and from thetelemetry unit70 to ensure communication is successful. Theprocessor module60 then logs the interrogation indata memory64. For example, theprocessor60 may, for example, log a time at which each incoming transmission is received, a time at which each outgoing transmission was transmitted, a length of each outgoing transmission, a nature or type associated with incoming and outgoing transmissions and an identification of theimplantable device12. Theprocessor60 utilizesuser interface68 to show/display the requested information to the user.
• FIG. 4 illustrates a process to control the interrogation of theimplantable device12 utilizing the patient'sexternal device15 in accordance with at least one embodiment of the present invention. At100, the patient utilizes theexternal device15 to make a request to interrogate the implantablemedical device12. At102, theexternal device15 compares the time elapsed from the last request for interrogation with a value for the current time threshold. The time threshold is the amount of time that must elapse before an interrogation is permitted. If the time elapsed from the last interrogation is less than the required time threshold,external device15 denies the request and no interrogation toimplantable device12 is initiated. The patient must wait until the time threshold has elapsed before making another request for interrogation.
• The time threshold is dynamically modified by the device that keeps record of the time elapsed since last interrogation (e.g., either patient'sexternal device15 or implantable device12) based on the battery power level reported byimplantable device12. Table 1 shows an embodiment of how the time threshold can be modified based onimplantable device12's battery power level.

• 	TABLE 1
  	BATTERY POWER STATUS	TIME THRESHOLD
  	FULL	Thr1
  	MID	Thr2 > Thr1
  	LOW	Thr3 > Thr2
  	CRITICAL	Thr4 > Thr3

  
  For instance, when the battery power level is “full” (e.g. battery is fully charged) the time threshold is initially at a value of Thr1. In one embodiment, Thr1 may allow the patient to perform an interrogation utilizing the patient'sexternal device15 once per hour. In another embodiment, Thr1 may allow the patient to perform an interrogation once per day. As the battery power decreases to a “mid” level (e.g. 50% power charge),processor module30 will assign a new time threshold value, Thr2, where Thr2 will have a greater value than Thr1. Thus, Thr2 will restrict the frequency of interrogation in comparison to Thr1. In one embodiment, Thr2 may allow the patient to perform an interrogation utilizing the patient'sexternal device15 up to once a week. In another embodiment, Thr2 may allow an interrogation to be performed once a month. As the battery power level decreases to a “low” level (e.g. less than 50%),processor module30 will assign Thr3 as the time threshold value. The value or Thr3 will be greater than Thr2. In one embodiment, Thr3 may allow a patient to interrogate the implantablemedical device12 once every three months. In an alternative embodiment, Thr3 may allow a patient to perform an interrogation once every six months. As the battery power level drops to a “critical” level (e.g. less than 10%),process module30 will assign Thr4 as the time threshold value. At the “critical” level, the maximum time period allowable is assigned to a time threshold value. In one embodiment, Thr4 will not allow the patient to perform any interrogations ofimplantable device12. There can be a plurality of time thresholds. For example, in one embodiment, a time threshold can be assigned for every 10% drop in battery power (e.g., 100% corresponds to Thr1, 90% corresponds to Thr2, 80% corresponds to Thr3, 70% corresponds to Thr4, etc., and at the “critical”level 10% corresponds to Thr10).
• If the time elapsed from last interrogation is longer than the required time threshold per102, then at104, patient'sexternal device15 sends a request for interrogation via a wireless connection toimplantable device12.Telemetry unit52 receives the request for interrogation, and transfers the request viadata bus32 tomonitoring module36. TheProcess module30 then retrieves the required information from thememory module38 and has the I/O module40 transfer the requested information to the patient'sexternal device15.
• At106, I/O module40 monitors the process of interrogation and the status of the wireless connection. If the wireless connection fails or the communication between theexternal device15 and the implantablemedical device12 fails for any reason during the interrogation process,monitoring module36 will end the process. No log will be kept of the interrogation, and the patient must request another interrogation.
• At106, if the interrogation proceeds successfully, then at108 a log of the interrogation (e.g. time and date of interrogation) will be made and stored on patient'sexternal device15.
• FIG. 5 illustrates a processing sequence where the time logs of an interrogation are stored in theimplantable device12 in accordance with an embodiment of this invention. Beginning at200, the patient controlsexternal device15 and starts a request to interrogate theimplantable device12. For example, in one embodiment, the patient may push a button onexternal device15 to request an interrogation.
• At202, the patient'sexternal device15 initiates the interrogation by sending a request via a wireless connection to theimplantable device12. In one embodiment,external device15 may be inductively coupled with theimplantable device12. The request is received bytelemetry unit52 and the request is transferred alongdata bus32 tomonitoring module36.
• At204,processor module30 checks if the time elapsed from the last interrogation fromexternal device15 is longer than the current time threshold value. If the threshold has not expired, the process will be terminated at206 and no response will be made. However, if the threshold value has expired, the process continues. At208,implantable device12 responds toexternal device15 by havingprocessor30 retrieve the requested information frommemory module38 and transmit the information via I/O module40 toexternal device15. At210,implantable device12 logs the time and date of the interrogation inmemory module38.
• It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

Claims (11)

1. An implantable device, comprising:

an input/output module to receive wirelessly a request for information from an external device;

a monitoring module to record a last request for information from the external device and to determine whether a threshold period of time has elapsed since the last request for information; and

a telemetry unit to establish a wireless communication link with the external device, and to transmit the information requested over the wireless link based on an amount of time elapsed since the last request for the information.

2. The device according toclaim 1, further comprising memory that stores the information within the device.

3. The device according toclaim 1, wherein the information requested includes at least one of physiological information, programmable information, timing information, and a battery condition.

4. The device according toclaim 1, wherein the information constitutes physiological information that includes at least one of a heart rate, an electrical activation pattern of the heart, a strength of contraction of heart muscle, an amount of fluid in the lungs, a tachycardia rate, a bradycardia rate, a fibrillation rate, and an arrhythmia rate.

5. The device according toclaim 1, wherein the information constitutes programmable information that includes at least one of a tachycardia detection rate, a fibrillation detection rate, a ventricular tachycardia rate, a ventricular fibrillation detection rate, a bradycardia rate, stability algorithm settings, onset algorithm settings, specific therapies for each cardiac zone, and a duration of therapy required for each zone.

6. The device according toclaim 1, wherein the information constitutes battery condition that includes at least one of a low power battery status, a battery internal resistance, a number of charge/discharge cycles, battery age, a battery voltage and a remaining battery charge.

7. The device according toclaim 1, wherein the information constitutes timing information that includes at least one of a time the data is transmitted, a date the data is transmitted, a number of total interrogations performed, and the date and time of each interrogation request.

8. The device according toclaim 1, wherein the monitoring module prevents transmission of the information when the period of time elapsed since the last request for the information is shorter than the threshold period of time.

9. The device according toclaim 1, wherein the monitoring module prevents transmission of the information when a battery power level being less than a threshold battery value.

10. The device according toclaim 1, wherein the implantable device constitutes at least one of a pacemaker, an implantable cardioverter defibrillator, and a defibrillator.

11. The device according toclaim 1, wherein the monitoring module dynamically updates the threshold period of time to a new value based on a power level of a battery within the implantable device.

Images