Hypnosis augmented ICD

A system and method for employing hypnosis and other pain self-management techniques to mitigate pain experienced by patients receiving therapeutic ICD shocks. In one aspect, a patient is screened for hypnotic inducibility and provided with at least one of redirection/suggestion training, training in self-hypnosis and hypnotic inducement and direct suggestions for pain mitigation. In other aspects, an implantable stimulation device monitors the patient for an arrhythmic event and provides an indication that a therapeutic shock is impending. The patient can then initiate a pain management technique prior to delivery of the shock. Indications can include an audible tone that can help induce a hypnotic state, a tactile vibration, and/or an electrical stimulation. In certain aspects, delivery of the shock is delayed until the device determines that the patient has achieved an effective pain self-management state, which can include implantee activation of certain therapies.

FIELD OF THE INVENTION

The invention relates to the field of implantable medical devices and, in particular, to an implantable cardioverter-defibrillator (ICD) with provision for assisting an implantee enter into a hypnotic state to reduce the sensation of pain from any delivered shocks.

BACKGROUND OF THE INVENTION

ICDs are implantable devices adapted to automatically detect and interrupt rapid, irregular atrial and/or ventricular heart muscle contractions. ICDs typically deliver a high energy and voltage electrical shock to the heart upon detection of an arrhythmic event, such as fibrillation, to override the electrochemical conduction and enable the heart to resume normal rhythm. However, the high energy and voltage shocks delivered by ICDs can cause significant pain to the patient and pain control remains a major issue in ICD therapy.

The pain felt by the patient upon delivery of a shock from the ICD causes moderate to severe physical and psychological trauma. Atrial fibrillation reduces cardiac efficiency, but is not generally lethal, at least on a short term basis. Pain is a major issue limiting the success of high voltage atrial fibrillation (AF) therapies in the patients that are unwilling to tolerate pain for something that was not immediately lethal. Thus, it would be very attractive to have additional techniques to deal with pain for atrial fibrillation.

An additional problem that is often not recognized is how serious the pain issue is for patients with ventricular arrhythmias which can be immediately lethal unless terminated. Even though many patients have no viable alternative other than to accept the pain because the alternative is death, the pain issue causes many patients significant physical and emotional distress.

The pain of the shocks is generally due to two sources: First, inappropriate shocks resulting from a misdiagnosis of or for non-sustained lethal arrhythmias. A misdiagnosis occurs when the device incorrectly detects an arrhythmia and delivers a shock when the patient is not in fact experiencing an arrhythmia that would indicate a shock. A non-sustained arrhythmia in this context is an arrhythmia that self-terminates and can result in inducing the device to appropriately prepare a shock and inappropriately deliver the shock even though the potentially lethal arrhythmia has terminated. In these cases, the patient may be fully conscious to feel the full pain of an inappropriate shock.

The second problem is that rapidly charging devices can deliver the shock while the patient is still conscious in about one third of all cases. This is advantageous as it can eliminate some sequelae due to car accidents, falls, etc., but the patient is conscious so as to feel the full pain of the shock.

The use of rounded waveforms can reduce the pain of the shock as can possible nerve stimulus blocking. However, neither of these measures alone or even in conjunction is generally adequate to eliminate the shock pain or even make it completely tolerable.

Hypnosis has long been used for the control of mild to severe pain. In fact, before the discovery of ether and chloroform in the 1840s, it was one of the few methods available for surgical anesthesia. Careful studies have shown that hypnotizable subjects can reduce pain perception by 3 to 4 points on the classic 10-point pain scale. This is a significant reduction even greater than what would be expected with the use of rounded shock waveforms, for example. Different people have different levels of hypnotic inducibility. It is found that at least 80% of psychologically normal patients are at least somewhat hypnotically inducible. Even those patients that would not be considered clinically inducible can benefit from hypnotic pain reduction. Hypnotic pain reduction is a demonstrable physiological occurrence and can be observed by reduced brainwave response to painful stimuli.

From the foregoing, it will be understood that there is an ongoing need for a system that alleviates a patient's sensation of pain under ICD shocks for both atrial and ventricular arrhythmia treatments. There is a further need to provide this alleviation while maintaining the capability, where possible through rapid charging, to deliver shocks as rapidly as possible to avoid sequelae that may occur if a delay in shocking would lead to unconsciousness.

SUMMARY

The aforementioned needs are satisfied by the invention which, in certain embodiments, is a process of delivering therapeutic electrical stimulation to a patient from an implantable medical device, the process comprising conditioning the patient in a pain management technique, monitoring the patient with the implantable medical device to detect an event indicating delivery of therapeutic electrical stimulation, signaling the patient that a therapeutic electrical stimulation is to be delivered upon detection of the event to thereby allow the patient to implement the pain management technique, and delivering the therapeutic electrical stimulation after the patient has initiated the pain management technique.

In one illustrative embodiment, conditioning the patient in a pain management technique can comprise implanting a hypnotic suggestion in the mind of the patient such that the patient, upon receiving the signal from the implantable medical device, enters a hypnotic state such that the perception of pain by the patient is reduced when the therapeutic electrical stimulation is provided to the patient. Alternatively or in addition, conditioning the patient in a pain management technique can comprise training the patient to self-hypnotize upon receiving the signal.

Another embodiment is a method of delivering therapeutic stimulation to patients provided with implantable cardiac stimulation devices, the method comprising evaluating the patient to determine a hypnotic inducibility score, performing at least one of the following in accordance with the determined inducibility score of the patient: 1) inducing hypnosis and providing a direct suggestion to self-manage pain; 2) training the patient to self-hypnotize; and 3) attempting hypnotic induction and teaching the patient redirection and suggestion techniques, monitoring the patient to detect an arrhythmic condition indicating delivery of a therapeutic shock, notifying the patient upon detection of the arrhythmic condition, confirming indication of delivery of a therapeutic shock, and delivering a therapeutic shock. Delivering the therapeutic shock can be delayed a determined period after detection of an arrhythmic condition.

Yet another illustrative embodiment is an implantable therapeutic cardiac device comprising at least one implantable sensor, a stimulation circuit adapted to provide therapeutic electrical stimulation, a controller in communication with the at least one implantable sensor and the stimulation circuit such that upon detection of a cardiac arrhythmia as sensed by the at least one implantable sensor, the controller can induce the stimulation circuit to provide a therapeutic stimulation, and an annuciator in communication with the controller and adapted to notify a patient when the device has detected an arrhythmia indicating delivery of a therapeutic stimulation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown inFIG. 1, there is a stimulation device augmented with hypnosis10, referred to hereafter as “device10” for brevity, in electrical communication with a patient's heart12by way of three leads,20,24and30, suitable for delivering multi-chamber stimulation and shock therapy. To sense atrial cardiac signals and to provide right atrial chamber stimulation therapy, the stimulation device10is coupled to an implantable right atrial lead20having at least an atrial tip electrode22, which typically is implanted in the patient's right atrial appendage.

To sense left atrial and ventricular cardiac signals and to provide left chamber pacing therapy, the stimulation device10is coupled to a “coronary sinus” lead24designed for placement in the “coronary sinus region” via the coronary sinus os for positioning a distal electrode adjacent to the left ventricle and/or additional electrode(s) adjacent to the left atrium. As used herein, the phrase “coronary sinus region” refers to the vasculature of the left ventricle, including any portion of the coronary sinus, great cardiac vein, left marginal vein, left posterior ventricular vein, middle cardiac vein, and/or small cardiac vein or any other cardiac vein accessible by the coronary sinus.

Accordingly, an exemplary coronary sinus lead24is designed to receive atrial and ventricular cardiac signals and to deliver left ventricular pacing therapy using at least a left ventricular tip electrode26, left atrial pacing therapy using at least a left atrial ring electrode27, and shocking therapy using at least a left atrial coil electrode28.

The stimulation device10is also shown in electrical communication with the patient's heart12by way of an implantable right ventricular lead30having, in this embodiment, a right ventricular tip electrode32, a right ventricular ring electrode34, a right ventricular (RV) coil electrode36, and an superior vena cava (SVC) coil electrode38. Typically, the right ventricular lead30is transvenously inserted into the heart12so as to place the right ventricular tip electrode32in the right ventricular apex so that the RV coil electrode36will be positioned in the right ventricle and the SVC coil electrode38will be positioned in the superior vena cava. Accordingly, the right ventricular lead30is capable of receiving cardiac signals, and delivering stimulation in the form of pacing and shock therapy to the right ventricle.

In this embodiment, the device10also includes an annuciator11. In one embodiment, the annuciator11comprises a speaker that provides physical vibrations that can be discerned by the patient either as audible sounds and/or as a tactile sensation. In other embodiments, the annuciator11comprises a relatively low voltage electrical stimulator that provides discernable, but non-painful distinctive electrical stimulation to the patient. The output of the annuciator11serves to notify the patient when the device10has determined that an arrhythmic condition is present and that a potentially painful shock is indicated and will follow shortly. With the notification thus provided by the device10, the patient can initiate a pain management technique such as will be described in greater detail below with reference toFIGS. 3 and 4.

In this embodiment, the annuciator11is shown as comprised within the device10, however, in alternative embodiments, a annuciator11can be provided as part of an implantable device that can be implanted in another location to facilitate notification of the patient. In other alternative embodiments, the annuciator11can be included as a non-implantable device, such as with a bedside monitor or a device worn on the wrist or belt.

The housing40for the stimulation device10, shown schematically inFIG. 2, is often referred to as the “can”, “case” or “case electrode” and may be programmably selected to act as the return electrode for all “unipolar” modes. The housing40may further be used as a return electrode alone or in combination with one or more of the coil electrodes,28,36and38, for shocking purposes. The housing40further includes a connector (not shown) having a plurality of terminals,42,44,46,48,52,54,56, and58(shown schematically and, for convenience, the names of the electrodes to which they are connected are shown next to the terminals). As such, to achieve right atrial sensing and pacing, the connector includes at least a right atrial tip terminal (ARTIP)42adapted for connection to the atrial tip electrode22.

To achieve left chamber sensing, pacing and shocking, the connector includes at least a left ventricular tip terminal (VLTIP)44, a left atrial ring terminal (ALRING)46, and a left atrial shocking terminal (ALCOIL)48, which are adapted for connection to the left ventricular tip electrode26, the left atrial ring electrode27, and the left atrial coil electrode28, respectively.

To support right chamber sensing, pacing and shocking, the connector further includes a right ventricular tip terminal (VRTIP)52, a right ventricular ring terminal (VRRING)54, a right ventricular shocking terminal (RVCOIL)56, and an SVC shocking terminal (SVC COIL)58, which are adapted for connection to the right ventricular tip electrode32, right ventricular ring electrode34, the RV coil electrode36, and the SVC coil electrode38, respectively.

As shown inFIG. 2, an atrial pulse generator70and a ventricular pulse generator72generate pacing stimulation pulses for delivery by the right atrial lead20, the right ventricular lead30, and/or the coronary sinus lead24via an electrode configuration switch74. It is understood that in order to provide stimulation therapy in each of the four chambers of the heart12, the atrial and ventricular pulse generators,70and72, may include dedicated, independent pulse generators, multiplexed pulse generators, or shared pulse generators. The pulse generators,70and72, are controlled by the microcontroller60via appropriate control signals,76and78, respectively, to trigger or inhibit the stimulation pulses.

The microcontroller60further includes timing control circuitry79which is used to control the timing of such stimulation pulses (e.g., pacing rate, atrio-ventricular (AV) delay, atrial interconduction (A—A) delay, or ventricular interconduction (V—V) delay, etc.) as well as to keep track of the timing of refractory periods, post-ventricular atrial refractory period (PVARP) intervals, noise detection windows, evoked response windows, alert intervals, marker channel timing, etc., which is well known in the art.

The switch74includes a plurality of switches for connecting the desired electrodes to the appropriate I/O circuits, thereby providing complete electrode programmability. Accordingly, the switch74, in response to a control signal80from the microcontroller60, determines the polarity of the stimulation pulses (e.g., unipolar, bipolar, combipolar, etc.) by selectively closing the appropriate combination of switches (not shown) as is known in the art.

Atrial sensing circuits82and ventricular sensing circuits84may also be selectively coupled to the right atrial lead20, coronary sinus lead24, and the right ventricular lead30, through the switch74for detecting the presence of cardiac activity in each of the four chambers of the heart12. Accordingly, the atrial (ATR. SENSE) and ventricular (VTR. SENSE) sensing circuits,82and84, may include dedicated sense amplifiers, multiplexed amplifiers, or shared amplifiers. The switch74determines the “sensing polarity” of the cardiac signal by selectively closing the appropriate switches, as is also known in the art. In this way, the clinician may program the sensing polarity independent of the stimulation polarity.

Each sensing circuit,82and84, preferably employs one or more low power, precision amplifiers with programmable gain and/or automatic gain control, bandpass filtering, and a threshold detection circuit, as known in the art, to selectively sense the cardiac signal of interest. The automatic gain control enables the device10to deal effectively with the difficult problem of sensing the low amplitude signal characteristics of atrial or ventricular fibrillation.

The outputs of the atrial and ventricular sensing circuits,82and84, are connected to the microcontroller60which, in turn, are able to trigger or inhibit the atrial and ventricular pulse generators,70and72, respectively, in a demand fashion in response to the absence or presence of cardiac activity in the appropriate chambers of the heart12. The sensing circuits,82and84, in turn, receive control signals over signal lines,86and88, from the microcontroller60for purposes of controlling the gain, threshold, polarization charge removal circuitry (not shown), and the timing of any blocking circuitry (not shown) coupled to the inputs of the sensing circuits,82and86, as is known in the art.

Cardiac signals are also applied to the inputs of an analog-to-digital (A/D) data acquisition system90. The data acquisition system90is configured to acquire intracardiac electrogram (IEGM) signals, convert the raw analog data into a digital signal, and store the digital signals for later processing and/or telemetric transmission to an external device102, such as a remote monitor for example. The data acquisition system90is coupled to the right atrial lead20, the coronary sinus lead24, and the right ventricular lead30through the switch74to sample cardiac signals across any pair of desired electrodes.

Advantageously, the data acquisition system90may be coupled to the microcontroller, or other detection circuitry, for detecting an evoked response from the heart12in response to an applied stimulus, thereby aiding in the detection of “capture”. Capture occurs when an electrical stimulus applied to the heart12is of sufficient energy to depolarize the cardiac tissue, thereby causing the heart muscle to contract. The microcontroller60detects a depolarization signal during a window following a stimulation pulse, the presence of which indicates that capture has occurred. The microcontroller60enables capture detection by triggering the ventricular pulse generator72to generate a stimulation pulse, starting a capture detection window using the timing control circuitry79within the microcontroller60, and enabling the data acquisition system90via a control signal92to sample the cardiac signal that falls in the capture detection window and, based on the amplitude, determines if capture has occurred.

Capture detection may occur on a beat-by-beat basis or on a sampled basis. Preferably, a capture threshold search is performed once a day during at least the acute phase (e.g., the first 30 days) and less frequently thereafter. A capture threshold search would begin at a desired starting point (either a high energy level or the level at which capture is currently occurring) and decrease the energy level until capture is lost. The value at which capture is lost is known as the capture threshold. Thereafter, a safety margin is added to the capture threshold.

The microcontroller60is further coupled to a memory94by a suitable data/address bus96, wherein the programmable operating parameters used by the microcontroller60are stored and modified, as required, in order to customize the operation of the stimulation device10to suit the needs of a particular patient. Such operating parameters define, for example, pacing pulse amplitude, pulse duration, electrode polarity, rate, sensitivity, automatic features, arrhythmia detection criteria, and the amplitude, waveshape and vector of each shocking pulse to be delivered to the patient's heart12within each respective tier of therapy.

As previously described, the memory94can also store sensed data relating to cardiac activity. A feature of the present invention is the ability to sense and store a relatively large amount of data (e.g., from the data acquisition system90), which data may then be used for subsequent analysis to guide the programming of the device10. A further feature of the invention is to automatically manage the operation of the device10to improve the efficiency of storage of sensed data as well as device10programming as will be described in greater detail below.

Advantageously, the operating parameters of the implantable device10may be non-invasively programmed into the memory94through a telemetry circuit100in telemetric communication with the external device102, such as a programmer, transtelephonic transceiver, or a diagnostic system analyzer. The telemetry circuit100is activated by the microcontroller by a control signal106. The telemetry circuit100advantageously allows intracardiac electrograms and status information relating to the operation of the device10(as contained in the microcontroller60or memory94) to be sent to the external device102through an established communication link104.

In the preferred embodiment, the stimulation device10further includes a physiologic sensor108, commonly referred to as a “rate-responsive” sensor because it is typically used to adjust pacing stimulation rate according to the exercise state of the patient. However, the physiological sensor108may further be used to detect changes in cardiac output, changes in the physiological condition of the heart12, or diurnal changes in activity (e.g., detecting sleep and wake states). Accordingly, the microcontroller60responds by adjusting the various pacing parameters (such as rate, AV Delay, V—V Delay, etc.) at which the atrial and ventricular pulse generators,70and72, generate stimulation pulses.

While shown as being included within the stimulation device10, it is to be understood that the physiologic sensor108may also be external to the stimulation device10, yet still be implanted within or carried by the patient. A common type of rate responsive sensor is an activity sensor, such as an accelerometer or a piezoelectric crystal, which is mounted within the housing40of the stimulation device10. Other types of physiologic sensors are also known, for example, sensors which sense the oxygen content of blood, respiration rate and/or minute ventilation, pH of blood, ventricular gradient, etc. However, any sensor may be used which is capable of sensing a physiological parameter which corresponds to the exercise state of the patient. The type of sensor used is not critical to the present invention and is shown only for completeness.

The stimulation device additionally includes a battery110which provides operating power to all of the circuits shown inFIG. 2. For the stimulation device10, which employs shocking therapy, the battery110must be capable of operating at low current drains for long periods of time (preferably less than 10 μA), and then be capable of providing high-current pulses (for capacitor charging) when the patient requires a shock pulse (preferably, in excess of 2 A, at voltages above 2 V, for periods of 10 seconds or more). The battery110must also have a predictable discharge characteristic so that elective replacement time can be detected.

As further shown inFIG. 2, the device10is shown as having an impedance measuring circuit112which is enabled by the microcontroller60via a control signal114. The known uses for an impedance measuring circuit112include, but are not limited to, lead impedance surveillance during the acute and chronic phases for proper lead positioning or dislodgment; detecting operable electrodes and automatically switching to an operable pair if dislodgment occurs; measuring respiration or minute ventilation; measuring thoracic impedance for determining shock thresholds; detecting when the device has been implanted; measuring stroke volume; and detecting the opening of heart valves, etc. The impedance measuring circuit112is advantageously coupled to the switch74so that any desired electrode may be used. The impedance measuring circuit112is not critical to the present invention and is shown for only completeness.

In the case where the stimulation device10is intended to operate as an implantable cardioverter/defibrillator (ICD) device, it must detect the occurrence of an arrhythmia, and automatically apply an appropriate electrical shock therapy to the heart12aimed at terminating the detected arrhythmia. To this end, the microcontroller60further controls a shocking circuit116by way of a control signal118. The shocking circuit116generates shocking pulses of low (up to 0.5 joules), moderate (0.5–10 joules), or high energy (11 to 40 joules), as controlled by the microcontroller60. Such shocking pulses are applied to the patient's heart12through at least two shocking electrodes, and as shown in this embodiment, selected from the left atrial coil electrode28, the RV coil electrode36, and/or the SVC coil electrode38. As noted above, the housing40may act as an active electrode in combination with the RV electrode36, or as part of a split electrical vector using the SVC coil electrode38or the left atrial coil electrode28(i.e., using the RV electrode36as a common electrode).

In certain embodiments, the device10further comprises a user input13. The user input13is in communication with the microcontroller60so as to allow a user, such as for example an implantee provided with the device10, to provide control inputs to the microcontroller60so as to affect device10operation. In one embodiment, the user input13allows a user to provide a control input to the microcontroller60following a signal from the annuciator11that a therapeutic stimulation from the device10is indicated. The control input provided to the device10via the user input13can indicate that the user has received notification of the indicated therapeutic stimulation, has initiated an appropriate pain management technique, and that the user is ready to receive the therapeutic stimulation. The user input13can be in direct communication with the microcontroller60as shown inFIG. 2or can be in indirect communication, such as via the telemetry circuit100.

InFIGS. 3 and 4, flow charts are shown describing overviews of the operation and novel features implemented in embodiments of the device10. It should be understood that the actions performed as indicated inFIGS. 3 and 4and described in greater detail below are partially performed by the implantable device10. In these flow charts, the various algorithmic steps are summarized in individual “blocks”. Such blocks describe specific actions or decisions that are made or carried out as the algorithm proceeds. Where a microcontroller (or equivalent) is employed, the flow charts presented herein provide the basis for a “control program” that may be used by such a microcontroller (or equivalent) to effectuate the desired control of the stimulation device. Those skilled in the art may readily write such a control program based on the flow charts and other descriptions presented herein.

To begin with, the patient is screened for hypnotic inducibility in step300. This results in a hypnotic inducibility score called the “Hypnotic Induction Profile.” The HIP indicates the patient's motivation and willingness to comply with the clinician's directives and suggestions as part of the hypnotic induction ritual. It also assesses the patient's capacity to experience hypnotic phenomena relative to inducing hypnotic analgesia. These phenomena include speed and authenticity of responsiveness to hypnotic suggestions; imagination capability; and the ability to: enter a relaxed state; suspend voluntary control; experience an altered state of consciousness; feel a floating sensation; produce a signaled arm levitation; perceive physical disassociations; respond to post-hypnotic suggestions; and experience spontaneous amnesia.

A HIP can generally be determined within ten minutes by a practitioner of ordinary skill. The HIP is a numeric score indicating the inducibility of the patient with larger scores indicating a greater inducibility.

Once the HIP is determined, a decision is made in step302according to the patient's HIP score. If the HIP is greater than or equal to 14, then the patient is considered highly hypnotizable and direct suggestion will generally be effective for blocking the pain of delivered shocks. In step304, the patient is then induced into hypnosis. A direct suggestion will be given. An example suggestion would be “When you hear the tone, you will then experience a mild tingling in your chest. This tingling is good for you and will not hurt.”

If the patient has a intermediate HIP score of, in this embodiment, 7–13, then the practitioner will train the patient to self-hypnotize in step306. Each patient will then be instructed to self-hypnotize when they perceive the notification, such as pleasant sounds, from the annuciator11warning of an impending shock. As previously described the annuciator11may be embodied within the device10, but can also be embodied solely in and/or be augmented by a remote hip worn speaker, wrist watch worn device, or a bedside monitor.

For patients with a low HIP score (≦6 in this embodiment), the practitioner will briefly attempt induction in step310. If the induction is not satisfactory, then the practitioner will focus on redirection suggestions and training. The patient will be instructed on how to relax when the alert is given. Redirection strategies can include having the patient visualize that the stimulation is coming from another part of the body such as, for example, the foot, to distract them from the strong sensation in the chest.

It will be understood by one of ordinary skill in the art that there are a variety of known methodologies and approaches to inducing hypnosis and providing suggestions. The exact methods of inducing or attempting to induce hypnosis or the exact suggestions or redirection training provided as previously described are not crucial to the invention. It is intended to be within the scope of the invention to include a variety of specific hypnotizing techniques well known in the art and the variety of specific techniques will not be described in greater detail here.

Following the screening of step300and the training of step304,306, or310, the patient is then discharged home in step312. The device10then monitors the heart12on an ongoing manner for detection of a possible arrhythmia indicating delivery of a shock in step314. If such an arrhythmia is detected, then the device10will begin capacitor charging in step316. Substantially simultaneously, in step320, the device10will activate the annuciator11which, in certain embodiments, begins to emit a pleasant, distinctive sound. The annunciation will generally lead the highly inducible patient (HIP≧14) directly into the direct suggestion so they will literally feel little to no pain. The annunciation will help a moderately hypnotizable (7≦HIP≦13) trained patient to self-hypnotize and significantly reduce their sensation of the pain of a shock delivery. The annunciation will also, in many cases, help the low hypnotizable patient (HIP≦6) to begin relaxation and redirection thinking.

The device10then evaluates the arrhythmia to confirm continued indication of shock delivery in step322. If the device10determines that a shock is no longer indicated, the device10will then generally discharge the capacitors in one of a variety of manners known in the art and return to the ongoing monitoring of state314. If the device10determines that delivery of a shock is indicated, it will then do so in step324and return to the monitoring of state314.

FIG. 4is a flow chart of an alternative embodiment of a stimulation device augmented with hypnosis10. The operation of the device10in this embodiment is substantially similar to that previously described with respect toFIG. 3and the same reference numbers will indicate substantially identical processes, however with the addition of an additional decision state326. In particular, the decision state326comprises a confirmation of the utilization of a pain management technique.

In certain embodiments, the decision of state326occurs passively from the perspective of the patient. For example, the device10may introduce an intentional delay between the onset of capacitor charging of step316and activation of the annuciator in state320until the delivery of the shock in state324under the assumption that the delay provides the patient time to undertake appropriate pain management techniques. The delay may be a programmable aspect of the device10operation. For example, a physician may program a delay determined by an average or minimum time for a particular patient to initiate their particular pain management technique(s).

The device10may also actively monitor one or more patient physiological measured parameters and evaluate these monitored parameters to determine whether the pain management technique(s) have been engaged. For example, in certain embodiments, the physiological sensor(s)108of the device10are adapted to determine a transthoracic impedance. This physiological measurement can determine the rate and depth of the patient's breathing. A deepening of respiration tidal volume and a generally corresponding reduction in respiration rate is indicative of a focused state of relaxation that corresponds to achievement of a hypnotic state or other pain management technique diverting the patient's attention from pain of a potential shock. Upon observation that this deepening and slowing of breathing has occurred, the device10would then return a positive result of the decision of state326. Determined values or ranges for a change in respiration rate and/or depth or other physiological parameters may also be programmable aspects of the device10operation.

In yet other alternative embodiments, the determination of state326can include active input from the patient for non-lethal arrhythmias. For example, the device10can include provision for patient input via the input device13and a positive decision result of state326can comprise patient activation of the input device13indicating sufficient engagement of a pain management technique. In this case, the method is modified so that, once the patient has achieved a hypnotic or relaxed state, the shock is discharged voluntarily.

It will be understood that in the previously described embodiments, delivery of the shock in state324would not be delayed beyond a safe time delay in case of potentially lethal arrhythmias, such as ventricular arrhythmias. Thus, in cases of potentially lethal arrhythmias, the device10would deliver a shock as indicated in state324whether or not a positive decision has been returned by state326.

Another aspect of the invention is to have the annuciator11, such as tone generator, embodied in and generated by a remote home monitor. In this embodiment, the device10would signal the remote monitor, such as via the telemetry circuit100, that a shock was needed. After confirming that the patient was in acoustical range (for an atrial shock) the remote monitor would deliver the annunciation, such as for example, hypnotic tones or speech and signal the device10that it could deliver the shock. In the case of a ventricular fibrillation, the monitor would still attempt the hypnosis but the device10would not wait for the confirmation to deliver the shock.

A variant on this embodiment would have a patient activator give the annunciation, such as hypnotic tones or verbal suggestion. When the patient wished to have an AF shock, they would then actuate the user input13, such as pushing the appropriate button on the activator. The activator would then begin delivering the hypnotic tones or speech while the device10was charging its capacitors and waiting for the hypnosis to occur. A second stage could be added to this embodiment in which the patient would be instructed to provide a subsequent user input, such as pushing a second button after the trance had occurred or they were deep enough into hypnosis.

Although the preferred embodiments of the present invention have shown, described and pointed out the fundamental novel features of the invention as applied to those embodiments, it will be understood that various omissions, substitutions and changes in the form of the detail of the device illustrated may be made by those skilled in the art without departing from the spirit of the present invention. Consequently, the scope of the invention should not be limited to the foregoing description but is to be defined by the appended claims.