Chemical information in health index

Abstract

Systems and methods for determining or adjusting a health index of a patient are disclosed, including receiving physiological information of the patient, receiving chemical information of the patient, determining a comprehensive health index of the patient as a weighting function of one or more physiological features of the received physiological information and one or more chemical features of the received chemical information, and determining a health index of the patient as a function of weighting the one or more physiological features of the received physiological information and the one or more chemical features of the received chemical information. And generating a comprehensive health index alert as a function of the determined composite health index and an alert threshold.

Description

[0001] Priority requirements

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 604,098, filed November 29, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0003] This document generally relates to medical devices, and more specifically, to the determination of health indices that include chemical information. 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 for sensing physiological information from a patient, and one or more circuits for using the sensed physiological information to detect one or more physiological events, or to 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] Accurate identification of patients or patient groups at high risk of future adverse events can control the mode or feature selection or resource management of one or more mobile medical devices, control notifications or messages to various users associated with a specific patient or patient group in the connected system, organize or schedule doctor or patient contacts or treatments, or prevent or reduce 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] A system and method for determining or adjusting a patient's health index are disclosed, including receiving physiological information of the patient, receiving chemical information of the patient, determining the patient's comprehensive health index as a weighted function of one or more physiological features of the received physiological information and one or more chemical features of the received chemical information, and generating a comprehensive health index alarm as a function of the determined comprehensive health index and an alarm threshold. In some examples, the chemical information may include one or more of potassium information or creatinine information.

[0007] Examples of the subject (e.g., medical device systems) may include signal receiver circuitry configured to receive physiological and chemical information of a patient, and assessment circuitry configured to determine a patient’s overall health index as a weighted function of one or more physiological features of the received physiological information and one or more chemical features of the received chemical information, and to generate an overall health index alarm as a function of the determined overall health index and an alarm threshold.

[0008] In one example, the evaluation circuit is configured to determine the patient’s overall health index as a function of at least two features of the received physiological information and one or more features of the received chemical information.

[0009] In examples that can be combined with any one or more of the foregoing examples, one or more chemical features include one or more indications of relatively high or relatively low values ​​of received chemical information relative to one or more chemical feature thresholds.

[0010] In an example that can be combined with any one or more of the foregoing examples, the evaluation circuit is configured to determine one or more chemical feature thresholds as a function of the chemical information received within a first time period, and to use a comparison of the value of the received chemical information with the determined one or more chemical feature thresholds to determine an indication of a relatively high or relatively low value of the received chemical information.

[0011] In examples that can be combined with any or more of the foregoing examples, the evaluation circuit is configured to determine the weights of one or more chemical features as a function of the values ​​of one or more chemical features.

[0012] In an example that can be combined with any or more of the foregoing examples, the evaluation circuit is configured to determine, independently of one or more physiological characteristics, the value of a comprehensive health index that exceeds an alarm threshold for a first range of values ​​for one or more chemical characteristics.

[0013] In an example that can be combined with any or more of the foregoing examples, the evaluation circuit is configured to determine the alarm threshold as a function of the received chemical information.

[0014] In an example that can be combined with any or more of the foregoing examples, the evaluation circuit is configured to determine an alarm threshold to increase the sensitivity of the comprehensive health index alarm to a second range of values ​​for one or more chemical characteristics.

[0015] In examples that can be combined with any one or more of the foregoing examples, the evaluation circuit is configured to determine one or more physiological features or one or more chemical features of the weighted function of the comprehensive health index as a function of one or more values ​​of one or more chemical features.

[0016] In an example that can be combined with any or more of the foregoing examples, the evaluation circuit is configured to increase the number of features of one or more physiological features or one or more chemical features for a third range of values ​​for one or more chemical features, increasing the weighting function for one or more physiological features or one or more chemical features.

[0017] In an example that can be combined with any one or more of the foregoing examples, the comprehensive health index includes a comprehensive heart failure index, and the comprehensive health index alarm threshold includes a comprehensive heart failure alarm threshold, at least one of one or more chemical characteristics or chemical information includes at least one of the patient's potassium information or creatinine information, and the evaluation circuit is configured to provide the output of the generated comprehensive health index alarm 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.

[0018] In an example that can be combined with any or more of the foregoing examples, one method includes receiving physiological information and chemical information of a patient using a signal receiver circuit, determining a comprehensive health index of the patient as a weighted function of one or more physiological features of the received physiological information and one or more chemical features of the received chemical information using an evaluation circuit, and generating a comprehensive health index alarm as a function of the determined comprehensive health index and an alarm threshold using the evaluation circuit.

[0019] In an example that can be combined with any or more of the foregoing examples, one or more chemical features include one or more indications of a relatively high or relatively low value of the received chemical information relative to one or more chemical feature thresholds. The method includes using an evaluation circuit to determine one or more chemical feature thresholds as a function of the received chemical information within a first time period, and determining an indication of a relatively high or relatively low value of the received chemical information by comparing the value of the received chemical information with the determined one or more chemical feature thresholds.

[0020] In an example that can be combined with any or more of the foregoing examples, the method includes using an evaluation circuit to determine the weights of one or more chemical characteristics as a function of the values ​​of one or more chemical characteristics, and, independently of one or more physiological characteristics, using the evaluation circuit to determine the value of a comprehensive health index that exceeds an alarm threshold for a first range of values ​​for one or more chemical characteristics.

[0021] In an example that can be combined with any or more of the foregoing examples, the method includes using an evaluation circuit to determine an alarm threshold as a function of the received chemical information, including determining an alarm threshold to increase the sensitivity of the comprehensive health index alarm to a second range of values ​​for one or more chemical characteristics.

[0022] In an example that can be combined with any or more of the foregoing examples, the medical device system may include a signal receiver circuit configured to receive physiological information and chemical information of a patient, and an assessment circuit configured to determine the patient’s overall health index as a weighted function of one or more physiological features of the received physiological information and one or more chemical features of the received chemical information, and to generate an overall health index alarm as a function of the determined overall health index and an alarm threshold.

[0023] In examples that can be combined with any or more of the foregoing examples, the evaluation circuit is configured to determine the patient’s overall health index as a function of at least two features of the received physiological information and one or more features of the received chemical information.

[0024] In examples that can be combined with any one or more of the foregoing examples, one or more chemical features include one or more indications of relatively high or relatively low values ​​of received chemical information relative to one or more chemical feature thresholds.

[0025] In an example that can be combined with any one or more of the foregoing examples, the evaluation circuit is configured to determine one or more chemical feature thresholds as a function of the chemical information received within a first time period, and to use a comparison of the value of the received chemical information with the determined one or more chemical feature thresholds to determine an indication of a relatively high or relatively low value of the received chemical information.

[0026] In examples that can be combined with any or more of the foregoing examples, the evaluation circuit is configured to determine the weights of one or more chemical features as a function of the values ​​of one or more chemical features.

[0027] In examples that can be combined with any one or more of the foregoing examples, the evaluation circuit is configured to determine the value of a comprehensive health index that exceeds an alarm threshold for a first range of values ​​for one or more chemical characteristics, independent of one or more physiological characteristics.

[0028] In an example that can be combined with any or more of the foregoing examples, the evaluation circuit is configured to determine the alarm threshold as a function of the received chemical information.

[0029] In an example that can be combined with any or more of the foregoing examples, the evaluation circuit is configured to determine an alarm threshold to increase the sensitivity of the comprehensive health index alarm to a second range of values ​​for one or more chemical characteristics.

[0030] In examples that can be combined with any one or more of the foregoing examples, the evaluation circuit is configured to determine one or more physiological features or one or more chemical features of the weighted function of the comprehensive health index as a function of one or more values ​​of one or more chemical features.

[0031] In examples that can be combined with any or more of the foregoing examples, the evaluation circuit is configured to increase the number of features of one or more physiological features or one or more chemical features for a third range of values ​​for one or more chemical features.

[0032] In examples that can be combined with any one or more of the foregoing examples, the comprehensive health index includes the comprehensive heart failure index, and the comprehensive health index alarm threshold includes the comprehensive heart failure alarm threshold, and at least one of one or more chemical features or chemical information includes at least one of the patient's potassium information or creatinine information.

[0033] In examples that can be combined with any one or more of the foregoing examples, the evaluation circuit is configured to provide the output of the generated comprehensive health index alarm to the user interface for display to the user, or to provide it to the control circuit to control or adjust the process or function of the medical device system.

[0034] In an example that can be combined with any or more of the foregoing examples, one method includes receiving physiological information and chemical information of a patient using a signal receiver circuit, determining a comprehensive health index of the patient as a weighted function of one or more physiological features of the received physiological information and one or more chemical features of the received chemical information using an evaluation circuit, and generating a comprehensive health index alarm as a function of the determined comprehensive health index and an alarm threshold using the evaluation circuit.

[0035] In examples that can be combined with any one or more of the foregoing examples, determining a patient’s overall health index includes determining the patient’s overall health index as a function of at least two features of the received physiological information and one or more features of the received chemical information.

[0036] In an example that can be combined with any or more of the foregoing examples, one or more chemical features include one or more indications of a relatively high or relatively low value of the received chemical information relative to one or more chemical feature thresholds. The method includes using an evaluation circuit to determine one or more chemical feature thresholds as a function of the chemical information received within a first time period, and determining an indication of a relatively high or relatively low value of the received chemical information by comparing the value of the received chemical information with the determined one or more chemical feature thresholds.

[0037] In examples that can be combined with any or more of the foregoing examples, the method includes using an evaluation circuit to determine the weights of one or more chemical features as a function of the values ​​of one or more chemical features.

[0038] In examples that can be combined with any or more of the foregoing examples, the method includes using an evaluation circuit to determine a value of a comprehensive health index that exceeds an alarm threshold for a first range of values ​​for one or more chemical characteristics, independent of one or more physiological characteristics.

[0039] In an example that can be combined with any or more of the foregoing examples, the method includes using an evaluation circuit to determine an alarm threshold as a function of the received chemical information.

[0040] In an example that can be combined with any or more of the foregoing examples, the method includes using an evaluation circuit to determine an alarm threshold to increase the sensitivity of the comprehensive health index alarm to a second range of values ​​for one or more chemical characteristics.

[0041] In examples that can be combined with any or more of the foregoing examples, the method includes using an evaluation circuit to determine one or more physiological features or one or more chemical features of a weighted function of a comprehensive health index as a function of one or more values ​​of one or more chemical features.

[0042] In one 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 one or more of the functions or methods in the above examples, or at least one "non-transitory machine-readable medium" including instructions that, when executed by a machine, cause the machine to perform any one or more of the functions or methods in the above examples.

[0043] This overview 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 about this patent application. Other aspects of this disclosure will be apparent to those skilled in the art upon reading and understanding the following detailed description and viewing the accompanying drawings, which form a part of it, and each of the drawings should not be considered limiting. Attached Figure Description

[0044] In accompanying drawings that are not necessarily drawn to scale, the same numbers may describe similar parts in different views. Similar numbers with different letter suffixes may represent different instances of similar parts. The accompanying drawings illustrate, by way of example and not limitation, the various embodiments discussed in this document.

[0045] Figure 1An example representation of determining chemical characteristics based on received chemical information 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 health indicators 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 is shown, on which any one or more of the techniques discussed in this paper can be implemented. 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 other things, include one or more of the following: the patient's 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.); the patient's 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, steps, 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 individually, comprehensive health indices determined using combinations of physiological information, such as two or more individual characteristics of different physiological measures. For example, while respiratory rate and tidal volume are both respiratory information, they are independent features of respiratory information, making it possible to determine a comprehensive health index using only respiratory rate and tidal volume. In contrast, single-feature health indices can be determined using respiratory information, such as using only the trend or measure of tidal volume.

[0053] In some examples, a 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, a 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 one example, different combinations of clinical information can be determined separately.

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

[0055] In some examples, the HeartLogic™ index may 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, the different combinations or weights of the HeartLogic™ index may be adjusted or determined based on risk stratification factors. In some examples, risk stratification factors may be identified 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 mean activity level or a specific threshold).

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

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

[0058] Implantable and mobile medical devices typically 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.).

[0059] Heart sounds are recurring mechanical signals associated with the vibrations of the heart or accelerations resulting 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 closure of the atrioventricular (AV) valves (mitral and tricuspid valves) and the opening of the aortic valve at the onset of systole or ventricular contraction. The second heart sound (S2) is a vibration produced by the closure of the aortic and pulmonary valves at the onset of diastole or ventricular relaxation. 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 variation, detected using methods such as measuring 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 nocturnal heart rate (HR), related to sensing the patient's sleep or using a preset or optional time of day corresponding to the patient's sleep. In some examples, changes in impedance information may be used to determine a patient's respiratory information, and therefore can be considered electrophysiological information, but distinct from cardiac electrical information. In other examples, changes in activity or acceleration information may be used to determine a patient's respiratory information, and therefore 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 indications of the amplitude or energy of a specific heart sound for a particular cardiac cycle, or a representation of the number of cardiac cycles of a patient over a particular time period. Daily values ​​representing the patient's average daily values ​​may be determined, corresponding to waking hours or a 24-hour period, etc. Respiratory values ​​may include, among other things, mean or median respiratory rate, binned values ​​of rate, and representative values ​​of specific rate bins, etc. Heart rate values ​​may include average nighttime heart rate, minimum nighttime 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 thoracic 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 an implantable medical device implanted subcutaneously in the patient's thoracic 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 thoracic cavity, or otherwise indicate the patient's thoracic impedance.

[0063] Temperature information may include the patient's internal temperature at the location of a mobile medical device (such as a device implanted in the patient's chest cavity), or the result of 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, at, or within 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., lactic acid, 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 one 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 that, among other things, systems and methods for determining a patient's health index using one or more chemical pieces of information (such as a patient's potassium or creatinine information) provide a more accurate determination of the health index or its value, such as compared to using electrophysiological or other non-chemical physiological information alone. A more accurate determination of a patient's health can lead to more efficient use of device resources controlled by or dependent on such determination, including reduced power consumption of devices and sensors or communication or processing resources, such as by increasing the specificity or sensitivity of health index determination, improving control of device resources, increasing the sensitivity or specificity of alarm state determination, reducing false alarm state determination and associated device switching or adjustments, and reducing the storage or transmission of physiological information or device switching associated with false alarm state determination, etc.

[0066] In one example, a health index can be determined as a function of a patient’s chemical information. For example, a comprehensive health index can be determined as a function of two or more chemical characteristics (e.g., no electrical or mechanical characteristics) (e.g., a weighted function), or individually as a function of one or more physiological characteristics (e.g., electrical or mechanical characteristics, etc.) and one or more chemical characteristics (e.g., a weighted function).

[0067] Chemical characteristics, such as the values ​​of chemical features or parameters, can be determined using one or more pieces of chemical information, such as those sensed by or received from one or more chemical sensors. Chemical characteristics can include raw forms of chemical information (e.g., values ​​of sensor outputs, such as electrical signals, chemical values ​​in basic units, such as concentrations, etc.). In other examples, chemical characteristics can 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, such as adjusting to account for temperature, pressure, other chemical concentrations, etc.), and so on. For example, a chemical characteristic can be determined based on one or more of the amount, direction, or rate of change of the chemical information relative to one or more thresholds or baselines.

[0068] In one example, a chemical characteristic can be determined using chemical information (e.g., a value determined from received chemical information) compared to one or more thresholds or baselines. For example, the chemical information can be compared to one or more chemical characteristic thresholds (such as thresholds corresponding to one or more of relatively high or relatively low values) to provide an indication of whether the chemical information is relatively high or low relative to one or more chemical characteristic thresholds. In some examples, one or more thresholds can be determined as 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 short-term and / or long-term patient averages (e.g., a deviation above the 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 can be determined for a specific patient or a specific population), or a combination or arrangement thereof.

[0069] In one example, if a chemical trait is above a relatively high value or below a relatively low value, the health index, or other features or parameters within the health index, can be gated or adjusted as a function of that chemical trait to indicate a deteriorating patient condition, such as compared to a health index determined without that chemical trait. Conversely, if the chemical trait is within a normal threshold of baseline (e.g., within 30% above or below baseline), or otherwise determined to be between relatively high and low values, the chemical trait can be assigned a value that has little effect on the health index, or it can be used to indicate an improving and / or stable patient condition.

[0070] In one example, one or more thresholds or baselines may include specified predetermined values ​​(e.g., fixed values, which may be determined based on the patient or the patient's medical history with or without input, with or without clinician input, etc.). In one example, the baseline may include a moving baseline, which may represent a patient's moving average over a specified time period (e.g., a predefined length of 3 days, 7 days, 14 days, 21 days, 31 days, etc.). For example, the baseline may represent a chemical characteristic threshold, which is determined as a function of the chemical characteristic (e.g., mean, average, moving average, other central tendency, weighted central tendency, etc.) over a first time period (e.g., a predefined length of 3 days, 7 days, 14 days, 21 days, 31 days, etc.).

[0071] When a chemical characteristic deviates from baseline, it can be assigned a value indicative of a worsening patient condition. If a chemical characteristic deviates rapidly from baseline (e.g., the amount of deviation over 10 days compared to the amount of deviation over one day) or deviates further from baseline, the indicative level of a worsening patient condition can be increased. A chemical characteristic can be assigned a value that considers one or more of the statistical outcome indicated by the chemical characteristic value, the theoretical outcome predicted by the chemical characteristic value, a clinician-programmed value, etc.

[0072] In one example, a chemical trait can be determined in the form of a statistical function, such as a logistic function (e.g., a sigmoid (e.g., starting from 0 and then tending towards 1), an inverse sigmoid (e.g., starting from 1 and then tending towards zero), a translational sigmoid (e.g., sliding along the x-axis), etc.). For example, a chemical trait can indicate a risk that typically increases with increasing chemical trait, and this can be represented by a sigmoid or other statistical function tailored to the chemical trait (e.g., the shape of the chemical trait is configured such that the trait value is aligned with the patient's relative risk based on the chemical trait, such as by matching relative risk through a customized statistical function (e.g., expanding horizontally, expanding vertically, sliding vertically, sliding horizontally, etc.).

[0073] In one example, a chemical trait may have normal values, and values ​​above and below normal can indicate a worsening patient condition or adverse outcome. For example, potassium information may have a normal range, and deviations above or below the normal range indicate an increased risk of adverse outcomes. For chemical traits with these and similar properties, summing statistical functions to represent the chemical trait values ​​can be beneficial. For example, sigmoid and inverse sigmoid can be summed to generate a mapping from chemical traits to trait values, such as... Figure 1 As shown.

[0074] For example, a gated health index can be determined as a function of chemical information, thus providing a better indication of certain instability, deterioration, or adverse outcomes.

[0075] (1)

[0076] In function (1), H can be a chemical characteristic (e.g., determined as a function of chemical information X), and H can be a health index value (e.g., in the absence of...). Health indices determined under certain conditions, health indices determined using electrophysiological or mechanophysiological information, and health indices determined without chemical information, using... Specific health indicators, such as the HeartLogic™ index. In one example... Potassium information can be used (e.g., such as...) Figure 1 The health index is determined by one or more specific features in the chemical trait (as shown) or creatinine information, and H can be a HeartLogic™ index. When the chemical trait is neutral (e.g., 0), such as when the chemical information is normal, the gated health index can be equal to or nearly equal to H. As the chemical trait increases, it determines an increasingly larger portion of the health index, eventually reaching a point where the chemical trait is independent of H in the gated health index.

[0077] In one example, received chemical information can be used to adjust a function used to determine a health index. For example, identified chemical characteristics (e.g., chemical characteristics used in the health index, chemical properties not used in the comprehensive health index) can be used to adjust the function used to determine the comprehensive health index. In one example, when a chemical characteristic indicates a worsening patient condition, that chemical characteristic can lead to the addition of one or more other physiological or chemical characteristics to the health index function that were not present in the function prior to the chemical characteristic indicating a worsening patient condition. In one example, when a chemical characteristic indicates a worsening patient condition, the weights of one or more characteristics in the comprehensive health index can be adjusted (e.g., increasing the relative weight of one or more characteristics, decreasing the relative weight of one or more characteristics, etc.). Similar actions can be taken when chemical characteristics indicate a combination of improvements, as well as any combination or permutation of actions indicating either worsening or improvement.

[0078] In one example, a health index may have a single value (e.g., a numeric value), and this value may be compared to one or more thresholds to determine the system's health index alarm state. The evaluation circuitry can be configured to compare the health index to one or more health index alarm thresholds (e.g., a single health index alarm threshold, first and second health index alarm thresholds, etc.) to determine the patient's health index alarm state. In one example, the health index may have a numeric value, where a higher value indicates a poorer health condition for the patient, and a lower value indicates a better health condition. The health index alarm threshold may represent a high threshold; if the health index value exceeds the health index alarm threshold, an alarm state is triggered.

[0079] The health index alert threshold can be a fixed value, or it can be an adaptive threshold that varies based on one or more factors. In one example, the health index alert 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 can result in the patient being in an alert state being relative, even if the health index alert threshold is fixed.

[0080] The health index alarm state of the system can be determined by comparing the health index value with the health index alarm threshold. The health index alarm state may be at least partially based on the received chemical information if it includes or is determined using one or more features generated using chemical information, or if the health index alarm state is influenced by chemical information in one or more ways (e.g., weights of features in an adjustment function, features in an adjustment function, gating functions, adjustment alarm thresholds, etc.).

[0081] In some examples, if a health index value crosses a health index alarm threshold, the system can enter a health index alarm state. The system can remain in the health index alarm state until the health index value crosses a health index exit alarm threshold. The health index alarm threshold and the health index 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, while any health index value below the shared threshold results in an exit alarm state being determined). The health index alarm threshold and the health index exit alarm threshold can have different values. For example, the health index 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) can be lower than the health index alarm 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 result in 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 an alert status before an exit from an alert status is determined), which may prevent rapid switching between alert and exit from alert status, requiring meaningful improvement in the patient's condition before transitioning to an exit from alert status, etc.

[0082] In one example, received chemical information can be used to adjust a health index alarm threshold. For instance, identified chemical features (e.g., those used in the health index and those not used in the health index) can be used to adjust the health index alarm threshold. In one example, if a chemical feature indicates a worsening condition, the health index alarm threshold can be adjusted to make the health index more sensitive (e.g., make it more likely to trigger an alarm state). For example, if a chemical feature is not used in the health index, the chemical feature can still influence health index alarms by changing the health index alarm threshold.

[0083] In one example, a determined value of the comprehensive health index can exceed a comprehensive health index alarm threshold, regardless of any physiological features used in the function that determines the comprehensive health index. For example, one or more chemical features in the health index may cause a health index value that triggers an alarm, even if one or more physiological features do not indicate a deteriorating patient condition. For a first range of values ​​for one or more chemical features in the comprehensive health index, the alarm threshold may be exceeded independently of one or more physiological features. For example, certain combinations and permutations of chemical feature values ​​that cause the health index alarm threshold to be exceeded are independent of physiological features (e.g., a health index with a single chemical feature will have a set of values ​​for that single feature (e.g., a range) (e.g., certain points and ranges along a line), a health index with two chemical features will have a set of values ​​for those two features (e.g., points and areas in a two-dimensional plane), a health index with three chemical features will have a set of values ​​for all three features (e.g., points and volumes in a rectangular prism), etc.). In one example, the gating function shown in Equation 1 can trigger an alarm state by crossing an alarm threshold (which may include when a chemical feature is between 1 and the minimum value required to exceed the comprehensive health index (e.g., a first range of values)). For example, if the health index alarm threshold is 50, then independent of the value of H, values ​​exceeding the health index alarm threshold will be 0.5. Therefore, the first range of values ​​will be when... From 0.5 to 1 (for example, the system at) It will be in an alert state at any time between 0.5 and 1, regardless of the value of any other characteristic.

[0084] In one example, a health index alarm threshold can be adjusted for a second range of values ​​for one or more chemical features, which can increase the sensitivity of the health index. The second range of values ​​can differ from the first range of values, but can have a similar structure. For example, certain combinations and arrangements of chemical feature values ​​can lead to adjustments in the health index alarm threshold (e.g., a health index with a single chemical feature will have a set of values ​​for that single feature (e.g., a range) (e.g., certain points and ranges along a line), a health index with two chemical features will have a set of values ​​for those two features (e.g., points and areas in a two-dimensional plane), a health index with three chemical features will have a set of values ​​for all three features (e.g., points and volumes in a rectangular prism), etc.). The adjustment to the health index alarm threshold can differ for different parts of the range (e.g., a greater increase in sensitivity corresponding to one or more chemical features indicating a greater risk of adverse outcomes, etc.), or it can remain consistent throughout the entire range.

[0085] In one example, the number of features in a health index can be increased for a third range of values ​​for one or more chemical features. This can increase the sensitivity or specificity of the health index. The third range of values ​​can differ from the first range and / or the second range of values, but can have a similar structure. For example, certain combinations and arrangements of chemical feature values ​​can lead to an increase in the number of features in a comprehensive health index (e.g., a health index with a single chemical feature will have a set of values ​​for that single feature (e.g., a range) (e.g., certain points and ranges along a line), a health index with two chemical features will have a set of values ​​for those two features (e.g., points and areas in a two-dimensional plane), a health index with three chemical features will have a set of values ​​for all three features (e.g., points and volumes in a rectangular prism), etc.). The number of features added and / or the features added can vary for different parts of the range (e.g., one feature is added when a chemical feature indicates a moderate anomaly, and two features are added when a chemical feature indicates a severe anomaly, etc.), or can be consistent throughout the range. In one example, one or more features can be added to a HeartLogic™ index when a chemical feature (e.g., a chemical feature corresponding to potassium information, a chemical feature corresponding to creatinine information, etc.) indicates an outlier. This can increase the overall sensitivity of the HeartLogic™ index, or it can increase specificity or otherwise customize the HeartLogic™ index to detect deteriorating patient conditions in specific cases of abnormal chemical information (e.g., different features, feature weights, and alarm thresholds can be used when one or more chemical information is abnormal, which can result in the health index providing a better indication of patient condition during abnormal chemical levels than when the health index is not customized based on chemical information (e.g., constant or customized only based on non-chemical factors) (e.g., high potassium levels can lead to health index monitoring or more close monitoring of cardiac rhythm measures).

[0086] Health indicators can be used to identify indicators or warnings of deteriorating patient conditions, including worsening heart failure, such as those caused by volume overload (e.g., excessive fluid, excessive blood volume, high plasma concentration). Chemical values ​​can also indicate patient condition.

[0087] In some examples, interstitial chemical information, such as the chemical levels of one or more interstitial spaces (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 can follow or reflect changes in serum potassium levels, or vice versa), making serum potassium chemical information include interstitial potassium. In some examples, one of the interstitial or serum chemical information may lead or lag behind the other, making changes in one that could indicate a worsening patient condition detectable before the other. In one example, interstitial potassium information may lead serum potassium information as an indicator of electrolyte imbalance.

[0088] Regarding potassium, a normal range (e.g., a medically acceptable range, such as a range determined based on medical data, a healthy range, etc.) can be defined as “normal serum potassium” and can include values ​​from 3.6 to 5.2 mmol / L (e.g., millimoles per liter). Potassium levels above and / or below normal serum potassium can lead to adverse outcomes. For example, a low range below normal serum potassium can be defined as “hypokalemia” and can include values ​​below 3.6 mmol / L. Moderate hypokalemia can include values ​​from 2.5 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 can be defined as “hyperkalemia” and can include values ​​above 5.2 mmol / L. Moderate hyperkalemia can include values ​​from 5.2 to 6.5 mmol / L. Severe hyperkalemia, which may require immediate medical attention, can include values ​​above 6.5 mmol / L.

[0089] Hypokalemia can prolong action potentials. It can play a pathogenic role in one or more processes associated with the progression of heart failure, such as peripheral muscle dysfunction, rhabdomyolysis, vasodilatory dysfunction, myocardial diastolic dysfunction, atherosclerosis, or diuretic resistance. Hyperkalemia increases the risk of one or more of cardiac arrest, ventricular fibrillation, or sudden cardiac death. Patients with heart failure may have a high prevalence of chronic kidney disease, which increases the risk of hyperkalemia. Use of RAAS inhibitors further increases the risk of hyperkalemia. For these and other reasons, hypokalemia and / or hyperkalemia can indicate a deteriorating patient condition and / or predict adverse patient outcomes such as hospitalization or death. This makes it beneficial to include potassium information when determining health indicators (e.g., including potassium information in any aspect as discussed above, and not just limited to including potassium-based characteristics in health indicators).

[0090] Regarding 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, in some cases worsening heart failure symptoms and / or increasing the risk of adverse outcomes (e.g., hospitalization, readmission, mortality, etc.). Monitoring creatinine levels may be desirable to determine whether renal function is affecting the state of heart failure. For example, increasing creatinine levels over time (e.g., serum or interstitial creatinine levels, etc.), such as long-term trends, can indicate that renal impairment is leading to volume overload, which may affect the risk of adverse patient outcomes. For these and other reasons, it is beneficial to include creatinine information when determining health indices (e.g., including creatinine information from any aspect as discussed above, and not just limited to including creatinine-based characteristics in health indices).

[0091] In some examples, health index alarm states (e.g., health index in alarm state, health index out of alarm state, etc.) can be determined and provided to the patient, clinician, or one or more other users or devices associated with the patient. Health indices (such as HeartLogic™ indices) can be used to determine health index alarm states. The system can provide the output of the determined health index alarm state to a user interface for display to the user, or to control circuitry to control or adjust processes or functions of the medical device system.

[0092] In one example, the health index may include a comprehensive heart failure index, the health index alarm threshold may be a comprehensive heart failure alarm threshold, and the received chemical information may include one or more of potassium levels or creatine levels.

[0093] In some examples, the techniques described above or herein can be used in various combinations or arrangements. For example, combinations or arrangements of the techniques described above or herein can be selected based on patient history, clinician input, etc.

[0094] Figure 1 Examples of chemical characteristic values ​​102 are shown 100, representing different ranges, from a normal characteristic range 136 to ranges 134 and 138 that are above or below the normal characteristic range, and ranges 132 and 140 that are significantly above and below the normal characteristic range. Chemical characteristic values ​​102 have specified output values ​​on a vertical axis 120 within a specified range of input values ​​represented on a horizontal axis 110. Figure 1In the example, chemical eigenvalue 102 can be in the form of a sum of logic functions (e.g., the sum of a first inverse logic function approaching 0 from the maximum eigenvalue 122, appearing on the left side of the graph, and a second logic function approaching the maximum eigenvalue 122, appearing on the right side of the graph). In one example, chemical eigenvalue 102 can have a maximum eigenvalue 122 of 1 (e.g., the maximum value of an unweighted logic function). In one example, the maximum eigenvalue 122 can be any value. The maximum eigenvalue can indicate a negative patient condition, and 0 can indicate a stable and / or positive patient condition.

[0095] Different ranges can be separated by different boundaries, such as thresholds. For example, the boundary between significantly below the normal feature range 132 and below the normal feature range 134 could be significantly below the normal threshold 112. The boundary between the normal feature range 134 and the normal feature range 136 could be below the normal feature threshold 114. The boundary between the normal feature range 136 and above the normal feature range 138 could be above the normal feature threshold 116. The boundary between above the normal feature range 138 and significantly above the normal feature range 140 could be significantly above the normal feature threshold 118.

[0096] In one example, on the horizontal axis 110... Figure 1 The input to the illustrated feature can be a chemical information, which can be a chemical characteristic (e.g., a chemical value). In one example, the input could be a potassium level. If the input is a potassium level, significantly below the normal feature range 132 can indicate a severe hypokalemia condition (e.g., indicating a serum potassium level below a significantly below normal threshold 112, such as 2.5 mmol / L). Below the normal feature range 134 can indicate a moderate hypokalemia condition (e.g., indicating a serum potassium level between 2.5 and 3.6 mmol / L). The normal feature range 136 can indicate a normal serum potassium condition (e.g., indicating a serum potassium level between below the normal feature threshold 114 and above the normal feature threshold 116 (e.g., 3.6 and 5.2 mmol / L, respectively)). Above the normal feature range 138 can indicate a moderate hyperkalemia condition (e.g., indicating a serum potassium level between above the normal feature threshold 116 and significantly above the normal feature threshold 118 (e.g., 5.2 and 6.5 mmol / L, respectively)).

[0097] Figure 1The results show that the chemical characteristic value 102 in the normal characteristic range 136 can be close to zero, and is significantly lower than the chemical characteristic value 102 in the normal characteristic range 132 and significantly higher than the chemical characteristic value 102 in the normal characteristic range 140, which can be close to the maximum characteristic value 122. The chemical characteristic values ​​102 in the normal characteristic range 134 and the normal characteristic range 138 can respectively smooth the trend from the maximum characteristic value 122 to 0 or from 0 to the maximum characteristic value 122.

[0098] Figure 1 The chemical characteristics shown (e.g., when based on potassium levels) can be used in any way, which may include the use of chemical characteristics as discussed above. For example, Figure 1 The chemical characteristics shown can be used for health indices, for gating health indices, for adjusting health index features, and for adjusting health index alarm thresholds or other thresholds, etc. Although in Figure 1 Information about potassium (e.g., serum potassium, interstitial potassium, etc.) is shown in other examples, but chemical characteristics may include creatinine information about one or more other thresholds associated with normal, above / below normal, or significantly above / below normal values, as shown in the potassium information herein.

[0099] Figure 2 An example system 200 (e.g., a medical device system) is illustrated. In one example, one or more aspects of the example system 200 may be components or communications coupled to a medical device, such as an implantable medical device (IMD), an insertable cardiac monitor, a mobile medical device (AMD), etc. The 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.

[0100] 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 one 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, intrathoracic 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 patient physiological information.

[0101] 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 from a patient (or group of patients). 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 factors, 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 other things, 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.

[0102] In some examples, evaluation circuit 203 may 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 for one or more patients based on the information, and transmit messages or alarms to one or more remote devices indicating that one or more patients have been detected or that the information has been stored or transmitted, so that one or more additional processes or systems may use the stored or transmitted detection or information for one or more other reviews or processes.

[0103] In some examples, such as to detect improvement or deterioration in a patient's condition, preliminary assessments are typically required to establish a baseline level or condition from one or more sensors or physiological information. Subsequent detection of deviations from the baseline level or condition can then 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 event) in conjunction with or separately from any baseline level or condition.

[0104] Variations in different physiological information can be aggregated and weighted based on one or more patient-specific stratification factors, and in some examples, compared to one or more thresholds, such as those with clinical sensitivity and specificity for a specific condition (e.g., heart failure) in a target population, 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 time periods or more days (sometimes different from the number of days used for short-term averages, e.g., non-overlapping)).

[0105] System 200 may include output circuitry 204 configured to provide output to a user, or to provide output to a user via an output terminal, display, or one or more other user interfaces, including ratings, 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, dosing determination, or recommendations. In one example, treatment circuitry 205 may include one or more of stimulation control circuitry, cardiac stimulation circuitry, neural stimulation circuitry, dosing determination, or control circuitry. In other examples, treatment circuitry 205 may be controlled by evaluation circuitry 203 or one or more other circuitry. 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, which may provide a signal based on the output determined by evaluation circuit 203, so that the user interface provides output to the user.

[0106] A technical problem 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 certain trade-offs between battery life, or in the case of implantable medical devices with non-rechargeable batteries, device replacement cycles (typically including surgical procedures), and the sampling resolution and sampling period for processing, storing, and transmitting sensed physiological information or features or pattern selection within or within the medical device. Medical devices may include higher-power and lower-power modes. Physiological information, such as that indicating potential adverse physiological events, can be used to switch 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, when physiological information detected in a low-power mode indicates a possible event, valuable information has been lost and cannot be recorded in the high-power mode.

[0107] Conversely, the same applies, as erroneous or inaccurate detection of high-power modes unnecessarily and excessively limits the lifespan of some mobile medical devices. For a variety of reasons, accurate detection and identification of physiological events, and avoiding unnecessary transitions from low-power to high-power modes, are beneficial for improving the utilization of medical device resources.

[0108] For example, a change in mode may enable higher resolution sampling, 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, in some examples, different physiological information is typically sensed using non-overlapping time periods of the same sensor at different sampling frequencies and power costs. In one example, heart sounds and patient activity may be detected using non-overlapping time periods of the same, single-axis or multi-axis accelerometer at different sampling frequencies and power costs. In some examples, a transition to a high-power mode may include using an accelerometer to detect heart sounds, etc., throughout the high-power mode or at a larger percentage of the high-power mode than during the corresponding low-power mode. In other examples, waveforms for 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 or a summary of the event may be transmitted. In response, the complete event may be requested for subsequent transmission and review. However, even when the event is stored but not transmitted, the resources used for storing and processing the event are still used by the medical device.

[0109] 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.

[0110] 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.).

[0111] In one example, the implantable medical device 302 may include one or more cardiac rhythm management devices implanted in the chest of a patient, 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) within, on, or around the heart of the patient 301, or in one or more other locations in the chest, abdomen, or neck. In another example, the implantable medical device 302 may include, for example, a monitor implanted subcutaneously in the chest of the patient 301, the implantable medical device 302 including a housing containing a circuitry system, and in some examples, including one or more sensors, such as temperature sensors.

[0112] 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 aspects located subcutaneously but close to the patient's distal skin, and aspects located near one or more organs of the patient, such as leads or electrodes. Separately from or in addition to the leads and the electrodes or other sensors, cardiac rhythm management devices 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 the one or more electrodes or other sensors may be configured to detect physiological information from the patient or to provide the patient with one or more treatments or stimulations.

[0113] Implantable devices may additionally or separately include leadless cardiac pacemakers (LCPs), small (e.g., smaller than conventional implantable rhythm management devices, approximately 1 cc in some examples), and 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 physiological conditions associated with the heart (e.g., tachycardia), or deliver one or more treatments or stimulations to the heart without the complications of conventional leaded or implantable 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 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 treatments or stimulations to them. Multiple leadless pacemakers may communicate with each other or with one or more other implantable or external devices.

[0114] Implantable medical device 302 may include assessment circuitry configured to detect or determine specific physiological information of patient 301, or to determine one or more conditions, or to provide information or alerts to users (such as patient 301, for example, a patient), clinicians, or one or more other caregivers or processes, as described herein. Implantable medical device 302 may alternatively or additionally be configured as a treatment device configured to treat one or more medical conditions of patient 301. Treatment may be delivered to 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 patient 301, such as using implantable medical device 302 or other mobile medical devices. In some examples, treatment may include a cardiac reflex (CRT) for correcting asynchrony and improving cardiac function in patients with heart failure. In other examples, implantable medical device 302 may include a drug delivery system, such as a drug infusion pump, to deliver medication to a 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.

[0115] 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-worn or finger-worn medical device, such as finger-based photoplethysmography sensor, etc.).

[0116] 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 via communication link 311, or wearable medical device 303 may be connected to external system 305. This may include, for example, programming implantable medical device 302 to perform actions such as collecting physiological data, performing at least one self-diagnostic test (e.g., for device operational status), analyzing physiological data, or optionally delivering or adjusting treatment for patient 301. Furthermore, 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 also possible.

[0117] External system 305 may include an external device 306 located near one or more mobile medical devices, and a 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, among other possible functions, evaluate collected patient or patient information and provide alarm notifications. In one example, remote device 308 may include a centralized server that acts as a central hub for data storage and analysis 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 for evaluating the collected data to determine whether specific alarm conditions are met. The fulfillment of alarm conditions can trigger the generation of alarm notifications, for example, provided by one or more human-perceptible user interfaces. In some examples, alarm conditions may alternatively or additionally be evaluated 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, text or "instant" messages, as well as messages to patients and direct notifications to both emergency services and clinicians. Other alarm notifications are also possible. The server may include alarm prioritization 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.

[0118] Remote device 308 may also 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.

[0119] The communication network 307 can provide wired or wireless interconnection. In one example, the communication network 307 can 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.

[0120] 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 processes including, for example, instances of computer programs executable in a microprocessor. In one example, the process may include automatically generating recommendations for antiarrhythmic treatment, or recommendations for further diagnostic tests or treatments. In one example, external device 306 or remote device 308 may include a corresponding display unit for displaying physiological or functional signals, or alarms, alerts, emergency calls, or other forms of warning 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.

[0121] 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.

[0122] Treatment device 310 can be configured to send or receive information from one or more of mobile medical devices or external systems 305 using communication link 311. In one 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 information 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.

[0123] In some examples, event storage can be triggered, such as by received physiological information, or in response to one or more detected events or determined parameters reaching 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 devices (such as loop recorders) to long-term or non-volatile memory, or in some examples, prepared for transfer to external devices detached from the medical device. In one example, 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 one example, multiple loop recorder windows (e.g., 2-minute windows) can be stored sequentially. In systems without early detection, loop recorders with longer periods require significant additional costs (e.g., power, processing resources, component costs, memory requirements, etc.) to record this information. Using such early detection to store multiple windows up to a single event provides a complete event assessment, saving power and cost compared to longer loop recorder windows. Furthermore, early detection can trigger additional parameter calculations or storage at different resolutions or sampling frequencies without excessively consuming limited system resources.

[0124] In some examples, one or more alarms may be provided to a patient, clinician, or one or more other caregivers (e.g., using a patient smartwatch, mobile phone or smartphone, computer, etc.) 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 alarms to alert the patient to a detected condition. For example, a detected condition may alert the patient so that they take a corrective action, such as sitting down.

[0125] In some examples, treatment can be provided in response to a detected condition. For example, pacing therapy can be provided, activated, or adjusted 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.) can 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.

[0126] In some examples, a patient's physiological information can be sensed, such as through one or more sensors located inside, on, or near the patient, such as a cardiac sensor, a heart sound sensor, or one or more other sensors described herein. For example, a cardiac sensor can be used to sense a patient's cardiac electrical information. In other examples, a heart sound sensor can be used to sense a 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, for example, through processing circuitry of the cardiac sensor or one or more other medical devices or medical device components, etc. In some examples, timing measures may include the interval or measure between a first cardiac feature and a second cardiac feature of 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 of a patient's corresponding successive first cardiac interval and second cardiac interval. In one 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, etc.) or one or more other features of cardiac electrical signals.

[0127] In one example, 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 ECG features, or as one or more energy values ​​relative to a heart sound signal window, typically determined relative to one or more cardiac electrical characteristics. For example, the value and timing of the S1 signal can be detected using the amplitude or energy of a heart sound signal occurring at or near the R wave of a 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 a cardiac interval. In one example, the S4 interval can be defined as a set time period within a cardiac interval relative to one or more other cardiac electrical or mechanical features, such as forward from one or more of the R wave, T wave, or forward from one or more features of the heart sound waveform (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 one 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.

[0128] In one 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 a composite S1 parameter representing multiple S1 parameters, such as within a certain time period (e.g., multiple cardiac cycles, representative time period, etc.).

[0129] In one example, the heart sound parameter may include an overall average of a specific heart sound on a heart sound waveform, such as that 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 its disclosure of overall averaging of acoustic signals and determination of a specific heart sound on a heart sound waveform. In other examples, the signal receiver circuit may receive at least one heart sound parameter or composite parameter, such as from a heart sound sensor or heart sound sensor circuitry.

[0130] In one 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 one example, the received cardiac electrical information may include a timing measurement between a first cardiac characteristic and a second cardiac characteristic of the patient.

[0131] In one example, cardiac acceleration information of the patient can be received from a heart sound sensor (e.g., an accelerometer, etc.) or a heart sound sensor circuit (e.g., including one or more amplifier or filter circuits, etc.) using the same or different signal receiver circuitry of a medical device. In one example, the received cardiac acceleration information may include an S4 signal portion that appears between the patient's first and second cardiac features. In some examples, additional physiological information, such as one or more of heart rate information, patient activity information, or patient posture information, can be received from one or more other sensors or sensor circuitry.

[0132] 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 sensor group to a higher-power sensor or sensor group, 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 cycle recorder in long-term memory, or increasing the storage capacity or time period of the cycle recorder, or otherwise altering the device behavior to capture additional or higher-resolution physiological information or perform more processing, etc.

[0133] Additionally, or alternatively, event storage can be triggered. Information sensed or recorded in high-power mode can be transferred from short-term storage devices (such as cyclic recorders) to long-term or non-volatile memory, or in some examples, prepared for transfer to external devices detached from the medical device. In one example, 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 one example, multiple cyclic recorder windows (e.g., 2-minute windows) can be stored sequentially. In systems without early detection, recording this information with cyclic recorders with longer periods would require significant additional costs (e.g., power, processing resources, component costs, etc.).

[0134] Figure 4 An example method 400 for determining a health index using one or more chemical information points is shown. Figure 4In the examples, the health index includes a comprehensive health index determined using one or more physiological information and one or more chemical information.

[0135] At step 401, patient physiological information may 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 patient physiological information.

[0136] At step 402, the patient's chemical information may be received, such as using signal receiver circuitry. This chemical information may include information about chemical substances or other properties within the patient's blood or interstitial space, as discussed elsewhere herein.

[0137] At step 403, an evaluation circuit may be used, for example, to determine the comprehensive health index as a function of one or more features of the patient's physiological information and one or more chemical information, as discussed elsewhere herein. One or more physiological features may include functions of physiological information received by the signal receiver circuitry. For example, a feature corresponding to respiratory rate may be calculated using a high feature value corresponding to a healthy respiratory rate and a low feature value corresponding to an unhealthy respiratory rate. A high respiratory rate (e.g., 30 breaths per minute) may be assigned a value of 200, and a low respiratory rate (e.g., 12 breaths per minute) may be assigned a value of 0. The functional mapping between high and low respiratory rates may be assigned in one or more ways, such as linearly, logarithmically, etc.

[0138] One or more chemical characteristics may include functions of chemical information received by a signal receiver circuit. Chemical characteristics may include chemical values ​​determined based on the received chemical information. Chemical characteristics may include chemical information in its raw form (e.g., sensor output, such as an electrical signal, chemical values ​​in basic units (e.g., concentration), etc.), or may be determined by processing the received chemical information (e.g., converting sensor output into chemical values, adjusting chemical values ​​based on one or more factors (e.g., considering temperature, pressure, other chemical concentrations, etc.), etc.), etc. For example, a characteristic based on a patient's potassium information, as discussed above.

[0139] In one example, more than one chemical feature may be used, which may include a first chemical feature and a second chemical feature. As discussed above, the first and second chemical features can be determined. In one example, the first chemical feature may represent potassium levels, and the second chemical feature may represent creatinine levels. A health index can be determined as a function of different features or combinations of physiological and chemical information, such as one or more weighted combinations (e.g., average, product, summation, etc.) of two or more features (e.g., each feature having a corresponding weight). This combination may include linear combinations or one or more nonlinear or other combinations.

[0140] At step 404, the weights of one or more features of the function used to determine the comprehensive health index can be adjusted as a function of one or more chemical features, as discussed elsewhere herein. For example, the weights of one or more chemical features in the comprehensive health index can be determined as a function of the values ​​of one or more of the one or more chemical features.

[0141] At step 405, the value of the comprehensive health index exceeding one or more thresholds discussed below with respect to step 407 can be determined independently of one or more physiological characteristics, as discussed elsewhere herein. For example, for a first range of values ​​of one or more of the one or more chemical characteristics, the value of the comprehensive health index exceeding the comprehensive health index alarm threshold (discussed below with respect to step 7) can be determined.

[0142] At step 406, the features of the comprehensive health index can be determined as a function of the received chemical information, as discussed separately above. For example, in step 403, additional features can be added to the function used to determine the comprehensive health index. In one example, features can be removed from the function used to determine the comprehensive health index in step 403. In one example, any combination of adding or removing features can be used (e.g., adding two features and removing one feature). For example, the method can include a third range for the values ​​of one or more of the chemical features, increasing the number of features in the comprehensive health index.

[0143] At step 407, the determined comprehensive health index value can be compared with a comprehensive health index alarm threshold, such as using an evaluation circuit. If the comprehensive health index value is on a specified side of the threshold (e.g., above the threshold, below the threshold), the method may include returning to step 403 to redetermine the comprehensive health index. The comprehensive health index value determined in step 403 can be determined and repeatedly compared with the comprehensive health index threshold. For example, the comprehensive health index can be compared with the comprehensive health index threshold at set intervals, which may include 1 minute, 5 minutes, 30 minutes, 1 hour, 12 hours, or 1 day.

[0144] At step 408, if the overall health index value is on the opposite side of a threshold (e.g., the opposite side of the threshold, causing a return to step 403), it can be determined that the overall health index is in an alarm state. An indication that the determined health index is in an alarm state can be provided to the patient, clinician, or one or more other users associated with the patient. In one example, an alarm can be generated and provided to indicate a transition or adjustment from leaving an alarm state to being in an alarm state. Alarms can be provided based on the priority of the determined alarm state with a specified level of urgency (e.g., auditory, visual, or tactile alarms, emergency notifications, etc.). 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 leaving the alarm state is appropriate (e.g., the health index value drops below the health index leaving the alarm threshold). During an alarm state, the device's power consumption may increase, which could be due to one or more of the following: the power required to generate and / or transmit one or more alarms, increased monitoring intervals, increased processor load, etc.

[0145] At step 409, one or more thresholds used in step 407 to determine the comprehensive health index alarm can be determined as a function of the received chemical information, as discussed above. For example, the alarm thresholds can be adjusted to increase the sensitivity of the comprehensive health index to a second range of values ​​for one or more of the chemical characteristics.

[0146] In some examples, the techniques of any one or more of steps 404-406 and 409 can be used in various combinations or arrangements. In some examples, any one or more of steps 404-406 or 409 can be applied to multiple chemical information.

[0147] Figure 5 An 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 through one or more lead ports, such as a first lead port 541, a second lead port 542, or a third lead port 543 in the head 502 of the IMD 500. In one 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.

[0148] 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 at or near locations in or near the heart, such as one or more atria or ventricles. Separate from or in addition to the leads, the IMD 500 may 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, the IMD 500, or combinations thereof, and the 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.

[0149] 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 be used 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.

[0150] In one example, the IMD 500 can sense impedance such as that between electrodes located on one or more leads or CAN 501. The IMD 500 can be configured to inject current between a pair of electrodes, sense the voltage generated between the same or different pairs of electrodes, and determine 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; in 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 in a quadrupole configuration, where the electrodes used for current injection can be different from those used for voltage sensing, and so on. In one example, the IMD 500 can be configured to inject current between electrodes on one or more of the first lead 520, second lead 525, third lead 530, or fourth lead 535 and CAN 501, and sense the voltage generated between the same or different electrodes and CAN 501.

[0151] Figure 5 An example lead configuration includes a first lead 520, a second lead 525, and a third lead 530 located in the coronary veins 516 (e.g., the coronary sinus) above the right atrium (RA) 506, right ventricle (RV) 507, and left atrium (LA) 508 and left ventricle (LV) 509, respectively, in a conventional lead placement manner; and a fourth lead 535 positioned in the RV 507, near the His bundle 511, between the AV node 510 and the right bundle branch 512 and left bundle branch 513, as well as the Purkinje fibers 514 and 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.

[0152] 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.

[0153] 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, for example for placement in or near the superior vena cava (SVC) 517.

[0154] Different CRM devices include varying numbers of leads and lead placements. For example, some CRM devices are single-lead devices with 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 typically use lead ports designated for the LV or RV lead to deliver stimulation to the His bundle 511.

[0155] 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 frameworks 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.

[0156] As described herein, examples may include logic or multiple components or mechanisms in machine 600, or those that can be operated by it. 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 one example, the hardware of the circuit system may be designed immutably to perform a specific operation (e.g., hardwired). In one example, the hardware of the circuit system may include physically connected components (e.g., execution units, transistors, simple circuits, etc.) and a machine-readable medium including physically modified (e.g., magnetic, electrical, movable placement of immutable aggregated particles, etc.) to encode instructions for a specific operation. When the physical components are connected, the fundamental electrical properties of the hardware components are altered, 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 one example, the machine-readable medium element is part of the circuit system, or communicatively coupled to other components of the circuit system during device operation. In one 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. The following are additional examples of these components of machine 600.

[0157] 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 one 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 the actions to be taken by the machine. Furthermore, while only a single machine is shown, the term "machine" should also be considered to include any collection of machines that individually or jointly execute a set (or more) of instructions to perform any one or more methods discussed herein, such as cloud computing, software as a service (SaaS), and other computer cluster configurations.

[0158] 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 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 one example, the display unit 610, input device 612, and UI navigation device 614 may be a touchscreen display. Machine 600 may also 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, etc.) connection, to communicate with or control one or more peripheral devices (e.g., a printer, a card reader, etc.).

[0159] The registers, main memory 604, static memory 606, or mass storage 608 of the hardware processor 602 may be or include a machine-readable medium 622 storing a set or more sets of data structures or instructions 624 (e.g., software) embodying or utilized by any one or more of the technologies or functions described herein. During execution of the instructions 624 by the machine 600, the instructions 624 may also reside wholly or at least partially within any of the registers, main memory 604, static memory 606, or mass storage 608 of the hardware processor 602. In one example, one or any combination of the hardware processor 602, main memory 604, static memory 606, or mass storage 608 may constitute the machine-readable medium 622. While the machine-readable medium 622 is shown as a single medium, the term "machine-readable medium" can 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.

[0160] The term "machine-readable medium" can include any medium capable of storing, encoding, or carrying instructions executable by machine 600 and enabling machine 600 to perform any one or more of the technologies disclosed herein, 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 one example, a non-transitory machine-readable medium includes a machine-readable medium containing a plurality of particles having invariant (e.g., rest) mass, and is therefore a composition of matter. Thus, a non-transitory machine-readable medium is a machine-readable medium that does not include transiently propagating signals. Specific examples of non-transitory machine-readable media may include: non-volatile memories, such as semiconductor storage devices (e.g., electrically programmable read-only memory (EPROM) and electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROMs and DVD-ROMs.

[0161] Instruction 624 can also utilize 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.) to further transmit or receive data via a transport medium through network interface device 620 and communication network 626. 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 IEEE 802.11 family of standards known as Wi-Fi®, the IEEE 802.16 family of standards known as WiMax®), the IEEE 802.15.4 family of standards, peer-to-peer (P2P) networks, etc. In one example, network interface device 620 may include one or more physical jacks (e.g., Ethernet, coaxial cable, or telephone jacks) or one or more antennas for connection to communication network 626. In one 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.

[0162] Various embodiments are illustrated in the accompanying drawings. One or more features from one or more of these embodiments may be combined to form other embodiments. Examples of methods 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 this method 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.

[0163] The above detailed description is intended to be illustrative and not limiting. Therefore, the scope of this disclosure should be determined by reference to the appended claims and the full scope of their equivalents.

Claims

1. A medical device system, comprising: The signal receiver circuit is configured to receive: Patient's physiological information; and The patient's chemical information; as well as The evaluation circuit is configured as follows: The patient's overall health index is determined as a weighted function of one or more physiological features from the received physiological information and one or more chemical features from the received chemical information; and Generate a comprehensive health index alert as a function of the determined comprehensive health index and alert threshold.

2. The medical device system according to claim 1, wherein, The evaluation circuit is configured to determine the patient’s overall health index as a function of at least two features of the received physiological information and one or more features of the received chemical information.

3. The medical device system according to any one of claims 1-2, wherein, The one or more chemical features include one or more indications of relatively high or relatively low values ​​of the received chemical information relative to one or more chemical feature thresholds.

4. The medical device system according to claim 3, wherein, The evaluation circuit is configured as follows: The one or more chemical feature thresholds are determined as a function of the chemical information received within the first time period; as well as The value of the received chemical information is used to determine an indication of a relatively high or relatively low value of the received chemical information by comparing it with one or more defined chemical characteristic thresholds.

5. The medical device system according to any one of claims 1-4, wherein, The evaluation circuit is configured to determine the weights of the one or more chemical features as a function of the values ​​of the one or more chemical features.

6. The medical device system according to claim 5, wherein, The evaluation circuit is configured to determine, independently of the one or more physiological characteristics, the value of the comprehensive health index that exceeds the alarm threshold value within a first range for the one or more chemical characteristics.

7. The medical device system according to any one of claims 1-6, wherein, The evaluation circuit is configured to determine the alarm threshold as a function of the received chemical information.

8. The medical device system according to claim 7, wherein, The evaluation circuit is configured to determine the alarm threshold to increase the sensitivity of the comprehensive health index alarm to a second range of values ​​for the one or more chemical characteristics.

9. The medical device system according to any one of claims 1-8, wherein, The evaluation circuit is configured to determine the weighting function of the comprehensive health index as a function of one or more physiological features or one or more chemical features as one or more values ​​of the one or more chemical features.

10. The medical device system according to claim 9, wherein, The evaluation circuit is configured to increase the number of features of the one or more physiological features or the one or more chemical features in the weighting function for a third range of values ​​of the one or more chemical features.

11. The medical device system according to any one of claims 1-10, wherein, The comprehensive health index includes a comprehensive heart failure index, and the comprehensive health index alarm threshold includes a comprehensive heart failure alarm threshold. Wherein, at least one of the one or more chemical characteristics or the chemical information includes at least one of the patient's potassium information or creatinine information; and The evaluation circuit is configured to provide the generated comprehensive health index alarm output to the user interface for display to the user, or to provide it to the control circuit to control or adjust the process or function of the medical device system.

12. A method comprising: Received using a signal receiver circuit: Patient's physiological information; and The patient's chemical information; Using an evaluation circuit, the patient's overall health index is determined as a weighted function of one or more physiological features of the received physiological information and one or more chemical features of the received chemical information. as well as The evaluation circuit is used to generate a comprehensive health index alarm, which is a function of the determined comprehensive health index and alarm threshold.

13. The method according to claim 12, wherein, The one or more chemical features include one or more indications of relatively high or relatively low values ​​of the received chemical information relative to one or more chemical feature thresholds. The method includes using the evaluation circuit: One or more chemical feature thresholds are determined as a function of the chemical information received within a first time period; and The indication of a relatively high or relatively low value of the received chemical information is determined by comparing the value of the received chemical information with one or more defined chemical characteristic thresholds.

14. The method of claim 13, further comprising using the evaluation circuit to determine the weights of the one or more chemical features as a function of the values ​​of the one or more chemical features; and Using the evaluation circuit, independently of the one or more physiological characteristics, the value of the comprehensive health index is determined for values ​​exceeding the alarm threshold within a first range for the one or more chemical characteristics.

15. The method of claim 12, further comprising using the evaluation circuit to determine the alarm threshold as a function of the received chemical information, including determining the alarm threshold to increase the sensitivity of the comprehensive health index alarm to a second range of values ​​of the one or more chemical features.

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