Monitoring window based on chemical information

Abstract

Systems and methods of triggering a diuretic monitoring window are disclosed, including determining a health index of a patient as a function of received physiological information, determining a health index alarm status of the patient using the determined value of the health index and a health index alarm threshold, monitoring the health index in the health index alarm status, and triggering the diuretic monitoring window. In response to a change in the detected health index in the health index alert state indicating an improved patient condition, a start of a diuresis monitoring window is triggered, chemical information of the patient is received during the diuresis monitoring window, and a chemical parameter of the patient is monitored during the diuresis monitoring window using the received chemical information.

Description

[0001] Priority requirements

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 604,089, filed November 29, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0003] This document generally pertains to medical devices, and more specifically, to the monitoring of chemical information following health index alerts. Background Technology

[0004] Ambulatory medical devices (AMDs), including implantable, subcutaneous, wearable, or other medical devices, can monitor, detect, or treat various conditions, including heart failure (HF) and atrial fibrillation (AF). AMDs may include sensors that sense physiological information from a patient, and one or more circuits that use the sensed physiological information to detect one or more physiological events or transmit the sensed physiological information or detected physiological events to one or more remote devices. Frequent patient monitoring can provide early detection of deteriorating patient conditions, including worsening heart failure or atrial fibrillation.

[0005] Accurately identifying patients or patient groups at high risk of future adverse events allows for control over the mode or feature selection or resource management of one or more mobile medical devices. It also enables control over notifications or messages sent to various users associated with a specific patient or patient group within connected systems, organizing or scheduling doctor-patient contacts or treatments, or preventing or reducing patient hospitalizations. Properly identifying and safely managing the risk of patient deterioration can avoid unnecessary medical interventions, extend the lifespan of mobile medical devices, and reduce healthcare costs. Summary of the Invention

[0006] Systems and methods for monitoring a patient's chemical status using one or more chemical information points following a health index alert are disclosed. The chemical information may include one or more of the following: potassium information, creatinine information, etc. Additional alerts or signals may be provided to the user or process based on the monitored information.

[0007] Examples of the subject matter (e.g., a medical device system) may include a signal receiver circuit configured to receive physiological information of a patient; and an evaluation circuit configured to: determine a patient’s health index as a function of the received physiological information; determine a patient’s health index alarm state using the determined health index value and a health index alarm threshold; monitor the health index in the health index alarm state; and trigger the start of a diuretic monitoring window in response to a change in the health index detected in the health index alarm state indicating an improved patient condition, wherein the signal receiver circuit is configured to receive the patient’s chemical information during the diuretic monitoring window, and wherein the evaluation circuit is configured to monitor the patient’s chemical parameters during the diuretic monitoring window using the received chemical information.

[0008] In the example, it can be combined with any one or more of the preceding examples, and the health index includes a comprehensive health index, wherein the assessment circuit is configured to determine the patient’s comprehensive health index as a function of at least two features of the received physiological information.

[0009] In the example, it can be combined with any one or more of the preceding examples. Determining the patient's health index alarm state includes using the determined health index value and the health index being at an alarm threshold to determine that the patient's health index is in an alarm state. Monitoring the health index includes monitoring the health index while it is in an alarm state. Triggering the start of the diuretic monitoring window includes indicating an improved patient condition in response to a change in the value of the health index detected while it is in an alarm state toward the health index being at an alarm threshold or the health index being away from the alarm threshold being greater than a first threshold.

[0010] In this example, it can be combined with any one or more of the preceding examples. Monitoring a patient's chemical parameters includes determining the value of the patient's chemical parameters using received chemical information, monitoring the determined chemical parameters during a diuretic monitoring window, and determining the patient's chemical alarm status if the value of the determined chemical parameter exceeds a chemical alarm threshold during the diuretic monitoring window. The evaluation circuit is configured to provide the output of the determined chemical alarm status to a user interface for display to a user, or to a control circuit for controlling or adjusting the process or function of the medical device system.

[0011] In the example, it can be combined with any one or more of the preceding examples, and the chemical alarm threshold is determined as a function of the rate of change of the detected value of the chemical parameter determined in at least a portion of the diuretic monitoring window.

[0012] In the example, it can be combined with any one or more of the preceding examples, the health index includes the heart failure index, and the chemical parameters or chemical information include at least one of the patient's potassium information or creatinine information.

[0013] In the example, it can be combined with any one or more of the preceding examples, the health index alarm state includes one of health index being in an alarm state and health index being out of an alarm state, and the diuretic monitoring window includes an initial duration, which includes the first time period after the detected transition from health index being in an alarm state to health index being out of an alarm state.

[0014] In the example, it can be combined with any one or more of the previous examples, with the first time period having an initial duration including a predefined number of days, between 3 and 31 days.

[0015] In this example, it can be combined with any one or more of the preceding examples. The evaluation circuit is configured to extend the duration of the diuretic monitoring window in response to the received chemical information exceeding a first chemical alarm threshold during the initial duration of the diuretic monitoring window, and the evaluation circuit is configured to terminate the extended duration of the diuretic monitoring window in response to the received chemical information exceeding a second chemical alarm threshold during the extended duration of the diuretic monitoring window.

[0016] In this example, it can be combined with any one or more of the preceding examples. Monitoring a patient's chemical parameters includes determining the value of the patient's chemical parameters using received chemical information, monitoring the determined chemical parameters during a diuretic monitoring window, and determining a patient's chemical alarm state if the rate of change of the value of the determined chemical parameter exceeds a chemical rate of change threshold during the diuretic monitoring window. The evaluation circuit is configured to provide the output of the determined chemical alarm state to a user interface for display to a user, or to a control circuit for controlling or adjusting the process or function of the medical device system.

[0017] In this example, it can be combined with any one or more of the preceding examples, the alarm state includes being in an alarm state and being out of an alarm state, and the evaluation circuit is configured to trigger the start of the diuretic monitoring window in response to a detected transition from being in an alarm state to being out of an alarm state.

[0018] In this example, it can be combined with any one or more of the preceding examples. One method may include: receiving physiological information of a patient using a signal receiver circuit; determining a patient's health index as a function of the received physiological information using an evaluation circuit; determining a patient's health index alarm state using the determined health index value and a health index alarm threshold; monitoring the health index while in the health index alarm state; and triggering the start of a diuretic monitoring window in response to a change in the health index detected while in the health index alarm state indicating an improved patient condition; receiving the patient's chemical information during the diuretic monitoring window using the signal receiver circuit; and monitoring the patient's chemical parameters during the diuretic monitoring window using the received chemical information using the evaluation circuit.

[0019] In this example, it can be combined with any one or more of the preceding examples. Determining a patient's health index alarm state includes using the determined health index value and the health index being at an alarm threshold to determine that the patient's health index is in an alarm state. Monitoring the health index includes monitoring the health index while it is in an alarm state. Triggering the start of the diuretic monitoring window includes indicating an improved patient condition in response to a change in the health index detected while it is in an alarm state toward the health index being at an alarm threshold or the health index being away from the alarm threshold being greater than a first threshold.

[0020] In this example, it can be combined with any one or more of the preceding examples. Monitoring a patient's chemical parameters includes determining the value of the patient's chemical parameters using received chemical information, monitoring the determined chemical parameters during a diuretic monitoring window, and determining the patient's chemical alarm status if the value of the determined chemical parameter exceeds a chemical alarm threshold during the diuretic monitoring window. The evaluation circuit is configured to provide the output of the determined chemical alarm status to a user interface for display to a user, or to a control circuit for controlling or adjusting the process or function of the medical device system.

[0021] In the example, it can be combined with any one or more of the preceding examples, the method comprising determining a chemical alarm threshold as a function of the detected rate of change of the value of a chemical parameter determined in at least a portion of a diuretic monitoring window, wherein the health index includes a heart failure index, and wherein the chemical parameter or chemical information includes at least one of the patient’s potassium information or creatinine information.

[0022] In this example, which can be combined with any one or more of the preceding examples, the medical device system may include a signal receiver circuit configured to receive physiological information from a patient; and an evaluation circuit configured to: determine a patient’s health index as a function of the received physiological information; determine a patient’s health index alarm state using the determined health index value and a health index alarm threshold; monitor the health index in the health index alarm state; and trigger the start of a diuretic monitoring window in response to a change in the health index detected in the health index alarm state indicating an improved patient condition, wherein the signal receiver circuit is configured to receive the patient’s chemical information during the diuretic monitoring window, and wherein the evaluation circuit is configured to monitor the patient’s chemical parameters during the diuretic monitoring window using the received chemical information.

[0023] In the example, it can be combined with any one or more of the preceding examples, and the health index includes a comprehensive health index, wherein the assessment circuit is configured to determine the patient’s comprehensive health index as a function of at least two features of the received physiological information.

[0024] In the example, it can be combined with any one or more of the preceding examples. Determining the patient's health index alarm state includes using the determined health index value and the health index being at an alarm threshold to determine that the patient's health index is in an alarm state. Monitoring the health index includes monitoring the health index while it is in an alarm state. Triggering the start of the diuretic monitoring window includes indicating an improved patient condition in response to a change in the value of the health index detected while it is in an alarm state toward the health index being at an alarm threshold or the health index being away from the alarm threshold being greater than a first threshold.

[0025] In this example, it can be combined with any one or more of the preceding examples. Monitoring a patient's chemical parameters includes determining the value of the patient's chemical parameters using received chemical information, monitoring the determined chemical parameters during a diuretic monitoring window, and determining the patient's chemical alarm status if the value of the determined chemical parameter exceeds a chemical alarm threshold during the diuretic monitoring window. The evaluation circuit is configured to provide the output of the determined chemical alarm status to a user interface for display to a user, or to a control circuit for controlling or adjusting the process or function of the medical device system.

[0026] In the example, it can be combined with any one or more of the preceding examples, and the chemical alarm threshold is determined as a function of the rate of change of the detected values ​​of chemical parameters determined in at least a portion of the diuretic monitoring window.

[0027] In the example, it can be combined with any one or more of the preceding examples, the health index includes the heart failure index, and the chemical parameters or chemical information include at least one of the patient's potassium information or creatinine information.

[0028] In the example, it can be combined with any one or more of the preceding examples, the health index alarm state includes one of health index being in an alarm state and health index being out of an alarm state, and the diuretic monitoring window includes an initial duration, which includes the first time period after the detected transition from health index being in an alarm state to health index being out of an alarm state.

[0029] In the example, it can be combined with any one or more of the previous examples, with the first time period having an initial duration including a predefined number of days, between 3 and 31 days.

[0030] In this example, it can be combined with any one or more of the preceding examples. The evaluation circuit is configured to extend the duration of the diuretic monitoring window in response to the received chemical information exceeding a first chemical alarm threshold during the initial duration of the diuretic monitoring window, and the evaluation circuit is configured to terminate the extended duration of the diuretic monitoring window in response to the received chemical information exceeding a second chemical alarm threshold during the extended duration of the diuretic monitoring window.

[0031] In this example, it can be combined with any one or more of the preceding examples. Monitoring a patient's chemical parameters includes determining the value of the patient's chemical parameters using received chemical information, monitoring the determined chemical parameters during a diuretic monitoring window, and determining a patient's chemical alarm state if the rate of change of the value of the determined chemical parameter exceeds a chemical rate of change threshold during the diuretic monitoring window. The evaluation circuit is configured to provide the output of the determined chemical alarm state to a user interface for display to a user, or to a control circuit for controlling or adjusting the process or function of the medical device system.

[0032] In this example, it can be combined with any one or more of the preceding examples, the alarm state includes being in an alarm state and being out of an alarm state, and the evaluation circuit is configured to trigger the start of the diuretic monitoring window in response to a detected transition from being in an alarm state to being out of an alarm state.

[0033] In this example, it can be combined with any one or more of the preceding examples. One method may include: receiving physiological information of a patient using a signal receiver circuit, and using an evaluation circuit to determine the patient's health index as a function of the received physiological information; determining the patient's health index alarm state using the determined health index value and a health index alarm threshold; monitoring the health index in the health index alarm state; and triggering the start of a diuretic monitoring window in response to a change in the health index detected in the health index alarm state indicating an improved patient condition; receiving the patient's chemical information during the diuretic monitoring window using the signal receiver circuit, and using an evaluation circuit to monitor the patient's chemical parameters during the diuretic monitoring window using the received chemical information.

[0034] In the example, it can be combined with any one or more of the preceding examples, the health index includes a comprehensive health index, and the determination of the health index includes a function that determines the patient’s comprehensive health index as a function of at least two features of the received physiological information.

[0035] In this example, it can be combined with any one or more of the preceding examples. Determining a patient's health index alarm state includes using the determined health index value and the health index being at an alarm threshold to determine that the patient's health index is in an alarm state. Monitoring the health index includes monitoring the health index while it is in an alarm state. And triggering the start of the diuretic monitoring window includes indicating an improved patient condition in response to a change in the value of the health index detected while it is in an alarm state toward the health index being at an alarm threshold or the health index being away from the alarm threshold being greater than a first threshold.

[0036] In this example, it can be combined with any one or more of the preceding examples. Monitoring a patient's chemical parameters includes determining the value of the patient's chemical parameters using received chemical information, monitoring the determined chemical parameters during a diuretic monitoring window, and determining the patient's chemical alarm status if the value of the determined chemical parameter exceeds a chemical alarm threshold during the diuretic monitoring window. The evaluation circuit is configured to provide the output of the determined chemical alarm status to a user interface for display to a user, or to a control circuit for controlling or adjusting the process or function of the medical device system.

[0037] In the example, it can be combined with any one or more of the preceding examples, and the method can include determining a chemical alarm threshold as a function of the detected rate of change of the value of a chemical parameter determined in at least a portion of the diuretic monitoring window, wherein the health index includes a heart failure index, and wherein the chemical parameter or chemical information includes at least one of the patient's potassium information or creatinine information.

[0038] In the example, it can be combined with any one or more of the preceding examples, the health index alarm state includes one of health index being in an alarm state and health index being out of an alarm state, and the diuretic monitoring window includes an initial duration, which includes the first time period after the detected transition from health index being in an alarm state to health index being out of an alarm state.

[0039] In this example, it can be combined with any one or more of the preceding examples. The method may include using an evaluation circuit to extend the duration of the diuretic monitoring window in response to a received chemical information exceeding a first chemical alarm threshold during the initial duration of the diuretic monitoring window, and using an evaluation circuit to terminate the extended duration of the diuretic monitoring window in response to a received chemical information exceeding a second chemical alarm threshold during the extended duration of the diuretic monitoring window.

[0040] In this example, it can be combined with any one or more of the preceding examples. Monitoring a patient's chemical parameters includes determining the value of the patient's chemical parameters using received chemical information, monitoring the determined chemical parameters during a diuretic monitoring window, and determining a patient's chemical alarm state if the rate of change of the value of the determined chemical parameter exceeds a chemical rate of change threshold during the diuretic monitoring window. The method includes using evaluation circuitry to provide the output of the determined chemical alarm state to a user interface for display to a user, or to control circuitry to control or adjust the process or function of the medical device system.

[0041] In this example, it can be combined with any one or more of the preceding examples. The alarm state includes being in an alarm state and being out of an alarm state. The method includes using an evaluation circuit to trigger the start of a diuretic monitoring window in response to a detected transition from being in an alarm state to being out of an alarm state.

[0042] In the example, the system or apparatus may optionally combine any part or combination of any one or more of the above examples to include "means for..." performing any part of any one or more of the functions or methods of the above examples, or at least one "non-transient machine-readable medium" including instructions that, when executed by a machine, cause the machine to perform any part of any one or more of the functions or methods of the above examples.

[0043] The present invention is intended to provide an overview of the subject matter of this patent application. It is not intended to provide an exclusive or exhaustive interpretation of this disclosure. Detailed descriptions are included to provide further information regarding this patent application. Other aspects of this disclosure will be apparent to those skilled in the art upon reading and understanding the following detailed descriptions and viewing the drawings that form a part thereof, and none of these should be construed in a limiting sense. Attached Figure Description

[0044] In the drawing, it is not necessarily drawn to scale, and similar numbers can describe similar parts in different views. Similar numbers with different letter suffixes can represent different instances of similar parts. Figure 1 The various embodiments discussed in this document are shown by way of example rather than by way of limitation.

[0045] Figure 1 An example of determining a chemical alarm state is shown.

[0046] Figure 2 An example medical device system is shown.

[0047] Figure 3 An example patient management system is shown.

[0048] Figure 4 An example method for using chemical information to determine the state of a chemical alarm is shown.

[0049] Figure 5 An example implantable medical device (IMD) electrically coupled to the heart is shown.

[0050] Figure 6 A block diagram of an example machine on which any one or more of the techniques discussed in this article can be executed is shown. Detailed Implementation

[0051] Mobile medical devices may include or be configured to receive physiological information from one or more sensors located inside, on, or near a patient's body. The patient's physiological information may, among others, include one or more of the following: electrical information, such as cardiac electrical information (e.g., heart rate, heart rate variability, etc.), impedance information, temperature information, and in some examples, respiratory information (e.g., respiratory rate, respiratory volume (tidal volume), etc.); mechanical information, such as cardiac acceleration information (e.g., cardiac vibration information, pressure waveform information, heart sound information, endocardial acceleration information, acceleration information, activity information, posture information, etc.), body activity information (e.g., activity, stepping, etc.), posture or position information, pressure information, plethysmography information, and in some examples, respiratory information; chemical information; or other physiological information of the patient.

[0052] In some examples, one or more health indices can be determined as a function of different physiological information of a patient or various combinations thereof. Health indices can include single-feature health indices determined using a single characteristic or measure of a single type of physiological information, or composite health indices determined solely using combinations of physiological information, such as two or more individual characteristics from different physiological measures. For example, while respiratory rate and tidal volume are both respiratory information, they are individual characteristics of respiratory information, making it possible to determine a composite health index using only respiratory rate and tidal volume. In contrast, single-feature health indices can be determined using respiratory information, such as trends or measures of tidal volume alone.

[0053] In some examples, the health index can be a device-based index, such as one determined using physiological information detected from the patient, without requiring input of separate clinical information about the patient, such as clinician diagnosis or risk assessment, patient history, patient age, comorbidities, previous hospitalizations, and type of implanted device. In other examples, the health index can be a combination of device-based and clinically-based mortality risk indices, including or taking into account clinical information about the patient, such as clinician diagnosis or risk assessment, patient history, patient age, comorbidities, previous hospitalizations, and type of implanted device. In these examples, different combinations of clinical information can be determined separately.

[0054] An example of a comprehensive health index is HeartLogic. TM Index, HeartLogic during alert time TM Or one or more other comprehensive measurements or their measures. HeartLogic TM The index is a comprehensive measurement of a patient's electrophysiological information from multiple motion sensors, including S1 and S3 heart sounds, thoracic impedance, activity information, respiratory information, and nighttime heart rate (nHR). It can indicate the state of heart failure, the risk of heart failure events, or the deterioration of the patient's heart failure state or the risk of heart failure events over time. HeartLogic is in the alarm period. TM It is HeartLogic TM A measure of the time the index is above the alarm threshold.

[0055] In some examples, HeartLogic TMThe index can be determined using different combinations or weights of electrophysiological information, including one or more of S1 and S3 heart sounds, thoracic impedance, activity information, rapid shallow breathing index (RSBI), respiratory rate, and nocturnal heart rate (nHR). In some examples, HeartLogic TM Different combinations or weights of the indices can be adjusted or determined based on a risk stratifier. In some examples, the risk stratifier can be determined as different combinations of physiological information, including one or more of S3, respiratory rate, and activity time (e.g., the amount of time spent at a specific activity level above the patient's average activity level or a specific threshold).

[0056] For example, if the risk stratifier is low or below the first threshold, then HeartLogic TM The index can be determined using a first combination of physiological information. If the risk stratification is high, or above a second threshold, then HeartLogic... TM The index can be determined using a first combination of physiological information and a second combination of physiological information (including additional information compared to that included in the first combination). If the risk stratifier falls between the first and second thresholds, then HeartLogic... TM The index can be determined using one or more indicators or components of the first and second combinations, or using the first and second combinations (but the second combination has less weight than when the risk stratifier is above the second threshold (e.g., using a smaller second combination)).

[0057] In the example, HeartLogic TMIndices and alert times may include detection of worsening heart failure or physiological events, including risk indications or stratification, such as those disclosed in U.S. Patent No. 9,968,266, co-assigned by An et al., entitled "RISK STRATIFICATIONBASED HEART FAILURE DETECTION ALGORITHM," or in U.S. Patent No. 9,622,664, co-assigned by An et al., entitled "METHODS AND APPARATUS FOR DETECTING HEART FAILURE DECOMPENSATION EVENT AND STRATIFYING THE RISK OF THE SAME," or in U.S. Patent No. 10,660,577, co-assigned by Thakur et al., entitled "SYSTEMS AND METHODS FOR DETECTING WORSENING HEART FAILURE," or in U.S. Patent No. 10,660,577, co-assigned by An et al., entitled "HEART FAILURE PATIENT." The disclosures in U.S. Patent Application No. 2014 / 0031643 entitled “STRATIFICATION”, or in U.S. Patent No. 10,085,696 entitled “DETECTION OF WORSENING HEART FAILURE EVENTSUSING HEART SOUNDS”, co-assigned Thakur et al., each of which is incorporated herein by reference in its entirety, including their disclosures on detection of heart failure and worsening heart failure, detection of heart failure risk indicators, and their stratification, etc.

[0058] Implantable and mobile medical devices often include one or more accelerometer sensors and corresponding processing circuitry to determine and monitor patient acceleration information, such as cardiac vibration information (e.g., heart sounds, heart wall motion, etc.) associated with blood flow or movement in the heart or the patient's vascular system, patient body activity or location information (e.g., patient posture, activity, etc.), respiratory information (e.g., respiratory rate, phase, breath sounds, etc.), etc.

[0059] Heart sounds are recurring mechanical signals associated with the vibrations of the heart or accelerations from blood flow through the heart or other cardiac movements during each cardiac cycle, and can be separated and classified according to the activities associated with these vibrations, accelerations, movements, pressure waves, or blood flow. Heart sounds comprise four main characteristics: the first to the fourth heart sounds (S1 to S4, respectively). The first heart sound (S1) is a vibration produced by the heart during the closure of the atrioventricular (AV), mitral, and tricuspid valves, and during the opening of the aortic valve at the onset of systole or ventricular systole. The second heart sound (S2) is a vibration produced by the heart during the closure of the aortic and pulmonary valves at the onset of diastole or ventricular diastole. The third and fourth heart sounds (S3, S4) are related to the filling pressure of the left ventricle during diastole. An abrupt cessation of early diastolic filling can result in the third heart sound (S3). Vibrations caused by atrial kicks can result in the fourth heart sound (S4). The closure of valves in the heart and changes in blood flow and pressure can cause acceleration, vibration, or movement of the heart wall, which can be detected using an accelerometer or microphone, thus providing an output referred to in this paper as cardiac acceleration information.

[0060] Respiratory information may include, among other things, a patient's respiratory rate (RR), tidal volume (TV), rapid shallow breathing index (RSBI), or other respiratory information. Respiratory rate is a measure of the rate of a patient's inspiratory and expiratory breathing, typically measured as breaths per minute. Tidal volume is a summary measure of respiratory changes, such as those detected using measured changes in thoracic impedance. RSBI is the ratio of a measured respiratory rate to a patient's relative tidal volume. nHR is a measure of a patient's heart rate (HR) at night, related to sensing patient sleep or using a preset or selectable time of day corresponding to patient sleep. In some examples, a patient's respiratory information can be determined using changes in impedance information and thus can be considered electrophysiological information, but distinct from cardiac electrical information. In other examples, a patient's respiratory information can be determined using changes in activity or acceleration information and thus can be considered mechanophysiological information.

[0061] As described herein, physiological values ​​or characteristics may include one or more different measures of the rate, amplitude, energy, etc., of different physiological information over one or more time periods (such as representative daily values). For example, heart sound values ​​may be determined for each heart sound (e.g., the first heart sound (S1) through the fourth heart sound (S4), etc.) and may include an indication of the amplitude or energy of a specific heart sound in a particular cardiac cycle, or a representation of the number of cardiac cycles of a patient over a particular time period. Daily values ​​may be determined representing the patient's average daily values, corresponding to awake time or a 24-hour period, etc. Respiratory values ​​may include, among other things, the average or median respiratory rate, binned values ​​of the rate, and representative values ​​of specific rate bins, etc. Heart rate values ​​may include the average nocturnal heart rate, minimum nocturnal heart rate, etc.

[0062] Activity information may include measurements of the patient's activity, such as those detected using an accelerometer, posture sensor, pedometer, or one or more other activity sensors associated with the mobile medical device. Impedance information may include, among other things, the patient's thoracic impedance information, such as measurements of impedance across the patient's chest cavity from one or more electrodes associated with the mobile medical device (e.g., one or more leads of an implantable medical device located near the patient's heart and the housing of the implantable medical device implanted subcutaneously in the patient's chest cavity, one or more external leads on the patient's body, etc.). In other examples, impedance information may include one or more other impedance measurements associated with the patient's chest cavity, or otherwise indicate the patient's thoracic impedance.

[0063] Temperature information may include the patient's internal temperature at a mobile medical device (such as one implanted in the patient's chest cavity), or one or more other temperature measurements taken at a specific location on the patient. Temperature information can be detected using a temperature sensor (such as one or more circuits or electronic components having electrical properties that change with temperature). The temperature sensor may include a sensing element located on, within, or on the mobile medical device, configured to determine a temperature indicating the patient's temperature at the location of the mobile medical device.

[0064] In contrast to and separate from the electrophysiological information discussed above, chemical information may include information about one or more chemical properties of a patient's blood, interstitial space (e.g., spaces between cells, such as those including interstitial fluid), or other tissues (e.g., muscle tissue, adipose tissue, organ tissue, etc.), such as information indicating or including one or more of glucose levels, pH levels, dissolved gas levels (e.g., oxygen, carbon dioxide, carbon monoxide, etc.), electrolyte levels (e.g., sodium, potassium, calcium, etc.), organic compound levels (e.g., lactate, cholesterol, hemoglobin, creatinine, etc.), or biological compound levels (e.g., enzymes, antibodies, receptors, etc.). Chemical information can be measured by one or more of electrical sensors, mechanical sensors, electrochemical sensors, biosensors (e.g., enzyme biosensors, etc.), ion-selective electrode sensors, optical sensors, etc. In the example, chemical information may include potassium information (e.g., one or more of interstitial potassium information, serum potassium information, etc.), creatinine information (e.g., one or more of interstitial creatinine information, serum creatinine information, etc.) or combinations thereof.

[0065] The inventors have recognized, among other things, systems and methods for monitoring a patient's chemical status after a health index alarm using chemical information, such as by reducing power consumption, improving the sensitivity or specificity of alarm status determination, reducing false positive alarm status determinations, alarm status transitions or adjustments, or otherwise reducing the storage or transmission of physiological information associated with false positive alarm status determinations or transitions associated with false positive alarm status determinations, and the associated power and processing resources. In examples, the system may determine one or more chemical information and monitor the chemical information after a health index alarm to determine the patient's chemical alarm status.

[0066] For example, health indicators can be used to determine an indication or alarm of a deteriorating patient condition, including worsening heart failure, such as that driven by volume overload (e.g., excessive body fluid, excessive blood volume, excessive plasma ratio in the blood, etc.). Volume overload is typically treated with diuretics (e.g., reducing body fluid levels with the goal of reducing volume overload). Furthermore, the inventors have recognized that confirmation or indication of therapeutic efficacy and patient condition can be provided, for example, using sensed or received chemical information about the patient. For example, chemical information can be used to determine whether a diuretic is working, such as by monitoring the patient's potassium levels. Potassium levels can be used to determine one or more of the following: how quickly the treatment takes effect, whether the dosage of the diuretic needs to be adjusted.

[0067] In the example, chemical information could be used to determine whether a patient has engaged in excessive diuresis (e.g., administration of an overdose of diuretic medication or its prolonged use), which could lead to adverse health outcomes (e.g., electrolyte imbalance in the blood, which could result in arrhythmias) or increase the risk of adverse health outcomes. In the example, fluid volume depletion (e.g., due to dehydration, excessive diuresis, etc.) could improve health indicators (e.g., HeartLogic). TM (Indices). This may result in health indices showing improved patient condition, even if the patient may be at increased risk of some adverse outcomes. This can make chemosusceptibility monitoring beneficial, because even if the overall health metrics are positive, chemosusceptibility monitoring information may indicate that the patient is not in a stable condition.

[0068] In some examples, interstitial chemical information, such as one or more chemical levels in the interstitial space (e.g., the space between one or more of connective tissue, muscle fibers, nerve tissue, etc.) or interstitial fluid, can indicate serum chemical information. For example, potassium can move between cells or tissues and interstitial fluid (e.g., changes in interstitial potassium levels may accompany or reflect changes in serum potassium levels, or vice versa), such that serum potassium chemical information can include interstitial potassium. In some examples, one of the interstitial or serum chemical information may lead or lag behind the other, such that a change in one that could indicate a worsening patient condition can be detected before the other. In one example, interstitial potassium information may lead serum potassium information as an indicator of electrolyte imbalance.

[0069] Regarding potassium information, a normal range (e.g., a medically acceptable range, such as a healthy range determined based on medical data, etc.) can be defined as “normal serum potassium levels” and can include values ​​from 3.6 mmol / L to 5.2 mmol / L (e.g., millimoles per liter). Potassium levels higher and / or lower than normal serum potassium levels can lead to adverse outcomes. For example, a low range below normal serum potassium levels can be defined as “hypokalemia” and can include values ​​below 3.6 mmol / L. Moderate hypokalemia can include values ​​from 2.5 mmol / L to 3.6 mmol / L. Severe hypokalemia, which may require immediate medical attention, can include values ​​below 2.5 mmol / L. A high range above normal serum potassium levels can be defined as “hyperkalemia” and can include values ​​above 5.2 mmol / L. Moderate hyperkalemia can include values ​​from 5.2 mmol / L to 6.5 mmol / L. Severe hyperkalemia, which may require immediate medical attention, can include values ​​above 6.5 mmol / L.

[0070] Thiazide diuretics may increase the risk of hypokalemia. Potassium-sparing diuretics can cause hyperkalemia. Chemical information about a patient's potassium levels can help inform the decision of which class of medication to use. For example, if a patient has hyperkalemia, a thiazide diuretic may be recommended. If a patient has hypokalemia, a potassium-sparing diuretic may be recommended.

[0071] Compared to creatinine, low renal perfusion and / or worsening renal function can lead to increased creatinine levels (e.g., serum or interstitial creatinine levels, etc.), which can result in fluid accumulation in the lungs and / or other tissues, and in some examples, worsen heart failure symptoms and / or increase the risk of adverse outcomes (e.g., hospitalization, readmission, death, etc.). Monitoring creatinine levels may be desirable to determine whether renal function is affecting the heart failure status. For example, an increase in creatinine levels over time (e.g., serum or interstitial creatinine levels, etc.), such as a long-term trend, can indicate that renal dysfunction is causing volume overload, which can inform decisions regarding diuretic therapy (e.g., if kidney failure is present, increasing diuretics may not help with volume overload, while switching to a more bioavailable diuretic may be helpful). In some examples, health index alert states (e.g., health index in alert state, health index out of alert state, etc.) can be identified and provided to the patient, clinician, or one or more other users or devices associated with the patient. Health index alert states can be achieved using health indices (such as HeartLogic). TM It is determined by an index.

[0072] In the example, the health index may have a value (e.g., a numerical value), and this value may be compared to one or more thresholds to determine the system's health index alarm state. The evaluation circuitry may be configured to compare the health index to one or more health index alarm thresholds (e.g., a single health index alarm threshold, a first health index alarm threshold, a second health index alarm threshold, etc.) to determine the patient's health index alarm state. In the example, the health index may have a numerical value, where a higher value indicates a worse health condition for the patient, and a lower value indicates a better health condition. The health index alarm threshold may represent a high threshold that triggers an alarm state for the health index if its value exceeds the health index alarm threshold.

[0073] The health index alarm threshold can be a fixed value, or it can be an adaptive threshold that varies based on one or more factors. In the example, the health index alarm threshold can be fixed, but the health index value can be based in part on one or more relative factors (e.g., based on measurements from the patient over the past 30 days, rather than on a fixed value). This could result in the patient being in an alarm state threshold condition being relative, even if the health index alarm threshold is fixed.

[0074] The health index alarm status of the system can be determined by comparing the health index value with the health index alarm threshold. If the health index includes one or more features generated using chemical information or is determined using such features, the health index alarm status will be at least partially based on the received chemical information; otherwise, if the health index is not determined using any features generated using chemical information, the health index alarm status will be not based on the received chemical information.

[0075] In some examples, if a health index value exceeds a health index alarm threshold, the system can enter an alarm state. The system can remain in an alarm state until the health index value exceeds a health index exit alarm threshold. The alarm state threshold and the exit alarm threshold can have the same value (e.g., any health index value above a shared threshold results in an alarm state being determined, and any health index value below the shared threshold results in an exit alarm state being determined). The alarm state threshold and the exit alarm threshold can also have different values. For example, the exit alarm threshold (e.g., the threshold that a health index value must cross to transition from an alarm state to an exit alarm state once an alarm state is determined) may be lower than the alarm state threshold (e.g., the threshold that a health index value must cross to transition from an exit alarm state to an alarm state). This can cause a lag in health index alert status (e.g., once an alert status is determined, the health index value must drop to a specified margin below the health index value required to enter the alert status before it is determined to exit the alert status), which can prevent rapid switching between alert and exit states, requiring meaningful improvement in the patient's condition before transitioning to an exit state, etc.

[0076] After determining that an alert state is in effect, the system can begin monitoring changes in health indices that indicate improvement in patient conditions (e.g., a patient's health is determined to be improving, the likelihood of a patient experiencing an adverse health event is determined to be decreasing, etc.). An improved patient condition can be determined if any decrease in the health index value occurs, or if the health index value decreases by a specified amount (e.g., a specified numerical decrease, a specified percentage decrease, etc.), such as from a high value. An improved patient condition can be determined if the health index value moves toward one or more of the alert thresholds or moves away from the alert threshold by an amount greater than an improvement threshold (e.g., five units toward the threshold, five percent of the total health index value toward the threshold, thirty percent of the difference between the health index value toward the threshold and the threshold value, etc.). In the example, if an improved patient condition has not been otherwise determined before the system determines that the patient is out of alert status, an improved patient condition can be determined upon transitioning from an alert state to an out-of-alert state (e.g., the system can determine an improved patient condition upon transitioning to an out-of-alert state if the health index value and associated thresholds have not been otherwise determined to indicate an improved patient condition before the transition to an out-of-alert state, etc.). In the example, an improved patient condition can be determined without first identifying an alarm state (e.g., a health index value comes within a specified range where the health index is an alarm value and then improves by a specified amount).

[0077] After confirming an improvement in the patient's condition, the system can trigger the start of a chemical monitoring window. During the chemical monitoring window, the system can receive the patient's chemical information. In one example, the system does not receive the patient's chemical information outside the chemical monitoring window. In other examples, the system can receive chemical information outside the chemical monitoring window, but at a reduced frequency relative to when it is inside the chemical monitoring window. For example, power consumption outside the chemical monitoring window can be reduced compared to operating at an increased frequency inside the chemical monitoring window. In the example, during the chemical monitoring window, the operating mode or characteristics of one or more sensors can be adjusted, such as sensing information at different frequencies (e.g., enabling different sensors, increasing sampling frequency, etc.), expanding the sensing window, changing the storage amount (e.g., increasing the amount of data stored), changing the upload or transmission schedule (e.g., increasing the frequency, the amount of data transmitted, or reducing the duration between transmissions, etc.). The system can use the received chemical information to monitor the patient's chemical parameters during the monitoring window.

[0078] A chemical monitoring window can extend from the beginning of a triggered chemical monitoring window to the end of a defined chemical monitoring window. For example, a chemical monitoring window can have a predefined length (e.g., a predefined length of 3 days, 7 days, 14 days, 21 days, 31 days, etc.) and can end after the predefined length. In the example, if another chemical monitoring window is triggered during the predefined length, such as in response to the same or one or more different triggering conditions, the monitoring window can be extended to run a separate predefined duration from the new triggering event, replacing the previous predefined duration. In other examples, the original duration can be retained. In the example, the chemical monitoring window can continue until termination (e.g., by a clinician or procedure).

[0079] Monitoring a patient's chemical parameters may include using received chemical information to determine the value of the chemical parameter, monitoring the determined value on a chemical monitoring window, and using the determined or monitored value to determine the patient's chemical alarm status. In one example, the chemical alarm status is not determined outside the chemical monitoring window. In other examples, the chemical alarm status may be determined outside the chemical monitoring window at a lower frequency or with lower sensitivity or specificity, such as reducing power consumption outside the chemical monitoring window compared to the higher frequency, sensitivity, or specificity within the chemical monitoring window. If the chemical parameter exceeds a chemical alarm threshold or is outside a predefined range within the chemical monitoring window, it can be determined that the chemical is in an alarm state. If the chemical parameter does not exceed the chemical alarm threshold, it can be determined that the chemical is out of an alarm state. In the example, the chemical alarm status may be determined using different chemical alarm thresholds and chemical out-of-alarm thresholds, such as those discussed above regarding health index alarm status, including hysteresis between the alarm and out-of-alarm thresholds. Similarly, hysteresis may also be applied at both ends of the range.

[0080] In some examples, the duration of the monitoring window can be adjusted based on the value of the chemical parameter. For example, the chemical monitoring window can end in response to a chemical parameter crossing a lower threshold, transitioning to an alert state, etc. In one example, the chemical monitoring window can extend from when an improvement in the patient's condition is confirmed until the health index ends in an alert state. In another example, the chemical monitoring window can extend for a specified number of days (e.g., 3 days, 7 days, 14 days, 21 days, 31 days, etc.) after the health index transitions to an alert state.

[0081] In the example, the system can determine the rate of change of a chemical parameter. The chemical alarm threshold can depend on the rate of change of a chemical parameter determined for one or more portions of a chemical monitoring window (e.g., the entire window, a portion of the window where health index values ​​are above a specified threshold, etc.). (E.g., a higher rate of change leads to a lower threshold, such as avoiding overshoot). In the example, the system can determine the patient's chemical alarm status based on the determined rate of change of the chemical parameter. If the determined rate of change of the chemical parameter value exceeds a chemical rate of change threshold, a chemical alarm state can be triggered. In the example, both the chemical parameter value and the rate of change of the chemical parameter value can be considered for a comprehensive determination (e.g., triggering an alarm state when the rate of change exceeds a threshold based on the chemical parameter value).

[0082] The system can provide the output of the determined chemical alarm status to the user interface for display to the user, or to the control circuitry to control or adjust the process or function of the medical device system.

[0083] In the example, the health index may include a comprehensive heart failure index, the chemical monitoring window may be a diuretic (e.g., related to the use of diuretics, related to electrolyte levels in the blood, related to hydration levels, etc.) monitoring window, and the received chemical information may include one or more of potassium levels or creatine levels.

[0084] The identified chemical alert status can be provided to clinicians with instructions to perform, schedule, or consider one or more actions based on multiple monitored physiological and chemical information (e.g., recommending a drug or drug class from multiple options, recommending optimized guideline-directed medical therapy (GDMT), etc.). In examples, the identified chemical alert status may include instructions or recommendations to administer or provide a class of drugs or to reduce the dosage or application of a class of drugs, or one or more instructions or recommendations related to GDMT. GDMT can provide a standard course of action to be followed in the patient's treatment. For example, GDMT may recommend administering a certain amount of drug or a rate of dose escalation, etc. In the example, when the received chemical information indicates that one or more of the potassium or creatinine levels are outside the normal range, the chemical alarm status may include one or more of the following: providing instructions to administer or provide a specific class of diuretics (e.g., thiazide diuretics, potassium-sparing diuretics, etc.) or other drugs (e.g., vasodilators), or reducing the use of diuretics. This may include instructions to deviate from GDMT (e.g., reduce GDMT below the standard recommendation, reduce the dosage of the drug, reduce the rate of drug increase, etc.).

[0085] In some examples, the techniques described above or in this article can be used in various combinations or arrangements. For example, the combination or arrangement of the techniques described above or in this article can be selected based on patient history, clinician input, etc.

[0086] Figure 1 Example representation 100 shows the patient's monitoring status and physiological information (including health index value 102 and chemical parameter value 122). Figure 1 The system can have one or more monitoring states, such as first state 140, second state 142 and third state 144.

[0087] The first state 140 can be an initial and / or basic state, such as a health index monitoring state (e.g., a worsening heart failure monitoring state, etc.). During the first state 140, the system can determine a health index and monitor the health index by comparing a health index value 102 with a health index threshold 114. When the health index value 102 crosses above the health index threshold 114, the system can enter an alarm state. Figure 1 The diagram illustrates a configuration where the health index is at an alarm threshold but below the health index exits an alarm threshold. When the health index value 102 crosses the health index at an alarm threshold, the system enters an alarm state, but it does not transition to an exits alarm state until the health index value 102 crosses the exits alarm threshold at point 108 (e.g., a step drop in the health index threshold 114 indicates that the exits alarm threshold is below the alarm threshold).

[0088] After transitioning to an alert state during the first state 140, the system can begin monitoring indicators of improved patient condition. To determine improved patient condition, the system can retain a record of the worst (e.g., highest) value of the health index and record it as a high health index value 112 (e.g., the high health index value 112 increases with the health index value 102 until the health index value 102 begins to decline). The system can compare the current value of the health index value 102 with the high health index value 112 and determine the improved patient condition based on the comparison at point 106 (e.g., the health index value 102 is lower than the high health index value 112 by a specified first threshold value).

[0089] After confirming an improved patient condition at point 106, a second state 142 can commence. The second state 142 may be a chemical monitoring window, and may include additional chemical monitoring functions beyond those present during the first state 140. For example, during the second state 142, the system may determine a chemical parameter value 122 and compare it to a first threshold 132 (e.g., a high threshold) and a second threshold 134 (e.g., a low threshold). The system may also continue to determine a health index value 102 and a health index alarm status. The chemical monitoring window may be defined as having an initial duration, such as a specified number of days from the start of the chemical monitoring window. During the second state 142 (e.g., during the corresponding chemical monitoring window), one or more of the monitoring frequency and / or duration, or transmission and / or upload rate, may be increased.

[0090] If the chemical parameter value 122 is determined to exceed either the first threshold 132 or the second threshold 134, the system can transition to a chemical alarm state. For example, the system can transition to a chemical alarm state at point 124 when the chemical parameter value 122 exceeds the first threshold 132. In response to the chemical alarm state, actions can be taken, as described herein.

[0091] In response to a chemical alert being activated, the system can extend the duration of the chemical monitoring window (e.g., extend the window until the system transitions out of the chemical alert state, extend the window by a specified number of days, etc.). For example, Figure 1 The second state 142 is shown to extend until the chemical parameter value 122 falls below the first threshold 132 at point 126. After point 126, the system can enter a third state 144, which could be a health index monitoring state similar to or the same as the first state 140. Similar actions can be taken relative to the chemical parameter value 122 falling below the second threshold 134.

[0092] Figure 2 An example system 200 (e.g., a medical device system) is illustrated. In the example, one or more aspects of the example system 200 may be components of or communicatively coupled to a medical device, such as an implantable medical device (IMD), an insertable cardiac monitor, a mobile medical device (AMD), etc. System 200 may be configured to monitor, detect, or treat various physiological conditions of the body, such as cardiac conditions associated with a reduced ability of the heart to adequately deliver blood to the body, including heart failure, arrhythmias, asynchrony, etc., or one or more other physiological conditions, and in some examples, may be configured to provide electrical stimulation or one or more other therapies or treatments to the patient.

[0093] System 200 may include a single or multiple medical devices implanted in or otherwise positioned on or around a patient to monitor the patient’s physiological information using information from one or more sensors, such as sensor 201. In the example, sensor 201 may include one or more of the following: a respiratory sensor configured to receive respiratory information (e.g., respiratory rate, respiratory volume (tidal volume), etc.); an acceleration sensor (e.g., accelerometer, microphone, etc.) configured to receive cardiac acceleration information (e.g., cardiac vibration information, pressure waveform information, heart sound information, endocardial acceleration information, acceleration information, activity information, posture information, etc.); an impedance sensor (e.g., intrathoracic impedance sensor, transthoracic impedance sensor, pleural impedance sensor, etc.) configured to receive impedance information; a cardiac sensor configured to receive cardiac electrical information; an activity sensor configured to receive information about body movement (e.g., activity, steps, etc.); a posture sensor configured to receive posture or position information; a pressure sensor configured to receive pressure information; a volumetric sensor (e.g., photoplethysmography sensor, etc.); a chemical sensor (e.g., electrolyte sensor, pH sensor, anion gap sensor, etc.); a temperature sensor; a skin elasticity sensor; or one or more other sensors configured to receive physiological information of a patient.

[0094] Example system 200 may include signal receiver circuitry 202 and evaluation circuitry 203. Signal receiver circuitry 202 may be configured to receive physiological information from sensor 201 about a patient (or patient group). Evaluation circuitry 203 may be configured to receive information from signal receiver circuitry 202 and use the received physiological information (such as that described herein) to determine one or more parameters (e.g., physiological parameters, stratification, etc.) or existing or altered patient conditions (e.g., indications of patient dehydration, respiratory status, cardiac status (e.g., heart failure, arrhythmia), sleep apnea, etc.). Physiological information may include, among others, cardiac electrical information, impedance information, respiratory information, heart sound information, activity information, posture information, temperature information, or one or more other types of physiological information.

[0095] In some examples, evaluation circuit 203 can aggregate information from multiple sensors or devices, use information from each sensor or device individually or in combination to detect various events, update the detection status of one or more patients based on the information, and transmit messages or alarms to one or more remote devices that one or more patients have been detected, or that information has been stored or transmitted, so that one or more other processes or systems can use the stored or transmitted detection or information for one or more other checks or processes.

[0096] In some examples, such as to detect improvement or deterioration in a patient's condition, some initial assessment is often required to establish a baseline level or condition from one or more sensors or physiological information. Subsequent detections of deviations from the baseline level or condition can be used to determine whether the patient's condition has improved or deteriorated. However, in other examples, the amount of change or alteration (e.g., relative or absolute change) in physiological information over different time periods can be used to determine the risk of adverse medical events, or to predict or stratify the risk of a patient experiencing an adverse medical event (e.g., heart failure) some time after the change is detected, in conjunction with or separately from any baseline level or condition.

[0097] Changes in different physiological information can be aggregated and weighted based on one or more patient-specific stratifiers and, in some examples, compared to one or more thresholds, such as those that are clinically sensitive and specific in the target population relative to a specific condition (e.g., heart failure), and one or more specific time periods, such as daily values, short-term averages (e.g., daily values ​​aggregated over several days), long-term averages (e.g., daily values ​​aggregated over multiple short-term periods or more numbers of days (sometimes different from the number of days used for short-term averages, e.g., non-overlapping)).

[0098] System 200 may include output circuitry 204 configured to provide output to a user, or to make output available to a user via an output, display, or one or more other user interfaces, including scores, trends, alarms, or other indications. In other examples, output circuitry 204 may be configured to provide output to another circuit, machine, or process (such as treatment circuitry 205, e.g., cardiac resynchronization therapy (CRT) circuitry, chemotherapy circuitry, stimulation circuitry, etc.)) to control, adjust, or stop treatment by a medical device, drug delivery system, etc., or otherwise alter one or more processes or functions of one or more other aspects of the medical device system, such as one or more CRT parameters, drug delivery, dosage determination, or recommendations. In examples, treatment circuitry 205 may include one or more of stimulation control circuitry, cardiac stimulation circuitry, neural stimulation circuitry, dosage determination or control circuitry, etc. In other examples, treatment circuitry 205 may be controlled by evaluation circuitry 203 or one or more other circuitry, etc. In some examples, evaluation circuit 203 may include output circuit 204, or may be configured to determine the output to be provided by output circuit 204, and output circuit 204 may provide a signal that causes the user interface to provide output to the user based on the output determined by evaluation circuit 203.

[0099] A technical challenge exists in medical devices and systems where, in low-power monitoring modes, mobile medical devices (e.g., including IMDs) powered by one or more rechargeable or non-rechargeable batteries must make trade-offs between battery life, or, in the case of implantable medical devices with non-rechargeable batteries, device replacement periods (typically including surgery), and the sampling resolution, sampling period, or selection of processing, storage, and transmission of sensed physiological information or features within or within the medical device. Medical devices may include higher-power and lower-power modes. Physiological information, such as indications of potential adverse physiological events, can be used to transition from a low-power mode to a high-power mode. In some examples, a low-power mode may include a low-resource mode characterized by requiring less power, processing time, memory, or communication time or bandwidth (e.g., transmitting less data) than a corresponding high-power mode. A high-power mode may include a relatively high-resource mode characterized by requiring more power, processing time, memory, or communication time or bandwidth than a corresponding low-power mode. However, by the time the physiological information detected in the low-power mode indicates a possible event, valuable information has been lost and cannot be recorded in the high-power mode.

[0100] The opposite is also true, as erroneous or inaccurate determinations that trigger high-power modes unnecessarily and excessively limit the usable lifespan of some mobile medical devices. For many reasons, accurate detection and determination of physiological events, and avoiding unnecessary transitions from low-power to high-power modes, are beneficial for improving the utilization of medical device resources.

[0101] For example, a change in mode can enable higher resolution sampling or an increase in sampling frequency, or an increase in the number or type of sensors used to sense physiological information, up to and including potential events. For instance, different physiological information is often sensed using non-overlapping time periods of the same sensor, in some examples, at different sampling frequencies and power costs. In one example, heart sounds and patient activity can be detected using the same non-overlapping time periods of a single-axis or multi-axis accelerometer, at different sampling frequencies and power costs. In some examples, a shift to a high-power mode may include using an accelerometer to detect heart sounds throughout the high-power mode or at a larger percentage of the high-power mode than the corresponding low-power mode. In other examples, waveforms of medical events may be recorded, stored in long-term memory, and transmitted to a remote device for review by a clinician. In some examples, only a notification that the event has been stored is transmitted, or summary information about the event is transmitted. In response, the full event can be requested for subsequent transmission and review. However, even when events are stored but not transmitted, the resources used for storing and processing events are still used by the medical device.

[0102] Figure 3An example patient management system 300 and a portion of the environment in which the patient management system 300 may operate are shown. The patient management system 300 can perform a range of activities, including remote patient monitoring and diagnosis of disease conditions. These activities can be performed near the patient 301 (such as in the patient's home or office), via a centralized server (such as in a hospital, clinic, or doctor's office), or via a remote workstation (such as a secure wireless mobile computing device).

[0103] The patient management system 300 may include one or more medical devices, an external system 305, and a communication link 311, which provides communication between the one or more mobile medical devices and the external system 305. The one or more medical devices may include mobile medical devices (AMDs), such as implantable medical devices (IMDs) 302, wearable medical devices 303, or one or more other implantable, leadless, subcutaneous, external, wearable, or medical devices configured to monitor, sense, or detect information from the patient 301, determine physiological information about the patient 301, or provide one or more treatments to treat various conditions of the patient 301, such as one or more cardiac or non-cardiac conditions (e.g., dehydration, sleep apnea, etc.).

[0104] In one example, implantable medical device 302 may include one or more cardiac rhythm management devices implanted in a patient's chest, the device having a lead system including one or more transvenous, subcutaneous, or non-invasive leads or catheters to position one or more electrodes or other sensors (e.g., heart sound sensors) in, on, or around the heart, chest, abdomen, or neck of the patient 301. In another example, implantable medical device 302 may include, for example, a monitor subcutaneously implanted in the chest of the patient 301, the implantable medical device 302 including a housing containing circuitry, and in some examples, one or more sensors, such as temperature sensors.

[0105] Cardiac rhythm management devices, such as insertable cardiac monitors, pacemakers, defibrillators, or cardiac resynchronizers, include implantable or subcutaneous devices with hermetically sealed housings configured for implantation in a patient's chest. Cardiac rhythm management devices may include one or more leads to position one or more electrodes or other sensors at various locations in or near the heart, such as one or more atria or ventricles. Thus, cardiac rhythm management devices may include an aspect located subcutaneously but close to the patient's distal skin, and an aspect located near one or more organs of the patient, such as leads or electrodes. Separate from or other than the leads, one or more electrodes or other sensors may include one or more electrodes or other sensors (e.g., pressure sensors, accelerometers, gyroscopes, microphones, etc.) powered by a power source within the cardiac rhythm management device. The leads, the cardiac rhythm management device, or combinations thereof, and one or more electrodes or other sensors may be configured to detect physiological information from the patient or to provide one or more treatments or stimulations to the patient.

[0106] Implantable devices may additionally or separately include leadless cardiac pacemakers (LCPs), small (e.g., smaller than conventional implantable cardiac rhythm management devices, having a volume of about 1 cc in some examples), self-contained devices comprising one or more sensors, circuitry, or electrodes configured to monitor physiological information from the heart (e.g., heart rate, etc.), detect cardiac-associated physiological conditions (e.g., tachycardia), or deliver one or more therapies or stimuli to the heart without the complications of conventional leaded or implantable cardiac rhythm management devices (e.g., required incisions and pockets, complications associated with lead placement, breakage, or displacement, etc.). In some examples, leadless pacemakers may have more limited power and processing capabilities than conventional cardiac rhythm management devices; however, multiple leadless pacemakers may be implanted in or around the heart to detect physiological information from one or more chambers of the heart, or to deliver one or more therapies or stimuli to one or more chambers of the heart. Multiple leadless pacemakers may communicate between themselves or one or more other implantable or external devices.

[0107] The implantable medical device 302 may include assessment circuitry configured to detect or determine specific physiological information of the patient 301, or to determine one or more conditions, or to provide information or alerts to users such as the patient 301 (e.g., a patient), a clinician, or one or more other caregivers or processes, as described herein. The implantable medical device 302 may alternatively or additionally be configured as a treatment device configured to treat one or more medical conditions of the patient 301. Treatment may be delivered to the patient 301 via a lead system and associated electrodes or using one or more other delivery mechanisms. Treatment may include delivering one or more medications to the patient 301, such as using one or more of the implantable medical device 302 or other mobile medical devices. In some examples, treatment may include a CRT for correcting asynchrony in patients with heart failure and improving cardiac function in patients with heart failure. In other examples, the implantable medical device 302 may include a medication delivery system, such as a medication infusion pump, to deliver medications to the patient for managing arrhythmias or complications arising from arrhythmias, hypertension, hypotension, or one or more other physiological conditions. In other examples, the implantable medical device 302 may include one or more electrodes configured to stimulate the patient’s nervous system or to provide stimulation to the muscles of the patient’s airway, etc.

[0108] Wearable medical device 303 may include one or more wearable or external medical sensors or devices (e.g., automatic external defibrillator (AED), Holter monitor, patch-based device, smartwatch, smart accessory, wrist or finger-worn medical device, such as finger-based photoplethysmography sensor, etc.).

[0109] External system 305 may include dedicated hardware / software systems, such as a programmer, a remote server-based patient management system, or alternatively, a software-defined system primarily running on a standard personal computer. External system 305 may manage patient 301 via implantable medical device 302 or one or more other mobile medical devices connected to external system 305 via communication link 311. In other examples, implantable medical device 302 may be connected to wearable medical device 303, or wearable medical device 303 may be connected to external system 305 via communication link 311. This may include, for example, programming implantable medical device 302 to perform one or more of the following: acquiring physiological data, performing at least one self-diagnostic test (such as for device operating status), analyzing physiological data, or optionally delivering or adjusting treatment for patient 301. Additionally, external system 305 may send or receive information from implantable medical device 302 or wearable medical device 303 via communication link 311. Examples of information may include real-time or stored physiological data from patient 301, diagnostic data such as detection of patient hydration status, hospitalization, response to treatment delivered to patient 301, or device operating status (e.g., battery status, lead impedance, etc.) of implantable medical device 302 or wearable medical device 303. Communication link 311 may be an inductive telemetry link, a capacitive telemetry link, or a radio-frequency (RF) telemetry link, or wireless telemetry based on standards such as “Strong” Bluetooth or IEEE 502.11 Wireless Fidelity “Wi-Fi”. Other configurations and combinations of patient data source docking are possible.

[0110] External system 305 may include external device 306 located near one or more mobile medical devices, and remote device 308 located relatively far from the one or more mobile medical devices, communicating with external device 306 via communication network 307. Examples of external device 306 may include a medical device programmer. Remote device 308 may be configured to evaluate collected patient or patient information and provide alarm notifications, among other possible functions. In an example, remote device 308 may include a centralized server acting as a central hub for storing and analyzing collected data from multiple different sources. The combination of information from multiple sources may be used to make determinations and update individual patient statuses, or to adjust one or more alarms or determinations for one or more other patients. The server may be configured as a single, multiple, or distributed computing and processing system. Remote device 308 may receive data from multiple patients. Data may be collected by one or more mobile medical devices, in addition to other data acquisition sensors or devices associated with patient 301. The server may include storage devices to store data in a patient database. The server may include alarm analyzer circuitry to evaluate the collected data to determine whether specific alarm conditions are met. The fulfillment of alarm conditions can trigger the generation of alarm notifications, such as those provided by one or more human-perceptible user interfaces. In some examples, alarm conditions may be evaluated alternatively or additionally by one or more mobile medical devices, such as implantable medical devices. For example, alarm notifications may include web page updates, telephone or pager calls, emails, SMS messages, text or "instant" messages, as well as messages to patients and simultaneous direct notifications to emergency services and clinicians. Other alarm notifications are possible. The server may include alarm priority ordering circuitry configured to prioritize alarm notifications. For example, alarms for detected medical events may be prioritized using a similarity metric between physiological data associated with a detected medical event and physiological data associated with historical alarms.

[0111] Remote device 308 may additionally include one or more locally configured clients or remote clients securely connected to the server via communication network 307. Examples of clients may include personal desktop computers, laptops, mobile devices, or other computing devices. System users, such as clinicians or other qualified medical professionals, can use the clients to securely access stored patient data aggregated in a database on the server and select and prioritize patients and alerts for healthcare provisioning. In addition to generating alert notifications, remote device 308, including the server and interconnected clients, can also execute follow-up protocols by sending follow-up requests to one or more mobile medical devices, or by sending messages or other communications as compliance notifications to patients 301 (e.g., patients), clinicians, or authorized third parties.

[0112] Communication network 307 can provide wired or wireless interconnection. In this example, communication network 307 may be based on the Transmission Control Protocol / Internet Protocol (TCP / IP) network communication specification, although other types or combinations of network implementations are possible. Similarly, other network topologies and arrangements are possible.

[0113] One or more of external devices 306 or remote devices 308 may output detected medical events to system users, such as patients or clinicians, or to a process including, for example, an instance of a computer program executable in a microprocessor. In examples, this process may include automatically generating recommendations for antiarrhythmic treatment, or recommendations for further diagnostic tests or treatments. In examples, external devices 306 or remote devices 308 may include corresponding display units for displaying physiological or functional signals, or alarms, warnings, emergency calls, or other forms of alerts to signal the detection of an arrhythmia. In some examples, external system 305 may include an external data processor configured to analyze physiological or functional signals received by one or more mobile medical devices and confirm or deny the detection of an arrhythmia. Computationally intensive algorithms, such as machine learning algorithms, may be implemented in the external data processor to retrospectively process data to detect cardiac arrhythmias.

[0114] One or more portions of a mobile medical device or external system 305 may be implemented using hardware, software, firmware, or a combination thereof. One or more portions of a mobile medical device or external system 305 may be implemented using dedicated circuitry, which may be constructed or configured to perform one or more functions, or may be implemented using general-purpose circuitry, which may be programmed or otherwise configured to perform one or more functions. Such general-purpose circuitry may include a microprocessor or a portion thereof, a microcontroller or a portion thereof, or programmable logic circuitry, memory circuitry, network interfaces, and various components for interconnecting these components. For example, among others, a “comparator” may include an electronic circuit comparator that may be constructed to perform a specific function of comparing two signals, or a comparator may be implemented as part of a general-purpose circuitry that may be driven by code instructing a portion of the general-purpose circuitry to perform a comparison between two signals. A “sensor” may include electronic circuitry configured to receive information and provide an electronic output representing such received information.

[0115] Treatment device 310 can be configured to send or receive information from one or more mobile medical devices or external systems 305 using communication link 311. In the example, one or more mobile medical devices, external devices 306, or remote devices 308 can be configured to control one or more parameters of treatment device 310. External system 305 can allow programming of one or more mobile medical devices and can receive information about one or more signals acquired by one or more mobile medical devices, such as those received via communication link 311. External system 305 may include a local external implantable medical device programmer. External system 305 may include a remote patient management system, which can, for example, monitor patient status from a remote location or adjust one or more treatments.

[0116] In some examples, event storage can be triggered, such as by receiving physiological information, or in response to one or more detected events or determined parameters meeting or exceeding a threshold (e.g., a static threshold, a dynamic threshold, or one or more other thresholds based on patient or population information). Information sensed or recorded in high-power mode can be transferred from short-term storage (such as in a cyclic recorder) to long-term or non-volatile memory, or in some examples, prepared for transmission to an external device separate from the medical device. In examples, cardiac electrical or cardiac mechanical information up to and, in some examples, including detected atrial fibrillation events can be stored, such as to increase the specificity of the detection. In examples, multiple cyclic recorder windows (e.g., 2-minute windows) can be stored sequentially. In systems without early detection, recording this information would require a cyclic recorder with a long time period at a significant additional cost (e.g., power, processing resources, component costs, memory requirements, etc.). Storing multiple windows using early detection up to a single event provides a complete event assessment, saving power and cost compared to a longer cyclic recorder window. Furthermore, early detection can trigger additional parameter calculations or storage at different resolutions or sampling frequencies without unduly burdening limited system resources.

[0117] In some examples, one or more alerts may be provided to the patient, clinician, or one or more other caregivers (e.g., using the patient's smartwatch, cellular or smartphone, computer, etc.), such as in response to a transition to a high-power mode, in response to a detected event or condition, or after information is updated or transmitted from a first device to a remote device. In other examples, the medical device itself may provide audible or tactile alerts to alert the patient to a detected condition. For example, an alert may be issued to the patient in response to a detected condition so that they may take a corrective action, such as sitting down.

[0118] In some examples, treatment may be provided in response to a detected condition. For example, pacing therapy may be provided, activated, or adjusted, such as to interrupt or reduce the effects of a detected atrial fibrillation event. In other examples, the delivery of one or more medications (e.g., vasoconstrictors, vasopressors, etc.) may be triggered, provided, or adjusted, such as by using a drug pump, in response to a detected condition, alone or in combination with pacing therapy, as described above, such as to increase arterial pressure, maintain cardiac output, and interrupt or reduce the effects of a detected atrial fibrillation event.

[0119] In some examples, a patient's physiological information can be sensed, for example, by one or more sensors (such as a cardiac sensor, a heart sound sensor, or one or more other sensors described herein) located within, on, or near the patient. For example, a cardiac sensor can be used to sense the patient's cardiac electrical information. In other examples, a heart sound sensor can be used to sense the patient's cardiac acceleration information. The cardiac sensor and the heart sound sensor can be components of one or more (e.g., the same or different) medical devices (e.g., implantable medical devices, mobile medical devices, etc.). Timing measures between different features (e.g., first cardiac features and second cardiac features, etc.) can be determined, such as by processing circuitry of the cardiac sensor or one or more other medical devices or medical device components. In some examples, timing measures may include the interval or measure between a first cardiac feature and a second cardiac feature in a patient's first cardiac interval (e.g., the duration of a cardiac cycle or interval, QRS width, etc.), or the interval or measure between a first cardiac feature and a second cardiac feature in a patient's corresponding successive first cardiac interval and second cardiac interval. In the example, the first cardiac feature and the second cardiac feature include equivalent detection features in successive first cardiac intervals and second cardiac intervals, such as successive R waves (e.g., RR intervals) or one or more other features of cardiac electrical signals.

[0120] In the examples, the value of a heart sound signal portion or a corresponding heart sound signal of a cardiac interval can be detected as the amplitude relative to one or more cardiac electrical features, or as one or more energy values ​​relative to a window of the heart sound signal, typically determined relative to one or more cardiac electrical features. For example, the value and timing of the S1 signal can be detected using the amplitude or energy of the heart sound signal occurring at or near the R wave of the cardiac interval. The S4 signal portion can be determined, for example, by processing circuitry of a heart sound sensor or one or more other medical devices or medical device components. In some examples, the S4 signal portion may include a filtered signal from the S4 window of the cardiac interval. In the examples, the S4 interval can be defined as a set time period within the cardiac interval relative to one or more other cardiac electrical or mechanical features, such as forward from one or more features of the R wave, T wave, or one or more heart sound waveforms (such as the first heart sound, second heart sound, or third heart sound (S1, S2, S3)), or backward from the detected S1 of a subsequent R wave or subsequent cardiac interval. In some examples, the length of the S4 window may depend on heart rate or one or more other factors. In the example, the timing measure of cardiac electrical information can be the timing measure of the first cardiac interval, and the S4 signal portion can be the S4 signal portion of the same first cardiac interval.

[0121] In the example, heart sound parameters may include information or information about the same heart sound parameter or multiple combinations of heart sound parameters within one or more cardiac cycles or a specified time period (e.g., 1 minute, 1 hour, 1 day, 1 week, etc.). For example, heart sound parameters may include composite S1 parameters representing multiple S1 parameters, for example, within a certain time period (e.g., multiple cardiac cycles, representative time period, etc.).

[0122] In the examples, heart sound parameters may include the overall average of a particular heart sound on a heart sound waveform, such as those disclosed in commonly assigned U.S. Patent No. 7,115,096, entitled "THIRD HEART SOUND ACTIVITY INDEX FOR HEART FAILURE MONITORING" by Siejko et al., or in commonly assigned U.S. Patent No. 7,853,327, entitled "HEART SOUND TRACKING SYSTEM AND METHOD" by Patangay et al., each of which is incorporated herein by reference in its entirety, including their disclosures of overall averaging of acoustic signals and determination of a particular heart sound on a heart sound waveform. In other examples, the signal receiver circuitry may receive at least one heart sound parameter or composite parameter, such as from a heart sound sensor or heart sound sensor circuitry.

[0123] In the example, a patient's cardiac electrical information can be received from a cardiac sensor (e.g., one or more electrodes) or a cardiac sensor circuit (e.g., including one or more amplifier or filter circuits) using a signal receiver circuit, such as a medical device. In the example, the received cardiac electrical information may include a timing measurement between a first cardiac characteristic and a second cardiac characteristic of the patient.

[0124] In the examples, the patient's cardiac acceleration information can be received from a heart sound sensor (e.g., an accelerometer) or a heart sound sensor circuit (e.g., including one or more amplifier or filter circuits) using the same or different signal receiver circuitry of a medical device. In the examples, the received cardiac acceleration information may include an S4 signal portion appearing between the patient's first and second cardiac features. In some examples, additional physiological information, such as heart rate information, patient activity information, or patient posture information, may be received from one or more other sensors or sensor circuits.

[0125] In some examples, a high-power mode may be contrasted with a low-power mode and may include one or more of the following: enabling one or more additional sensors, switching from a low-power sensor or set of sensors to a higher-power sensor or set of sensors, triggering additional sensing from one or more additional sensors or medical devices, increasing the sensing frequency or sensing or storage resolution, increasing the amount of data to be collected, transmitted (e.g., from a first medical device to a second medical device, etc.), or stored, triggering the storage of currently available information from the loop recorder in long-term storage, or increasing the storage capacity or time period of the loop recorder, or otherwise altering the device behavior to capture additional or higher-resolution physiological information or perform more processing, etc.

[0126] Additionally or alternatively, event storage can be triggered. Information sensed or recorded in high-power mode can be transferred from short-term storage (such as in a cyclic recorder) to long-term or non-volatile memory, or in some examples, prepared for transmission to an external device separate from the medical device. In examples, cardiac electrical or mechanical information up to and, in some examples, including detected atrial fibrillation events can be stored, such as to increase the specificity of detection. In examples, multiple cyclic recorder windows (e.g., 2-minute windows) can be stored sequentially. In systems without early detection, recording this information would require a cyclic recorder with a longer time period at significant additional cost (e.g., power, processing resources, component costs, etc.).

[0127] Figure 4 An example method 400 is shown for monitoring a patient’s chemical status after a health index alert using one or more chemical information.

[0128] At step 401, the patient's physiological information can be received, such as using a signal receiver circuit. The patient's physiological information may include at least one of the following: respiratory information (e.g., respiratory rate, tidal volume, RSBI, etc.), cardiac electrical information (e.g., heart rate, impedance, etc.), impedance information, cardiac acceleration information (e.g., heart sounds, etc.), mechanical acceleration information (e.g., activity information, heart sounds, etc.), mechanical position information (e.g., patient posture, sleep tilt, etc.), or other physiological information of the patient.

[0129] At step 402, the health index can be determined as a function of one or more characteristics of the patient's physiological or other information, such as those discussed elsewhere herein, for example, using assessment circuitry. One or more characteristics can include functions of the physiological information received by the signal receiver circuitry. For example, a characteristic corresponding to respiratory rate can be calculated using a high characteristic value corresponding to a healthy respiratory rate and a low characteristic value corresponding to an unhealthy respiratory rate. A high respiratory rate (e.g., 30 breaths per minute) can be assigned a value of 200, and a low respiratory rate (e.g., 12 breaths per minute) can be assigned a value of 0. The functional mapping between high and low respiratory rates can be assigned in one or more ways, such as linearly, logarithmically, etc. The health index can be determined as a function of different characteristics or combinations of physiological information, such as one or more weighted combinations (e.g., average, product, summation, etc.) of two or more characteristics (e.g., each characteristic having a corresponding weight). This combination can include linear combinations or one or more nonlinear or other combinations.

[0130] At step 403, the health index alarm state can be determined using the determined health index and health index alarm threshold (e.g., health index in alarm state, health index out of alarm state, health index in priority alarm state, etc.), such as using an evaluation circuit. In the example, a health index (such as HeartLogic) can be used. TM A health index is used to determine the health index alarm state. For example, the health index alarm state can be determined by comparing the health index value determined in step 402 with a health index alarm threshold. If the health index is on the specified side of the threshold (e.g., above the threshold, below the threshold), then the health index can be determined to be in an alarm state.

[0131] Indications of a determined health index alarm state can be provided to patients, clinicians, or one or more other users associated with the patient. In the example, alarms can be generated and provided to transition or adjust from an out-of-alarm state to an alarm state. Alarms can be provided based on the priority of the determined alarm state with a specified level of urgency (e.g., audible, visual, or tactile alarms, emergency notifications, etc.). If an out-of-alarm state is determined, the alarm state can be rechecked at intervals, such as set intervals (e.g., which may include 1 minute, 5 minutes, 30 minutes, 1 hour, 12 hours, or 1 day). If an alarm state is determined, the system can remain in the alarm state until one or more alarms are reset, or until the system determines that it is appropriate to leave the alarm state (e.g., the health index value falls below an out-of-alarm threshold). During an alarm state, device power consumption may increase, possibly due to one or more of the power required to generate and / or transmit one or more alarms, increased monitoring intervals, increased processor load, etc.

[0132] At step 404, the health index can be monitored for signs of improvement while it is in an alarm state, as discussed elsewhere herein, such as using an assessment circuit. If it is determined that the patient's condition has not improved, the method may include returning to step 402 to determine the health index before again determining at step 404 whether the health index indicates an improved patient condition, and then proceeding to step 403 to determine the health index alarm state.

[0133] At step 405, if it is determined at step 404 that the patient's condition is improving, a diuretic monitoring window (e.g., a chemical monitoring window), such as using assessment circuitry, can be triggered. During the diuretic monitoring window, the device's power consumption may increase, possibly due to one or more of the following: the power required to generate and / or transmit one or more alarms, increased monitoring intervals for physiological information, receiving and / or monitoring chemical information, increased processor load, etc.

[0134] At step 406, patient chemical information may be received, such as using signal receiver circuitry, and patient chemical parameters may be monitored, such as using evaluation circuitry. The chemical information may include information about chemical substances or other properties in the patient's blood, as discussed elsewhere herein. Chemical parameters may include chemical values ​​determined based on the received chemical information. Chemical parameters may include chemical information in its raw form (e.g., sensor output, such as electrical signals, chemical values ​​in basic units (e.g., concentrations, etc.)), or a first chemical parameter may be determined by processing the received chemical information (e.g., converting sensor outputs into chemical values, adjusting chemical values ​​based on one or more factors (e.g., adjusting to take into account temperature, pressure, other chemical concentrations, etc.)). In this example, more than one chemical parameter may be monitored, such as including a first chemical parameter and a second chemical parameter. The first and second chemical parameters may be determined, as described above. In this example, the first chemical parameter may represent a potassium level, and the second chemical parameter may represent a creatinine level.

[0135] At step 407, monitoring the chemical parameter may optionally include comparing the chemical parameter to a threshold. For example, the chemical parameter may be compared to a chemical alarm threshold, such as including one or more of a first chemical alarm threshold corresponding to a relatively high value (e.g., at or above this value, the chemical parameter is determined to be outside the normal level) or a relatively low value (e.g., at or below this value, the chemical parameter is determined to be outside the normal level). The first chemical parameter may also be compared to a second chemical alarm threshold corresponding to one or more of a relatively high or relatively low value. Relative values ​​may include a percentage change from the patient's baseline (e.g., a value above 30% of the patient's baseline may represent a relatively high value, a value below 30% of the patient's baseline may represent a relatively low value, etc.), a deviation from a short-term and / or long-term average greater than a threshold (e.g., a deviation above a specified long-term average greater than a specified threshold may represent a relatively high value, etc.), a value above or below one or more patient-specific or population-specific thresholds (e.g., a high threshold may be determined for a specific patient or a specified population), or combinations or arrangements thereof. The results of one or more comparisons may be used to determine a chemical alarm status.

[0136] Indications of a determined chemical alarm state can be provided to patients, clinicians, processes, etc. In the example, an alarm can be generated and provided to indicate a transition or adjustment from an out-of-alarm state to an alarm state. Outputs can be provided to a user interface for display to a user, or to control circuitry to control or adjust the process or function of a medical device system. For example, the output can automatically adjust a medical device system that is providing one or more treatments to a patient (e.g., drug administration, such as those described herein, cardiac rhythm management, etc.). Alarms can be provided with a specified level of urgency based on the priority of the determined alarm state (e.g., audible, visual, or tactile alarms, emergency notifications, etc.). If an out-of-alarm state is determined, the alarm state can be rechecked at intervals, such as set intervals (e.g., may include 1 minute, 5 minutes, 30 minutes, 1 hour, 12 hours, or 1 day). If an alarm state is determined, the system can remain in the alarm state until one or more alarms are reset, or the system determines that it is appropriate to leave the alarm state (e.g., a chemical parameter value falls below a chemical alarm threshold).

[0137] At step 408, the diuretic monitoring window can be extended until the chemical parameter is within a threshold, such as using an evaluation circuit. For example, if the chemical parameter is determined to be outside a threshold (e.g., above a relatively high threshold) at step 407, the duration of the diuretic monitoring window can be extended until the chemical parameter is within that threshold. This can include extending the diuretic monitoring window beyond the initial duration determined in step 405.

[0138] At step 409, the rate of change of chemical parameters can be monitored, as discussed elsewhere herein, such as using evaluation circuitry. The determined rate of change can be used to determine a chemical alarm state, determine or adjust one or more thresholds to be used in step 407, or extend one or more of the chemical monitoring window.

[0139] In some examples, the techniques of any one or more of steps 407 to 409 can be used in various combinations or arrangements. In some examples, any one or more of steps 407 to 409 can be applied to more than one chemical information.

[0140] Figure 5An implantable medical device (IMD) 500 electrically coupled to a heart 505 is illustrated, such as via one or more leads coupled to the IMD 500 (via one or more lead ports in the head 502 of the IMD 500, such as a first lead port, a second lead port, or a third lead port 541, 542, 543)). In the example, the IMD 500 may include an antenna, such as in the head 502, configured to enable communication with external systems and one or more electronic circuits (e.g., evaluation circuitry, etc.) in a hermetically sealed housing (CAN) 501. The IMD 500 illustrates an example medical device (or medical device system) as described herein.

[0141] The IMD 500 may include an implantable medical device (IMD), such as an implantable cardiac monitor (ICM), pacemaker, defibrillator, cardiac resynchronizer, or other subcutaneous IMD or cardiac rhythm management (CRM) device, configured to be implanted in the chest of a subject, having one or more leads to position one or more electrodes or other sensors in or near the heart 505, such as one or more in the atria or ventricles. Separate from or in addition to the leads, the IMD 500 may also include one or more electrodes or other sensors (e.g., pressure sensors, accelerometers, gyroscopes, microphones, etc.) powered by a power source within the IMD 500. The leads, one or more electrodes or other sensors of the IMD 500, or combinations thereof, may be configured to detect physiological information from the patient or to provide one or more treatments or stimuli to the patient.

[0142] IMD 500 may include one or more electronic circuits configured to sense one or more physiological signals, such as electrograms or signals representing the mechanical function of the heart 505. In some examples, CAN 501 may function as an electrode, such as for sensing or pulse delivery. For example, electrodes from one or more leads may be used with CAN 501, such as for unipolar sensing for electrograms or for delivering one or more pacing pulses. Defibrillation electrodes (e.g., first defibrillation coil electrode 528, second defibrillation coil electrode 529, etc.) may be used with CAN 501 to deliver one or more cardioversion / defibrillation pulses.

[0143] In the example, the IMD 500 can sense impedance between electrodes, such as those located on one or more leads or on the CAN 501. The IMD 500 can be configured to inject current between a pair of electrodes, sense the resulting voltage between the same or different pairs of electrodes, and determine the impedance, such as using Ohm's law. Impedance can be sensed in a bipolar configuration (where the same pair of electrodes can be used for both current injection and voltage sensing), a tripolar configuration (where the pair of electrodes used for current injection and the pair used for voltage sensing can share a common electrode), or a quadrupole configuration (where the electrodes used for current injection can be different from those used for voltage sensing), etc. In the example, the IMD 500 can be configured to inject current between electrodes on one or more of the first, second, third, or fourth leads 520, 525, 530, 535 and the CAN 501, and sense the resulting voltage between the same or different electrodes and the CAN 501.

[0144] Figure 5 Example lead configurations include first, second, and third leads 520, 525, and 530, respectively, placed in the coronary veins 516 (e.g., coronary sinuses) on the right atrium (RA) 506, right ventricle (RV) 507, and left atrium (LA) 508 and left ventricle (LV) 509, using conventional lead placement; and a fourth lead 535 positioned in RV 507, near His bundle 511, between AV node 510 and the right and left bundle branches 512, 513 and Purkinje fibers 514, 515. Each lead can be configured to position one or more electrodes or other sensors at various locations in or near the heart 505 to detect physiological information or provide one or more treatments or stimulations.

[0145] The first lead 520, located in RA 506, includes a first tip electrode 521 located at or near the distal end of the first lead 520 and a first ring electrode 522 located near the first tip electrode 521. The second lead 525 (dashed line), located in RV 507, includes a second tip electrode 526 located at or near the distal end of the second lead 525 and a second ring electrode 527 located near the second tip electrode 526. The third lead 530, located in the coronary vein 516 above LV 509, includes a third tip electrode 531 located at or near the distal end of the third lead 530, a third ring electrode 532 located near the third tip electrode 531, and two additional electrodes 533 and 534. The fourth lead 535, located near the His bundle 511 in RV 507, includes a fourth tip electrode 536 located at or near the distal end of the fourth lead 535 and a fourth ring electrode 537 located near the fourth tip electrode 536. Tip electrodes and loop electrodes may include pacing / sensing electrodes configured to sense electrical activity or provide pacing stimulation.

[0146] In addition to the tip electrode and the loop electrode, one or more leads may also include one or more defibrillation coil electrodes configured to sense electrical activity or provide cardioversion or defibrillation shock energy. For example, the second lead 525 includes a first defibrillation coil electrode 528 located near the distal end of the second lead 525 in RV 507 and a second defibrillation coil electrode 529 located at a distance from the distal end of the second lead 525, such as for placement in or near the superior vena cava (SVC) 517.

[0147] Different CRM devices include varying numbers of leads and lead placements. For example, some CRM devices are single-lead devices with only one lead (e.g., RV only, RA only, etc.). Other CRM devices are multi-lead devices with two or more leads (e.g., RA and RV; RV and LV; RA, RV, and LV, etc.). CRM devices suitable for His bundle pacing often use lead ports designated for the LV or RV lead to deliver stimulation to the His bundle 511.

[0148] Figure 6 A block diagram of example machine 600 is shown, on which any one or more of the techniques (e.g., methods) discussed herein can be executed. Parts of this description can be applied to the computational framework of one or more of the medical devices described herein, such as implantable medical devices, external programmers, etc. Furthermore, as described herein with respect to medical device components, systems, or machines, this may require regulatory compliance that cannot be met by general-purpose computers, components, or machines.

[0149] Examples, as described herein, may include logic or multiple components or mechanisms in machine 600, or those that can be operated by them. A circuit system (e.g., a processing circuit system, an evaluation circuit, etc.) is a collection of circuits implemented in a tangible entity of machine 600, which includes hardware (e.g., simple circuits, gates, logic, etc.). Circuit system members can be flexible over time. A circuit system includes members that can perform a specified operation individually or in combination during operation. In the example, the hardware of the circuit system may be designed immutably to perform a specific operation (e.g., hardwired). In the example, the hardware of the circuit system may include physically connected components (e.g., execution units, transistors, simple circuits, etc.) including machine-readable media that are physically modified (e.g., magnetic ground, electrical ground, movable placement of immutable aggregate particles, etc.) to encode instructions for a specific operation. When the physical components are connected, the underlying electrical characteristics of the hardware composition change, for example, from an insulator to a conductor, or vice versa. Instructions enable embedded hardware (e.g., an execution unit or loading mechanism) to create members of the circuit system in the hardware via variable connections to perform portions of a specific operation during operation. Therefore, in this example, the machine-readable medium element is part of the circuit system, or is communicatively coupled to other components of the circuit system during device operation. In this example, any of the physical components can be used in more than one member of more than one circuit system. For example, under operation, an execution unit can be used at one point in time in a first circuit of a first circuit system, and reused at different times by a second circuit of the first circuit system or by a third circuit of the second circuit system. Additional examples of these components of machine 600 are as follows.

[0150] In alternative embodiments, machine 600 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, machine 600 may operate as a server machine, a client machine, or both in a server-client network environment. In the example, machine 600 may act as a peer-to-peer (P2P) (or other distributed) network environment. Machine 600 may be a personal computer (PC), tablet PC, set-top box (STB), personal digital assistant (PDA), mobile phone, web appliance, network router, switch, or bridge, or any machine capable of executing instructions (sequentially or otherwise) specifying actions to be taken by that machine. Furthermore, although only a single machine is shown, the term "machine" should also be considered to include any collection of machines, such as cloud computing, software as a service (SaaS), and other computer cluster configurations, that individually or jointly execute a set (or more) of instructions to perform any one or more of the methods discussed herein.

[0151] Machine 600 (e.g., a computer system) may include a hardware processor 602 (e.g., a central processing unit (CPU), graphics processing unit (GPU), hardware processor core, or any combination thereof), main memory 604, static memory 606 (e.g., memory or storage device for firmware, microcode, basic-input-output (BIOS), unified extensible firmware interface (UEFI), etc.), and mass storage device 608 (e.g., hard disk drive, tape drive, flash memory, or other block device), some or all of which may communicate with each other via interconnect 630 (e.g., a bus). Machine 600 may also include a display unit 610, an input device 612 (e.g., a keyboard), and a user interface (UI) navigation device 614 (e.g., a mouse). In this example, the display unit 610, input device 612, and UI navigation device 614 may be a touchscreen display. Machine 600 may additionally include a signal generating device 618 (e.g., a speaker), a network interface device 620, and one or more sensors 616, such as a global positioning system (GPS) sensor, a compass, an accelerometer, or one or more other sensors. Machine 600 may include an output controller 628, such as a serial (e.g., universal serial bus, USB), parallel, or other wired or wireless (e.g., infrared, near field communication, NFC) connection, to communicate with or control one or more peripheral devices (e.g., a printer, a card reader, etc.).

[0152] The registers, main memory, static memory, or mass storage device 608 of the hardware processor 602 may be or include a machine-readable medium 622 on which one or more sets of data structures or instructions 624 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein are stored. During execution of the instructions 624 by the machine 600, the instructions 624 may also reside wholly or at least partially within any one of the registers, main memory, static memory, or mass storage device 608 of the hardware processor 602. In the example, one or any combination of the hardware processor 602, main memory 604, static memory 606, or mass storage device 608 may constitute the machine-readable medium 622. Although the machine-readable medium 622 is shown as a single medium, the term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database and / or associated caches and servers) configured to store one or more instructions 624.

[0153] The term "machine-readable medium" can include any medium capable of storing, encoding, or carrying instructions that are executed by machine 600 and cause machine 600 to perform any one or more of the techniques of this disclosure, or any medium capable of storing, encoding, or carrying data structures used by or associated with those instructions. Examples of non-limiting machine-readable media can include solid-state memory, optical media, magnetic media, and signals (e.g., radio frequency signals, other photon-based signals, sound signals, etc.). In examples, non-transient machine-readable media includes machine-readable media with a plurality of particles having invariant (e.g., rest) mass, and is therefore a composition of matter. Thus, a non-transient machine-readable medium is a machine-readable medium that does not include transiently propagating signals. Specific examples of non-transient machine-readable media may include: non-volatile memories, such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM) and electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable hard disks; magneto-optical disks; and CD-ROMs and DVD-ROMs.

[0154] Instruction 624 can be further transmitted or received on communication network 626 via network interface device 620 using a transmission medium, utilizing any of a variety of transport protocols (e.g., Frame Relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), etc.). Example communication networks may include, among others, local area networks (LANs), wide area networks (WANs), packet data networks (e.g., the Internet), mobile phone networks (e.g., cellular networks), plain old telephone (POTS) networks, and wireless data networks (e.g., the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard family known as Wi-Fi®, the IEEE 802.16 standard family known as WiMax®), the IEEE 802.15.4 standard family, and peer-to-peer (P2P) networks. In the example, network interface device 620 may include one or more physical jacks (e.g., Ethernet, coaxial, or telephone jacks) or one or more antennas for connection to communication network 626. In the example, network interface device 620 may include multiple antennas for wireless communication using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) technologies. The term "transmission medium" should be considered to include any intangible medium capable of storing, encoding, or carrying instructions executable by machine 600, and includes digital or analog communication signals or other intangible media to facilitate communication of such software. The transmission medium is a machine-readable medium.

[0155] Various embodiments are illustrated in the figures above. One or more features from one or more of these embodiments may be combined to form other embodiments. The method examples described herein may be implemented, at least in part, by a machine or computer. Some examples may include a computer-readable or machine-readable medium encoded with instructions operable to configure an electronic device or system to perform the methods described in the examples above. Implementations of such methods may include code, such as microcode, assembly language code, or high-level language code or similar code. Such code may include computer-readable instructions for performing various methods. The code may form part of a computer program product. Furthermore, the code may be tangibly stored on one or more volatile or non-volatile computer-readable media during execution or at other times.

[0156] The detailed description above is intended to be illustrative and not restrictive. Therefore, the scope of this disclosure should be determined by reference to the appended claims together with the full scope of the equivalents to which such claims are entitled.

Claims

1. A medical device system, comprising: A signal receiver circuit configured to receive physiological information from the patient; as well as The evaluation circuit is configured as follows: The patient's health index is determined as a function of the received physiological information. The patient's health index alert status is determined using the determined health index value and health index alert threshold; Monitor the health index during the health index alarm state; and In response to a change in the health index detected during the health index alarm state, indicating an improved patient condition, the diuretic monitoring window is triggered. The signal receiver circuit is configured to receive the patient's chemical information during the diuresis monitoring window. The evaluation circuit is configured to monitor the patient's chemical parameters during the diuretic monitoring window using the received chemical information.

2. The medical device system according to claim 1, wherein, The health index includes a comprehensive health index, wherein the assessment circuit is configured to determine the patient's comprehensive health index as a function of at least two features of the received physiological information.

3. The medical device system according to any one of claims 1 to 2, wherein, Determining the patient's health index alarm state involves using the determined health index value and the health index being at an alarm threshold to determine if the patient's health index is in an alarm state. Monitoring the health index includes monitoring the health index when it is in an alarm state. The triggering of the diuretic monitoring window includes responding to a change in the value of the health index detected when the health index is in an alarm state toward the health index being at an alarm threshold or the health index being outside the alarm threshold being greater than a first threshold, indicating an improved patient condition.

4. The medical device system according to any one of claims 1 to 3, wherein, Monitoring the patient's chemical parameters includes determining the values ​​of the patient's chemical parameters using received chemical information, monitoring the determined chemical parameters during the diuresis monitoring window, and determining the patient's chemical alarm status if the value of the determined chemical parameter exceeds a chemical alarm threshold during the diuresis monitoring window. The evaluation circuit is configured to provide the output of the determined chemical alarm state to a user interface for display to the user, or to a control circuit for controlling or adjusting the process or function of the medical device system.

5. The medical device system according to claim 4, wherein, The chemical alarm threshold is determined as a function of the rate of change of the values ​​of chemical parameters determined in at least a portion of the diuretic monitoring window.

6. The medical device system according to any one of claims 4 to 5, wherein, The health index includes the heart failure index. The chemical parameters or chemical information include at least one of the patient's potassium information or creatinine information.

7. The medical device system according to any one of claims 1 to 6, wherein, The health index alarm status includes either the health index being in an alarm state or the health index being out of an alarm state. The diuretic monitoring window includes an initial duration, which comprises a first time period following the detected transition from when the health index is in an alarm state to when the health index leaves the alarm state.

8. The medical device system according to claim 7, wherein, The first time period has an initial duration including a predefined number of days, which is between 3 and 31 days.

9. The medical device system according to any one of claims 7 to 8, wherein, The evaluation circuit is configured to extend the duration of the diuresis monitoring window in response to a received chemical information exceeding a first chemical alarm threshold during the initial duration of the diuresis monitoring window. The evaluation circuit is configured to terminate the duration of the extended diuretic monitoring window in response to a received chemical information exceeding a second chemical alarm threshold during the duration of the extended diuretic monitoring window.

10. The medical device system according to any one of claims 1 to 9, wherein, Monitoring the patient's chemical parameters includes determining the values ​​of the patient's chemical parameters using received chemical information, monitoring the determined chemical parameters during the diuresis monitoring window, and determining a chemical alarm status for the patient if the rate of change of the determined chemical parameter values ​​exceeds a chemical change rate threshold during the diuresis monitoring window. The evaluation circuit is configured to provide the output of the determined chemical alarm state to a user interface for display to the user, or to a control circuit for controlling or adjusting the process or function of the medical device system.

11. The medical device system according to any one of claims 1 to 10, wherein, The alarm status includes either being in an alarm state or being out of an alarm state. The evaluation circuit is configured to trigger the start of the diuretic monitoring window in response to a detected transition from the state of being in an alarm state to the state of being out of an alarm state.

12. A method comprising: Use a signal receiver circuit to receive the patient's physiological information; and Use the evaluation circuit: The patient's health index is determined as a function of the received physiological information. The patient's health index alert status is determined using the determined health index value and health index alert threshold; Monitor the health index during the health index alarm state; and In response to a change in the health index detected during the health index alarm state, indicating an improved patient condition, the start of the diuresis monitoring window is triggered; The signal receiver circuit is used to receive the patient's chemical information during the diuretic monitoring window; and Using the assessment circuit, the patient's chemical parameters are monitored during the diuretic monitoring window using the received chemical information.

13. The method according to claim 12, wherein, Determining the patient's health index alarm state involves using the determined health index value and the health index being at an alarm threshold to determine if the patient's health index is in an alarm state. Monitoring the health index includes monitoring the health index when it is in an alarm state. The triggering of the diuretic monitoring window includes responding to a change in the value of the health index detected when the health index is in an alarm state toward the health index being at an alarm threshold or the health index being outside the alarm threshold being greater than a first threshold, indicating an improved patient condition.

14. The method according to any one of claims 12 to 13, wherein, Monitoring the patient's chemical parameters includes determining the values ​​of the patient's chemical parameters using received chemical information, monitoring the determined chemical parameters during the diuresis monitoring window, and determining the patient's chemical alarm status if the value of the determined chemical parameter exceeds a chemical alarm threshold during the diuresis monitoring window. The evaluation circuit is configured to provide the output of the determined chemical alarm state to a user interface for display to the user, or to a control circuit for controlling or adjusting the process or function of the medical device system.

15. The method of claim 14, further comprising determining the chemical alarm threshold as a function of the detected rate of change of the value of a chemical parameter determined in at least a portion of the diuretic monitoring window, wherein the health index includes a heart failure index, and wherein the chemical parameter or the chemical information includes at least one of the patient's potassium information or creatinine information.

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