SYSTEM AND METHOD FOR INTRA-BODY COMMUNICATION OF SENSED PHYSIOLOGIC DATA

A system for collecting real-time on-demand measurements. The system includes an implantable sensor that has a power source, a sensing circuit, a communications circuit, a memory, and one or more processors. The sensing circuit senses a physiologic parameter of interest (PPOI) and generates signals indicative of the PPOI. The communications circuit communicates with at least one of an implantable medical device (IMD) or an external device (ED). The one or more processors execute program instructions stored in the memory to collect real-time on-demand measurements by activating the sensing circuit to generate the signals indicative of the PPOI, converting the signals to physiologic data indicative of the PPOI, storing the physiologic data in the memory, and directing the communications circuit to transmit the physiologic data to the at least one of the IMD or the ED.

BACKGROUND

Embodiments of the present disclosure generally relate to methods and devices for communications between implanted sensors, other implanted medical devices within a patient, and external devices outside a patient.

Passive implantable medical sensors are currently available to monitor certain physiologic conditions, such as blood pressure. One example is a pulmonary arterial (PA) pressure sensor. However, passive implantable medical sensors require active patient participation in order to collect the physiologically relevant data and to make the data available to a clinician. For example, PA pressure sensors utilize an external device, outside of the patient body, for supplying energy to the sensors to power the generation and communication of the physiological data. Consequently, the system requires initial patient training and periodic reminders for the patient to utilize the external device for data collection and communication. The physiologic data is analyzed to improve the patient outcome, such as by modifying a treatment of the patient based on the physiologic data generated by the sensor.

The current mechanism, which depends on external devices to power and communicate with the implantable sensor, requires large and highly specialized circuitry within the external device. The circuitry is not available nor easy to integrate in a typical implantable device, such as a pacemaker or cardiac resynchronization therapy (CRT) device. Because user interaction may be required to utilize the external device to activate the passive sensor, the sensor operation may be dependent on patient cooperation and attentiveness. In effect, a sensor may only collect data when it is convenient for the patient, so there may be significant delays between a time at which a physiologic condition of the patient changes and a time in which physiologic data generated by the passive implantable medical sensor indicating that change is communicated for analysis and updating the treatment of the patient based on the change. The physiologically relevant data, that is collected by passive sensor, may not be readily available to other implanted devices such as pacemakers and CRT devices, so the real-time treatment parameter update is not possible.

Furthermore, the size of the passive implantable medical sensors may be limited due to target implant locations within the patient, such as within blood vessels. Due to the size constraint, even if the sensors have an onboard battery, the battery may not be large enough to store sufficient charge to power the physiological data generation and conventional communication operations for an extended period of time.

A need remains for a system and method of communicating sensed physiologic data from an implantable medical sensor for real-time analysis and modification of patient treatment to improve patient outcome, without relying on active patient cooperation or an external energy source to power the sensor at the time of data collection and transmission.

SUMMARY

In accordance with an embodiment, methods, devices and systems are provided that enable implantable sensors such as PA pressure sensors to transmit measured data directly to other implantable medical devices to be analyzed for real-time therapy optimization and disease state diagnosis. The other implantable medical devices may include cardiac resynchronization therapy (CRT) devices, blood glucose monitors, implantable cardiac monitoring devices (ICM), implantable cardioverter defibrillators (ICD), and the like.

In accordance with embodiments herein, an implantable sensor measures a physiologic parameter and generates physiologic data indicative of a value of the physiologic parameter. The sensor transmits the measured physiologic data to a second device, implanted or external, through intra-body communication. The communication mechanism may be radio-frequency (RF), direct wired connection, or wireless conductive communication. The physiologic data is analyzed by the second device, such as an implanted CRT device, a bedside monitoring device, a remote server, or the like, to enhance the therapy delivered to the patient based on the physiologic data. Additionally or alternatively, the physiologic data can be sent from the sensor to a second implantable medical device (IMD) within the patient, such as a CRT device, which transmits the physiologic data externally to an external device outside of the patient. The external device may be a web-enabled device such as a bedside monitor, a hand-held smartphone, a wearable device, or the like, which can store the data in a database and/or communicate the data via a network to a remote server. The implantable sensor includes an onboard power source, such as a battery, which powers the operations of the implantable sensor. The sensor may have a low power internal clock that is employed to cycle the operation of the sensor to reduce power consumption and extend battery life.

In accordance with an embodiment, a system is provided for collecting real-time on-demand measurements. The system includes an implantable sensor. The implantable sensor includes a power source, a sensing circuit, a communications circuit, a memory, and one or more processors. The sensing circuit is configured to sense a physiologic parameter of interest (PPOI) and to generate signals indicative of the PPOI. The communications circuit is configured to communicate with at least one of an implantable medical device (IMD) or an external device (ED). The memory is configured to store program instructions. The one or more processors are coupled to the memory. The program instructions are executable by the one or more processors to collect real-time on-demand measurements by activating the sensing circuit to generate the signals indicative of the PPOI, converting the signals to physiologic data indicative of the PPOI, storing the physiologic data in the memory, and directing the communications circuit to transmit the physiologic data to the at least one of the IMD or the ED.

Optionally, the communication circuit is configured to receive a data collection instruction, and the one or more processors are configured to perform the activating, converting, storing and directing operations in response to the data collection instruction in real-time on-demand. Optionally, the memory is configured to store the physiologic data over a collection period of time, and the one or more processors are configured to perform the directing operation to transmit the physiologic data in real-time at least one of i) on-demand upon request from at least one of the IMD or the ED, or ii) at a time according to a predetermined data transmission schedule.

Optionally, the system also includes the IMD. The IMD is configured to deliver a therapy and to modify at least one parameter of the therapy in response to receiving and analyzing the physiologic data from the implantable sensor. Optionally, the communications circuit is configured to communicate bidirectionally with the IMD through at least one of far field radio frequency wireless communication, conductive communication, or a direct wired connection.

Optionally, the power source is configured to store an amount of energy to supply the sensing circuit, the communications circuit, and the one or more processors for at least a predetermined number of data collection operations and communication sessions. The data collection operations and communication sessions are performed without any external energy delivery.

Optionally, the sensor includes a housing having a hermetically sealed interior cavity that holds the sensing circuit, the memory, the one or more processors, and the communications circuit. The communications circuit further includes a radiofrequency (RF) antenna provided within the interior cavity, and the housing is at least partially composed of a resistive material that is at least partially transparent to RF fields. The RF antenna may be at least one of i) a surface mount chip antenna, or ii) a conductive metallic trace arranged in a serpentine design. The RF antenna may be located on a printed circuit board or on an inner wall of the housing.

Optionally, the sensor includes a first housing portion at a first end of the sensor, a second housing portion at a second end of the sensor opposite the first end, and a flexible cable disposed between and connected to the first and second housing portions. The sensor includes a first electrode of the communications circuit held by the first housing portion and a second electrode of the communications circuit held by the second housing portion. The first electrode is electrically coupled to the second electrode via the flexible cable. The one or more processors are configured to direct the communications circuit to transmit the physiologic data by applying voltage bursts to the first and second electrodes to create a polarized electric field around the sensor.

Optionally, the one or more processors are configured to remain in a sleep mode until transitioning to a wake mode in response to receiving a wake-up instruction from a clock of the implantable sensor. The one or more processors are configured to perform at least one of the activating, converting, storing, and directing operations when in the wake mode. In the sleep mode, the power supply may be configured to supply power to the clock without supplying power to the one or more processors, the sensing circuit, or the communications circuit.

Optionally, the sensing circuit is configured to sense, as the PPOI, at least one of pressure, temperature, respiration, or a body generated analyte (BGA). The signals generated by the sensing circuit may represent electrical signals, for which at least one of voltage, current, capacitance, inductance or resistance varies based on a level of the PPOI.

Optionally, the power source includes a secondary battery that is electrically connected to one of (i) the IMD via a direct wired connection to receive electrical power from the IMD or (ii) an energy harvesting unit of the sensor. The energy harvesting unit includes a coil configured to inductively connect to an external recharge device to transfer electrical power from the external recharge device to the secondary battery via the energy harvesting unit.

In accordance with an embodiment, a method is provided for collecting real-time on-demand measurements. The method includes activating a sensing circuit of an implantable sensor to sense a physiologic parameter of interest (PPOI) and generate signals indicative of the PPOI. The sensing circuit is powered by a power source onboard the sensor. The method includes converting the signals to physiologic data indicative of the PPOI via one or more processors of the sensor, and storing the physiologic data in a memory of the sensor. The method also includes directing a communications circuit of the sensor to transmit the physiologic data to at least one of an implantable medical device (IMD) or an external device (ED).

Optionally, the physiologic data is transmitted to the IMD which delivers a therapy, and the method further comprises modifying at least one parameter of the therapy in response to receiving and analyzing the physiologic data from the communications circuit of the implantable sensor.

Optionally, converting the signals to the physiologic data includes digitizing the signals that are generated to form the physiologic data, and the directing of the communications circuit to transmit the physiologic data is in real-time in accordance with a predetermined schedule or on-demand in response to a request from at least one of the IMD or the ED.

Optionally, the method includes receiving a data collection instruction via the communications circuit. The activating, converting, storing, and directing operations are performed in real-time on-demand in response to receiving the data collection instruction. Optionally, the method includes determining a scheduled time according to a data transmission schedule stored in the memory. The activating, converting, storing, and directing operations are performed in real-time at the scheduled time.

Optionally, the method includes assembling the implantable sensor to include a first housing portion, a second housing portion, and a flexible cable disposed between and connected to the first and second housing portions. The assembling operation includes installing a first electrode of the communications circuit to the first housing portion, installing a second electrode of the communications circuit to the second housing portion, and electrically coupling the first electrode to the second electrode via the flexible cable. The directing operation to direct the communications circuit of the sensor to transmit the physiologic data includes applying voltage bursts to the first and second electrodes to create a polarized electric field around the sensor.

DETAILED DESCRIPTION

The methods described herein may employ structures or aspects of various embodiments (e.g., systems and/or methods) discussed herein. In various embodiments, certain operations may be omitted or added, certain operations may be combined, certain operations may be performed simultaneously, certain operations may be performed concurrently, certain operations may be split into multiple operations, certain operations may be performed in a different order, or certain operations or series of operations may be re-performed in an iterative fashion. It should be noted that, other methods may be used, in accordance with an embodiment herein. Further, wherein indicated, the methods may be fully or partially implemented by one or more processors of one or more devices or systems. While the operations of some methods may be described as performed by the processor(s) of one device, additionally, some or all of such operations may be performed by the processor(s) of another device described herein.

FIG.1illustrates a system101that includes an IMD100, an implantable sensor150, and an external device104implemented in accordance with embodiments herein. The IMD100and the implantable sensor150are implanted within the body of a patient. The external device104is outside of the patient body. The external device104may be a programmer, an external defibrillator, a workstation, a portable computer (e.g., laptop or tablet computer), a personal digital assistant, a cell phone (e.g., smartphone), a bedside monitor, and the like. The IMD100may represent a cardiac monitoring device, a pacemaker, a cardioverter, a cardiac rhythm management device, a defibrillator, a neurostimulator, a leadless monitoring device, a leadless pacemaker, and the like, implemented in accordance with one embodiment of the present invention. The IMD100may be a dual-chamber stimulation device capable of treating both fast and slow arrhythmias with stimulation therapy, including cardioversion, defibrillation, anti-tachycardia pacing and pacing stimulation, as well as capable of detecting heart failure, evaluating its severity, tracking the progression thereof, and controlling the delivery of therapy and warnings in response thereto. Exemplary structures for the IMD100and the implantable sensor150are discussed and illustrated in the drawings herewith.

The IMD100includes a housing106that is joined to a header assembly108that holds receptacle connectors connected to a right ventricular lead130and an atrial lead120, respectively. The atrial lead120includes a tip electrode122and a ring electrode123. The right ventricular lead130includes an RV tip electrode132, an RV ring electrode134, an RV coil electrode136, and an SVC coil electrode138. The leads120and130detect intracardiac electrogram (IEGM) signals that are processed and analyzed as described herein, and also deliver therapies as described herein.

The IMD100may be implemented as a full-function biventricular pacemaker, equipped with both atrial and ventricular sensing and pacing circuitry for four chamber sensing and stimulation therapy (including both pacing and shock treatment). Optionally, the IMD100may further include a coronary sinus lead with left ventricular electrodes. The IMD100may provide full-function cardiac resynchronization therapy. Alternatively, the IMD100may be implemented with a reduced set of functions and components. For instance, the IMD may be implemented without ventricular sensing and pacing.

The implantable sensor150is configured to be implanted at a location remote from the electrodes of the leads120and130. The implantable sensor150may be implanted in a blood vessel, such as an artery or vein. In an embodiment, the sensor150is implanted within the pulmonary artery (PA). The sensor150may be anchored to the vessel wall of a blood vessel using one or more expandable loop wires. The diameter of each loop should be larger than the diameter of target blood vessel in order to provide adequate anchoring force. Optionally, instead of the loop wire, the sensor150may be attached to the end of a self-expandable stent and deployed into the blood vessel through a minimally invasive method. This method may be preferable over the loop wire(s) in situations in which strong anchoring is needed.

Alternatively, the implantable sensor150may be secured to tissue outside of blood vessels. The sensor150may be secured in place by using a fixation screw (e.g., helix) attached to the housing. The screw may anchor the sensor150to patient heart tissue, such as cardiac tissue of the left or right ventricle. The sensor150is configured to sense a physiologic parameter of interest (PPOI) and to generate signals indicative of the PPOI. In a non-limiting example, when the sensor150is disposed within the PA, the sensor150may sense, as the PPOI, blood pressure.

FIG.2illustrates a block diagram of the system101formed in accordance with embodiments herein, showing components of the implantable sensor150. The sensor150comprises a sensing circuit152, a controller154, a power source156, a communications circuit158and a memory160. The controller154includes one or more processors155. The one or more processors155are operably coupled to the memory160. The sensor150includes a housing151that holds and encapsulates the sensing circuit152, the controller154, the power source156, the communications circuit158, and the memory160, to protect these components from the harsh organic environment of the body. The housing151may be hermetically sealed.

The sensing circuit152is configured to sense a physiologic parameter of interest (PPOI) and to generate signals indicative of the PPOI. The sensing circuit152is configured to sense, as the PPOI, at least one of pressure (e.g., blood pressure), cardiac output, temperature, respiration, or a body generated analyte (BGA) (e.g., blood glucose level). The signals generated by the sensing circuit152represent electrical signals. Electrical parameters of the signals, such as voltage, current, capacitance, inductance or resistance, may vary based on a level of the PPOI. The sensing circuit152includes one or more sensing elements that sense the PPOI, and circuitry that generates the electrical signals indicative of the PPOI. In an embodiment, the sensing circuit may include elements such as amplifiers and analog-to-digital converters. The elements of the sensing circuit may create a representation of the PPOI that can be read by the microcontroller.

The controller154may be implemented as a microcontroller unit or another processor configuration. The controller154performs at least some of the operations described herein to collect real-time on-demand measurements by generating physiologic data and communicating the physiologic data to at least a second device, without requiring patient interaction or external energy delivery at the time of data generation and communication. The controller154represents hardware circuitry that includes and/or is connected with the one or more processors155(e.g., one or more microprocessors, integrated circuits, field programmable gate arrays, etc.).

The controller154includes and/or is connected with the memory160, which is a tangible and non-transitory computer-readable storage medium. The memory160stores program instructions (e.g., software) that is executed by the one or more processors155to perform the operations of the sensor150described herein. The memory160additionally may store different information, such as the physiologic data that is generated by the sensing circuit152. The memory160may store the physiologic data until the sensor150transmits the physiologic data to the IMD100and/or the ED104.

In an embodiment, the controller154includes and/or is connected with an internal clock153or timer. The clock153may be used to cycle the sensor150between wake and sleep modes to conserve electrical energy. The controller154may refer to the clock153to determine when to activate the sensing circuit152to generate the signals indicative of the PPOI according to a data collection schedule. For example, if the data collection schedule in the memory160indicates that new physiologic data should be generated at a specific time (e.g., 6 AM) of the current day, then the controller154can utilize the clock153to determine when it is the specific time to activate the sensing circuit152according to the schedule, such that the physiologic data is generated and collected in real-time at specific prescribed times.

The communications circuit158is operably connected to the controller154via conductive elements. The communications circuit158communicates with the IMD100and/or the ED104. The communications circuit158may be communicatively connected to the IMD100via an intra-body bidirectional link, which enables the sensor150to transmit information (e.g., data) to the IMD100and receive information from the IMD100. The communications circuit158may include an RF module157and/or a conductive communication module159. The RF module157includes an antenna for sending and receiving RF signals. The conductive communication module159includes at least two spaced-apart electrodes, connected via a conductive wire or cable, that are powered to create a polarized electric field around the sensor150, as described herein with reference toFIG.5.

The power source156supplies electrical energy to power the operations of the sensor150. The power source156may include one or more secondary (e.g., rechargeable) batteries, one or more primary batteries, one or more capacitors, and/or associated circuitry, such as inductive coils, charging circuits, and the like.

In operation, the controller154may directly convert, or manage conversion of, the signals from the sensing circuit152to digital physiologic data. The controller154may execute the program instructions stored in the memory160to activate the sensing circuit to generate the signals indicative of the PPOI. The controller154may activate the sensing circuit152on-demand in response to receiving a request (e.g., a data collection instruction) from another device or at a prescribed time according to a schedule stored in the memory160. The controller154also executes the program instructions to convert the signals from the sensing circuit152to physiologic data indicative of the PPOI. After converting, the controller154stores the physiologic data in the memory160. In an embodiment, the controller154(e.g., the one or more processors155thereof) are configured to digitize the signals generated by the sensing circuit to form the physiologic data.

The controller154then directs the communications circuit158to transmit at least some of the physiologic data stored in the memory160to the IMD100and/or the ED104. For example, the memory160may store the physiologic data that is recently converted and digitized until the controller154directs the communications circuit158to transmit the physiologic data. The communications circuit158may be directed to transmit the data in real-time in accordance with a predetermined schedule or on-demand in response to a request from at least one of the IMD or the ED. For example, the transmission may be triggered by a stimulus, which may be a determination that it is time for a scheduled data transmission, a receipt of an impromptu, on-demand request from the IMD100and/or the ED104, a determination by the controller154that the PPOI has crossed a threshold value or has changed more than a threshold rate or extent, or the like. The communications of the physiologic data may be controlled according to a predetermined schedule, a request, and/or a detected exceptional value or trend in the measured PPOI.

In an embodiment, the IMD100is utilized as a bridge component to relay communications between the sensor150and the ED104. For example, the controller154may use the communication circuit158to transmit a message within the body of the patient to the IMD100. Upon receipt, the IMD100may retransmit the message (or generate a new message that includes the content of the received message) to the ED104. The IMD100may also relay messages received from the ED104to the sensor150. Optionally, the sensor150may have sufficient onboard power to communicate information to the ED104and/or receive information from the ED104without utilizing the IMD100as a relay.

In an embodiment for pressure sensors, the ED104includes an atmospheric pressure gauge that monitors atmospheric pressure either periodically or on-demand. The sensor150produces pressure data along with a time stamp, or time synchronized relative to ED104or IMD100. The on-demand or time-stamped atmospheric pressure measurement of ED104can be used to convert time-stamped or time synchronized absolute blood pressure measured by the sensor150to relative blood pressure, upon time-synchronization between the sensor150and the ED104. For example, to help with time-synchronization, the ED104can instruct the sensor150or IMD100to collect the pressure data when the patient is near-by the ED150. In another example, the pressure measurement time of sensor150and ED104can be pre-scheduled relative to the sleep schedule of the patient (e.g., 3 AM), to reduce the variability of blood pressure measurements attributable to changes in patient posture.

In accordance with embodiments described herein, the intra-body communication between the sensor150and the IMD100provides various benefits. For example, the PPOI is measured by the sensor150and the physiologic data is transferred to the IMD100. The IMD100may provide a treatment for the patient. When the IMD100is a CRT/pacemaker, the treatment may be stimulation therapy. When the IMD100is an implantable glucose dispenser, the treatment may be a dose of insulin. Communication between the IMD100and the sensor150enables autonomous and prompt adjustment of treatment parameters based on real-time feedback from the PPOI. For example, in response to a change in the PPOI, the system101enables quicker modification of the treatment parameters provided by the IMD100than a conventional system that requires the patient to periodically activate the sensor via an external energy source. The earlier adoption of a modified treatment improves patient outcome because the treatment is tailored and timely for the current patient conditions.

The IMD100is able to timelier modify the treatment parameters, relative to the conventional system that requires operator-involved sensor activation to collect a measurement, because the sensor150may autonomously collect and communicate updated, real-time physiologic data. The data collection and communication may occur more often and/or with less delay after a change in the PPOI than relying on patient interaction to activate the sensor. For example, the sensor150may collect measurements and transmit the physiologic data on a schedule that is more reliable and/or more frequent than schedules that rely on patient involvement. Furthermore, the treatment parameters may be quickly modified because the sensor150can autonomously provide on-demand updates to the IMD100and/or ED104. Thus, instead of requiring the ED104or another device to prompt the patient or another person to activate the sensor for acquiring an updated measurement, the IMD100and/or ED104can simply communicate a request or instruction to the sensor150whenever the requesting device desires updated physiologic data, and the sensor150responds with a real-time update. Optionally, the sensor150may also provide unsolicited and unscheduled updates to the IMD100and/or ED104in certain situations. For example, the sensor150may collect and store data measurements at a greater frequency than the data is typically transmitted to the IMD100and/or ED104. Optionally, the controller154may monitor the PPOI over time and determine when a value of the PPOI crosses a designated threshold and/or changes at a rate or extent that is outside of an expected rate or extent of change. In response to making this determination, the sensor150may notify the IMD100and/or ED104, even if the notification occurs outside of a scheduled communication session and is not prompted by a received request for updated physiologic data, and provides the IMD100and/or the ED104early access to information that could require a medical response, thereby improving the patient outcome.

The intra-body communication also overcomes difficulties with prior implantable sensors, the size of which was limited due to the target implant locations, such as blood vessels. The size constraints limited the size of the batteries and other energy sources onboard the sensor, which also limits the energy storage capability. The limited energy storage in prior sensors limited the operational lifespan of the sensors (at least between charging sessions), and also limited the distance that the sensor could communicate, which created problems for direct communication to the external device such as a bedside monitoring device. In accordance with at least some embodiments herein, these issues are addressed by energy conservation and the use of the IMD100as a bridge or relay communication device between the sensor150and the ED104. For example, the physiologic data from the sensor150is sent to the IMD100, which has an established communication link with the ED104. The implantable sensor150according to embodiments herein is implemented in a small form factor to retain the ability to implant the sensor150in narrow locations, such as blood vessels. The sensor150can increase reliability and consistency of physiologic data collection by autonomously collecting physiologic data, independent of patient interaction, which promotes a better patient outcome.

FIG.3aillustrates a side cross-sectional view of one example configuration for the implantable sensor150formed in accordance with embodiments herein. In the illustrated embodiment, the sensing circuit152includes a parallel-plate pressure-sensitive capacitor161. The capacitor161includes a first capacitor plate166and a second capacitor plate168that are parallel and spaced apart from one other by a predetermined distance. The plates166,168are electrodes. The first capacitor plate166may be mounted to a lower surface of a first portion of the housing151, and the second capacitor plate168is mounted to an upper surface of a second portion of the housing151. In the illustrated embodiment, the housing151is defined by an upper wafer162and a lower wafer164that couple together to define and enclose an interior cavity163. The first capacitor plate166is disposed on the upper wafer162, and the second capacitor plate168is mounted on a shelf170of the lower wafer164. The shelf170is spaced a predetermined distance from the lower surface of the upper wafer162to space the first and second capacitor plates166,168a predetermined distance from one another. The upper wafer162and the lower wafer164may be composed of a dielectric material. The upper and lower wafers162,164are fused together to form a monolithic housing that seals the components within the interior cavity163from the harsh biological environment outside of the housing151. The housing151may be flexible. For example, a portion of the upper wafer162may have a pressure sensitive deflective region underlying at least a portion of the first capacitor plate166, whereby the deflective region deflects in response to changes in ambient pressure in the medium in which the sensor150is disposed.

A conductive element171, such as a gold wire, is electrically connected to the second capacitor plate168and extends from the second capacitor plate168to a printed circuit board (PCB)172of the sensor150. The controller154is disposed on the PCB172. The conductive element171electrically connects the second capacitor plate168to the PCB172to conduct signals indicative of the PPOI to the controller154. The conductive element171may be flexible. Alternatively, the conductive element171may be inflexible. The sensing circuit152may include an inductor formed from one or more windings of a conductive material. The inductor may be electrically coupled to one of the first and second capacitor plates166,168.

In the illustrated embodiment, the PCB172is connected to the power source156, which may be a battery. The memory160is disposed on the PCB172along with a surface mount resistor or capacitor174.

In the illustrated embodiment, the sensor150includes an antenna176which represents a component of the communications circuit158. More specifically, the antenna176is a component of the RF module157(shown inFIG.2), and the antenna176is used to send and receive RF wireless communication signals. The antenna176is mounted on the upper wafer162(e.g., lid or upper housing portion) in the illustrated embodiment.FIG.3billustrates a top-down view of the sensor150according to an embodiment. The antenna176is shown as a conductive metallic trace arranged in a serpentine design of connected linear line segments. The antenna176may have another shape, such as spiral, in another embodiment. The size, design, and placement of the antenna176optionally may be selected to cause the antenna176to resonate at a predetermined target communication frequency, to increase the transmission efficiency and output amplitude relative to the antenna not resonating at the target communication frequency.

The antenna176inFIG.3ais secured to an inner surface or wall of the upper wafer162that faces towards the interior cavity163and the lower wafer164. As such, the antenna176is within the interior cavity163. The upper wafer162may be at least partially translucent to enable viewing the antenna176through the upper wafer162in the top-down view ofFIG.3b. In an alternative embodiment, the antenna176may be disposed on an inner surface or wall of the lower wafer164, integrated within the housing151itself such as within a thickness of the upper wafer162, or disposed on an outer (e.g., exterior) surface of the upper wafer162. For example, the antenna176may be a ceramic antenna that is sandwiched (or embedded) between layers of the housing151, such as within the thickness of the upper wafer162or the thickness of the lower wafer164.

The antenna176is electrically connected to the PCB172via a second conductive element178. The second conductive element178may be similar to the conductive element171. For example, the second conductive element178may be a gold wire or another flexible element. The controller154may communicate the physiologic data to the IMD100and/or the ED104by generating a message that is conveyed via the second conductive element178to the antenna176and emitted by the antenna176as an RF communication. The antenna176also receives RF messages and conveys the received messages to the controller154for analysis. The housing151may be at least partially composed of an electrically resistive material that is at least partially transparent to RF fields. The RF signals may propagate through the upper wafer162with insubstantial interference or loss. The electrically resistive material of the housing151may be glass, fused silica, ceramic, resistive metals, silicone, and the like.

The size of the antenna structure may be designed to be a fraction of a wavelength of the target communication frequency (ex, ½ or ¼ or ⅛ and etc. of wavelength) or integer multiples of wavelength (1×, 2× or 3× and etc. of wavelength) in order to efficiently broadcast and receive a signal. In order to increase the electrical size of the antenna within the limited physical size of the sensor150(i.e. to increase antenna efficiency), the antenna conductive traces may be covered by high dielectric materials. This changes the effective wavelength of the antenna. Encompassing the conductive traces in layers of high dielectric will greatly enhance the effective wavelength thus making the antenna more efficient at the frequency of interest. Although the antenna176is a conductive metallic trace in the illustrated embodiment, the antenna may be a surface mount chip antenna, or conductive traces patterned directly on the PCB172to resonate at the frequency of interest, in alternative embodiments.

Optionally, the RF module157(shown inFIG.2) of the communication circuit158may utilize a communication protocol such as Bluetooth low-energy (BLE). The BLE protocol also has the advantage that the physiologic data can be shared with cell phones, tablets and other consumer computer devices that are Bluetooth enabled without converting formats. Alternatively, lower frequency RF communication, such as 400 MHz MICS, or other frequencies bands in the ISM could be used to communicate to other sensors or devices.

FIG.4aillustrates a side cross-sectional view of another example configuration for the implantable sensor150formed in accordance with embodiments herein. The sensor150inFIG.4aonly differs from the sensor150inFIGS.3aand3bwith respect to the communications circuit158. The sensor150utilizes RF wireless communication with the IMD100and/or ED104without the presence of the discrete antenna176shown inFIGS.3aand3b. For example, there is no discrete antenna mounted to the upper wafer162. Instead, one or more existing conductive sensing elements of the sensor150are utilized as an antenna to send and receive RF signals.

In the illustrated embodiment, one or both of the capacitor plates166,168of the parallel-plate pressure-sensitive capacitor161function as an antenna. The capacitor plate(s)166,168may be designed to resonate at a predetermined target communication frequency. The capacitor161still performs the PPOI sensing. As a result, the capacitor161represents a component of both the sensing circuit152and the communications circuit158. Within the sensing circuit152, the capacitor161may function as a pressure sensing element.

FIG.4bis a top-down view of the implantable sensor150shown inFIG.4aaccording to an embodiment. Without the presence of the antenna176, the controller154and the memory160are visible through the light transmissible (e.g., translucent) upper wafer162.

FIG.4cis an enlarged top-down view of the parallel-plate pressure-sensitive capacitor161according to an embodiment. The capacitor plates166,168are stacked vertically, such that the first or upper plate166is above and at least partially overlaps the second or lower plate168. The plates166,168may be on the order of 0.5 to 3.5 mm in one dimension and 1 to 6 mm in a second dimension that is orthogonal to the first dimension. Optionally, the second or lower plate168may have a greater surface area than the first or upper plate166.

In an alternative embodiment, the housing may be composed at least partially of an electrically conductive material that can cause undesired shielding and interference, effectively blocking the RF field. In such an embodiment, the sensor150may include a hermetic electrical feed-through that extends through the conductive housing from the controller and/or PCB within the interior cavity to an antenna external to the sensor housing. In this case, conductive objects used to affix the sensor to the patient tissue, such as one or more wire loops, may be used as antenna elements. During use, an RF signal from inside the sensor may be conveyed to the external antenna element via the electrical feed-through. The wire loop or loops may be electrically insulated to reduce antenna loss due to electrical loading of conductive organic liquid such as blood.

FIG.5illustrates a perspective view of another example configuration for the implantable sensor150formed in accordance with embodiments herein. The sensor150in the illustrated embodiment uses the conductive communication module159(shown inFIG.2) of the communications circuit158to communicate with the IMD100. The conductive communication of physiologic data utilizes at least two exposed electrodes that are spaced apart from one another to create a polarized electric field around the sensor150, and the physiologic data is transmitted via the electric field. Optionally IMD100is used as a link to relay information received from the sensor150to the ED104.

The sensor150has an elongated, barbell shape in the illustrated embodiment. For example, the sensor150includes a first housing portion180at a first end182of the sensor150, a second housing portion184at a second end186of the sensor150opposite the first end182, and a narrow intermediate segment disposed between and connected to the first and second housing portions180,184. The intermediate segment may be defined by a flexible cable188. The communications circuit158includes a first electrode190held by the first housing portion180and a second electrode192held by the second housing portion184. The first electrode190is electrically coupled to the second electrode192via the flexible cable188, which includes one or more insulated conductors (e.g., wires). The other components of the sensor150that are shown and described with reference toFIG.3a, other than the antenna176, may be contained within one or both of the housing portions180,184. The components may be distributed between the two housing portions180,184. In one example, the power source156is disposed within the first housing portion180. The second housing portion184may contain the sensing circuit152(e.g., parallel-plate capacitor161) and the electronics on the PCB172, including the controller154and the memory160.

The electrodes190,192are exposed to the organic environment of the patient, such that patient tissue and/or fluid physically contacts the electrodes190,192. The sensor150transmits the digital physiologic data by applying voltage bursts to the two electrodes190,192, which creates polarized electric field around the implanted sensor150. The voltage bursts may be one or more series of short bursts. The bursts may be powered by the power source156, such as a battery. The IMD100within the patient may receive this electric field, that is based on the bursts, using existing leads120,130or electrodes (e.g.,122,123,132,134,136,138inFIG.1) exposed to the body. Since the data transmission is based on the short bursts of pulse voltage with a negligible current, the power consumption for the sensor150is minimal. The bursts may be on the order of microseconds. The IMD100may receive the transmitted physiologic data through an existing cardiac monitoring channel by sensing the polarized electric field generated by the electrodes190,192. Additional information about conductive communication is described in U.S. Pat. No. 9,168,383, which is incorporated by reference herein.

Because the electrodes190,192are exposed to the organic material of the patient, the electrodes190,192are composed at least partially of a biocompatible and corrosion-resistant material. The electrode material may include one or more metals, such as platinum, platinum-iridium, titanium, MP35N (e.g., an alloy of nickel, cobalt, chromium, and molybdenum), and/or the like.

The flexible cable188lengthens the separation distance between the two electrodes190,192, which improves data delivery performance. The separation distance between the first electrode190and the second electrode192may be at least 0.5 inches. For example, the separation distance may be at least 0.5 inches and no greater than 3 inches. Increasing the separation distance between the electrodes190,192to at least 0.5 inches can increase the performance and efficiency of the intra-device communications. For example, an increase in the separation distance may provide a bump in the amplitude or energy level of the electric field located father away from sensor without increasing the power consumption of the sensor150, thereby increasing communication distance between the sensor150and the IMD100. The flexible cable188is used to achieve this separation while enabling the deliverability of the sensor150during implant using a conventional catheterization process. The cable length of the cable188can be adjusted depending on the energy budget of the power source156. In an alternate embodiment, the housing portions180and184can be combined into a single housing. In this case, one end of the cable188is electrically connected to the combined single housing that includes the electrode192in one end, and the other end of the cable188is terminated with the electrode190. This arrangement still provides separation between two electrodes for efficient communication.

In an alternative embodiment, instead of using wireless communication, the sensor150may have a direct wired connection to the IMD100. For example, the sensor150can be connected directly to other implantable medical devices via one or more wires. A first wire may provide power and data communication, and a second wire may provide the return path. Alternatively, the one wire could be used with one conductive electrode (e.g.,190or192) on each of the sensor150and the IMD100. In this case the electrode would serve as either the return path or the power/data communication path.

Reference is now made to the power source156shown inFIGS.2and3awhich powers the operations of the sensor150, such as data generation and transmission. In one embodiment, the power source156includes at least one primary battery. The primary battery may have sufficient energy density and charge capacity to support the lifetime of the sensor150, particularly if actions are taken to conserve power consumption, as described below. The primary battery may have an electrochemical composition that includes lithium ion or lithium monofluoride (CFx).

In another embodiment, the power source156includes at least one secondary or rechargeable battery. When the secondary battery is at least partially depleted, external power can be used to charge the secondary battery. For example, the controller154may determine, based on electrical sensor data, when the remaining charge stored within the battery drops to or beyond a preset low voltage or energy threshold. In response, the controller154may communicate a notification to the IMD100and/or the ED104that a recharge session for the sensor150is necessary.

In a first example, the power source156includes an energy harvesting unit in conjunction with the secondary battery and used to support recharge of the secondary battery. The energy harvesting unit includes a coil. The coil inductively connects to an external recharge device to transfer electrical power (e.g., electric current) from the external recharge device to the secondary battery via the energy harvesting unit. The external recharge device may include an external device coil that provides power. The energy harvesting unit may include AC-DC rectification with an optional voltage multiplier electrically coupled to the battery. To support the extended recharge process time of a few mins to hours, for non-direct wired systems, the external recharge coil can be configured in the form of the body pads, a patch taped to the surface of body or a wearable vest/band/belts. Once charged, the secondary battery stores a sufficient amount of energy to successfully supply power to the sensing circuit152, the controller154, and the communications circuit158for at least a predetermined number, greater than one, of data collection operations and communication sessions. As a result, the data collection operations and communication sessions are performed by the sensor150between recharge sessions, without any patient interaction or external energy delivery. The predetermined number may be in the hundreds or thousands.

In the embodiment described above in which the sensor150has a direct wired connection to the IMD100, the at least one secondary battery of the sensor150can recharge by receiving electrical energy directly from the IMD100. The IMD100is larger than the sensor150and may store more electrical energy onboard than the sensor150. The IMD100may have sufficient electrical energy to power the operations of the IMD100as well as recharge the secondary battery of the sensor150. The IMD100may periodically send power to the sensor150from its own power source, usually a primary battery, to keep the sensor150active. The recharge session may take place over the same communication lines as the data communication.

The secondary batteries may have an electrochemical composition that includes lithium ion, lithium ion polymer (Li-poly), or the like. Optionally, the batteries may be or include thin film batteries that can be fabricated in a planar process.

In order to extend the operational lifetime of the sensor150, the controller154operates the sensor150according to a scheme designed to limit power consumption and conserve charge. For example, the sensor150performs data collection operations and communication sessions. During a data collection operation, the sensing circuit152senses the PPOI and generates the signals indicative of the PPOI. The controller154may digitize the signals generated by the sensing circuit152to form the physiologic data, and then store the digital physiologic data in the memory160. The signals that are stored for each data collection operation represent the physiologic data generated over a collection period of time. During the communication session, the communications circuit158is controlled to transmit the physiologic data from the memory160to the IMD100and/or the ED104. Both the data collection and communication operations require power from the power source156.

In an embodiment, the controller154conserves power by limiting the performance of each of the data collection operations and communication sessions to designated times according to predetermined schedules and/or requests received from authorized devices, such as the IMD100and/or the ED104. The data collection operation refers to collecting real-time on-demand measurements, and includes activating the sensing circuit152to generate the signals indicative of the PPOI, converting the signals to physiologic data indicative of the PPOI, and storing the physiologic data in the memory160. The communication session refers to directing the communications circuit158to transmit at least some of the physiologic data stored in the memory160to the IMD100and/or ED104. The memory160may store a data collection schedule that identifies specific times at which the data collection operation should be performed, or a designated interval or frequency between data collection operations. The memory160may also store a data transmission schedule that identifies specific times at which the stored data should be communicated to the IMD100and/or the ED104, or a designated interval or frequency between communication sessions. The controller154may abide by the schedules based on the low power clock153. For example, absent a specific on-demand request for data collection or transmission or a detection by the controller154in real-time that the value of the PPOI is outside of a preferred range, the controller154may use the clock153to only perform the data collection operations and/or the communication sessions at the times specified in the predetermined schedules.

In an embodiment, the data collection operations may be scheduled to occur more frequently than the communication sessions. As such, after a first communication session in which the data stored in the memory160is extracted and transmitted, several data collection operations may occur before the subsequent, second communication session in the data transmission schedule. The data may aggregate in the memory160over a collection period of time until it is time for the next communication session or a transmission request is received from the IMD100and/or ED104.

The other stimulus for performing the data collection operation and/or the communication session is receipt of a specific request for an on-demand update. For example, the sensor150may receive a data collection instruction from the IMD100or the ED104. In response to receiving a data transmission instruction, the controller154retrieves physiologic data from the memory160and transmits the physiologic data, via the communications circuit158to the IMD100and/or ED104. Optionally, the controller154may perform a data collection operation to generate new physiologic data, and then store the new physiologic data in the memory160, even if it is not yet time to collect new data according to the schedule. The physiologic data that is retrieved from the memory160includes the new physiologic data that is generated after receiving the data collection instruction. The controller154directs the communications circuit158to transmit the new physiologic data to the IMD100and/or ED104responsive to the data collection instruction, such that the requesting device receives updated measurements in real-time and on-demand, without requiring human interaction or an external energy transfer to the sensor150between the time at which the instruction is received and the time at which the new physiologic data is transmitted.

To reduce power consumption and increase the longevity of the implantable sensor150, the low power clock153can be used to cycle the sensor150between wake and sleep modes of operation. In the sleep mode, most of the components of the sensor150are inactive and draw little to no power from the power source156. For example, the power source156may only supply power to the clock153, which is a low power device. The one or more processors155, the sensing circuit152, and/or the communications circuit158may not receive power from the power source156during the sleep mode. The clock153may provide a wake-up instruction to the one or more processors155and other components, for transitioning the sensor150to the wake mode, in response to determining that it is a scheduled time to perform a data collection operation and/or a communication session. Even in the sleep mode, the communications circuit158may be configured to sense and receive messages, such as requests to collect data and/or transmit data. The sensor150transitions to the wake mode in response to receiving and verifying the receipt of such a request. After performing the scheduled and/or requested tasks, the sensor150may return to the sleep mode.

The implantable sensor can be in the low power sleep mode for most of the time, while only the timer (e.g., clock153) is running to wake-up the controller154in the predetermined time interval. In this scheme, the operational duration and occurrence of relatively power-demanding activities is reduced to extend energy storage life.

Optionally, the operating schedule of the sensor150may be synchronized to a schedule of the IMD100and/or ED104that communicates with the sensor150to reduce system-wide power consumption. For example, internal timing intervals in the devices may be synced so that the communication session of the sensor150may occur at a common time period as the listening for data signals from a communication device onboard the IMD100. As a result, the communication function in both sides is enabled only for a short amount of time, such as at a designated frequency per day according to a predetermined schedule. The overall energy consumption of the system101can be reduced through this synchronization.

When the IMD100receives the physiologic data from the sensor150, the IMD100analyzes the data. If the data indicates a change in a physiologic parameter or condition that is outside of a designated range, then the IMD100may modify at least one setting or characteristic of a therapy delivered to the patient based on the change. For example, the IMD100may modify the therapy by increasing or decreasing an amplitude or frequency of stimulation pulses administered to the patient. The IMD100may also modify therapy by switching to defibrillation shock therapy from pacing therapy, or vice-versa.

FIG.6is a flow chart200of a method for intra-body communications from an implantable medical sensor according to an embodiment. The method may include additional steps than shown inFIG.6, fewer steps than shown inFIG.6, and/or different steps than shown inFIG.6. Furthermore, the order of the steps presented inFIG.6is not a limitation unless one step is specifically described as following or based on another step.

Referring toFIGS.1through5, the method begins at202, where the implantable sensor is active to collect real-time on-demand measurements. The sensor is active to collect the measurements without any patient action or intervention. The measurements are collected in real-time contemporaneous with normal or abnormal episode occurrences (e.g., a sinus rhythm or an arrhythmia). The sensor operates on-demand, in that the sensor activates the measurement operation without patient action or intervention. For example, the sensor may be activated by a data collection instruction received from the IMD or ED. Additionally or alternatively, the sensor may be activated based on a data collection schedule. The data collection schedule may be stored in the sensor, in the IMD or in the ED. At202, the controller154activates a sensing circuit152of the implantable sensor150to collect the real-time on-demand measurements. Specifically, the sensing circuit152is activated to sense a physiologic parameter of interest (PPOI). The sensing circuit152is powered by a power source156onboard the sensor150. The PPOI may be pressure, temperature, respiration, a BGA, or the like.

At204, signals indicative of the PPOI are generated. The signals may be generated by the sensing circuit152. The sensing circuit152may include a parallel-plate capacitor161. The signals may be electrical signals for which a voltage, current, impedance, capacitance, or inductance varies based on a level of the PPOI.

At206, the signals are converted to physiologic data indicative of the PPOI via one or more processors155of the sensor150. The one or more processors155may convert the signals generated by the sensing circuit152to the physiologic data by digitizing the signals to form the physiologic data. At208, the physiologic data is stored in a memory160of the sensor150, at least temporarily. The memory160may store the physiologic data until the one or more processors155direct a communications circuit158to transmit the physiologic data.

At210, the communications circuit158of the sensor150is directed to transmit the physiologic data to an implantable medical device (IMD)100and/or an external device (ED)104. The communications circuit158may be directed (e.g., via the one or more processors155) to retrieve the physiologic data from the memory160and transmit the physiologic data to another device. The transmission may be performed in response to receiving a request by the IMD100and/or the ED104. Furthermore, the communications circuit158may be prompted to transmit the physiologic data in response to an internal clock153indicating that it is time to transmit the physiologic data according to a predetermined schedule that is stored in the memory160.

At212, a determination is made whether the physiologic data that is transmitted indicates a change that prompts a modification of treatment provided by the IMD100to the patient. The change may be a PPOI value that falls outside of a designated range, such as above or below respective thresholds. If the determination is in the affirmative, then flow proceeds to214and at least one parameter of the therapy provided by the IMD100is modified based on the physiologic data received from the communications circuit158of the implantable sensor150. If there is no change or the change is minor and within the designated range, then the determination at212is in the negative and flow proceeds to216in which the current treatment provided by the IMD100to the patient is maintained.

FIG.7shows a block diagram of the IMD100according to an embodiment. The IMD100shown inFIGS.1and2is not limited to the features described in this embodiment. The housing106or case of the IMD100holds the electronic and/or computing components. The housing106further includes a connector (not shown) with at least one terminal52and optionally additional terminals54,56,58,60. The terminals may be connected to electrodes that are located in various locations within and about the heart, such as on the electrodes122,123,132,134,136,138on the leads120,130(shown inFIG.1). The electrodes may include various combinations of ring, tip, coil, shocking electrodes, and the like.

The IMD100includes a programmable microcontroller20that controls various operations of the IMD100, including cardiac monitoring and stimulation therapy. Microcontroller20includes a one or more processors (e.g., a microprocessors or equivalent control circuitry), RAM and/or ROM memory, logic and timing circuitry, state machine circuitry, and I/O circuitry. Microcontroller20includes an arrhythmia detector34that is configured to cardiac activity data to identify potential atrial fibrillation (AF) episodes as well as other arrhythmias (e.g., tachycardias, bradycardias, asystole, etc.).

An electrode configuration switch26is optionally provided to allow selection of different electrode configurations under the control of the microcontroller20. The electrode configuration switch26may include multiple switches for connecting the desired electrodes to the appropriate I/O circuits, thereby facilitating electrode programmability. The switch26is controlled by a control signal28from the microcontroller20. Optionally, the switch26may be omitted and the I/O circuits directly connected to a housing electrode.

The IMD100may include a chamber pulse generator22that generates stimulation pulses for connecting the desired electrodes to the appropriate I/O circuits, thereby facilitating electrode programmability. The pulse generator22is controlled by the microcontroller20via control signals24. The IMD100includes a sensing circuit44selectively coupled to one or more electrodes that perform sensing operations through the switch26to detect cardiac activity. The sensing circuit44may include dedicated sense amplifiers, multiplexed amplifiers, or shared amplifiers. The sensing circuit44may operate in a unipolar sensing configuration or a bipolar sensing configuration. The output of the sensing circuit44is connected to the microcontroller20which, in turn, triggers, or inhibits the pulse generator22in response to the absence or presence of cardiac activity. The sensing circuit44receives a control signal46from the microcontroller20for purposes of controlling the gain, threshold, polarization, and timing of any blocking circuitry (not shown) coupled to the sensing circuit.

The IMD100further includes an analog-to-digital A/D data acquisition system (DAS)84coupled to one or more electrodes via the switch26to sample cardiac signals across any pair of desired electrodes. The A/D DAS84is controlled by a control signal86from the microcontroller20.

The IMD100is further equipped with a communication modem (modulator/demodulator) or circuit40to enable wireless communication. The communication circuit40enables timely and accurate data transfer directly between the IMD100and the sensor150and/or between the IMD100and the external device104. In an embodiment, the communication circuit40receives physiologic data, representative of a PPOI, that is generated and communicated by the implantable sensor150. The communication circuit40conveys the physiologic data to the microcontroller20for analysis and potentially updating one or more treatment settings or parameters provided by the IMD100to the patient based on the newly received physiologic data. The wireless communication link with the external device104also enables the IMD100to communicate the physiologic data, or a message based on the physiologic data, to one or more external devices to facilitate access by physicians and/or patients to the data generated by the sensor150.

The communication circuit40may utilize radio frequency (RF), Bluetooth, or Bluetooth Low Energy telemetry protocols. The signals are transmitted in a high frequency range and will travel through the body tissue in fluids without stimulating the heart or being felt by the patient. The communication circuit40may be implemented in hardware as part of the microcontroller20, or as software/firmware instructions programmed into and executed by the microcontroller20. Alternatively, the circuit40may reside separately from the microcontroller20as a standalone hardware component.

The microcontroller20is coupled to a non-transitory data storage device, referred to herein as memory device88, by a suitable data/address bus62. The memory device88stores programmable operating parameters used by the microcontroller20and/or data associated with the detection and determination of arrhythmias.

The IMD100optionally includes one or more physiologic sensors70that are utilized by the microcontroller20to adjust treatment settings or parameters. The physiologic sensors70may sense changes in pacing stimulation rates, changes in cardiac output, changes in the physiological condition of the heart, and/or diurnal changes in activity (e.g., detecting sleep and wake states). Examples of physiological sensors70might include sensors that, for example, sense respiration rate, pH of blood, ventricular gradient, activity, body movement, position/posture, minute ventilation (MV), and/or the like.

The battery72provides operating power to all of the components in the IMD100. The battery72is capable of operating at low current drains for long periods of time, and is capable of providing a high-current pulses (for capacitor charging) when the patient requires a shock pulse (e.g., in excess of 2 A, at voltages above 2 V, for periods of 10 seconds or more).

The IMD100further includes an impedance measuring circuit74, which can be used for many things, including sensing respiration phase. The IMD100may be further equipped with a telemetry circuit64that can selectively communicate with an external device, such as the device104, when connected via a physical (e.g., wired) communication link. The IMD100includes a shocking circuit80controlled by control signals82generated by the microcontroller20. The shocking circuit80generates shocking pulses of low (e.g., up to 0.5 joules), moderate (e.g., 0.5-10 joules), or high energy (e.g., 11 to 40 joules), as controlled by the microcontroller20. In an alternative embodiment in which the IMD100senses and monitors cardiac activity without administering stimulation therapy, the IMD100may lack the pulse generator22and the shocking circuit80.

The microcontroller20may include other dedicated circuitry and/or firmware/software components, such as a timing control (module)32and a morphology detector (module)36. The timing control32is used to control various timing parameters, such as stimulation pulses (e.g., pacing rate, atria-ventricular (AV) delay, atrial interconduction (A-A) delay, ventricular interconduction (V-V) delay, etc.) as well as to keep track of the timing of RR-intervals, refractory periods, blanking intervals, noise detection windows, evoked response windows, alert intervals, marker channel timing, and the like. The morphology detector36is configured to review and analyze one or more features of the morphology of cardiac activity signals, such as the morphology of detected R waves to determine whether to include or exclude one or more beats from further analysis.

The embodiments described herein provide an implantable medical sensor that has a small form factor designed to enable the sensor to be implanted within small volumes, such as within a blood vessel. The sensor includes an onboard power source that powers the generation and transmission of physiologic data representative of a PPOI. The physiologic data is transmitted from the sensor to another device, which may be another implanted device within the same patient (e.g., an IMD). The sensor is able to accomplish such operation with a power source that fits within the small form factor by using various power-conservation techniques. For example, the sensor may function in a low-power sleep mode most of the time except when prompted, via a clock according to a schedule or via a received request, to wake in order to collect and/or transmit additional physiologic data. Furthermore, the sensor may utilize an IMD as a communication bridge or relay to avoid consuming energy on transmitting the physiologic data directly from the sensor to an external device. In addition, the power source of the sensor may be rechargeable, such that the power source can charge when implanted, to prolong the operational lifespan of the sensor within the patient. A technical benefit of the implantable medical sensor is the lack of reliance on patient involvement to collect the physiologic data. The sensor may autonomously operate, which can provide more reliable and consistent real-time data updates than relying on active participation of the patient. The sensor may provide real-time on-demand updates upon request. The reliable, consistent data updates and on-demand updates can improve the patient outcome by enabling more timely treatment modifications based on measured changes in physiologic condition of the patient.

In an embodiment, a method for collecting real-time on-demand measurements includes assembling an implantable sensor to include a power source, a sensing circuit, a communications circuit, a memory, and one or more processors. The sensing circuit is configured to sense a physiologic parameter of interest (PPOI) and to generate signals indicative of the PPOI. The communications circuit is configured to communicate with at least one of an implantable medical device (IMD) or an external device (ED). The memory is configured to store program instructions, and the one or more processors are coupled to the memory. The method also includes collecting, via the one or more processors executing the program instructions, real-time on-demand measurements. The measurements are collected by activating the sensing circuit to generate the signals indicative of the PPOI, converting the signals to physiologic data indicative of the PPOI, storing the physiologic data in the memory, and directing the communications circuit to transmit the physiologic data to the at least one of the IMD or the ED.

The method may include receiving a data collection instruction, and performing the activating, converting, storing and directing operations in response to the data collection instruction in real-time on-demand.

The method may include storing a data collection schedule in the memory, and performing the activating, converting, and storing operations based on the data collection schedule in real-time.

The method may include storing the physiologic data over a collection period of time, and performing the directing operation to transmit the physiologic data in real-time at least one of i) on-demand upon request from at least one of the IMD or the ED, or ii) at a time according to a predetermined data transmission schedule.

The method may include delivering a therapy, via an IMD, and modifying at least one parameter of the therapy in response to receiving and analyzing the physiologic data from the implantable sensor.

The method may include communicating bidirectionally with the IMD through at least one of far field radio frequency wireless communication, conductive communication, or a direct wired connection.

The method may include storing, in the power source, an amount of energy to supply the sensing circuit, the communications circuit, and the one or more processors for at least a predetermined number of data collection operations and communication sessions, and performing the data collection operations and communication sessions without any external energy delivery.

The method may include assembling the sensor to include a housing having a hermetically sealed interior cavity that holds the sensing circuit, the memory, the one or more processors, and the communications circuit, including a radiofrequency (RF) antenna of the communications circuit. The housing at least partially composed of a resistive material at least partially transparent to RF fields. Optionally, the RF antenna is at least one of i) a surface mount chip antenna, or ii) a conductive metallic trace arranged in a serpentine design. The assembling operation may include locating the RF antenna on a printed circuit board or on an inner wall of the housing.

The method may include assembling the sensor to include a first housing portion at a first end of the sensor, a second housing portion at a second end of the sensor opposite the first end, and a flexible cable disposed between and connected to the first and second housing portions. The assembling operation may include installing a first electrode of the communications circuit to the first housing portion and a second electrode of the communications circuit to the second housing portion. The sensor is assembled to electrically couple the first electrode to the second electrode via the flexible cable. The directing operation includes directing the communications circuit to transmit the physiologic data by applying voltage bursts to the first and second electrodes to create a polarized electric field around the sensor.

The method may include retaining the one or more processors in a sleep mode until transitioning the one or more processors to a wake mode responsive to receiving a wake-up instruction from a clock of the implantable sensor. At least one of the activating, converting, storing, and directing operations are performed when in the wake mode. Optionally, the method includes supplying power to the clock without supplying power to (any of) the one or more processors, the sensing circuit, and/or the communications circuit, when the one or more processors are in the sleep mode.

The sensing operation may include sensing, as the PPOI, at least one of pressure, temperature, respiration, or a body generated analyte (BGA). The signals generated by the sensing circuit represent electrical signals, for which at least one of voltage, current, capacitance, inductance or resistance varies based on a level of the PPOI.

The method may include electrically connecting a secondary battery, which represents the power source, to one of (i) the IMD via a direct wired connection to receive electrical power from the IMD or (ii) an energy harvesting unit of the sensor. The energy harvesting unit includes a coil configured to inductively connect to an external recharge device to transfer electrical power from the external recharge device to the secondary battery via the energy harvesting unit

In accordance with embodiments herein, the methods, devices, and systems may be implemented in connection with the holistic systems and methods described in U.S. patent application Ser. No. 16/930,791, filed on Jul. 16, 2020 and entitled Methods, Devices and Systems for Holistic Integrated Healthcare Patient management, which is incorporated herein by reference in its entirety.

FIG.8illustrates a block diagram of a system300for integrating external diagnostics with remote monitoring of data generated by implantable medical devices in accordance with embodiments herein. The system300may be implemented with various architectures that are collectively referred to as a distributed healthcare system320. The healthcare system320may be implemented with the implantable sensor150described according to the embodiments herein. The healthcare system320is configured to receive data from a variety of external and implantable sources including, but not limited to, active IMDs100capable of delivering therapy to a patient, the implantable sensor150, BGA test devices306, wearable sensors308, and point-of-care (POC) devices310(e.g., at home or at a medical facility). Optionally, a POC device310may represent one type of BGA test device306.

The data from one or more of the external and/or implantable sources is collected and transmitted to one or more secure databases within the healthcare system320. Optionally, the patient and/or other users may utilize a patient data entry (PDE) device, such as a smart phone, tablet device, etc., to enter behavior related medical (BRM) data. For example, a patient may use a smart phone to provide feedback concerning activities performed by the patient, a patient diet, nutritional supplements and/or medications taken by the patient, how a patient is feeling (e.g., tired, dizzy, weak, good), etc.

For example, the external BGA test device306may collect lab test results for specific tests and then transmit the lab test results to the healthcare system320. The BGA test device306may measure and/or sense one or more body generated analytes (e.g., blood glucose). For example, a cartridge based BGA test device may be configured to test patient levels for one or more body generated analytes. The BGA test device306may be implemented at a variety of physical locations, such as one or more “core” laboratories, a physician's office, ER (emergency room), OR (operating room) and/or a medical facility POC (e.g., during hospitalizations or routine healthcare visits). Optionally, the BGA test device306may be implemented as a fully implantable “lab on a chip”, such as an implantable biosensor array, that is configured to collect lab test results.

The at-home POC device310may periodically or continuously monitor the body generated analytes (e.g., blood glucose) measured by the BGA test device306. The at-home POC device310may transmit the raw BGA data to the medical network (e.g., a local external device and/or remote server). Additionally or alternatively, the at-home POC device310may analyze the BGA data and/or perform a test of the BGA data for a characteristic of interest (COI) such as a malnutrition state COI, an electrolyte COI, a cardiac marker COI, a hematology COI, a blood gas COI, a coagulation COI, an endocrinology COI. The POC device310transmits the COI (and optionally the BGA data) to the healthcare system320as the tests are performed at home or elsewhere. The POC device310may implement periodic or continuous tests for glucose levels, such as through sensors and handheld devices offered under the trademark FREESTYLE LIBRE® by Abbott Laboratories.

In an embodiment, the components of the system300may be independently powered and capable of communicating with each other. For example, the sensor150can communicate physiologic data to the IMD100, the BGA test device306, the wearable sensor308, and/or the POC devices310. Measurements by the sensor150may be synchronized with measurements by the IMD100, the BGA test device306, and/or the wearable sensor308. The synchronized measurements may be transmitted to a common device, such as a POC device310or a PDE device, to enable real-time, on-demand analysis of multiple different physiologic conditions in combination. For example, up-to-date blood glucose data may be analyzed with up-to-date blood pressure data from the sensor150to enable more timely treatment modifications based on measured changes in physiologic condition of the patient.

In an embodiment, the device that analyzes the data may calculate a health risk index based on the incoming BGA data, sensor physiologic data, and/or IMD data, alone or in combination with previously stored data. The health risk index represents a general indicator of a degree to which the patient is experiencing a health state or potential health risk. As a patient's health deteriorates, indicated by one or more characteristics reflected in the BGA, sensor, and IMD data, the health risk index will similarly elevate. When the health risk index is determined by the device (e.g., the POC device310, a PDE device, the IMD100, etc.) to exceed a designated threshold, the device determines that the patient's health condition is deteriorating and intervention is appropriate. The device may generate a treatment notification based on the treatment diagnosis, and directs the treatment notification to be sent to the patient and/or a care provider. The treatment notification may include an instruction or recommendation to modify treatment of the patient. The treatment modification may include changing a cardiac stimulation therapy delivered by the IMD. The device may also instruct the BGA test device306, the sensor150, and the IMD100to collect supplemental data for confirming the diagnosis and tracking the condition of the patient.

For example, the IMD100may track the IMD data and detect possible deterioration of a patient's health. When the IMD100detects possible deterioration, the IMD notifies the implantable sensor150to perform a measurement to collect supplemental physiologic data indicative of the PPOI. Optionally, when the IMD detects possible deterioration, the IMD may also automatically convey a device command (as a treatment notification) to the BGA test device306. In response, the BGA test device306may automatically collect supplemental BGA data. This combination of IMD data, sensor physiologic data, and BGA data, collected in real-time on-demand without patient intervention, is analyzed to diagnose and modify treatment of the patient.

FIG.9Aillustrates a healthcare system500formed in accordance with embodiments herein. The healthcare system500includes one or more remote servers502, each of which is connected to one or more database504. The servers502and databases504may be located at a common physical location and/or distributed between multiple remote locations within a city, state, country or worldwide. The servers502communicate with at least one network512. The network512may be the internet, a voice over IP (VoIP) gateway, a local plain old telephone service (POTS) such as a public switched telephone network (PSTN), a cellular phone-based network, and the like. Alternatively, the network512may be a local area network (LAN), a campus area network (CAN), a metropolitan area network (MAN), or a wide area network (WAM). The network512facilitates the transfer/receipt of information such as IMD data, sensor physiologic data, and BGA data.

The system500also includes one or more IMDs503, one or more implantable medical sensors505, one or more local external devices508, one or more BGA test devices530, one or more PDE devices531, and one or more medical personnel (MP) devices532, all of which communicate (directly or indirectly) through the network512to the servers502and/or one another. The servers and devices described herein may wirelessly communicate with one another utilizing various protocols, such as Bluetooth, GSM, infrared wireless LANs, HIPERLAN, 3G, satellite, as well as circuit and packet data protocols, and the like. Alternatively, a hard-wired connection may be used to connect the servers and devices.

The IMD503may be the IMD100described in embodiments herein. The sensor505may be the sensor150described in embodiments herein. The IMD503may collect various types of data, such as cardiac electrical and/or mechanical activity data, PAP or other pressure related data, impedance data, RPM data, flow data, and the like. The sensor505may measure a PPOI, such as blood pressure, temperature, respiration, capacitance, resistance, etc. The BGA test device530may analyze various types of body generated analytes to derive the BGA data. The PDE device531collects BRM data, such as based on manual inputs from a patient or other user, and/or based on automatic video and/or audio monitoring.

The local external device508may be implemented as a variety of devices including, but not limited to, medical personnel programmer, a local RF transceiver and a user workstation, smart phone, tablet device, laptop computer, desktop computer and the like. The MP devices532may also be implemented as a variety of devices including, but not limited to, medical personnel programmer, workstation, smart phone, tablet device, laptop computer, desktop computer and the like. Functionality of the MP devices532related to embodiments herein may be implemented through dedicated hardware circuits, firmware, software, and/or application operating on one or more computing devices. The MP devices532may include a cell phone514, a tablet device515, a laptop516, and/or the like.

The server502is a computer system that provides services to other computing systems over a computer network. The servers502control the communication of information including IMD data, sensor physiologic data, patient entered data, medical record information and BGA. The servers502interface with the network512to transfer information between the servers502, databases504, local external devices508, PDE device531, medical personnel devices532for storage, retrieval, data collection, data analysis, diagnosis, treatment recommendations and the like. The databases504store all or various portions of the information described herein, including, but not limited to, IMD data, sensor physiologic data, BGA data, BRM data, medical record information, treatment diagnoses and recommendations, and the like.

The local external device508may reside in a patient's home, a hospital, or a physician's office. The local external device508communicates wired or wirelessly with the IMDs503, the sensors505, and/or BGA test devices530. The local external device508, when implemented as a programmer, may be configured to acquire cardiac signals from the surface of a person (e.g., ECGs), and/or intra-cardiac electrogram (e.g., IEGM) signals from the IMD503. The local external device508interfaces with the network512to upload the data and other information to the server502. The workstation510may interface with the network512to download various data, information, diagnoses and treatment recommendations from the database504.

The distributed “digital” healthcare system collects various types of data, enables the data to be analyzed by various computing devices within the system, and determines one or more treatment diagnosis and treatment recommendation substantially in real-time with the collection of new data. In this manner, unneeded and undesired hospitalizations may be avoided through preventative detection, reducing costs associated with emergency medical procedures. Additionally, such a system also assists in prolonging a human's life and increases patient care. Thus, an improved system and methodology are provided.

FIG.9Billustrates a distributed healthcare system550that collects and analyzes patient data in accordance with embodiments herein. The system550includes one or more patient data entry (PDE) devices560that communicate over a network562with various other devices, such as IMDs, BGA test devices, implantable medical sensors, MP devices, local external devices, servers and the like. When the PDE device560includes a GUI, the patient or other user may input patient data in addition to IMD data, sensor data, and BGA data. The PDE devices560may include one or more input devices, such as microphones, cameras, buttons, touchpads, and the like. One or more of the PDE devices560may include one or more processors564, memory566, a display568, a user interface570, a network communications interface572, and various other mechanical components, electrical circuits, hardware and software to support operation of the PDE device560. Optionally, the PDE device560may include an atmospheric pressure gauge that monitors atmospheric pressure either periodically or on-demand. The on-demand or time-stamped atmospheric pressure measurement of PDE560can be used to convert time-stamped or time-synchronized absolute blood pressure measured by the sensor150to relative blood pressure, upon time-synchronization of the data between the sensor150and the PDE560.

The user interface570is configured to receive behavior related medical (BRM) data related to information indicative of an action or conduct by a patient that will affect one or more physiologic characteristics of interest and/or information indicative of a present state experienced by a patient in connection with a physiologic characteristic of interest. The user interface570may include a variety of visual, audio, and/or mechanical devices, such as the input devices listed above. The user interface570can include a visual, mechanical, and/or audial output device. The user interface570permits the user to enter or generate the BRM data. As nonlimiting examples, the patient or a third-party (e.g., family member, caregiver) may enter, through the PDE device560, information related to the patient's diet and/or nutritional supplements (e.g., what, when and how much a patient is taking), information concerning whether a patient is following a physician's instructions, information indicative of a present state experienced by the patient and the like. For example, a user may use a keyboard, touch screen and/or mouse to enter BRM data. Optionally, the user may enter the BRM data through spoken words (e.g., “Alexa I just took my medication”, “Alexa I am eating3slices of peperoni pizza”, “Alexa I am eating an apple”, “Alexa I am drinking a 12 oz. soda and eating a candy bar).

Optionally, the PDE device may automatically monitor actions or conduct of interest. For example, the PDE device may include a position tracking device sold under the trademark FITBIT® by Fitbit Inc. or other types of position tracking devices. The position tracking device may monitor and collect, as BRM data, movement information, such as a number of steps or distance traveled in a select period of time, a rate of speed, a level of exercise and the like. Optionally, the PDE device may monitor and collect, as BRM data, heart rate.

The memory566can encompass one or more memory devices of any of a variety of forms (e.g., read only memory, random access memory, static random access memory, dynamic random access memory, etc.) and can be used by the processor564to store and retrieve data. The data that is stored by the memory566can include, but need not be limited to, operating systems, applications, and other information, in addition to BRM data578.

The network communications interface572provides a direct connection to other devices, auxiliary components, or accessories for additional or enhanced functionality, and in particular, can include a USB port for linking to a user device with a USB cable. Optionally, the network communications interface572may include one or more transceivers that utilize a known wireless technology for communication.

In connection with embodiments that automatically collect BRM data, the memory566includes, among other things, an object tracking (OT) application576, object catalogue574, BRM data578, a tracking log582and one or more templates590. The memory566may store pick-up zones, drop-off zones, secure zones and access levels as described herein. The functionality of the OT application576is described below in more detail. The templates590may include one or more types of templates that are descriptive of, and associated with, food objects, nutritional supplement objects, and other objects of interest.

The BRM data578may be collected over the network562from numerous types of PDE devices560that implement a tracking operation (also referred to as tracking devices). For example, different types of electronic tracking devices560may collect image-based tracking data, audio-based tracking data, voice-based tracking data and gesture-based tracking data. The OT application576utilizes the templates590to analyze incoming data to identify objects of interest. The OT application576updates the tracking log582based on the analysis.

In the foregoing example, the PDE device560implements the OT application576locally on a device that may be generally present within the physical area of a user. For example, the PDE device560may represent the user's cell phone, laptop computer, tablet device, DPA device and the like.

Additionally or alternatively, all or portions of the OT application may be implemented remotely on a remote resource, referred to as a patient behavior tracker592. The patient behavior tracker592includes one or more processors594that may perform limited operations, such as manage storage and creation of templates. The patient behavior tracker592may provide access to one or more memory596, and/or implement the OT application598. The patient behavior tracker592communicates with PDE devices560through one or more networks562to provide access to object catalogs and to implement processes described herein. The patient behavior tracker592may represent a server or other network-based computing environment. The patient behavior tracker may represent a single computing device, or a collection of computer systems located at a common location or geographically distributed.

The patient behavior tracker592includes one or more processors594and memory596, among other structures that support operation thereof. In accordance with embodiments herein, the patient behavior tracker592receives requests from various PDE devices560and returns resources in connection there with.

The memory551of the data store may store the object catalogs553organized in various manners and related to a wide variety of objects and types of tracking data. The object catalogs553may include various types of templates corresponding to different types of objects. Optionally, the memory551may store BRM data555, along with timing information such as when the patient behavior tracker592receives the BRM data555from PDE devices560that are performing tracking operations.

In an embodiment, the patient behavior tracker592and/or the PDE devices560may communicate with implanted medical devices, such as the implantable sensor150and the IMD100. Operations of the sensor150and/or the IMD100may be responsive to operations performed by the patient behavior tracker592and/or the PDE devices560, and vice-versa. For example, BRM data578generated by a PDE device560may indicate that the patient has a certain designated posture. The PDE device560may communicate with the IMD100, via the network562, to inform the IMD100that the patient has the designated posture. In response to receiving the notification, the IMD100may take one or more actions, such as generating supplemental IMD data of the patient by measuring physiologic conditions, communicating the notification to the sensor150, and/or initiating or modifying stimulation therapy provided by the IMD100. The IMD100may forward the notification to the sensor150as a command to generate supplemental sensor physiologic data and communicate the supplemental sensor data to the IMD100. As described, a single sensed event (e.g., a posture, detecting a physiologic data value or trend outside of a designated range, a user input, etc.) external to a patient can trigger the implanted sensor150and/or another medical device to take action without human intervention. The automated responses can provide updated information about multiple different parameters of a patient condition in real-time and on-demand to provide a greater indication of overall patient condition than a single patient parameter can.

The following example explains how BRM data and/or BGA data can be used to automatically trigger the collection of physiologic data by the implantable sensor150. The BGA test device and/or PDE device may track BGA and/or BRM data and detect possible deterioration of patient health. For example, the BGA data trend may cross a threshold, change direction or increase a downward trend. When the BGA test device detects possible deterioration, the BGA test device may automatically convey a device command (as a treatment notification) to the IMD100and/or the sensor150to collect supplemental sensor physiologic data. In response to receiving the command, the sensor150automatically collects physiologic data. Additionally or alternatively, a PDE device may analyze BRM data to identify when a BRM data trend crosses a threshold, changes direction, or increases a downward trend. The PDE device may identify an extended period of time in which no new BRM data is entered (e.g., an indicator of transmission noncompliance). When the PDE device detects possible deterioration and/or noncompliance, the PDE device may automatically convey a device command (as a treatment notification) to the IMD100and/or the sensor150to collect supplemental sensor physiologic data. In accordance with at least some embodiments, the various sources of information allow for remote monitoring to enable decision-making without any active input from the patient.

The supplemental sensor physiologic data is then conveyed to a processing device for analysis. For example, the sensor150may communicate the sensor data to the IMD100, which may process the data and/or may forward the sensor data to an external device (e.g., the external device104) for processing. The processing device calculates an IMD-based index (IMD Index) based on the new sensor physiologic data and/or IMD data generated by the IMD. Examples are discussed below for different physiologic COI that may be monitored in connection with different types of IMD Index calculations. For example, an IMD Index may represent a PAP systolic level, PAP diastolic level, PAP mean and the like. As another example, the IMD Index may represent a diuretic response profile that is calculated based on hemodynamic data (from the sensor data) and diuretic medication information. As another example, the IMD Index may represent PAP levels and/or trends derived from the sensor data. As another example, the IMD Index may represent ST segment levels and/or ST segment level shifts determined from cardiac activity data within IMD data generated by the IMD. As another example, the IMD Index may represent levels and/or trends in cardiac output, thoracic impedance, cardiogenic impedance, heart sounds and the like. As another example, the IMD Index may represent AF burden calculated based on CA signals indicative of AF episodes. The IMD Index may further represent MCS parameter levels and/or trends. Optionally, the processor may classify the IMD Index based on various predetermined criteria.

The processing device may receive data from multiple different sources/modalities. In order to organize and synchronize the data, the processing device may correlate a time stamp associated with the receipt of each collection of data, including IMD data, sensor physiologic data, BRM data, and/or BGA data. The processing device may analyze the sensor data, the IMD data, BRM data and BGA data in connection with one or more application specific models (ASM) to generate a treatment diagnosis and calculate a health risk index related to the treatment diagnosis. The ASM may be implemented in various manners, including but not limited to threshold-based algorithms, template correlation algorithms, lookup tables, decision trees, machine learning algorithms and the like. The ASM analyzes data points from dissimilar data sources (e.g., from the IMD, sensor, BRM and BGA data) relative to one another to generate the treatment diagnosis. The data points from the IMD, sensor, BRM and BGA data have a relative level of importance with respect to one another, that varies, in connection with calculating the health risk index and generating the treatment diagnosis. The relative level of importance may vary in the context of a particular disease state or health risk index of interest.

The processing device identifies a treatment diagnosis and treatment notification to be provided in connection with the health risk index. Treatment diagnoses and recommendations may relate to changes in prescriptions, changes in parameters of an IMD and the like. Additionally, treatment diagnoses and recommendations may be implemented in connection with digital health/patient application features that are communicated to the patient through smart phone or another electronic device. For example, an application implemented on a smart phone may allow a patient to track calorie, salt and fat intake as BRM data.

As one example, updated sensor physiologic data (from the implantable sensor150) may indicate that a patient's PAP level has increased (relative to prior PAP data). If the PAP levels were considered alone, a potential or candidate treatment diagnosis and recommendation would be to change the patient's diuretic medication (e.g., increase the dosage or change the type of diuretic if the patient is exhibiting a resistance to a particular diuretic). However, in the present example, BGA data is also obtained and analyzed contemporaneous in time with the sensor data. The BGA data may indicate that a blood glucose level is high, and a patient's diabetes may be in an uncontrolled state. The ASM analyzes the blood glucose level information in combination with the PAP information. Given the increase in the blood glucose level, the ASM may determine that it is not preferable to change the diuretic prescription at this time. Instead, the ASM generates a diagnosis and treatment recommendation that first treats the blood glucose level. Once the blood glucose level has returned to an acceptable range, the ASM may then render the diagnosis and treatment recommendation that treats the elevated PAP level. In the present example, the ASM affords a lower weight (or degree of importance) to the elevated PAP level in the decision-making process, given that the patient was also experiencing an unduly high blood glucose level.

By way of example, prior to rendering a diagnosis and treatment recommendation, the ASM may determine that additional information is warranted. For example, the ASM may determine that updates or re-measurements of one or more sensor physiologic parameters and/or BGA parameters is warranted. In the event that additional sensor and/or IMD data is needed, the ASM may convey a device command to the IMD to obtain and return the additional desired sensor and/or IMD data. Additionally or alternatively, the ASM may desire additional BGA data. Once the additional information is collected, the ASM may complete the analysis of the original and additional IMD, sensor, BGA and/or BRM data. In the event that the PAP level remains elevated, the ASM may render a diagnosis and treatment recommendation to treat the elevated PAP level. In the example above, the operations of the ASM may be performed by a processing device that implements the ASM.

In another example, embodiments may “override” an otherwise permanent change in a therapy/prescription based on elevated activity. For example, a patient may exhibit a level of activity that is unusually high relative to a preprogrammed activity level and/or a patient's history of activity. When the patient exhibits an unusually high level of activity for a select period of time, the ASM may recognize such behavior and determined that changes in the IMD data, BGA data and/or BRM data may not be indicative of a degradation of the health risk index and thus may not warrant a change in therapy/prescription. For example, when the patient undergoes an unusually high level of activity for an extended period of time during exercise, the patient's blood pressure may become unusually elevated, but does not warrant a therapy/prescription change. Additionally or alternatively, when a patient exhibits an unduly high level activity for a select period of time, the ASM may determine that the patient is not prescription compliant (e.g., the patient is not maintaining within a prescribed activity range), and thus may convey a communication to the patient recommending that the patient reduce the activity level.

When a patient with an IMD and/or BGA test device (who is diabetic or otherwise sensitive to sugar) consumes too much sugar, a notification may be sent to the patient to inform that the excessive sugar has caused a spike in the patient's glucose level. As another example, when a patient with an IMD and/or BGA test device avoids exercise for a period of time, the notification may inform a patient that the patient's lack of exercise has raised a PAP trend and/or introduced an undue burden on a patient's kidneys.

The embodiments described herein can be used to identify high risk behavior in heart failure (HF) patients. It has been shown that management of NYHA Class III heart failure based on home transmission of pulmonary artery pressure has significant long-term benefit in lowering hospital admission rates for heart failure. The management of an HF patient is further impacted by the patient's behavioral patterns. For example, aspects of patient behavior that affect progression of HF include, among other things, compliance with medication intake, salt restrictions and activity level and the like. The sensor data, such as PAP data, may also be beneficial for identifying HF patients who are candidates for implant of a ventricular assist device, a transplant, a valve repair procedure (e.g., a MitraClip™ valve repair to correct mitral regurgitation), and the like.

Embodiments herein describe methods and systems to identify characteristics of the PAP data indicative of poor patient health as well as indicative of candidates for certain types of implants. For example, embodiments herein analyze combinations of cardiac activity signals, such as from an ICM, with PAP data for characteristics indicative of unduly large perfusion resulting from pulmonary hypertension. For example, the ASM may analyze the CA signals and PAP signals in search of certain characteristics of interest in heart rate, arrhythmias pressures and the like. The ICM may measure the heart rate over an extended period of time (e.g. several weeks, months or longer). For example, the ASM may track the level of burden associated with the arrhythmia. Arrhythmias exhibiting high burden (e.g. a large number of events or long duration of events) will exhibit a high PAP pressure. As the PAP pressure reduces, the arrhythmia burden is also reduced. Additionally or alternatively, the active IMD, such as the ICM, may measure activity and provide the activity signals as part of the IMD data. Embodiments herein may examine PAP pressure during exercise to identify a reaction of the level of pulmonary hypertension to the level of exercise. For example, while a patient is exercising, and ICM may measure heart rate, while a PAP sensor measures pressure. As another example, an IMD may utilize an activity sensor to measure a level of exercise, in combination with the PAP sensor measuring pressure. The indication of the level of exercise, in combination with the PAP data, may be analyzed manually or with an ASM in search of an unduly large level of perfusion in connection with pulmonary hypertension.

Embodiments herein may track a manner in which patient behavior modulates PAP daily trends, PAP changes and PAP percentage changes over a week. The implantable sensor150is active and automated, which enables the sensor150to reliably and consistently provide PAP data, without requiring human intervention, resulting in more timely and accurate data. A higher modulation in PAP over a week is indicative of poorer PAP control which may lead to worsened health and worse outcomes such as hospitalizations. In accordance with aspects herein, methods and systems are provided that allow physicians to titrate a patient's medication based on their behavior and potentially increase the medication dosage on the weekdays with a preponderance of high PA pressures. In accordance with aspects herein, methods and systems are provided that allow patients to modify their behavior to keep spikes in PAP over weekends in check. The patient may be asked to increase/decrease their physical activity or reducing their salt intake based on their weekly PA pressure profiles and thereby managing PAP.

In the embodiments described herein, the various devices trigger corresponding contemporaneous measurements by other devices, on-demand and in real-time, without human intervention. For example, in response to the IMD100detecting an increasing AF burden trend, the IMD100may command the sensor150to perform a contemporaneous PAP measurement. The PAP can be reviewed with the AF in combination to augment treatment and improve diagnosis. In another example, a trend indicating increased BGA, such as due to diet, can be used as the trigger event to command the sensor150to perform a PAP measurement. Conversely, a detected increasing PAP trend based on sensor data can be analyzed in conjunction with contemporaneous trends in BGA data, BRM data, and/or cardiac data from the IMD for informed diagnosis.

Terms

The terms “treatment”, “arrhythmia treatment”, “in connection with treating a heart condition” and similar phrases, as used herein include, but are not limited to, delivering an electrical stimulation or drug therapy to a heart condition. By way of example, treating a heart condition may include, in whole or in part, i) identifying a progression of heart failure over time; ii) confirming an arrhythmia identified by an arrhythmia detection process; iii) instructing the patient to perform a posture recalibration procedure and/or iv) delivering a therapy.

The term “body generated analyte” (BGA) shall mean a test substance or specimen that is naturally generated by or naturally present in a human body. The test substance or specimen may be in liquid form (e.g., blood or other bodily fluid), solid form (e.g., tissue, fat, muscle, bone, or other organ-based material), gas form, cellular form or otherwise. Non-limiting examples of body generated analytes include hematocrit, troponin, CKMB, BNP, beta human chorionic gonadotropin (bHCG), carbon dioxide partial pressure (pCO.sub.2), partial pressure oxygen (pO.sub.2), pH, PT, ACT, activated partial thromboplastin time (APTT), sodium, potassium, chloride, calcium, urea, glucose, creatinine, lactate, oxygen, and carbon dioxide, thyroid stimulating hormone, parathyroid hormone, D-dimer, prostate specific antibody, TCO2, Anion Gap, ionized calcium, urea nitrogen, lactose, hemoglobin, pH, PCO2, PO2, HCO3, Base Excess, O2, ACT Kaolin, ACT Celite, PT/INR, β-hCG, cTnl, CK-MB, BNP and the like, and combinations thereof. The analyte may be tested in a liquid sample that is whole blood, however other samples can be used including blood, serum, plasma, urine, cerebrospinal fluid, saliva and amended forms thereof. Amendments can include diluents and reagents such as anticoagulants and the like.

The term “BGA test device” shall mean any and all equipment, devices, disposable products utilized to collect and analyze a BGA. The BGA test device may implement one or more of the methods, devices and systems described in the following publications, all of which are incorporated herein by reference in their entireties:U.S. Pat. No. 8,514,086, entitled “DISPLAYS FOR A MEDICAL DEVICE”, issued Aug. 20, 2013;U.S. Patent Publication Number 2011/0256024, entitled “MODULAR ANALYTE MONITORING DEVICE”, published Oct. 20, 2011;U.S. Patent Publication Number 2010/0198142, entitled “MULTIFUNCTION ANALYTE TEST DEVICE AND METHODS THEREFORE”, published Aug. 5, 2010;U.S. Patent Publication Number 2011/0160544, entitled “SYSTEM AND METHOD FOR ANALYSIS OF MEDICAL DATA TO ENCOURAGE HEALTHCARE MANAGEMENT”, published Jun. 30, 2011;U.S. Pat. No. 5,294,404, entitled “REAGENT PACK FOR IMMUNOASSAYS” issued Mar. 15, 1994;U.S. Pat. No. 5,063,081, entitled “METHOD OF MANUFACTURING A PLURALITY OF UNIFORM MICROFABRICATED SENSING DEVICES HAVING AN IMMOBILIZED LIGAND RECEPTOR” issued Nov. 5, 1991;U.S. Pat. No. 7,419,821, entitled “APPARATUS AND METHODS FOR ANALYTE MEASUREMENT AND IMMUNOASSAY” issued Sep. 2, 2008;U.S. Patent Publication Number 2004/0018577, entitled “MULTIPLE HYBRID IMMUNOASSAYS” published Jan. 29, 2004;U.S. Pat. No. 7,682,833, entitled “IMMUNOASSAY DEVICE WITH IMPROVED SAMPLE CLOSURE” issued Mar. 23, 2010;U.S. Pat. No. 7,723,099, entitled “IMMUNOASSAY DEVICE WITH IMMUNO-REFERENCE ELECTRODE” issued May 25, 2010; andBaj-Rossi et al. “FABRICATION AND PACKAGING OF A FULLY IMPLANTABLE BIOSENSOR ARRAY”, (2013) IEEE, pages 166-169.

The terms “behavior related medical data” and “BRM data” shall mean information indicative of an action or conduct by a patient that will affect one or more physiologic characteristics of interest and/or information indicative of a present state experienced by a patient in connection with a physiologic characteristic of interest. As nonlimiting examples of information indicative of an act or conduct, BRM data may represent information related to a patient's diet (e.g., what, when and how much a patient ate or drank), information related to whether a patient is following a physician's instructions (e.g., exercising, walking, following a fluid regiment, taking medication at prescribed times), information related to nutritional supplements (e.g., what, when and how much a patient is taking as nutritional supplements), self-reported quality of life information from the patient, signs and symptoms indicating fatigue, lack of mobility/exercise and the like. The foregoing examples concern BRM data that is directly relate to actions and/or conduct by the patient. Optionally, the BRM data may indirectly relate to actions and/or conduct by the patient. For example, the BRM data may indicate how often and/or volumes of certain food products and liquids ordered by the patient through a home delivery service (e.g., how often and in what volume the patient orders certain groceries and other food products that may be delivered to a patient's home).

Further, as nonlimiting examples of information indicative of a present state, the BRM data may represent information indicating how a patient feels (e.g., headaches, shortness of breath, tired, chest pains). The BRM data may be manually entered by the patient or a third-party through various types of PDE devices. Optionally, the BRM data may be automatically entered by a PDE device based on electronic monitoring of actions and conduct by the patient, as well as other types of sensors.

The term “obtains” and “obtaining”, as used in connection with data, signals, information and the like, include at least one of i) accessing memory of an external device or remote server where the data, signals, information, etc. are stored, ii) receiving the data, signals, information, etc. over a wireless communications link between the IMD and a local external device, and/or iii) receiving the data, signals, information, etc. at a remote server over a network connection. The obtaining operation, when from the perspective of an IMD, may include sensing new signals in real time, and/or accessing memory to read stored data, signals, information, etc. from memory within the IMD. The obtaining operation, when from the perspective of a local external device, includes receiving the data, signals, information, etc. at a transceiver of the local external device where the data, signals, information, etc. are transmitted from an IMD and/or a remote server. The obtaining operation may be from the perspective of a remote server, such as when receiving the data, signals, information, etc. at a network interface from a local external device and/or directly from an IMD. The remote server may also obtain the data, signals, information, etc. from local memory and/or from other memory, such as within a cloud storage environment and/or from the memory of a workstation or clinician external programmer.

The term “PA” shall mean pulmonary artery. The term “PAP” shall mean pulmonary arterial pressure.

The terms “processor,” “a processor”, “one or more processors” and “the processor” shall mean one or more processors. The one or more processors may be implemented by one, or by a combination of more than one implantable medical device, a wearable device, a local device, a remote device, a server computing device, a network of server computing devices and the like. The one or more processors may be implemented at a common location or at distributed locations. The one or more processors may implement the various operations described herein in a serial or parallel manner, in a shared-resource configuration and the like.

The term “real-time” shall mean a time frame contemporaneous with normal or abnormal episode occurrences. For example, a real-time process or operation would occur during or immediately after (e.g., within minutes or seconds after) a cardiac event, a series of cardiac events, an arrhythmia episode, and the like. For example, the term “real-time” may refer to a time period substantially contemporaneous with an event of interest. The term “real-time,” when used in connection with collecting and/or processing data utilizing an IMD, shall refer to processing operations performed substantially contemporaneous with a physiologic event of interest experienced by a patient. By way of example, in accordance with embodiments herein, cardiac activity signals are analyzed in real time (e.g., during a cardiac event or within a few minutes after the cardiac event). The term “real-time,” when used in connection with a body generated analyte, shall refer to operations performed substantially contemporaneous with an occurrence of a characteristic of interest in a malnutrition state experienced by the patient. By way of example, in accordance with embodiments herein, the body generated analyte may correspond to serum albumin that is analyzed and utilized in a diagnosis and treatment recommendation. The analysis of the serum albumin and generation of the diagnosis and treatment recommendation are performed in real-time, namely while the patient is experiencing a certain malnutrition state, not to exceed 24 hours from the time the BGA was collected.

The term “on-demand” shall mean at any time that the system automatically determines that a measurement is warranted and without any need for patient action or intervention. As one example, an implantable sensor will collect pressure measurements “on-demand” automatically and in real-time in response to a data collection instruction from an IMD. As another example, an implantable sensor will collect pressure measurements “on-demand” automatically and in real-time in response to a data collection instruction from an external device such as a bedside monitor, smart phone, physician's programmer and the like. As another example, an implantable sensor will collect pressure measurements “on-demand” automatically and in real-time in response to a data collection schedule stored at the sensor, IMD or ED.

Embodiments may be implemented in connection with one or more implantable medical devices (IMDs). Non-limiting examples of IMDs include one or more of neurostimulator devices, implantable leadless monitoring and/or therapy devices, and/or alternative implantable medical devices. For example, the IMD may represent a cardiac monitoring device, pacemaker, cardioverter, cardiac rhythm management device, defibrillator, neurostimulator, leadless monitoring device, leadless pacemaker and the like. For example, the IMD may include one or more structural and/or functional aspects of the device(s) described in U.S. Pat. No. 9,333,351 “Neurostimulation Method And System To Treat Apnea” and U.S. Pat. No. 9,044,610 “System And Methods For Providing A Distributed Virtual Stimulation Cathode For Use With An Implantable Neurostimulation System”, which are hereby incorporated by reference.

Additionally or alternatively, the IMD may be a leadless implantable medical device (LIMD) that include one or more structural and/or functional aspects of the device(s) described in U.S. Pat. No. 9,216,285 “Leadless Implantable Medical Device Having Removable And Fixed Components” and U.S. Pat. No. 8,831,747 “Leadless Neurostimulation Device And Method Including The Same”, which are hereby incorporated by reference. Additionally or alternatively, the IMD may include one or more structural and/or functional aspects of the device(s) described in U.S. Pat. No. 8,391,980 “Method And System For Identifying A Potential Lead Failure In An Implantable Medical Device” and U.S. Pat. No. 9,232,485 “System And Method For Selectively Communicating With An Implantable Medical Device”, which are hereby incorporated by reference.

Additionally or alternatively, the IMD may be a subcutaneous IMD that includes one or more structural and/or functional aspects of the device(s) described in U.S. application Ser. No. 15/973,195, titled “Subcutaneous Implantation Medical Device With Multiple Parasternal-Anterior Electrodes” and filed May 7, 2018; U.S. application Ser. No. 15/973,219, titled “Implantable Medical Systems And Methods Including Pulse Generators And Leads” filed May 7, 2018; U.S. application Ser. No. 15/973,249, titled “Single Site Implantation Methods For Medical Devices Having Multiple Leads”, filed May 7, 2018, which are hereby incorporated by reference in their entireties. Further, one or more combinations of IMDs may be utilized from the above incorporated patents and applications in accordance with embodiments herein.

Additionally or alternatively, the IMD may be a leadless cardiac monitor (ICM) that includes one or more structural and/or functional aspects of the device(s) described in U.S. Patent Application having Docket No. A15E1059, U.S. patent application Ser. No. 15/084,373, filed Mar. 29, 2016, entitled, “METHOD AND SYSTEM TO DISCRIMINATE RHYTHM PATTERNS IN CARDIAC ACTIVITY,” which is expressly incorporated herein by reference.

The implantable medical sensor disclosed herein may implement one or more structural and/or functional aspects of the device(s) described in U.S. patent application Ser. No. 16/194,103, filed Nov. 16, 2018, and entitled “Wireless Sensor for Measuring Pressure;” U.S. patent application Ser. No. 14/733,450, filed Jun. 8, 2015, now U.S. Pat. No. 10,143,388, and entitled “Method of Manufacturing Implantable Wireless Sensor for In Vivo Pressure Measurement;” U.S. patent application Ser. No. 12/612,070, filed Nov. 4, 2009, and entitled “Method of Manufacturing Implantable Wireless Sensor for In Vivo Pressure Measurement,” now U.S. Pat. No. 9,078,563; U.S. patent application Ser. No. 11/204,812, filed on Aug. 16, 2005 and entitled “Method of Manufacturing Implantable Wireless Sensor for In Vivo Pressure Measurement,” now U.S. Pat. No. 7,621,036; U.S. patent application Ser. No. 11/157,375, filed Jun. 21, 2005 and entitled “Implantable Wireless Sensor for In Vivo Pressure Measurement,” which are expressly incorporated herein by reference.

Embodiments may be implemented in connection with one or more PIMDs. Non-limiting examples of PIMDs may include passive wireless sensors used by themselves, or incorporated into or used in conjunction with other implantable medical devices (IMDs) such as cardiac monitoring devices, pacemakers, cardioverters, cardiac rhythm management devices, defibrillators, neurostimulators, leadless monitoring devices, leadless pacemakers, replacement valves, shunts, grafts, drug elution devices, blood glucose monitoring systems, orthopedic implants, and the like. For example, the PIMD may include one or more structural and/or functional aspects of the device(s) described in U.S. Pat. No. 9,265,428 entitled “Implantable Wireless Sensor”, U.S. Pat. No. 8,278,941 entitled “Strain Monitoring System and Apparatus”, U.S. Pat. No. 8,026,729 entitled “System and Apparatus for In-Vivo Assessment of Relative Position of an Implant”, U.S. Pat. No. 8,870,787 entitled “Ventricular Shunt System and Method”, and U.S. Pat. No. 9,653,926 entitled “Physical Property Sensor with Active Electronic Circuit and Wireless Power and Data Transmission”, which are all hereby incorporated by reference in their respective entireties.

Closing

It should be clearly understood that the various arrangements and processes broadly described and illustrated with respect to the Figures, and/or one or more individual components or elements of such arrangements and/or one or more process operations associated of such processes, can be employed independently from or together with one or more other components, elements and/or process operations described and illustrated herein. Accordingly, while various arrangements and processes are broadly contemplated, described and illustrated herein, it should be understood that they are provided merely in illustrative and non-restrictive fashion, and furthermore can be regarded as but mere examples of possible working environments in which one or more arrangements or processes may function or operate.

As will be appreciated by one skilled in the art, various aspects may be embodied as a system, method or computer (device) program product. Accordingly, aspects may take the form of an entirely hardware embodiment or an embodiment including hardware and software that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects may take the form of a computer (device) program product embodied in one or more computer (device) readable storage medium(s) having computer (device) readable program code embodied thereon.

Any combination of one or more non-signal computer (device) readable medium(s) may be utilized. The non-signal medium may be a storage medium. A storage medium may be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a storage medium would include the following: a portable computer diskette, a hard disk, a random access memory (RAM), a dynamic random access memory (DRAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Program code for carrying out operations may be written in any combination of one or more programming languages. The program code may execute entirely on a single device, partly on a single device, as a stand-alone software package, partly on single device and partly on another device, or entirely on the other device. In some cases, the devices may be connected through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made through other devices (for example, through the Internet using an Internet Service Provider) or through a hard wire connection, such as over a USB connection. For example, a server having a first processor, a network interface, and a storage device for storing code may store the program code for carrying out the operations and provide this code through its network interface via a network to a second device having a second processor for execution of the code on the second device.

Aspects are described herein with reference to the figures, which illustrate example methods, devices and program products according to various example embodiments. The program instructions may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing device or information handling device to produce a machine, such that the instructions, which execute via a processor of the device implement the functions/acts specified. The program instructions may also be stored in a device readable medium that can direct a device to function in a particular manner, such that the instructions stored in the device readable medium produce an article of manufacture including instructions which implement the function/act specified. The program instructions may also be loaded onto a device to cause a series of operational steps to be performed on the device to produce a device implemented process such that the instructions which execute on the device provide processes for implementing the functions/acts specified.

The units/modules/applications herein may include any processor-based or microprocessor-based system including systems using microcontrollers, reduced instruction set computers (RISC), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), logic circuits, and any other circuit or processor capable of executing the functions described herein. Additionally, or alternatively, the modules/controllers herein may represent circuit modules that may be implemented as hardware with associated instructions (for example, software stored on a tangible and non-transitory computer readable storage medium, such as a computer hard drive, ROM, RAM, or the like) that perform the operations described herein. The above examples are exemplary only, and are thus not intended to limit in any way the definition and/or meaning of the term “controller.” The units/modules/applications herein may execute a set of instructions that are stored in one or more storage elements, in order to process data. The storage elements may also store data or other information as desired or needed. The storage element may be in the form of an information source or a physical memory element within the modules/controllers herein. The set of instructions may include various commands that instruct the modules/applications herein to perform specific operations such as the methods and processes of the various embodiments of the subject matter described herein. The set of instructions may be in the form of a software program. The software may be in various forms such as system software or application software. Further, the software may be in the form of a collection of separate programs or modules, a program module within a larger program or a portion of a program module. The software also may include modular programming in the form of object-oriented programming. The processing of input data by the processing machine may be in response to user commands, or in response to results of previous processing, or in response to a request made by another processing machine.