Abstract: Embodiments herein relate to chemical sensors for detecting a physiological analyte. In an embodiment, an implantable medical device including a chemical sensor for detecting an ion concentration in a bodily fluid is provided. The chemical sensor can include a sensing element having an outer barrier layer forming a top, a bottom, and opposed sides, where the top of the outer barrier layer can be created from a polymeric matrix permeable to sodium ions, potassium ions, and hydronium ions. An active agent can be disposed within the top of the outer barrier layer, the active agent having anti-inflammatory effects. The chemical sensor can include an optical excitation assembly configured to illuminate the sensing element. The chemical sensor can also include an optical detection assembly configured to receive light from the sensing element. Other embodiments are also included herein.

Abstract: A ventricularly implantable medical device that includes a sensing module that is configured to gather information during a cardiac cycle and to identify a cardiac interval based at least on part on the gathered information. Control circuitry in the implantable medical device is configured to deliver a ventricular pacing therapy to a patient's heart, wherein the ventricular pacing therapy is time dependent, at least in part, on the identified cardiac interval.

Abstract: Systems and methods to determine an indication of patient dehydration are disclosed, including receiving first and second physiologic information of a patient, the first physiologic information including heart sound information of the patient and the second physiologic information different than the first physiologic information, and determining the indication of patient dehydration using the received first and second physiologic information.

Abstract: An implantable medical device (IMD) includes a heterogeneous housing configured to receive and store one or more components of the IMD. The housing includes an intrinsically non-conductive and non-magnetic base material and at least one dopant with a property of at least one of electrical conductance and magnetic permeability. The base material and the dopant form a first region of the housing including a first skin depth and a second region of the housing including a second skin depth different than the first skin depth.

Abstract: A ventricularly implantable medical device that includes a sensing module that is configured to identify a search window of time within a cardiac cycle to search for an atrial artifact. Control circuitry in the ventricular implantable medical device is configured to deliver a ventricular pacing therapy to a patient's heart, wherein the ventricular pacing therapy is time dependent, at least in part, on an atrial event identified in the search window of time.

Abstract: Arterial diastolic pressure of a patient can be estimated using ventricular pressure information of a heart of the patient and heart sound information of the heart of the patient, such as a timing of at least one of a first heart sound (S1) or a second heat sound (S2), in certain examples, adjusted by a respective correction factor.

Abstract: An implantable antibacterial barrier device for an elongated medical device, the elongated medical device configured to extend from a first site, through a second site, to a third site. The implantable antibacterial barrier device includes a housing configured to be disposed at the first site, a working electrode configured to be disposed at the second site, and a reference electrode configured to be disposed at the first site. The housing includes barrier circuitry. The working electrode electrically is coupled to the barrier circuitry. The reference electrode is electrically coupled to the barrier circuitry. The barrier circuitry is configured to selectively maintain the working electrode at a negative electrical potential relative to the reference electrode to form an antibacterial barrier.

Abstract: Systems and methods to determine presence of an analyte using an implantable medical device are disclosed. In an embodiment, a medical system includes an implantable medical device, a light source, an optical sensor and a processor. The implantable medical device includes an indicator tag, which is responsive to an analyte. The light source is configured to emit light onto the indicator tag, where the emitted light comprises at least one wavelength of light, and where the indicator tag emanates light, in response to the emitted light, that corresponds to whether the indicator tag is exposed the analyte. The optical sensor is configured to receive at least a portion of the emanated light, which includes at least one wavelength of light. And, the processor is configured to determine whether the indicator tag is exposed to the analyte based on the received light.

Abstract: Methods and devices for testing and configuring implantable medical device systems. A first medical device and a second medical device communicate with one another using test signals configured to provide data related to the quality of the communication signal to facilitate optimization of the communication approach. Some methods may be performed during surgery to implant one of the medical devices to ensure adequate communication availability.

Abstract: An Implantable Medical Device (IMD) configured to be implantable in a ventricle of a patient's heart may include a housing, a first electrode secured relative to the housing, a second electrode secured relative to the housing, the second electrode spaced from the first electrode, and circuitry in the housing operatively coupled to the first electrode and the second electrode. The circuitry may be configured to identify a measure of impedance between the first electrode and the second electrode at each of a plurality of times during a cardiac cycle. Each measure of impedance may represent a measure of volume of the ventricle in which the IMD is implanted. In some cases, the circuitry may generate a pacing pulse, the timing of which is based at least in part on the measure of volume of the ventricle at two or more of the plurality of times during the cardiac cycle.

Abstract: Systems and methods for communicating between medical devices. In one example, an implantable medical device comprising may comprise one or more electrodes and a controller coupled to the electrodes. The controller may be configured to receive a first communication pulse at a first communication pulse time and a second communication pulse at a second communication pulse time via the one or more electrodes. The controller may further be configured to identify one of three or more symbols based at least in part on the time difference between the first communication pulse time and the second communication pulse time.

Abstract: Methods, systems and devices for providing cardiac resynchronization therapy (CRT) to a patient using a leadless cardiac pacemaker (LCP) implanted in or proximate the left ventricle of a patient. A setup phase is used to establish parameters in the therapy delivery. In operation, the method and/or device will sense at least one non-paced cardiac cycle to determine a native R-R interval, and then delivers a synchronization pace at an interval less than the native R-R interval followed by a plurality of pace therapies delivered at the R-R interval or a modification thereof.

Abstract: An interrogation system for a medical device includes a memory storing a diagnostic algorithm, a processor configured to run the diagnostic algorithm, and a communication module configured to facilitate data transfer between the interrogation system and the medical device. The diagnostic algorithm is configured to reach a diagnostic conclusion based on data from the medical device. The diagnostic algorithm is configured to iteratively interrogate the medical device for the data from the medical device until the diagnostic algorithm reaches the diagnostic conclusion, each iterative interrogation requesting additional data as compared to prior iterations. The communication module is configured to receive the additional data from the medical device in response to each iterative interrogation. The diagnostic algorithm is further configured to store an indication of the diagnostic conclusion within the memory.

Abstract: Near-field energy transmitters for charging a rechargeable power source of an implantable medical device (IMD). In some cases, the transmitter may include an output driver that may drive a transmit coil such that near-field energy is transmitted to the IMD at a determined frequency. In some cases, the IMD may include a receiving coil that may capture the near-field energy and then convert the near-field energy into electrical energy that may be used to recharge the rechargeable power source. Since the rechargeable power source does not have to maintain sufficient energy stores in a single charge for the entire expected life of the IMD, the power source itself and thus the IMD may be made smaller while still meeting device longevity requirements.

Abstract: A leadless cardiac pacemaker (LCP) is configured to sense cardiac activity and to pace a patient's heart and is disposable within a ventricle of the patient's heart. The LCP MAY include a housing, a first electrode and a second electrode that are secured relative to the housing and are spaced apart. A controller is disposed within the housing and is operably coupled to the first electrode and the second electrode such that the controller is capable of receiving, via the first electrode and the second electrode, electrical cardiac signals of the heart. The LCP may include a pressure sensor and/or an accelerometer. The controller may determine a pace time within a cardiac cycle based at least in part upon an indication of metabolic demand.

Abstract: A ventricular implantable medical device that is configured to detect an atrial timing fiducial from the ventricle. The ventricular implantable medical is configured to deliver a ventricular pacing therapy to the ventricle based on the detected atrial timing fiducial. If the ventricular implantable medical device temporarily fails to detect atrial activity because of noise, posture, patient activity or for any other reason, an atrial implantable medical device may be configured to communicate atrial events to the ventricular implantable medical device and the ventricular implantable medical device may synchronize the ventricular pacing therapy with the atrium activity based on those communications.

Abstract: Regulating cardiac activity may include pacing the patient's heart at a starting pacing rate and instigating an intrinsic heart beat search algorithm that includes pacing at a reduced rate for a period of time and capturing electrical signals representative of cardiac electrical activity while pacing at the reduced rate in order to determine a presence or absence of intrinsic heart beats. If intrinsic heart beats are not detected, the heart may be paced at a further reduced rate for a period of time. If intrinsic beats are detected, the heart may be paced again at the starting pacing rate. This may continue until intrinsic heart beats are detected or until a lower search rate limit is reached. Diagnostic data may be collected at each stage and transmitted to a display device for analysis by a physician or the like.

Abstract: Embodiments herein include systems and methods for detecting, predicting and/or assessing acute kidney injury. In an embodiment, a monitoring system to detect acute kidney injury is included. The monitoring system can include a sensor circuit configured to collect renal data including at least one of systemic renal data, direct renal data, urinary tract data, and renal-relevant extracorporeal data. The monitoring system can also include a memory circuit to store collected renal data, an evaluation circuit to assess renal status, and a telemetry circuit. The evaluation circuit can determine whether acute kidney injury has occurred or is likely to occur by comparing the renal data to at least one of threshold values, personal historical values, patient population values and patterns indicative of acute kidney injury. The evaluation circuit can initiate a warning notification if acute kidney injury has occurred or is likely to occur. Other embodiments are also included herein.

Abstract: Systems and methods for monitoring patient for syncope are discussed. A syncope monitor system can detect a precipitating event associated with a syncope onset, and acquire hemodynamic data in response to the detection of the precipitating event. A syncope analyzer circuit may generate temporal profiles of one or more hemodynamic parameters using the hemodynamic data. The syncope analyzer may use the temporal profiles to detect a syncopal event and to classify the syncopal event into one of a plurality of syncope categories. The detection and classification information may be output to a user or a process.

Abstract: Intermittent delivery of ventricular pacing pulses synchronized to occur during an atrial diastole time period can be used to provide atrial stretch therapy and augment the production and release of atrial natriuretic hormone.