Medical Device for Implantation in Bone Tissue and Characterization of Fractures

Abstract

The smart medical device includes a structure configured to be at least partially implanted within a body and an electronics cartridge configured to be inserted into the structure after implantation of the structure within the body. The structure may be a cannulated screw used in treating bone fractures. The medical device includes an impedance sensor for monitoring and reporting the healing status of the fracture. The sensor includes electrodes associated with components of the electronics cartridge and either the cannulated screw or the insertable electronics cartridge.

Description

[Technical Field]

[0001] The present disclosure generally relates to medical devices having structures configured to extend at least partially into bone tissue. For example, the structures may be screws, pins, rods, nails, portions of joint replacement implants (e.g., hip, shoulder, knee, etc.), portions of spinal stabilization devices, or portions of other orthopedic devices. The medical devices have sensors that obtain measurements indicative of the healing status of bone tissue in a fractured condition in which the medical device is implanted, and communication circuitry that transmits such measurements to an external device.

[0002] REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 120,158, filed December 1, 2020, and U.S. Provisional Patent Application No. 62 / 979,349, filed February 20, 2020, under 35 U.S.C. § 119(e), which applications are incorporated by reference and incorporated herein by reference for all purposes. [Background technology]

[0003] Reliable assessment of bone healing is essential for successful fracture treatment. Delayed or nonunion of fractures has a high incidence rate (up to 5–10%), and individual cases of delayed or nonunion can be extremely painful and dangerous to the patient's health, resulting in unavoidable high costs. Current techniques for monitoring fracture healing utilize noninvasive imaging modalities, such as X-rays, CT scans, ultrasound, and magnetic resonance imaging (MRI). Because bridging callus formation in long bone fractures takes three months or more, reliance on traditional radiographs to monitor union is limited. Computed tomography (CT) scanning is a commonly used modality, and it can assess bridging callus formation in the later stages of healing to confirm union. Technological advances in dynamic contrast-enhanced MRI and nuclear imaging may offer advantages in the evaluation of infectious nonunions. Emerging evidence supports the use of ultrasound to detect bridging callus prior to radiographic confirmation, which may be useful in predicting patients at high risk for nonunion. However, each of these techniques tends to be most useful in the late stages of healing, and their effectiveness depends on patient compliance with regular imaging studies. Summary of the Invention [Problem to be solved by the invention]

[0004] It would therefore be desirable to provide a technique for characterizing the condition of a fracture throughout all stages of healing and in an automated manner that is not dependent on imaging or patient compliance. The concepts disclosed herein address these and other needs. [Means for solving the problem]

[0005] In summary, the present disclosure relates to medical devices, optionally referred to herein as implantable and / or smart medical devices, methods of manufacturing the medical devices, methods of using the medical devices, including, for example, methods of treating with the medical devices, methods of using the medical devices, including methods of characterizing healing using the medical devices, and other aspects disclosed herein. Medical devices generally include a structure configured to extend at least partially into bone tissue. For example, the structure may be a screw, pin, rod, nail, part of a joint replacement implant (e.g., hip, shoulder, knee, etc.), part of a spinal fixation device, or part of another orthopedic device. In one embodiment, the medical device is a screw. An implantable smart medical device may include, for example, a sensor that obtains one or more measurements indicative of, for example, the healing status of, for example, a fractured bone tissue in which the medical device is implanted, and communication circuitry for transmitting such measurements to an external device.

[0006] For example, in one aspect, the present disclosure provides a smart medical device having a structure configured to be at least partially implanted within a body and an electronics cartridge configured to be inserted into the structure after the structure is implanted within the body. The structure may be a cannulated screw used in treating bone fractures. The medical device has an impedance sensor that monitors and reports on the healing status of the fracture. The sensor includes components and electrodes of an electronics cartridge associated with either the cannulated screw or the insertable electronics cartridge.

[0007] In one aspect, the present disclosure relates to a medical device having a structure having a lumen extending at least partially therethrough and an insertable electronics cartridge containing electronics, the structure configured to be at least partially implanted within a body, and the electronics cartridge configured to be inserted into the lumen after implantation of the structure.

[0008] The present disclosure also relates to a medical device having a cannula-like structure with a plurality of electrodes on an exterior surface of the structure, and an insertable electronics cartridge, the cannula-like structure having a lumen extending therethrough, the cannula-like structure configured to be at least partially implanted within a body, the electronics cartridge containing electronics configured to be inserted into the lumen of the cannula-like structure such that one or more electrical connections between the electronics and the plurality of electrodes are established upon such insertion.

[0009] The present disclosure also relates to a medical device having a cannula-like structure having at least one hole extending through a sidewall of the structure, and an insertable electronics cartridge. The cannula-like structure has a lumen extending therethrough, and the cannula-like structure is configured to be at least partially implanted within a body. The electronics cartridge includes a plurality of electrodes and electronics electrically coupled to the electrodes. The electronics cartridge is configured to be inserted into the lumen and align the plurality of electrodes with the at least one hole upon insertion.

[0010] The present disclosure also relates to a medical device having a cannula-like structure with a distal end opening and a proximal end opening, and an insertable electronics cartridge. The cannula-like structure has a lumen extending therethrough, and the cannula-like structure is configured to be at least partially implanted within a body. The electronics cartridge has a plurality of electrodes and electronics electrically coupled to the electrodes. The electronics cartridge is configured to be inserted into the lumen and, upon insertion, to position a first electrode of the plurality of electrodes at the distal end opening of the cannula-like structure and a second electrode of the plurality of electrodes at the proximal end opening.

[0011] The present disclosure also relates to a medical device having a short cannula-like structure with distal and proximal openings, and an insertable electronics cartridge. The cannula-like structure has a lumen extending therethrough, and the cannula-like structure is configured to be at least partially implanted within a body. The electronics cartridge contains a plurality of electrodes and electronics electrically coupled to the electrodes. The electronics cartridge is configured to be inserted into the lumen and to position the plurality of electrodes beyond the distal opening of the cannula-like structure upon such insertion.

[0012] The present disclosure also relates to a medical device with pre-loaded electronics, the medical device configured to be at least partially implanted within a body, the medical device having a structure with a head and a shaft, each having a head cavity and a shaft cavity, respectively, the pre-loaded medical device further having electronics disposed in one or more of the head cavity and the shaft cavity, and at least one electrode associated with the shaft and electrically coupled to the electronics.

[0013] The present disclosure also relates to a medical device having a cannula-like structure with a pre-installed electronics cartridge. The cannula-like structure is configured to be implanted within the body, the cannula-like structure having a lumen extending at least partially therethrough. The electronics cartridge is at least partially located within the lumen, and the electronics are permanently secured within the lumen. The cannula-like structure has a plurality of holes extending through a sidewall and a plurality of electrodes, one associated with each of the plurality of holes. The electronics cartridge has electronics and a plurality of electrical contacts, each aligned with a respective one of the holes, for electrically coupling the electronics to each of the plurality of electrodes.

[0014] In one aspect, the medical device of the present disclosure can be used to help treat fractures in bone tissue. For example, the medical device can be in the form of a screw placed across a fracture in bone tissue, where the screw helps hold the bone tissue adjacent the fracture together, thus providing a stabilization function for the healing bone. Optionally, the medical device has little or no stabilization function; instead, the medical device is implanted within the fractured bone tissue, optionally across the fracture, primarily or solely to characterize the fracture during the healing process, thus providing a characterization function. Optionally, the implanted medical device performs both a stabilization function and a characterization function. Particularly in cases where the medical device of the present disclosure has little or no stabilization function, the medical device of the present disclosure can be used in conjunction with other medical devices, such as standard orthopedic screws that do not include sensors that primarily provide a stabilization function. Thus, in one aspect, the present disclosure provides a set of medical devices, where at least one member of the set is a smart medical device of the present disclosure that provides a characterization function (and optionally some stability function), and at least one member of the set is used primarily or exclusively to provide a stability function. In use, the smart medical device of the present disclosure can be placed in bone tissue at a location where a stability function is not required, i.e., a non-loaded / unloaded location. The medical device utilized primarily or exclusively to provide a stability function can be placed in a loaded location in the bone tissue.

[0015] The present disclosure also relates to an implantable medical device for characterizing a fracture in a bone. The medical device includes an implant configured to be implanted at least partially within the bone and across the fracture. The implant includes an impedance sensor having a first electrode and a second electrode, and a detection module configured to obtain impedance measurements between the first electrode and the second electrode. The implant further includes a controller with memory configured to process and store the impedance measurements, and communication circuitry configured to transmit the impedance measurements to an external device.

[0016] The present disclosure also relates to an implantable medical device for characterizing a fracture in a bone. The medical device includes a first implant and a second implant, each configured to be at least partially implanted within the bone, and a third implant configured to be positioned adjacent the bone across the fracture and secured in place by the first and second implants. The first implant includes a first electrode, and the second implant includes a second electrode. The medical device further includes an impedance sensor with the first and second electrodes and a detection module. The detection module is located within one or more of the first, second, or third implants, and is configured to obtain impedance measurements between the first and second electrodes. The medical device further includes a controller with memory configured to process and store the impedance measurements and communication circuitry configured to transmit the impedance measurements to an external device. The controller, memory, and communication circuitry may be located within one or more of the first, second, or third implants.

[0017] The present disclosure also relates to a method for characterizing a fracture via electrodes on opposite sides of the fracture, the method including obtaining a plurality of measurements of tissue electrical properties over time with a plurality of electrodes associated with a single implant and positioned within bone tissue and across the fracture, the plurality of electrodes including a first electrode and a second electrode on opposite sides of the fracture, the method further including processing the measurements to determine a characterization of the fracture, the characterization corresponding to a healing state of the fracture.

[0018] The present disclosure also relates to a method for characterizing a fracture via electrodes disposed within the fracture gap, the method comprising obtaining multiple measurements of tissue electrical properties over time with multiple electrodes associated with a single implant and positioned within bone tissue at the fracture, the multiple electrodes including a first electrode and a second electrode each positioned within the fracture gap, the method further comprising processing the measurements to determine a characterization of the fracture, the characterization corresponding to a healing state of the fracture.

[0019] The present disclosure also relates to a method for characterizing a bone fracture with electrodes spanning the fracture gap, the method including obtaining a plurality of measurements of tissue electrical properties over time with a plurality of electrodes positioned in bone tissue at the fracture, the plurality of electrodes including a first electrode and a second electrode each spanning the fracture gap, the method further including processing the measurements to determine a characterization of the bone fracture, the characterization corresponding to a healing state of the bone fracture.

[0020] The present disclosure also relates to a method of manufacturing an implantable medical device, the method including creating a plurality of holes through a sidewall of a cannular structure configured to be at least partially implanted within a body and having a lumen therethrough, the method further including associating an electrode with each of the plurality of holes and associating an electronics cartridge with the lumen of the cannular structure, the electronics cartridge including electronics and a plurality of electrical contacts, the association aligning each of the plurality of electrical contacts with a respective one of the holes to achieve electrical coupling between the electronics and each of the electrodes.

[0021] The present disclosure also relates to a method of implanting a medical device, the method including the step of at least partially implanting an implant structure within a body, the structure having a lumen extending at least partially therethrough, the method further including the step of inserting an electronics cartridge into the lumen after implantation of the implant structure.

[0022] The present disclosure also relates to a tool for implanting an implant structure having a proximal end with a head, a shaft extending from the head to a distal end of the implant structure, and a lumen extending through the shaft. The tool includes a drill bit and a mechanism for applying a rotational torque to the drill bit. The drill bit has a first portion configured to directly couple to the head of the implant structure and a second portion extending from the first portion. The second portion is configured to extend at least partially into the lumen of the implant structure.

[0023] The present disclosure also relates to a coupling tool for implanting an implant structure having a proximal end with a head and a shaft extending from the head to a distal end of the implant structure. The coupling tool has a body with a proximal end region and a distal end region. The distal end region is configured to provide a mechanical coupling to the distal end portion of the implant structure. The coupling tool may further include a cap configured to couple to the proximal end region of the body rather than directly to the implant structure.

[0024]

[0013] Exemplary features of the present disclosure, its nature, and various advantages will become apparent from the accompanying drawings and the following detailed description of various embodiments. Non-limiting and non-exclusive embodiments are described with reference to the accompanying drawings, in which like reference numerals refer to like parts throughout the various views unless otherwise specified. The dimensions and relative positions of elements in the figures are not necessarily drawn to scale. For example, the shapes of the various elements have been selected, enlarged, and positioned for clarity of the drawings. The particular shapes of the depicted elements have been selected for ease of recognition in the drawings.

[0014] One or more embodiments are described below with reference to the accompanying drawings. [Brief explanation of the drawings]

[0025] [Figure 1A] 1 is a schematic diagram of an example configuration of a smart medical device. [Figure 1B] 1 is a schematic diagram of an example configuration of a smart medical device having a partially threaded cannulated screw with a pair of electrodes. [Figure 1C] FIG. 1 is a schematic diagram of an example of a smart medical instrument having an electronics cartridge configured for insertion into a cannulated screw, showing a pair of electrical contacts carried by the cartridge aligned with a pair of electrodes. [Figure 1D] FIG. 1 is a schematic diagram of a partially threaded cannulated screw showing that the unthreaded portion is coated with a material. [Figure 2A]1 is a schematic diagram of one locking mechanism for securing an electronics cartridge within a cannulated screw. [Figure 2B] 10 is a schematic diagram of an alternative securing mechanism for securing an electronics cartridge within a cannulated screw. [Figure 3A] 10 is a schematic diagram of an alternative securing mechanism for securing an electronics cartridge within a cannulated screw. [Figure 3B] 10 is a schematic diagram of an alternative securing mechanism for securing an electronics cartridge within a cannulated screw. [Figure 4] 10 is a schematic diagram of an alternative securing mechanism for securing an electronics cartridge within a cannulated screw. [Figure 5A] 10 is a schematic diagram of an alternative securing mechanism for securing an electronics cartridge within a cannulated screw. [Figure 5B] 10 is a schematic diagram of an alternative securing mechanism for securing an electronics cartridge within a cannulated screw. [Figure 6A] 1A-1C are schematic diagrams of different configurations of a fully threaded cannulated screw that can be used in the medical device of FIGS. 1A-1C, showing an example configuration having only one pair of electrodes. [Figure 6B] 1A-1C are schematic diagrams of different configurations of a fully threaded cannulated screw that can be used in the medical device of FIGS. 1A-1C, showing an example configuration having two pairs of electrodes. [Figure 6C] 1A-1C are schematic diagrams of different configurations of a fully threaded cannulated screw that can be used in the medical device of FIGS. 1A-1C, showing an example configuration having electrodes arranged in an array. [Figure 7A] FIG. 1 is a schematic diagram of a smart medical instrument having a cannulated screw with a pair of electrodes and an electronics cartridge configured to be insertable into the cannulated screw, showing a pair of electrical contacts carried by the cartridge aligned with the electrodes. [Figure 7B]FIG. 1 is a schematic diagram of a smart medical instrument having a cannulated screw with a pair of electrodes and an electronics cartridge (shown in cross section) configured for insertion into the cannulated screw, showing a pair of electrical contacts carried by the cartridge aligned with the electrodes. [Figure 8A] FIG. 1 is a schematic diagram of a smart medical instrument having a cannulated screw with an array of electrodes and an electronics cartridge configured to be insertable into the cannulated screw, showing multiple electrical contacts carried by the cartridge aligned with the electrodes. [Figure 8B] FIG. 1 is a schematic diagram of a smart medical instrument having a cannulated screw with an array of electrodes and an electronics cartridge (shown in cross section) configured for insertion into the cannulated screw, showing multiple electrical contacts carried by the cartridge aligned with the electrodes. [Figure 9A] 1D is a schematic diagram of different configurations of the head end of the electronics cartridge of FIG. 1C. [Figure 9B] 1D is a schematic diagram of different configurations of the head end of the electronics cartridge of FIG. 1C. [Figure 10A] FIG. 1 is a schematic diagram of a smart medical instrument having a cannulated screw with a pair of electrodes covering the surface of the screw and an electronics cartridge configured to be insertable into the cannulated screw, showing a pair of electrical contacts carried by the cartridge aligned with the electrodes. [Figure 10B] FIG. 1 is a schematic diagram of a smart medical instrument having a cannulated screw with a pair of electrodes covering the surface of the screw and an electronics cartridge configured to be insertable into the cannulated screw, showing a pair of electrical contacts carried by the cartridge aligned with the electrodes. [Figure 11A]FIG. 1 is a schematic diagram of a smart medical instrument having a cannulated screw with four electrodes covering the surface of the screw and an electronics cartridge configured to be insertable into the cannulated screw, with four electrical contacts carried by the cartridge aligned with the conductive traces of the electrodes. [Figure 11B] FIG. 1 is a schematic diagram of a smart medical instrument having a cannulated screw with four electrodes covering the surface of the screw and an electronics cartridge configured to be insertable into the cannulated screw, with four electrical contacts carried by the cartridge aligned with the conductive traces of the electrodes. [Figure 12A] FIG. 1 is a schematic diagram of a smart medical instrument having a split cannulated screw having a distal portion and a proximal portion, each portion carrying an electrode, and an electronics cartridge configured for insertion into the cannulated screw, with electrical contacts carried by the cartridge aligned with the electrodes. [Figure 12B] FIG. 1 is a schematic diagram of a smart medical instrument having a split cannulated screw having a distal portion and a proximal portion, each portion carrying an electrode, and an electronics cartridge configured for insertion into the cannulated screw, with electrical contacts carried by the cartridge aligned with the electrodes. [Figure 12C] FIG. 1 is a schematic diagram of a smart medical instrument having a split cannulated screw having a distal portion and a proximal portion, each portion carrying an electrode, and an electronics cartridge configured for insertion into the cannulated screw, with electrical contacts carried by the cartridge aligned with the electrodes. [Figure 13A] 10A-10C are schematic diagrams of alternative configurations of smart medical devices, showing electrodes carried by cartridges aligned with slots. [Figure 13B] 10A-10C are schematic diagrams of alternative configurations of smart medical devices, showing electrodes carried by cartridges aligned with slots. [Figure 13C] 10 is a schematic diagram of another example configuration of a smart medical device having a cannulated screw with slots, showing electrodes carried by the cartridge aligned with the slots. FIG. [Figure 13D] FIG. 10 is a schematic diagram of another example configuration of a smart medical device having an electronics cartridge configured to be insertable into a cannulated screw, showing the electrodes carried by the cartridge aligned with the slots. [Figure 14A] FIG. 10 is a schematic diagram of another example configuration of a smart medical device, showing electrodes carried by a cartridge aligned with holes. [Figure 14B] FIG. 10 is a schematic diagram of another example configuration of a smart medical device, showing electrodes carried by a cartridge aligned with holes. [Figure 14C] FIG. 10 is a schematic diagram of another example configuration of a smart medical instrument having a cannulated screw with multiple holes, showing electrodes carried by a cartridge aligned with the holes. [Figure 14D] FIG. 10 is a schematic diagram of another example configuration of a smart medical instrument having an electronics cartridge configured for insertion into a cannulated screw, showing the electrodes carried by the cartridge aligned with the holes. [Figure 15A] FIG. 10 is a schematic diagram of another example configuration of a smart medical device, showing a pair of electrodes carried by a cartridge aligned with a pair of holes. [Figure 15B] FIG. 10 is a schematic diagram of another example configuration of a smart medical device, showing a pair of electrodes carried by a cartridge aligned with a pair of holes. [Figure 15C] FIG. 10 is a schematic diagram of another example configuration of a smart medical instrument having a cannulated screw with a pair of holes, showing a pair of electrodes carried by a cartridge aligned with the pair of holes. [Figure 15D]FIG. 10 is a schematic diagram of another example configuration of a smart medical instrument having an electronics cartridge configured for insertion into a cannulated screw, showing a pair of electrodes carried by the cartridge aligned with a pair of holes. [Figure 16A] FIG. 10 is a schematic diagram of another example configuration of a smart medical instrument, showing the tip electrode aligned with the distal end of the cannulated screw and the cap electrode, also carried by the cartridge, exposed at the head of the screw. [Figure 16B] FIG. 10 is a schematic diagram of another example configuration of a smart medical instrument, showing the tip electrode aligned with the distal end of the cannulated screw and the cap electrode, also carried by the cartridge, exposed at the head of the screw. [Figure 16C] FIG. 10 is a schematic diagram of another example configuration of a smart medical instrument having a cannulated screw, showing the tip electrode aligned with the distal end of the cannulated screw and the cap electrode, also carried by the cartridge, exposed at the head of the screw. [Figure 16D] FIG. 10 is a schematic diagram of another example configuration of a smart medical instrument having an electronics cartridge configured for insertion into a cannulated screw, showing the tip electrode aligned with the distal end of the cannulated screw and the cap electrode, also carried by the cartridge, exposed at the head of the screw. [Figure 17A] FIG. 10 is a schematic diagram of another example configuration of a smart medical device, showing a portion of a cartridge carrying a distal electrode and a proximal electrode extending through the distal end of a cannulated screw. [Figure 17B] FIG. 10 is a schematic diagram of another example configuration of a smart medical instrument having a cannulated screw, showing a portion of a cartridge carrying a distal electrode and a proximal electrode extending through the distal end of the cannulated screw. [Figure 17C]FIG. 10 is a schematic diagram of another example configuration of a smart medical instrument having an electronics cartridge configured for insertion into a cannulated screw, showing a portion of the cartridge carrying a distal electrode and a proximal electrode that extends through the distal end of the cannulated screw. [Figure 18A] 1 is a schematic illustration of tools and techniques for implanting smart medical devices. [Figure 18B] 1 is a schematic illustration of tools and techniques for implanting smart medical devices. [Figure 18C] 1 is a schematic illustration of tools and techniques for implanting smart medical devices. [Figure 18D] 1 is a schematic illustration of tools and techniques for implanting smart medical devices. [Figure 18E] 1 is a schematic illustration of tools and techniques for implanting smart medical devices. [Figure 18F] 1 is a schematic illustration of tools and techniques for implanting smart medical devices. [Figure 18G] 1 is a schematic illustration of tools and techniques for implanting smart medical devices. [Figure 18H] 1 is a schematic illustration of tools and techniques for implanting smart medical devices. [Figure 18I] 1 is a schematic illustration of tools and techniques for implanting smart medical devices. [Figure 18J] 1 is a schematic illustration of tools and techniques for implanting smart medical devices. [Figure 19A] 1 is a schematic diagram of an example pre-integrated configuration of a smart medical instrument having a screw with an integrated electronics package. [Figure 19B] 1 is a schematic diagram of an example pre-integrated configuration of a smart medical instrument having a screw with an integrated electronics package. [Figure 19C] 1 is a schematic diagram of an example pre-integrated configuration of a smart medical instrument having a screw with an integrated electronics package. [Figure 19D]1 is a schematic diagram of an example pre-integrated configuration of a smart medical instrument having a screw with an integrated electronics package. [Figure 20A] FIG. 1 is a schematic diagram of a pre-assembled configuration example of a smart medical device having a cannulated screw with a pair of electrodes deposited on the surface of the cannulated screw and coupled to an electronics package through vias in the sidewall of the screw. [Figure 20B] FIG. 1 is a schematic diagram of a pre-assembled configuration example of a smart medical device having a cannulated screw with a pair of electrodes deposited on the surface of the cannulated screw and coupled to an electronics package through vias in the sidewall of the screw. [Figure 21A] FIG. 1 is a schematic diagram of a pre-assembled configuration example of a smart medical device having a cannulated screw, showing the cannulated screw having four pin electrodes that couple to an electronics package through vias in the sidewall of the screw. [Figure 21B] FIG. 1 is a schematic diagram of a pre-assembled configuration example of a smart medical device having a cannulated screw, showing the cannulated screw having four pin electrodes that couple to an electronics package through vias in the sidewall of the screw. [Figure 22A] FIG. 1 is a block diagram illustrating components of an example implantable reporting processor (IRP) of a smart medical device having a sensor system for monitoring fracture healing status. [Figure 22B] FIG. 1 is a block diagram illustrating components of an example implantable reporting processor (IRP) of a smart medical device having a sensor system for monitoring fracture healing status. [Figure 23] FIG. 1 is a graphical illustration of the magnitude of impedance measured across a fracture as a function of time using a smart medical device. [Figure 24A] 1 is a schematic diagram of a smart medical device implanted for one type of fracture. [Figure 24B]1 is a schematic diagram of a smart medical device implanted for another type of fracture. [Figure 24C] 1 is a schematic diagram of a smart medical device implanted for another type of fracture. [Figure 24D] 1 is a schematic diagram of a smart medical device implanted for another type of fracture. [Figure 24E] 1 is a schematic diagram of a smart medical device implanted for another type of fracture. [Figure 25A] 1 is a flow diagram of a method for characterizing a fracture with a smart medical device. [Figure 25B] 1 is a diagram illustrating how a fracture can be characterized with a smart medical device. [Figure 26A] 1 is a flow diagram of another method for characterizing a fracture with a smart medical device. [Figure 26B] 1 is a diagram illustrating how a fracture can be characterized with a smart medical device. [Figure 27A] 1 is a flow diagram of another method for characterizing a fracture with a smart medical device. [Figure 27B] 1 is a diagram illustrating another way in which a fracture can be characterized with a smart medical device. [Figure 28] FIG. 1 is a situational diagram of smart medical devices in a patient's home. DETAILED DESCRIPTION OF THE INVENTION

[0026] The smart medical devices disclosed herein have electronics, such as an application specific integrated circuit (ASIC) chip containing memory, a microprocessor, and wireless telemetry elements, a power source (battery or supercapacitor), wireless and antenna environmental tuning (MICS or Bluetooth® (transliterated as Bluetooth®)), sensors to confirm in vivo bone healing measurements, and sensors to detect movement relative to the initial placement location of the sensor. Smart medical devices are utilized, for example, in orthopedic trauma and spine products, such as hip fracture screws, long bone fracture screws (with plates), and spinal pedicle screws.

[0027] Two configurations of the smart medical device are envisioned, one referred to herein as a cartridge configuration and the other as a pre-integrated configuration.

[0028] Cartridge configuration example 1A-1C, an example cartridge configuration of a smart medical device 100 includes a structure 102 or outer body characterized by a tubular body with a lumen 104 extending at least partially therethrough. The structure 102 is configured to be at least partially implanted within a body. The medical device 100 further includes an electronics cartridge 106 or inner body containing electronics, such as an ASIC chip, a power source, an antenna, etc. In some embodiments, the electronics cartridge 106 can include a shell that houses the electronics. In other embodiments, the electronics can be secured together or supported by a core element extending along the axis of the cartridge. The electronics cartridge 106 is configured to be inserted into and fitted into the lumen 104 of the structure 102 after implantation of the structure.

[0029] In some embodiments, the structure 102 is made entirely from a single biocompatible implantable grade material, such as titanium, stainless steel cobalt chromium molybdenum alloy, nitinol, ceramic, alumina zirconia carbon hydroxyapatite, or a composite, such as carbon fiber reinforced PEEK.

[0030] In some embodiments, the structure 102 can be segmented into different portions that are made of different material combinations. For example, the structure 102 can have a distal body, section, or portion made of a metallic material, a central body, section, or portion made of a different material than the distal portion, and a proximal body, section, or portion made of approximately the same metallic material as the distal portion. In one exemplary configuration, the metallic material of the distal and proximal portions can be an implantable-grade material with a Young's modulus of 100-200 gigapascals (GPa) and a tensile strength to enable similar or dissimilar material interaction, while the material of the central portion can be made of the same or a different implantable-grade material, such as a polymeric material, as the distal or proximal portions with the same or different Young's modulus. By providing a segmented structure 102, different portions of the structure can exhibit different strength and performance properties for a particular application. For example, the materials for the different portions, whether they are dissimilar or homogeneous, can be such that the strength of the material allows the structure 102 to penetrate and fit into the broken bone and draw the fracture together for healing. A structure 102 configured in this manner can assist in the sensing operations of the medical device 100, for example, electrochemical impedance spectroscopy (EIS) measurements before and after the fracture site.

[0031] In configurations in which the electronics cartridge 106 includes a shell or core element, the shell or core element may be formed of an electrically insulating, non-conductive implantable-grade material. In some embodiments, the electronics cartridge 106 may be configured to enhance a healing response at the implant site. To this end, the electronics cartridge 106 includes a mechanism for delivering a catalytic material that initiates a gaseous oxygen reaction and enhances the oxygen zone at the implant site through a chemical reaction. In some configurations, the mechanism is a reservoir that releases the catalytic material one or more times after implantation under the control of a sustained-release controller. In other configurations, the mechanism is a coating of catalytic material that is added to the cartridge during electrical processing of the cartridge. In either configuration, the substance released by the cartridge mechanism initiates an energy reaction that releases an oxygen-enriched environment in a localized zone around the implant, thereby enhancing healing.

[0032] 1A-1C, the structure 102 is a cannulated screw configured to be implanted into bone tissue. In one configuration, the lumen 104 of the cannulated screw 102 is configured to receive an implant tool during implantation of the screw 102 into bone tissue. In another configuration, the lumen 104 can be configured to receive a support element, such as a "blank" cartridge, that temporarily fills the lumen to provide support for the cannulated screw 102 and reduce the risk of fracture of the screw 102 as it is implanted into bone.

[0033] 1A-1C, the cannulated screw 102 has a shaft 118 with an outer diameter in the range of 4 millimeters or greater and a head 119. The length of the shaft 118 varies depending on the application of the medical device 100. For example, for applications related to hip femoral head fractures, the length of the shaft 118 can be approximately 115 millimeters. The cannulated screw 102 includes a shaft 118 having a continuous thread 111 disposed about a portion thereof that defines a threaded portion 112 of the screw configured to secure the screw into bone. The lumen 104 has a shaft portion with an inner diameter sized to receive the electronics cartridge 106 and a volume sized to receive the electronics cartridge. The electronics cartridge 106 has a proximal end 140, a distal end 142, a head 122 disposed at the proximal end, and a shaft 126 extending from the head toward the distal end.

[0034] The electronics cartridge 106 and the lumen 104 each have a respective form factor that allows placement of the electronics cartridge 106 within the lumen 104. Referring to FIG. 1B , in one embodiment, the form factor of the lumen 104 of the cannulated screw 102 includes a head portion 120 and a shaft portion 124, where the inner diameter of the head portion is larger than the inner diameter of the shaft. The head portion 120 of the lumen 104 can correspond to a recessed pocket in the head 119 of the cannulated screw 102, e.g., a polygonal head. The recessed pocket can be configured to receive a corresponding hexagonal head of an implant tool to transmit torque applied to the implant tool to the screw during implantation of the instrument into bone. Referring to FIG. 1C , the form factor of the electronics cartridge 106 includes a head 122 and a shaft 126, where the outer diameter of the head 122 is larger than the outer diameter of the shaft 126.

[0035] In one embodiment, the electronics cartridge 106 is configured to be secured within the lumen 104. In one embodiment, the electronics cartridge 106 is configured to be removed from the lumen without compromising the structural integrity of either the electronics cartridge or the structure.

[0036] For these purposes, various types of locking mechanisms are contemplated. For example, with reference to Figures 2A and 2B, the head 122 of the electronics cartridge 106 and the head portion 120 of the lumen 104 of the cannulated screw 102 may be sized relative to one another to result in a friction fit 182 when the cartridge is fully inserted into the screw's lumen 104. In this configuration, the head 122 of the electronics cartridge 106 may be pressed, e.g., hammered, into the head portion 120 of the lumen 104 of the cannulated screw 102 to achieve the friction fit. In variations of this configuration, the friction fit may be achieved based on the geometric shapes of the head portion 120 of the lumen 104 of the cannulated screw 102 and the head 122 of the electronics cartridge 106. For example, the head portion 120 of the lumen 104 may be oval in shape, and the cartridge head 122 may be rotated, for example, one-quarter turn, to achieve a friction fit between the head portion 120 and the cannulated screw head 119.

[0037] 3A and 3B, in another embodiment, the head 122 of the electronics cartridge 106 and the head portion 120 of the lumen 104 of the cannulated screw 102 have complementary mechanical features such that a mechanical coupling 184 results when the cartridge is fully inserted into the screw lumen 104. In one configuration, the mechanical feature of the electronics cartridge 106 is a toothed protrusion 186 and the mechanical feature of the cannulated screw 102 is an enlarged ring region 188 of the head portion 120 of the screw lumen 104. In this configuration, the head 122 of the electronics cartridge 106 can be pressed into the head portion 120 of the lumen 104 of the cannulated screw 102 until the tooth projections 186 snap into place within the ring region 188, thereby establishing a mechanical bond 184 and holding the electronics cartridge 106 in place within the cannulated screw by preventing movement of the cartridge outward from the cannulated screw. In a variation of this configuration, a snap-fit ​​feature, such as a round or hexagonal ring, can extend all the way around the head 122 of the electronics cartridge 106 and snap into the ring region 188.

[0038] 4 , in another embodiment, a section of the shaft 126 of the electronics cartridge 106 located below the head 122 includes a threaded portion 190 configured to mate with a complementary threaded portion (not shown) located on the lumen 104 of the cannulated screw 102. In this configuration, the electronics cartridge 106 has a circular cross-section along its length. The lumen 104 of the cannulated screw 102 also has a circular cross-section, thus allowing rotation of the electronics cartridge 106 within the lumen 104 and threaded engagement of the components 102, 106. In this configuration, the electronics cartridge 106 can then be removed from the cannulated screw 102 by loosening the cannulated screw 102. In a variation of this configuration, complementary threads can be located on the outer wall of the head 122 of the electronics cartridge and the inner wall of the head 119 of the cannulated screw 102. In this configuration, the head 119 of the cannulated screw has features on its exterior that mate with an implant tool to allow rotation of the screw during implantation.

[0039] 5A and 5B, in another embodiment, a section of the shaft 126 of the electronics cartridge 106 located below the head 122 includes an interlocking feature 192, which consists of multiple grooves running around the circumference of the shaft. In this configuration, an adhesive is applied to the interlocking feature 192 prior to insertion of the electronics cartridge 106 into the lumen 104 of the cannulated screw 102. The adhesive 194 can be, for example, polymethyl methacrylate (PMMA) or silicone. Upon full insertion of the electronics cartridge 106 into the lumen 104 of the cannulated screw 102, an adhesive interface 194 is formed between the interlocking feature 192 and an inner wall 196 of the cannulated screw 102.

[0040] Another contemplated securing mechanism includes a peel-off surface on the underside of the head 122 of the electronics cartridge 106 that, when peeled away, exposes a sticky surface. Upon full insertion of the electronics cartridge 106 into the lumen 104 of the cannulated screw, the sticky surface abuts the bottom surface of the head portion 120 of the lumen, thereby securing the electronics cartridge 106 in place.

[0041] 1B and 1D, in some embodiments, the cannulated screw 102 has an outer surface 113 and one or more electrodes 128, 130 located on the outer surface. The electrodes 128, 130 may be arcuate pad electrodes with a radius of curvature approximately equal to the radius of curvature of the shaft 118, and may extend along grooves between adjacent turns of the threads 111 that make up the threaded portion 112. For example, each electrode 128, 130 may extend 30° to 180° around the shaft 118. The electrodes 128, 130 are made of a conductive, implantable-grade material with low resistivity. Exemplary materials include platinum, platinum-iridium, gold, gold-plated copper, silver, or other low-resistivity materials used for electronic interconnects. The electrodes 128, 130 are electrically insulated from the shaft 118 of the cannulated screw 102. For this purpose, an insulating material may be applied between the surfaces of the electrodes 128, 130 that would otherwise contact the outer surface 113 of the shaft 118. A gas-tight feedthrough 115 may extend through the sidewall 117 of the cannular screw 102 and provide an electrical connection between the electrodes 128, 130 and the interior 121 of the cannular screw. The feedthrough 115 may be a conventional ceramic feedthrough with gold-brazed conductors, a glass feedthrough, or a fired ceramic feedthrough.

[0042] Referring to FIG. 1D, in embodiments having a partially threaded cannulated screw 102, such as the embodiment of FIGS. 1A-1C, a layer of insulating material 174 can be applied to the non-threaded portion of the screw to form a coating region. This material can be, for example, titanium dioxide or aluminum oxide applied to the non-threaded portion 172 using an anodizing process. Titanium dioxide has a resistivity similar to that of cobalt chrome oxide, which is an excellent insulator. The insulating material can be a diamond material applied to the non-threaded portion 172 using chemical vapor deposition, resulting in a highly insulating coating. This material can also be a ceramic material applied to the non-threaded portion 172 using electroless vapor deposition to initiate the coating bond, which can be a conductive or non-conductive metal liquid metal reflow created by a eutectic attachment process.

[0043] To minimize coating shear, the minor diameter of the threaded portion 112 of the cannula-screw 102 is increased by an amount substantially equal to the thickness of the layer of material 174. Thus, the outer diameter of the coated region of the cannula-screw 102 is generally equal to the minor diameter of the threaded portion 112 of the cannula-screw 102.

[0044] The electrodes 128, 130, in combination with other electronics of the medical device 100, can form a sensor or sensor system configured to monitor electrical properties of tissue. In some embodiments, the sensor system is an impedance sensor that functions as an EIS sensor to detect the location of a fracture and monitor the healing status of such a fracture. Details of the EIS sensor are disclosed further below. The electrodes 128, 130, in combination with other electronics of the medical device 100, can form a communication interface. Details of the communication interface are disclosed further below.

[0045] 1C , in some embodiments, the electronics cartridge 106 has an exterior surface and one or more electrical contacts 132, 134 disposed at the exterior surface and configured to electrically couple to one or more electrodes 128, 130 when the electronics cartridge is inserted into the lumen. An insulating seal 133 between the electrical contacts 132, 134 prevents harmful electrical contact between the two electrodes 128, 130 or the two electrical contacts 132, 134, even when the space between them is filled with a conductive fluid. The insulating seal 133 may be an O-ring or a conformable coated shaped silicone wiper. The cannulated screw 102 and the electronics cartridge 106 each have respective features for aligning the one or more electrodes 128, 130 with the one or more electrical contacts 132, 134 when the electronics cartridge is inserted into the lumen 104. These features may be complementary mechanical features, such as grooves in the surface of one of the cannulated screw 102 and the electronics cartridge 106, and protrusions extending from the other of the screw and the electronics cartridge.

[0046] 1B and 6A-6C, the cannulated screw 102 has a proximal end 136, a distal end 138, and one or more electrodes located along the shaft 118 between the proximal and distal ends. Different numbers and arrangements of electrodes are envisioned.

[0047] For example, with reference to Figures 1B and 6A, in some configurations, the cannulated screw 102 can have a single pair of spaced-apart electrodes on the shaft 118, including a distal electrode 130 near the distal end 138 and a proximal electrode 128 near the proximal end 136. In the configuration of Figure 1B, the electrodes 128, 130 are positioned on the shaft 118 on either side of the threaded portion 112 of the cannulated screw 102, and can be spaced apart by a distance of 20-30 mm or more. In the configuration of Figure 6A, each of the electrodes 128, 130 is positioned on the shaft 118 between adjacent turns of the shaft threads 111, and can be spaced apart by a distance of 20-30 mm or more. Electrodes 128, 130 may be arcuate pad electrodes with a radius of curvature approximately the same as the radius of curvature of shaft 118, and may extend along grooves between adjacent turns of thread 111. For example, each electrode 128, 130 may extend between 30° and 180° around shaft 118.

[0048] 6B, in some embodiments, the cannulated screw 102 can have two pairs of electrodes along the shaft 118. A pair of distal electrodes 130, 150 is positioned near the distal end 138, and a pair of proximal electrodes 128, 148 is positioned near the proximal end 136. In one configuration, the electrodes 128, 130, 148, 150 can be positioned between adjacent turns of the threads 111 of the shaft 118. The electrode pairs 128, 130, 148, 150 can be spaced apart by a distance of 2-10 mm, and electrode pairs can be spaced apart by a distance of 20-30 mm or more. Electrodes 128, 130, 148, and 150 may be arcuate pad electrodes with a radius of curvature approximately the same as the radius of curvature of shaft 118, and may extend along grooves between adjacent turns of thread 111. For example, each electrode 128, 130, 148, and 150 may extend between 30° and 180° around shaft 118.

[0049] 6C, in some embodiments, the cannulated screw 102 can include electrodes 164 arranged in an array along the shaft 118 between the distal end 138 and the proximal end 136 of the cannulated screw 102. In one configuration, each electrode in the electrode array 164 can be positioned between adjacent turns of the threads 111 on the shaft 118, and the electrodes can be spaced apart by a distance of 2 to 10 mm. The electrodes in the electrode array 164 can be arc-shaped pad electrodes with a radius of curvature approximately the same as the radius of curvature of the shaft 118, and the electrodes can extend along the grooves between adjacent turns of the threads 111. For example, each electrode in the electrode array 164 can extend between 30 and 180 degrees around the shaft 118.

[0050] 7A and 7B, in an embodiment of the medical device 100 having only one pair of electrodes 128, 130, the electrodes are electrically isolated from one another. For example, the shaft 118 extending between the proximal end 136 and the distal end 138 of the cannulated screw 102 may be formed of an electrically non-conductive material or may be coated with an insulating material. In either case, one or more electrodes 128, 130 are separated by insulating regions 152. Additional insulating regions 155, 156 located on the sides of the electrodes 128, 130 electrically insulate the electrodes 128, 130 from the surface of the cannulated screw 102, which may be electrically conductive.

[0051] 8A and 8B, in an embodiment of the medical device 100 having an array of electrodes 164, the electrodes are electrically isolated from one another. For example, the shaft 118 extending between the proximal and distal ends 136, 138 of the cannulated screw 102 may be formed of an electrically non-conductive material or may be coated with an insulating material. In either case, one or more electrodes 128, 130 are separated by an insulating region 158.

[0052] 1C, 7B, and 8B, as described above, the electronics cartridge 106 has a proximal end 140, a distal end 142, a head 122 disposed at the proximal end, and a shaft 126 extending from the head toward the distal end. The electronics cartridge 106 is configured to electrically couple the electrodes 128, 130, 148, 150, and 164 of the cannulated screw 102 to electronics housed within the cartridge.

[0053] 1C and 7B, in some embodiments, the electronics cartridge 106 has an exterior surface and a pair of electrical contacts 132, 134 disposed at the exterior surface and configured to electrically couple to the pair of electrodes 128, 130 of the cannula when the electronics cartridge is inserted into the lumen of the cannula. The pair of electrical contacts 132, 134 penetrate the wall of the shell of the electronics cartridge 106 and are electrically coupled to the electronics within the cartridge. As mentioned above, the shell is made of a non-conductive material. Thus, the pair of electrical contacts 132, 134 are electrically insulated from one another.

[0054] 8B, in some embodiments, the electronics cartridge 106 has an exterior surface and an array of electrical contacts 166 disposed at the exterior surface and configured to electrically couple to the array of electrodes 164 when the electronics cartridge is inserted into the lumen of the cannulated screw. Each electrical contact 166 in the array of electrical contacts penetrates the wall of the shell of the electronics cartridge 106 and is electrically coupled to electronics within the cartridge. As mentioned above, the shell is made of a non-conductive material. Therefore, the electrical contacts 166 are electrically isolated from one another.

[0055] 1C, 7B, and 8B, the electronics included in the electronics cartridge 106 may be associated with one or more electronics assemblies located within either or both of the head 122 and the shaft 126. The electronics of the electronics cartridge 106 include an implantable reporting processor (IRP), details of which are provided further below with reference to FIGS. 22A and 22B. Regarding the structure of the IRP, in some embodiments, the IRP includes one or more antennas 144, 145, one or more rechargeable power sources 154, and one or more electronics assemblies, which include: communication circuitry that allows the device to communicate with another device or apparatus (implanted within the body or located externally); One or more sensors that can be utilized to perform one or more of the following: 1) detecting, measuring, and / or monitoring one or more distinct aspects of body tissue (anatomy, physiology, metabolism, and / or function); 2) detecting, measuring, and / or monitoring one or more aspects of body or body segment / joint status or function (fracture healing, movement including measurement of body segment and joint position, angle, velocity, and acceleration); and / or 3) detecting, measuring, and / or monitoring one or more aspects of an orthopedic device or implant; and It includes various other components that enable the operation of the medical device 100, such as memory, switches, processors, etc.

[0056] The electronics are positioned within the electronics cartridge 106 to minimize stress on the electronic components, including particularly sensitive electronics such as the processor, CPU, communication circuitry, and ASICs or power supplies such as capacitors, batteries, or accumulators. To this end, the electronics are generally located away from high stress zones in the medical device 100 and in otherwise minimally loaded portions of the device. For example, in the case of a medical device 100 used in treating bone fractures, high stress zones include: a) the head-to-shaft body interface transition due to torque loading during implantation and compression at implantation; b) the distal transition from the threads to the shaft body due to diametrical changes and torque loading during implantation and compression at implantation; and c) the center of the shaft body due to torque, moment, and axial stress concentrations within this zone. Additionally, sensitive electronics, such as the processor, CPU, communication circuitry, and ASICs, are located at the proximal end of the electronics cartridge 106, while less sensitive electronics, such as the power supply 154, are located at the intermediate region of the cartridge. In some embodiments, the electronics may be located in high stress areas of the medical device 100 but may be configured to withstand the stresses, for example, by being flexible to allow some deformation under device loading conditions.

[0057] In applications requiring multiple medical devices, the devices located at the least stressed implant locations, i.e., locations that will experience the least stress on the implanted medical implant, may be selected to be smart medical devices 100. For example, for a medical device 100 used in treating a femoral neck fracture using the inverted triangle approach shown in FIG. 24B, the least stressed location corresponds to one apex of the inverted triangle. Thus, the medical device 100 may be positioned at one apex of the inverted triangle, where the medical device will primarily perform a characterization function for characterizing the fracture and its healing. Medical devices that perform a stabilization function, primarily or entirely without sensors, may optionally be positioned elsewhere in the inverted triangle, with the purpose of holding the bone tissue together securely during healing.

[0058] Thus, in one aspect, the present disclosure provides a set of medical instruments, i.e., at least two medical instruments, and optionally three, four, five, etc., that are used together to treat fractures in bony tissue. In one embodiment, the medical instruments in the set are all screws. In particular, where the medical instruments of the present disclosure are intended to provide little or no stabilization function, they may be used in conjunction with other medical instruments, such as standard orthopedic screws that lack sensors and primarily provide stabilization function to healing tissue. Thus, in one aspect, the present disclosure provides a set of medical instruments, where at least one member of the set is a smart medical instrument of the present disclosure that provides a characterization function (and optionally some stabilization function), and at least one member of the set is used primarily or exclusively to provide a stabilization function (optionally not a characterization function). For example, in one aspect, the present disclosure provides a set of three medical instruments, where one member of the set is a smart medical instrument of the present disclosure that performs a characterizing function (and optionally some stability function), and two members of the set are utilized primarily or exclusively to perform a stability function, where optionally each of the medical instruments is a screw. Thus, in use, the smart medical instrument of the present disclosure can optionally be placed in bone tissue in a location where the stability function is less necessary, i.e., in a location that is not or only slightly loaded. The medical instrument of the set utilized primarily or exclusively to provide a stability function can be placed in a relatively heavily loaded location in the bone tissue. Thus, in one embodiment, the present disclosure provides a method of treating a femoral neck fracture in an inverted triangle manner, the method including placing a medical instrument of the present disclosure, e.g., medical instrument 100, at one vertex of the inverted triangle and placing medical instruments without sensors at the other two vertices of the triangle.

[0059] In one aspect, the present disclosure provides a set of medical instruments, the set including at least one first medical instrument of the present disclosure and at least one second medical instrument configured for insertion into bone tissue, where the second medical instrument does not include a sensor. Optionally, each of the first medical instrument and the second medical instrument is a screw. Optionally, the set includes a single, i.e., only one, first medical instrument and a plurality, i.e., two or more, i.e., three or more, second medical instruments, where optionally each member of the set is a screw.

[0060] With respect to one or more antennas 144, 145 of the electronics cartridge 106, in some embodiments, the antenna 144 is located entirely inside the cartridge, and may be disposed within the cartridge head 122, within the cartridge shaft 126, or partially within the head and partially within the shaft. For example, referring to FIG. 9A, the head 122a of the electronics cartridge 106 may include an antenna 144a encapsulated within a material 147, such as PEEK. The antenna 144a may be a conductive wire 146 or trace that runs along an antenna board 149 parallel to the base 151 of the head 122. Referring to FIG. 9B, in another embodiment of the electronics cartridge 106, an antenna 144b configured to function as both a communication antenna and a charging element may be located at the top of the head 122b. The antenna 144b may be configured as a protruding pin arranged in a multi-faceted array.

[0061] 1C , in another embodiment of the electronics cartridge 106, an antenna 145 is associated with the shaft 126. The antenna 145 may be comprised of a conductive wire or trace that is wrapped around and extends along a portion of the shaft 126. For example, the antenna 145 may be a wire that extends in a helical pattern around the shaft 126. The antenna 145 is embedded in the shaft and is thus electrically isolated from the outer surface of the shaft 126 to avoid contact with the interior of the cannulated screw 102 when the electronics cartridge 106 is inserted into the screw lumen 104. The antenna 145 may be connected to the electronics in the head 122 via an insulated trace or wire that extends along the shaft 126 between the antenna and the head.

[0062] In some embodiments, the antenna may be located entirely outside the cartridge, hi some embodiments, the antenna may be located partially inside the cartridge and partially outside the cartridge.

[0063] 7B and 8B , the power supply 154 may be associated with the shaft 126 of the electronics cartridge 106 and may be located in an intermediate region along the length of the shaft for structural stability. The power supply 154 may be rechargeable, and a recharging mechanism, e.g., a coil, may be located within the head of the electronics cartridge 106. In another embodiment (not shown), a power source may be associated with the head 122 of the electronics cartridge 106, and a recharging mechanism, e.g., a coil, may be provided alongside a battery within the head of the electronics cartridge. As described further below, the power supply 154 may be one or more of a battery, e.g., a rechargeable battery, and a capacitor, e.g., a supercapacitor. The electronics may include an energy harvesting device configured to harvest energy via one of electrostatic energy, wireless energy transmission, and IR radiation.

[0064] With respect to the communications circuitry of the electronics cartridge 106, in one embodiment, one or more communications components include a radio frequency (RF) transceiver coupled to the antennas 144, 145 and configured to send and receive RF signals (e.g., via Bluetooth or MICS). With reference to FIG. 9A, the RF transceiver may be associated with an electronics assembly 153 in the form of a circuit board located within the head 122a. With reference to FIG. 9B, the RF transceiver may be associated with an electronics assembly 157 in the form of a circuit capsule located within the shaft 126. Details of RF telemetry communications are further described below with reference to FIG. 22A.

[0065] In another embodiment, the one or more communication components include tissue-based communication circuitry coupled to a pair of electrodes associated with the medical device 100 and configured and positioned in contact with tissue. The tissue-based communication circuitry may include a transmitter and a receiver. The pair of electrodes may correspond to the electrodes 128, 130 of the medical device 100. When configured in this manner, the one or more communication components may be configured to either enable capacitive coupling between the medical device 100 and another device or enable galvanic coupling between the medical device and another device. With reference to FIG. 9A, the tissue-based communication circuitry may be associated with an electronics assembly 153 in the form of a circuit board located within the head 122a. With reference to FIG. 9B, the tissue-based communication circuitry may be associated with an electronics assembly 157 in the form of a circuit capsule located within the shaft 126. Details of capacitive and galvanic coupled communication are further described below with reference to FIG. 22A.

[0066] With respect to the sensors of the electronics cartridge 106, in some embodiments, one or more sensors include an EIS sensor comprised of the electrodes 128, 130 of the medical device in combination with the electrode switch and detection circuitry / module of the medical device 100. With reference to FIG. 9A, the electrode switch and detection circuitry / module can be associated with an electronics assembly 153 in the form of a circuit board located within the head 122a. With reference to FIG. 9B, the electrode switch and detection circuitry / module can be associated with an electronics assembly 157 in the form of a circuit capsule located within the shaft 126. Details of the EIS sensor are disclosed further below with reference to FIGS. 22A and 22B.

[0067] In some embodiments, the one or more sensors may include an inertial measurement unit (IMU), such as an accelerometer or gyroscope, configured to output a signal corresponding to movement of the medical device 100 and, by association, movement of the bony structures in which the device is implanted, and corresponding to the movement or activity of the patient in which the device is implanted. The accelerometer may be a one-dimensional accelerometer, a two-dimensional accelerometer, a three-dimensional accelerometer, or an accelerometer of any available dimension. The electronics further include a processor coupled to the accelerometer to receive and process the signal and configured to provide an indication of one or more of patient activity, medical device health (fracture), and movement of the medical device relative to the implant placement site (backout). For example, the position of the accelerometer may be determined after implantation, and detection of a change in its position may be used to detect movement of the medical device at the implant site. Referring to FIG. 9A, the accelerometer or gyroscope and processor may be associated with an electronics assembly 153 in the form of a circuit board located within the head 122a. Referring to FIG. 9B, the accelerometer or gyroscope and processor may be associated with an electronics assembly 157 in the form of a circuit capsule located within the shaft 126 .

[0068] In some embodiments, the one or more sensors may include strain sensors associated with the medical device 100. The electronics further include a processor coupled to the strain sensors to receive and process signals and configured to provide the signals as an indication of one or more of the health of the medical device (fracture) and movement of the medical device relative to the implant placement location (indication of back-out movement or fracture healing). With reference to Figure 9A, the strain sensors and processor may be associated with an electronics assembly 153 in the form of a circuit board located within the head 122a. With reference to Figure 9B, the strain sensors and processor may be associated with an electronics assembly 157 in the form of a circuit capsule located within the shaft 126.

[0069] In some embodiments, the one or more sensors may include an acoustic resonant sensor associated with the medical device 100 and configured to output a signal corresponding to the level of acoustic vibration / movement of the medical device. The electronics further include a processor coupled to the acoustic resonant sensor to receive the signal and configured to process the signal to provide an indication of the fixation of the medical device within the bony structure at the implantation site, which may provide an indication of the healing status of the bone. The acoustic resonant sensor may be a single device that vibrates associated with the medical device 100, or may be a pair of devices consisting of an acoustic transmitter at one end of the medical device 100 and an acoustic receiver at the other end of the device. The acoustic transmitter outputs an acoustic signal into the medical device 100. The acoustic receiver detects the acoustic signal and outputs an electrical signal having an amplitude that represents the strength of the acoustic signal received by the acoustic receiver. The processor may analyze the amplitude to determine the healing status of the fracture, where a progression of the acoustic signal over time toward a lower amplitude (signaling lower vibration of the medical device) indicates bone healing. Referring to Figure 9A, the acoustic resonant sensor and processor may be associated with an electronics assembly 153 in the form of a circuit board located within the head 122a. Referring to Figure 9B, the acoustic resonant sensor and processor may be associated with an electronics assembly 157 in the form of a circuit capsule located within the shaft 126.

[0070] In some embodiments, the one or more sensors may include a stress sensor associated with the medical device 100 and configured to output a signal corresponding to the level of stress within the medical device. The electronics further include a processor coupled to the stress sensor to receive the signal and configured to process the signal to provide an indication of the degree of fixation of the medical device within the bony structure at the implantation site, which may provide an indication of the state of bone healing. The stress sensor may be a single device associated with the medical device 100 that detects local stress, or may be a device consisting of stress sensors disposed within or on the medical device 100. The stress sensor detects mechanical stress in a section of the medical device 100 and outputs an electrical signal having an amplitude representative of the magnitude of this stress. The processor analyzes the amplitude to assess the state of healing of the fracture, where a progression of the stress over time toward a lower amplitude (signaling lower vibrations of the medical device) is indicative of bone healing. Referring to FIG. 9A, the stress sensor and processor may be associated with an electronics assembly 153 in the form of a circuit board located within the head 122a. Referring to FIG. 9B, the stress sensor and processor may be associated with an electronics assembly 157 in the form of a circuit capsule located within the shaft 126.

[0071] In some embodiments, the one or more sensors can include a temperature sensor configured to output a signal corresponding to the temperature of the medical device 100 at the implantation site. With reference to Figure 9A, the temperature sensor and processor can be associated with an electronics assembly 153 in the form of a circuit board located within the head 122a. With reference to Figure 9B, the temperature sensor and processor can be associated with an electronics assembly 157 in the form of a circuit capsule located within the shaft 126. In some embodiments, the temperature sensor can be associated with the cannulated screw 102.

[0072] 9A, the electronics in head 122a may further include other components, such as memory, power switches, fuses, etc., associated with an electronics assembly 153 in the form of a circuit board located below antenna board 149. The electronics in head 122a may further include battery contacts 195 that extend to a power supply (not shown) located in shaft 126 of electronics cartridge 106. In other embodiments, some of the electronics may be implemented on a printed circuit board located in shaft 126. Referring to FIG. 9B, the electronics in shaft 126 may include a power supply 154 and other components, such as memory, power switches, fuses, etc., associated with an electronics assembly 157 in the form of a circuit capsule located in shaft 126. Details of these components are disclosed further below with reference to FIG. 22A.

[0073] In some embodiments, the electronics cartridge 106 includes a mechanism configured to deliver a catalytic material that chemically reacts to produce a gaseous oxygen reaction at the implantation site. The mechanism is a reservoir that releases the catalytic material one or more times after implantation under the control of a sustained release controller in a processor. The mechanism may be a coating of catalytic material on the cartridge that passively elutes into the body. The reaction of the catalytic material with the body can be stimulated by delivering electrical stimulation through the electrodes of the medical device.

[0074] 10A and 10B , in some embodiments, an example cartridge configuration of a smart medical device 1000 includes a cannula-like structure 1002 having a lumen 1004 extending therethrough and a plurality of electrodes 1028, 1030 disposed at an exterior surface of the structure. As with other embodiments of the medical device, the cannula-like structure 1002 is configured to be at least partially implanted within the body. The medical device 1000 further includes an electronics cartridge 1006 containing electronics. The electronics cartridge 1006 is configured to be insertable into the lumen 1004 of the cannula-like structure 1002. Upon insertion, the electronics cartridge 1006 provides one or more electrical connections 1008, 1010 between the cartridge electronics and the plurality of electrodes 1028, 1030.

[0075] The cannula tubular structure 1002 has a conductive substrate 1012 with a threaded portion 1011. The electronics cartridge 1006 has a first electrical contact 1016 and a second electrical contact 1022. The first electrical contact 1016 is positioned to contact an inner surface of the conductive substrate 1012, thereby establishing an electrical coupling 1010 between the electronics and a first electrode 1030. The second electrical contact 1022 is positioned to contact a portion of a second electrode 1028, thereby establishing an electrical coupling 1008 between the electronics and the second electrode 1028.

[0076] The outer surface of the conductive substrate 1012 is at least partially treated or coated with an insulating material 1014. For example, the titanium conductive substrate 1012 may be anodized to render the surface electrically insulating. A first electrode 1030 of the plurality of electrodes corresponds to an exposed portion of the conductive substrate 1012 that is connected to the electronics cartridge 1006 via a first electrical contact 1016 of the cartridge. The first electrical contact 1016 may be, for example, a leaf spring, a press-fit metal ring, a contacting metal surface, or the like. The surface of the first electrode 1030 and the surface in contact with the first electrical contact 1016 are free of any surface treatment or coating, thereby allowing electrical connection to the electronics cartridge 1006 via the conductive substrate 1012.

[0077] A second electrode 1028 of the plurality of electrodes is located on a portion of the insulating material 1014 at the proximal end of the cannula-like structure 1002 and is connected to the electronics cartridge 1006 via a second electrical contact 1022 of the electronics cartridge 1006. The second electrical contact 1022 may be, for example, a leaf spring, a press-fit metal ring, a contacting metal surface, or the like.

[0078] The second electrode 1028 is constructed by coating or treating the conductive substrate 1012 to form a conductive surface layer 1018 on top of the insulating material 1014. The coating that forms the conductive surface layer 1018 is thin to maintain the strength of the cannula-shaped structure 1002 and maintain approximately the same outer diameter as a conventional cannula-shaped structure. Electrical contact with the patient outside the area of ​​the second electrode 1028 is prevented by a thin insulating coating or coating 1020 and / or by slightly reducing the diameter of the cannula-shaped structure 1002 in a region of the second electrode to reduce contact with bone. The insulating coating or coating 1020 can be added by several processes, such as chemical vapor deposition, electroplating, silk screening, or powder coating. In this embodiment, the conductive surface layer 1018 wraps around the insulating head of the conductive substrate 1012 and coats the inside of the drive socket 1026.

[0079] The two electrical contacts 1016, 1022 of the electronics cartridge 1006 are separated from each other by an insulating seal 1032. The insulating seal 1032 prevents harmful electrical contact between the two electrodes 1028, 1030 or between the two electrical contacts 1016, 1022, even if the space between them is filled with a conductive fluid. The insulating seal 1032 may be an O-ring or a compliant overmolded silicone wiper. The second electrode 1028 may be protected from abrasion during insertion by a sacrificial anti-friction coating. The second electrode 1028 may also be mechanically protected by placing conductive and insulating coatings in a recessed channel cut into the screw wall. This construction technique allows for any electrode arrangement, shape, and size.

[0080] 10A and 10B employ layers or coatings of insulating, non-conductive material 1014 and conductive material 1018 to create multiple electrodes 1028, 1030 without modifying the conductive substrate 1012 of the tubular structure 1002. Using masking, the coating can be applied to various dimensions along the length of the tubular structure 1002 to create different electrodes. One area of ​​the conductive substrate 1012 serves as one electrode.

[0081] 11A and 11B, in some embodiments, an example cartridge configuration of a smart medical device 1100 includes a cannula-like structure 1102 having a lumen 1104 extending therethrough and a plurality of electrodes 1128, 1130, 1136, 1140 disposed on the exterior surface of the structure, each electrode having a corresponding electrical contact 1134, 1138, 1142, 1144 also disposed on the exterior surface of the structure. As with other embodiments of the medical device, the cannula-like structure 1102 is configured to be at least partially implanted within the body. The medical device 1100 further includes an electronics cartridge 1106 containing electronics. The electronics cartridge 1106 is configured to be inserted into the lumen 1104 of the cannula-like structure 1102. Upon insertion, the electronics cartridge 1106 provides one or more electrical connections (not shown) between the cartridge's electronics and the plurality of electrodes 1128 , 1130 , 1136 , 1140 .

[0082] The electronics cartridge 1106 has a plurality of electrical contacts 1131, 1135, 1139, 1143 that correspond in number to the plurality of electrodes 1128, 1130, 1136, 1140. Each of the electrical contacts 1131, 1135, 1139, 1143 of the electronics cartridge 1106 is positioned to contact a corresponding electrical contact 1134, 1138, 1142, 1144 of the cannulated screw 1102 upon insertion into the lumen 1104, thereby providing electrical coupling between the cartridge electronics and the electrodes 1128, 1130, 1136, 1140. The electrical contacts 1131, 1135, 1139, 1143 of the electronics cartridge 1106 can be, for example, leaf springs, press-fit metal rings, contacting metal surfaces, or the like.

[0083] The cannula 1102 comprises a conductive substrate with an outer surface that is at least partially treated or coated with an insulating material 1114. For example, the cannula 1102 may comprise a titanium substrate that has been anodized to render the outer surface electrically insulating. A plurality of electrodes 1128, 1130, 1136, and 1140, for example, four in the embodiment of FIG. 11, are formed by a conductive coating applied to the insulating material 1114. Traces 1129, 1133, 1137, and 1141 formed by this or the conductive coating extend from each electrode 1128, 1130, 1136, and 1140 to notches formed in the head 1119 of the cannula 1102, where the traces terminate at respective electrical contacts 1134, 1138, 1142, and 1144. An insulating coating covers the portion of each trace 1129 , 1133 , 1137 , 1141 that extends between a corresponding electrode 1128 , 1130 , 1136 , 1140 and a corresponding electrical contact 1134 , 1138 , 1142 , 1144 on the cannula-like structure 1102 .

[0084] Three of the four electrodes 1128, 1132, 1136 are C-shaped and do not completely wrap around the shaft 1126 of the cannula-like structure 1002. This allows one or more of the traces 1133, 1137, 1141 of the three more distal electrodes 1130, 1136, 1140 to pass through the gaps in the C-shaped electrodes 1128, 1130, 1136 on a single conductive layer. However, by adding an additional insulating layer, all four electrodes 1128, 1132, 1136, 1140 can be completely wrapped around the shaft 1126 and cross over the top of the conductive connections to the other electrodes.

[0085] The embodiment of Figures 11A and 11B utilizes electroplating of conductive and non-conductive materials on the exterior surface of the substrate of the cannulated tubular structure 1102. First, a non-conductive layer insulates most or all of the substrate. Second, the substrate is covered, and a conductive coating is applied to create electrical contacts 1134, 1138, 1142, and 1144, electrical traces 1129, 1133, 1137, and 1141, and electrodes 1128, 1130, 1136, and 1140. Third, non-conductive plating is applied only to electrical traces 1129, 1133, 1137, and 1141, thereby leaving electrical contacts 1134, 1138, 1142, and 1144 and electrodes 1128, 1130, 1136, and 1140 exposed.

[0086] 12A-12C, in some embodiments, an exemplary cartridge concept for a smart medical device 1200 includes a multi-component cannula-like structure 1202 having a lumen 1204 extending therethrough and a plurality of electrodes 1228, 1230 disposed at an exterior surface of the structure. As with other embodiments of the medical device, the cannula-like structure 1202 is configured to be at least partially implanted within the body. The medical device 1200 further includes an electronics cartridge 1206 containing electronics. The electronics cartridge 1206 is configured for insertion into the lumen 1204 of the multi-component cannula-like structure 1202. Upon insertion, the electronics cartridge 1206 provides one or more electrical connections 1208, 1210 between the cartridge electronics and the plurality of electrodes 1228, 1230.

[0087] The multi-component cannula structure 1202 includes a distal component 1212 and a proximal component 1214, each having a conductive substrate 1216a, 1216b with an outer surface at least partially coated with an insulating coating 1218. For example, the distal component 1212 and the proximal component 1214 may include titanium substrates 1216a, 1216b that are anodized to provide an insulating outer surface. The distal component 1212 includes a threaded portion 1220. While the multi-component cannula structure 1202 described herein includes two components 1212, 1214, each having an electrode 1228, 1230, the cannula structure 1202 may include three or more components. For example, the multi-component cannula structure may include four components, each having an electrode and each configured to couple to one or more adjacent components.

[0088] The electronics cartridge 1206 includes a shell 1240 housing the electronics, and first and second electrical contacts 1222, 1224 located on the exterior of the shell and coupled to the electronics. The shell 1240 is configured to electrically insulate the two electrical contacts 1222, 1224 from one another. To this end, the shell 1240 may be made of an electrically non-conductive material or a conductive material coated with an insulating material. The first electrical contact 1222 is positioned to contact the inner surface of the conductive substrate 1216a of the distal component 1212, thereby achieving the electrical coupling 1208 between the electronics and the first electrode 1230. The first electrical contact 1222 may be, for example, a leaf spring, a press-fit metal ring, a contacting metal surface, or the like. The inner surface of the conductive substrate 1216a is free of any surface treatment or coating. This allows for an electrical connection from the first electrode 1230 to the electronics cartridge 1206 via the conductive substrate 1216a. The second electrical contact 1224 is positioned to contact the inner surface of the conductive substrate 1216b of the proximal component 1214, thereby achieving an electrical coupling 1210 between the electronics and the second electrode 1228. The second electrical contact 1224 can be, for example, a leaf spring, a press-fit metal ring, a contacting metal surface, or the like. The inner surface of the conductive substrate 1216b is free of any surface treatment or coating. This allows for an electrical connection from the second electrode 1228 to the electronics cartridge 1206 via the conductive substrate 1216b.

[0089] The first electrode 1230 and the second electrode 1228 correspond to exposed areas of the corresponding conductive substrates 1216a, 1216b, respectively. The electrodes 1228, 1230 may be constructed by masking the outer surfaces of the corresponding conductive substrates 1216a, 1216b before applying the insulating coating 1218, or by mechanically polishing the conductive substrate to remove the insulating coating if one has already been applied. The first electrode 1230 and the second electrode 1228 are electrically insulated from each other by a non-conductive joint 1232 between the distal and proximal components 1212, 1214 of the cannula-shaped structure 1202.

[0090] The non-conductive joint 1232 may be an adhesive used to secure the proximal component 1214 to the distal component 1212 during implantation of the medical device 1200. For example, during implantation of the medical device 1200, the first component 1212 is first implanted into a portal hole drilled through bone tissue. Next, a non-conductive adhesive material is applied to the end of the proximal component 1214, which is then inserted into the portal hole until it is mechanically coupled to the distal component 1212. The coupling between the distal component 1212 and the proximal component 1214 may be achieved by their respective mechanical features 1234, 1236, e.g., mating sets of notches and protrusions. The electronics cartridge 1206 is then inserted through the head 1238 of the proximal component 1214 and into the lumen 1204. In another implantation procedure, the electronics cartridge 1206 can be inserted into the distal component 1212, after which the proximal component 1214 can be coupled to the distal component. In yet another procedure, the distal component 1212 and the proximal component 1214 can be assembled together outside the body, after which they can be implanted and then seated in the bone using any of the implant tools and techniques described below with reference to Figures 18A-18J. The electronics cartridge 1206 is then inserted into the assembled cannula-like structure 1202.

[0091] 13A-13D , in some embodiments, an example cartridge configuration of a smart medical device 1300 includes a cannulated screw 1302 and an electronics cartridge 1306 configured for insertion into the cannulated screw. In this embodiment, the electronics cartridge 1306 includes one or more electrodes, and the cannulated screw 1302 includes one or more holes. In some embodiments, various electronics of the electronics cartridge 1306 are located within the cartridge head 1322, and a power supply 1354 is located within a portion of the electronics cartridge shaft 1326 located below the head. This and other structures and characteristics of the cannulated screw 1302 and electronics cartridge 1306 are substantially identical to the structures and characteristics described above for the cannulated screw 102 and electronics cartridge 106 of the embodiment of FIGS. 1A-1C . Accordingly, such details will not be repeated here. Instead, further description of the smart medical device 1300 of FIGS. 13A-13D will focus on its distinct features.

[0092] 13C, the cannula screw 1302 has a bore 1308 in the form of a slot disposed through its sidewall 1310. The slot 1308 is located in a region of the cannula screw shaft 1318 proximal to the threaded region 1312 of the cannula screw 1302. In some embodiments, an insulating coating is applied to the outer surface 1316 of the cannula screw 1302 in an area of ​​the slot 1308.

[0093] 13D, the electronics cartridge 1306 has a spring-loaded electrode assembly 1314 that extends radially outward from the surface of the cartridge's shaft 1326. To this end, the electrode assembly 1314 is biased against the surface of the shaft 1326, allowing the electronics cartridge to transition between a compressed state, in which the outer surface of the electrode assembly 1314 is substantially flush with the surface of the shaft 1326, and an expanded state, in which the outer surface of the electrode assembly 1314 is elevated or offset from the surface of the shaft 1326 so as to pass through the slot 1308. The electrode assembly 1314 has a pair of electrodes 1328, 1330 spaced apart by a distance of at least 1 mm.

[0094] Continuing to refer to FIG. 13D , the form factors of the electrode assembly 1314, such as the geometric cross-section and thickness, as well as the distance d between the bottom of the head 1322 of the electronics cartridge 1306 and the top of the electrode protrusion, are such that when the electronics cartridge is fully inserted into the lumen 1304 of the tubular screw 1302, the electrode assembly 1314 aligns with and passes through the slot 1308, positioning the electrodes 1328, 1330 outward from the outer surface 1316 of the tubular screw.

[0095] The cannulated screw 1302 and electronics cartridge 1306 may include one or more features similar to those described above with reference to Figures 2A-5B to secure the cartridge within the cannulated screw 1302. Additionally, the passage of the electrode assembly 1314 through the slot 1308 also serves to secure the electronics cartridge 1306 within the cannulated screw 1302.

[0096] 13A-13D, when implanting the medical device 1300 for treatment of a fracture 1342, the cannulated screw 1302 can be implanted across the fracture such that the fracture is located between opposite ends of the slot 1308, preferably midway between such ends. Thus, when the electronics cartridge 1306 is inserted into the cannulated screw 1302, the electrodes 1328, 1330 are located on opposite sides of the fracture 1342.

[0097] The electrodes 1328, 1330, in combination with other electronics of the medical device 1300, can comprise a sensor or sensor system configured to monitor electrical properties of tissue. In some embodiments, the sensor system is an impedance sensor that functions as an EIS sensor to detect the location of a fracture and monitor the healing status of such a fracture. As described further below, in this configuration, the medical device 1300 enables data collection via the electrodes 1328, 1330 for characterization of the fracture 1342 and healing status analysis. The electrodes 1328, 1330, in combination with other electronics of the medical device 1300, can comprise a tissue-conductive communication interface. Details of the tissue-conductive communication interface are disclosed further below.

[0098] 14A-14D , in some embodiments, an example cartridge configuration of a smart medical device 1400 includes a cannulated screw 1402 and an electronics cartridge 1406 configured for insertion into the cannulated screw. In some configurations, various electronics of the electronics cartridge 1406 are located within the cartridge head 1422, and a power supply 1454 is located within a portion of the electronics cartridge shaft 1426 located below the head. This and other structures and characteristics of the cannulated screw 1402 and electronics cartridge 1406 are substantially identical to the structures and characteristics described above for the cannulated screw 102 and electronics cartridge 106 of the embodiment of FIGS. 1A-1C . Accordingly, such details will not be repeated here. Instead, further description of the smart medical device 1400 of FIGS. 14A-14D will focus on its distinct features.

[0099] 14C , the cannula screw 1402 has an array of holes 1408 disposed through its sidewall 1410. In the cannula screw 1402 of FIG. 14C , the array of holes 1408 includes eight individual holes. The array of holes 1408 is disposed within a region of the cannula screw shaft 1418 proximal to the threaded region 1412 of the cannula screw 1402. In some embodiments, an insulating coating is applied to the outer surface 1416 of the cannula screw 1402 within a section of the array of holes 1408. In some embodiments, an insulating coating is applied to the outer surface 1416 of the cannula screw 1402 along its entire length, excluding the threaded region 1412.

[0100] Referring to FIG. 14D , the electronics cartridge 1406 includes an array of electrodes 1414. In the electronics cartridge 1406 of FIG. 14D , the array of electrodes 1414 includes eight individual electrodes. The array of electrodes 1414 includes multiple individual electrodes separated by seals 1424 that seal and electrically insulate the individual electrodes from one another. In some embodiments, the seals 1424 correspond to a region of the hollow shell of the electronics cartridge 1406, which is formed of an insulating material, as described above. In other embodiments, the seal 1424 may be a ring made of a non-conductive metal or polymer material or a biocompatible elastomer disposed around the shell of the electronics cartridge 1406. The distance between adjacent individual electrodes may be at least 1 mm. The individual electrodes are recessed relative to an outer surface 1420 of the shaft 1426 of the electronics cartridge 1406. In one configuration, the individual electrodes are ring electrodes.

[0101] 14D , the distance d between the bottom of the head 1422 of the electronics cartridge 1406 and the top of the array of electrodes 1414 is such that when the electronics cartridge is fully inserted into the lumen 1404 of the cannulated screw 1402, each individual electrode in the array of electrodes 1414 is aligned with a corresponding hole in the array of holes 1408. Due to the recessed orientation of the individual electrodes relative to the shaft 1426 of the electronics cartridge 1406 upon insertion of the electronics cartridge 1406 into the cannulated screw 1402, a donut-shaped space is formed between the outer surface of each electrode and the inner wall of the cannulated screw 1402. An electrode-tissue interface between the electrode surface and tissue is achieved by tissue passing through the holes in the cannulated screw 1402 and into the donut-shaped space around the electrodes in the array of electrodes 1414.

[0102] The cannulated screw 1402 and electronics cartridge 1406 may include one or more mechanisms similar to those described above with reference to FIGS. 2A-5B for securing the cartridge within the cannulated screw. Additionally, one or more of the electrodes in the array of electrodes 1414 may be configured to radially expand to extend at least partially into, and in some cases entirely through, one of the holes in the array of holes 1408. To this end, the electrodes may be made of a material with shape memory, such as platinum or a platinum-iridium alloy, so that when the electronics cartridge 1406 is placed in an orthopedically defined location, a change in temperature causes the electrodes to change from a set configuration to another shape-set configuration that extends the electrodes into the hole. The electrode expansion change may be 0.001 inches (0.025 mm) or greater in the axial direction, radial direction, or both, thereby extending the electrodes into and through the hole, thereby securing the electronics cartridge 1406 within the cannulated screw 1402 and improving contact between the electrode surface and the bone tissue interface.

[0103] 14A-14D, when implanting the medical device 1400 for treatment of a fracture 1442, the cannulated screw 1402 can be implanted across the fracture such that the fracture is located between opposite ends of the array of holes 1408, preferably midway between such ends. Thus, when the electronics cartridge 1406 is inserted into the cannulated screw 1402, one or more of the electrodes are located on opposite sides of the fracture 1442.

[0104] At least two selected electrodes of the array of electrodes 1414, in combination with other electronics of the medical device 1400, can form a sensor or sensor system configured to monitor electrical properties of tissue. In some embodiments, the sensor system is an impedance sensor that functions as an EIS sensor to detect the location of a fracture and monitor the healing status of such a fracture. As described further below, in this configuration, the medical device 1400 enables data collection via selected electrodes on opposite sides of the fracture 1442 for fracture characterization and healing analysis purposes. Two selected electrodes of the array of electrodes 1414, in combination with other electronics of the medical device 1400, can form a tissue-based communication interface, details of which are described further below.

[0105] 15A-15D , in some embodiments, an example cartridge configuration of a smart medical device 1500 includes a cannulated screw 1502 and an electronics cartridge 1506 configured for insertion into the cannulated screw. In some configurations, various electronics of the electronics cartridge 1506 are located within the cartridge head 1522, and a power supply 1554 is located within a portion of the electronics cartridge shaft 1526 located below the head. This and other structures and characteristics of the cannulated screw 1502 and electronics cartridge 1506 are substantially identical to the structures and characteristics described above for the cannulated screw 102 and electronics cartridge 106 of the embodiment of FIGS. 1A-1C . Accordingly, such details will not be repeated here. Instead, further description of the smart medical device 1500 of FIGS. 15A-15D will focus on its distinct features.

[0106] 15C , the cannula screw 1502 has a pair of holes 1508, 1509 extending through its sidewall 1510. The holes 1508, 1509 are disposed in a region of the cannula screw shaft 1518 proximal to the threaded region 1512 of the cannula screw 1502. In some embodiments, an insulating coating is applied to the outer surface 1516 of the cannula screw 1502 within the region of the holes 1508, 1509. In some embodiments, the insulating coating is applied to the outer surface 1516 of the cannula screw 1502 along its entire length, excluding the threaded region 1512.

[0107] Referring to FIG. 15D, the electronics cartridge 1506 includes a pair of electrodes 1528, 1530. The electrodes 1528, 1530 are separated from one another by a seal 1524, which seals and electrically insulates the individual electrodes from one another. In some embodiments, the seal 1524 corresponds to a region of the hollow shell of the electronics cartridge 1506, which is formed of an insulating material, as described above. In other embodiments, the seal 1524 may be a ring made of a non-conductive metal or polymer material or a biocompatible elastomer disposed around the shell of the electronics cartridge 1506. The distance between the electrodes 1528, 1530 may be at least 1 mm. The electrodes 1528, 1530 are recessed relative to the outer surface 1520 of the shaft 1526 of the electronics cartridge 1506. In one configuration, the individual electrodes 1528, 1530 are ring electrodes.

[0108] 15D , the distance d between the bottom of the head 1522 of the electronics cartridge 1506 and the proximal electrode 1528 is such that when the electronics cartridge is fully inserted into the lumen 1504 of the cannulated screw 1502, each electrode 1528, 1530 is aligned with a corresponding hole 1508, 1509. Due to the recessed configuration of the individual electrodes 1528, 1530 relative to the shaft 1526 of the electronics cartridge 1506, a donut-shaped space is formed between the outer surface of each electrode and the inner wall of the cannulated screw 1502 upon insertion of the electronics cartridge 1506 into the cannulated screw 1502. An electrode-tissue interface between the electrode surface and tissue is achieved by the tissue passing through the holes 1508, 1509 of the cannulated screw 1502 and into the donut-shaped space around the electrodes 1528, 1530.

[0109] The cannulated screw 1502 and electronics cartridge 1506 may include one or more mechanisms for securing the cartridge within the screw, similar to those described above with reference to Figures 2A-5B. Additionally, one or more of the electrodes 1528, 1530 may be configured to expand radially to extend at least partially into, and in some cases entirely through, one of the holes 1508, 1509, as described with reference to Figure 14D.

[0110] 15A-15D, when implanting the medical device 1500 for treatment of a fracture 1542, the cannulated screw 1502 can be implanted across the fracture so that the fracture is located between, and preferably midway between, the pair of holes 1508, 1509. Thus, when the electronics cartridge 1506 is inserted into the cannulated screw 1502, the electrodes 1528, 1530 are positioned on opposite sides of the fracture 1542.

[0111] The electrodes 1528, 1530, in combination with other electronics of the medical device 1500, can form a sensor or sensor system configured to monitor electrical properties of tissue. In some embodiments, the sensor system is an impedance sensor that functions as an EIS sensor to detect the location of a fracture and monitor the healing status of such a fracture. As described further below, in this configuration, the medical device 1500 enables the collection of data via these electrodes for fracture characterization and healing analysis. The electrodes 1528, 1530, in combination with other electronics of the medical device 1500, can form a tissue-based communication interface. Details of the tissue-based communication interface are described further below.

[0112] 16A-16D , in some embodiments, an example cartridge configuration of a smart medical device 1600 includes a cannulated screw 1602 and an electronics cartridge 1606 configured for insertion into the cannulated screw. In some configurations, the various electronics of the electronics cartridge 1606 are located within the head 1622, and the power supply 1654 is located within a portion of the shaft 1626 of the electronics cartridge located below the head. This and other structures and characteristics of the cannulated screw 1602 and electronics cartridge 1606 are substantially identical to the structures and characteristics described above for the cannulated screw 102 and electronics cartridge 106 of the embodiment of FIGS. 1A-1C . Accordingly, such details will not be repeated here. Instead, further description of the smart medical device 1600 of FIGS. 16A-16D will focus on its distinct features.

[0113] 16D, the electronics cartridge 1606 has a cap electrode 1628 associated with the cartridge head 1622 and a tip electrode 1630 disposed at the distal end of the cartridge. The distance d between the bottom of the head 1622 of the electronics cartridge 1606 and the top of the tip electrode 1630 is such that when the electronics cartridge is fully inserted into the lumen 1604 of the cannulated screw 1602 (shown in FIG. 16B), the tip electrode 1630 is adjacent to or exposed at the distal end 1605 of the lumen 1604 of the cannulated screw 1602, and the cap electrode 1628 is exposed at the screw head 1619. In this embodiment, the exposure of the cap electrode 1628 and tip electrode 1630 is achieved without the need for sidewall slots or holes as in the embodiments of, for example, FIGS. 13A-15D.

[0114] Continuing to refer to FIG. 16D, in some embodiments, the cap electrode 1628 has a first portion 1632 that lies in a plane parallel to the top surface of the head 1622, a second portion 1634 that curves downward from the end of the first portion and extends in a plane different from the plane of the first portion and away from the side of the head, and a third portion 1636 that curves upward from the end of the second portion and extends in a plane substantially parallel to the plane of the first portion 1632 and further away from the side of the head.

[0115] 16A , exposure of the cap electrode 1628 at the head 1619 of the cannulated screw 1602 allows an electrode-tissue interface 1640 to be formed between the third portion 1636 of the cap electrode 1628 and the surface of bone tissue 1644 upon insertion of the electronics cartridge 1606 into the cannulated screw 1602. In this embodiment, because a portion of the cap electrode 1628, e.g., the first portion 1632 and possibly the second portion 1634, contacts the head 1619 of the cannulated screw 1602, the head of the cannulated screw 1602 can be coated with an insulating material or the entire cannulated screw 1602 can be coated with an insulating material.

[0116] In another embodiment (not shown), rather than providing a cap electrode 1628 exposed on the head 1622 of the electronics cartridge 1606, the cartridge may have an upper electrode located inside the cartridge (either at the head 1622 or at the upper region of the shaft 1626) that is exposed at the side of the cartridge for electrical contact with the conductive portion of the cannulated screw 1602. In this embodiment, the entire screw, except for the portion that contacts the upper electrode, is coated with an insulating material.

[0117] 16D , the tip electrode 1630 is recessed relative to the outer surface 1620 of the shaft 1626 of the electronics cartridge 1606. In one configuration, the tip electrode 1630 is a ring electrode. Due to the recessed configuration of the tip electrode 1630 relative to the shaft 1626 of the electronics cartridge 1606, a donut-shaped space is formed between the outer surface of the tip electrode 1630 and the inner wall of the cannulated screw 1602 upon insertion of the electronics cartridge 1606 into the cannulated screw 1602. An electrode-tissue interface between the tip electrode 1630 and tissue is achieved by tissue passing through the distal end 1605 of the cannulated screw 1602 and into the donut-shaped space around the tip electrode 1630. A seal 1652 disposed about the shaft 1626 and proximal to the tip electrode 1630 is located proximally of the seal to prevent ingress of tissue and bodily fluids into the portion of the medical device 1600, particularly the portion containing the cap electrode 1628. The seal 1652 may be formed of a biocompatible elastomeric or polymeric material having a durometer of 20 A or greater, or a polymer fiber-doped or polymer-encapsulated material capable of swelling when exposed to a solution, or a non-conductive metallic material.

[0118] The cannulated screw 1602 and electronics cartridge 1606 can include one or more features similar to those described above with reference to Figures 2A-5B to secure the cartridge within the cannulated screw. Additionally, the tip electrode 1630 can be configured to expand radially and axially to extend at least partially into, and in some cases entirely into, the distal end 1605 of the cannulated screw, as described with reference to Figure 14D. Such expansion helps secure the electronics cartridge 1606 within the cannulated screw 1602.

[0119] 16A-16D, during implantation of the medical device 1600 for treatment of a fracture 1642, the cannulated screw 1602 can be implanted across the fracture so that the fracture is located between the head 1619 and distal end 1621 of the screw, preferably midway between the head and distal end. Thus, when the electronics cartridge 1606 is inserted into the cannulated screw 1602, the electrodes 1628, 1630 are positioned on opposite sides of the fracture 1642.

[0120] The electrodes 1628, 1630, in combination with other electronics of the medical device 1600, can form a sensor or sensor system configured to monitor electrical properties of tissue. In some embodiments, the sensor system is an impedance sensor that functions as an EIS sensor to detect the location of a fracture and monitor the healing status of such a fracture. As described further below, in this configuration, the medical device 1600 enables the collection of data via these electrodes for fracture characterization and healing analysis. The electrodes 1628, 1630, in combination with other electronics of the medical device 1600, can form a tissue-based communication interface. Details of the tissue-based communication interface are described further below.

[0121] 17A-17C , in some embodiments, a cartridge configuration of a smart medical device 1700 includes a cannulated screw 1702 and an electronics cartridge 1706 configured for insertion into the cannulated screw, with a portion of the electronics cartridge extending through and beyond the distal end of the cannulated screw. In some configurations, the various electronics of the electronics cartridge 1706 are disposed within a head 1722 of the electronics cartridge, and a power supply 1754 is disposed within a first portion 1725 of a shaft 1726 of the electronics cartridge located below the head. This and other structures and characteristics of the cannulated screw 1702 and electronics cartridge 1706 are substantially identical to those described above for the cannulated screw 102 and electronics cartridge 106 of the embodiment of FIGS. 1A-1C . Accordingly, such details will not be repeated here. Instead, further description of the smart medical device 1700 of FIGS. 17A-17C will focus on its distinct features.

[0122] 17C, electronics cartridge 1706 has a rigid proximal portion 1760, a rigid intermediate portion 1761, and a non-load-bearing flexible distal portion 1762. Proximal portion 1760 includes head 1722 and first portion 1725 of shaft 1726, on which power supply 1754 is disposed. In some embodiments, the different portions 1760, 1761, and 1762 of electronics cartridge 1706 are made of the same implantable-grade material, with approximately the same or graded hardness. For example, proximal portion 1760 can be made of a metallic material with a hardness of RA25 or a polymer with a durometer of 95A or greater. Intermediate portion 1761 can be made of the same material, with approximately the same hardness as proximal portion 1760. The flexible distal portion 1762 can be made of the same material as the proximal portion 1760 and intermediate portion 1761, but has a lower stiffness than these regions to allow for flexing of the distal region. In some embodiments, the different portions 1760, 1761, 1762 of the electronics cartridge 1706 are made of different implantable-grade materials with similar or graded stiffness. In some embodiments, the flexible distal portion 1762 is formed of a matrix polymer.

[0123] The proximal portion 1760, the intermediate portion 1761, and the flexible distal portion 1762 join together to form a continuous shaft 1726. To this end, the first portion 1725 of the shaft 1726, the intermediate portion 1761 of the shaft, and the flexible distal portion 1762 of the shaft are joined together by a Morse taper connection, a single-locking threaded mechanism, or a keyway and single-thread lock that creates interconnected sections with specific axial load capabilities and that maintain a flexible deflection of 1° or more from the central axis. The flexible distal portion 1762 of the shaft has a pair of electrodes 1728, 1730. The electrodes are spaced at least 1 mm apart. The electrodes 1728, 1730 are approximately flush with the outer surface of the shaft 1726 of the electronics cartridge 1706. In one configuration, the electrodes 1728, 1730 are ring electrodes.

[0124] 17B, ​​in this embodiment, the cannulated screw 1702 has a length substantially shorter than the length of the electronics cartridge 1706 and functions to secure the electronics cartridge in place. In some embodiments, the cannulated screw 1702 has a shaft 1718 with a length substantially equal to the length of the first portion 1725 of the shaft 1726 of the electronics cartridge 1706, such that when the cartridge is inserted into the screw, the intermediate portion 1761 and flexible distal portion 1762 of the shaft 1726 extend through the end of the screw. In some embodiments, an insulating coating is applied to the outer surface 1716 of the cannulated screw 1702. In some embodiments, the cannulated screw 1702 does not have an insulating coating applied along its entire length.

[0125] 17A-17C, during implantation of the medical device 1700 for treatment of a fracture 1742, a portal hole sized to receive the electronics cartridge 1706 is formed across the fracture. The depth of the portal hole is such that, upon subsequent insertion of the electronics cartridge 1706 into and through the cannulated screw 1702, the fracture 1742 is positioned between the electrodes 1728, 1730, preferably midway between the electrodes. During implantation, the cannulated screw 1702 is implanted into the portal hole, and then the electronics cartridge 1706 is inserted into and partially through the screw. To this end, the electronics cartridge 1706 can have a closed-ended lumen for receiving a stylet that pushes the intermediate portion 1761 and flexible distal portion 1762 past the cannulated screw 1702 and into the portal hole. When the electronics cartridge 1706 is inserted into and through the cannulated screw 1702 , the electrodes 1728 , 1730 are positioned on opposite sides of the fracture 1742 .

[0126] The cannulated screw 1702 and electronics cartridge 1706 may include one or more mechanisms for securing the cartridge within the screw, similar to those described above with reference to Figures 2A-5B. Additionally, a region 1720 of the flexible distal portion 1762 of the electronics cartridge 1706 may be configured to swell or expand upon exposure to a fluid. To this end, the flexible distal portion 1762 may be made of a matrix polymer that swells upon exposure to flushed sterile water or saline after implantation. The radial and / or axial expansion of the region 1720 of the flexible distal portion 1762 helps to secure the electronics cartridge 1706 in place and create intimate contact between the electrodes 1728, 1730 and the bone tissue interface.

[0127] The electrodes 1728, 1730, in combination with other electronics of the medical device 1700, can form a sensor or sensor system configured to monitor electrical properties of tissue. In some embodiments, the sensor system is an impedance sensor that functions as an EIS sensor to detect the location of a fracture and monitor the healing status of such a fracture. As described further below, in this configuration, the medical device 1700 enables the collection of data via these electrodes for fracture characterization and healing analysis. The electrodes 1728, 1730, in combination with other electronics of the medical device 1700, can form a tissue-based communication interface. Details of the tissue-based communication interface are described further below.

[0128] How to implant cartridge configuration examples 1A and 1B includes at least partially implanting a structure 102 within a body and, after implantation of the structure, inserting an electronics cartridge 106 into the lumen 104. The method further includes securing the electronics cartridge 106 to the structure 102. Thereafter, after securing the electronics cartridge 106 to the structure 102, the cartridge can be removed from the lumen 104 without affecting the integrity of the structure or the cartridge. During implantation of the structure 102 within the body, a support element can be inserted into the lumen 104 to provide physical support along the length of the shaft of the structure 102. After the structure 102 is secured within the body, the support element is removed and the cartridge is inserted into the lumen 104.

[0129] 18A-18G, further details of a method of implanting a medical device, such as the medical device shown in Figures 1A and 1B, into a fractured bone are provided, the method including a two-stage insertion process during which one or more cannulated screws are implanted into bone tissue and an electronics cartridge is inserted into at least one of the cannulated screws.

[0130] Referring to FIG. 18A, a first guidewire 1802 is driven across a fracture 1804 of a bone 1806 to within a distance of, for example, 5 mm into the subchondral bone, the outer region of the bone containing the marrow. The first guidewire 1802 has an outer diameter smaller than the inner diameter of the cannulated screw to be implanted. Referring to FIG. 18B, a parallel drill guide 1808 is engaged with the first guidewire 1802 to create parallel guidewire paths, or portal holes. Referring to FIGS. 18C and 18D, three portal holes are drilled in the bone 1806 using the parallel drill guide 1808. A second guidewire 1810 and a third guidewire 1812 are inserted into the portal holes, and the drill guide is removed.

[0131] 18E, the length of the cannulated screws 1814 to be inserted into each portal hole can be measured with the use of a depth gauge (not shown). If the heads 1818 of the cannulated screws 1814 are countersunk, the heads are placed into the measuring device. Each of the cannulated screws 1814 is placed over and slid along its respective guidewire 1802, 1810, 1812 until the tip of the screw abuts the open end of its corresponding portal hole.

[0132] 18F, a cannulated screw 1814 is threaded into each of the portal holes with the use of an insertion tool 1822. The tool has a drill bit 1824 configured to engage the head 1818 of the cannulated screw 1814, and the tool has a lumen 1826 (shown in FIG. 18G) sized to receive and slide over the guidewires 1802, 1810, 1812.

[0133] 18G, in some embodiments, the drill bit 1824 can have a hexagonal cross-section that is sized to fit into a corresponding hexagonal socket in the head 1818. In this embodiment, the drill bit 1824 is slid over the guidewires 1802, 1810, 1812 toward and engage the head 1818 of the cannulated screw 1814. The drill bit 1824 is then turned to advance the cannulated screw 1814 through the portal hole and across the fracture 1804. The drill bit 1824 is disengaged from the head 1818 of the cannulated screw 1814, and the guidewires 1802, 1810, 1812 are then removed, leaving the cannulated screw in place.

[0134] 18H, in some embodiments, the drill bit 1824 can have a hexagonal cross-section sized to fit into a corresponding hexagonal socket in the head 1818, and a support shaft 1828 extends from the drill bit and is configured to fit within a lumen of the tubular screw 1814. The support shaft 1828 can have a feature 1830, such as a linear protrusion located along all or a portion of the shaft, configured to mate with a corresponding feature, such as a line or groove, along at least a portion of the inner sidewall of the shaft 1834 of the tubular screw 1814. The drill bit 1824 and the support shaft 1828 each further have a lumen 1832 sized to receive and slide over a guidewire 1802, 1810, 1812.

[0135] In this embodiment, the support shaft 1828 and drill bit 1824 are placed over the guidewires 1802, 1810, 1812 and slid toward the head 1818 of the cannulated screw 1814. The support shaft 1828 is positioned relative to the cannulated screw 1814 so that the protrusions 1830 on the support shaft are aligned with the slots in the cannulated screw shaft 1834. The support shaft 1828 is slid into the lumen of the cannulated screw 1814 until the drill bit 1824 engages the screw head 1818. The drill bit 1824 is turned together with the support shaft 1828 to advance the cannulated screw 1814 through the hole and across the fracture 1804. The drill bit 1824 and support shaft 1828 are disengaged from the cannulated screw 1814, and the guidewires 1802, 1810, and 1812 are then removed, leaving the cannulated screw in place. The support shaft 1828 provides support along the length of the shaft 1834 of the cannulated screw 1814 during insertion, and the support shaft functions to distribute torque application during rotation to both the head 1818 region of the screw and the shaft 1834 of the screw. This torque distribution reduces the risk of fracture of the cannulated screw 1814 during implantation.

[0136] In an alternative configuration, the support shaft 1828 can be smooth along its length and lack features such as linear projections or keys. This configuration supports the shaft 1834 of the cannulated screw during implantation but does not function to transmit torque. In another alternative configuration, the support shaft 1828 can be a separate component that is inserted into the lumen of the cannulated screw 1814 prior to engagement of the drill bit 1824. In this configuration, the support shaft 1828 can have features such as linear projections or keys that correspond to and engage features such as grooves or channels on the shaft 1834 of the cannulated screw 1814. In this case, the drill bit 1824 has features such as a hexagonal socket configured to engage the hexagonal end of the support shaft 1828 for the purpose of transmitting torque along the support shaft during rotation of the drill bit.

[0137] 18I, in some embodiments, the cannulated screw 1814 can be configured to be placed within a coupling device 1840 as part of an implantation procedure. The coupling device 1840 includes an annular body 1842 having a proximal end region with a proximal opening 1844 sized to receive the cannulated screw 1814 and a distal end region with a distal opening 1846 configured to receive and mate with a distal portion 1848 of the cannulated screw 1814. This engagement can be achieved by thread features on the outer periphery of the distal portion 1848 of the cannulated screw and thread features on the inner periphery of the annular body 1842. This engagement can also be via a locking mechanism. The coupling device 1840 can further include a cap 1850 configured to mate with the proximal end of the annular body 1842. This engagement can be achieved by thread features on the cap 1850 and the annular body 1842, respectively. The cap 1850 further includes a feature 1852, e.g., a hexagonal socket, configured to engage a drill bit. A portal hole drilled through the bone is of sufficient size to receive the annular body 1842 of the coupling device 1840 during implantation. In FIG. 181, the dimensions of the annular body 1842 relative to the dimensions of the cannular screw 1814 are not drawn to scale for clarity of illustration. Generally, the thickness 1854 of the tubular body 1842 is less than the diameter 1856 of the cannular screw 1814, and can be, for example, between ¼ and ½ of the diameter of the cannular screw.

[0138] In this embodiment, the cannulated screw 1814 is secured within the coupling device 1840, e.g., the distal portion 1848 of the cannulated screw is threaded into the distal opening 1846 of the annular body 1842, and a cap 1850 is coupled to the proximal end of the annular body. The coupling device 1840 and cannulated screw 1814 are fitted over and slid along their respective guidewires 1802, 1810, 1812 until the screw tip 1858 abuts the open end of its corresponding hole. Additionally, with reference to FIG. 18G, the drill bit 1824 can have a hexagonal cross-section sized to fit into a corresponding hexagonal socket in the cap 1850 of the coupling device 1840. The drill bit 1824 is fitted over the guidewires 1802, 1810, 1812 protruding from the cap 1850 of the coupling device 1840 and slid toward the cap to engage the cap.

[0139] The drill bit 1824 is then turned to advance the coupling device 1840 and cannulated screw 1814 through the portal hole and across the fracture 1804. The drill bit 1824 is turned in the opposite direction to disengage the coupling device 1840 from the cannulated screw 1814, and the coupling device is then removed from the portal hole, leaving the cannulated screw in place. At this stage, the cannulated screw 1814 can be further turned, if necessary, by direct engagement with the drill bit to fully seat the screw. For example, turning the cannulated screw 1814 can bring the screw head into abutting contact with the bone, thereby pressing the fractured bone portions together. The guidewires 1802, 1810, and 1812 are then removed from the cannulated screw 1814. During rotation of the coupling device 1840, torque energy applied at the proximal end of the coupling tool is transferred along the length of the annular body 1842 to the distal end of the tubular body 1842 and to the distal portion 1848 of the cannular screw, where the annular body couples to the screw. In this manner, torque transfer along the length of the shaft of the cannular screw 1814 is avoided. This torque distribution reduces the risk of fracture of the cannular screw 1814 during implantation.

[0140] In an alternative implantation procedure, the cannulated screw 1814 can be implanted using the tubular body 1842 without the cap 1850. In this embodiment, the proximal end of the annular body 1842 is configured to engage the drill bit 1824.

[0141] 18J, after the cannulated screws 1814 are implanted, an electronics cartridge 1820 is inserted into at least one of the cannulated screws. In some embodiments, the electronics cartridge 1820 can be inserted into the screws in a two-step process. In a first action, a syringe-like insertion tool is used to introduce and position the electronics cartridge 1820 within the cannulated screws 1814. In a second action, the electronics cartridge 1820 is secured in place within the cannulated screws 1814 using at least one of the mechanisms described above with reference to FIGS. 2A-5B.

[0142] In some embodiments, the electronics cartridge 1820 can be inserted into the screw using an introducer tool. The guide wire, which is located in the center of the cannulated screw 1814, can be removed, and then the electronics cartridge 1820 can be attached. The introducer tool is fitted over the guide wire before removing the guide wire. The tip of the introducer tool has a tapered end that abuts the head of the cannulated screw 1814. When positioned in this manner, the introducer tool extends from the surgical site but does not extend beyond the end of the guide wire. With the introducer tool against the screw head, the guide wire is removed, and the electronics cartridge 1820 is lowered within the introducer tool until it slides into the cannulated screw 1814.

[0143] Reserved load type configuration example 19A-19D , in some embodiments, a preloaded smart medical device 1900 has a structure 1902 including a head 1904 and a shaft 1906, each with a head cavity 1908 and a shaft cavity 1910, respectively. In some embodiments, the medical device 1900 is a screw configured to be implanted into bone tissue. The medical device 1900 further includes an antenna 1944 and an electronics assembly 1912 disposed in the head cavity 1908 and a power supply 1954 disposed in the shaft cavity 1910. At least one electrode 1914 is associated with the shaft 1906 and electrically coupled to the electronics assembly 1912 by a conductor 1916 passing through a sidewall of the shaft 1906. Regarding antenna 1944, the antenna may be a conductive wire 1946 or trace running along an antenna board 1949 inserted within a material 1947, such as PEEK, ceramic, or other material that allows for communication and connectivity, such as RF signal transmission or reception. Regarding power supply 1954, the power supply is coupled to electronics assembly 1912 via a pair of battery contacts 1955.

[0144] A preloaded smart medical device may be structurally similar to any one of the cartridge configurations described above, but with the electronics cartridge permanently secured within a structure, such as a cannulated screw, during manufacturing. For example, a preloaded smart device may be fabricated by inserting an electronics cartridge into a cannulated screw and welding or securing the head of the electronics cartridge into the head of the cannulated screw with a biocompatible adhesive, such as a silicone or urethane adhesive, and then hermetically sealing the assembly at each of the distal and proximal ends. In these preloaded configurations, one of the head of the electronics cartridge and the head of the cannulated screw is configured to receive an implantation tool. For example, the electronics cartridge may have a socket head that engages with the implantation tool, or the head of the cannulated screw may have features on its exterior that engage with the implantation tool, such as those shown in FIG. 4.

[0145] The structural features of the preloaded configuration are substantially the same as those described for the cartridge configuration, and therefore a description of these features will not be repeated here.

[0146] 20A and 20B , in some embodiments, a preloaded smart medical device 2000 includes a cannula-like structure 2002 configured to be at least partially implanted within a body. The cannula-like structure 2002 has a lumen 2004 extending therethrough, a plurality of holes 2006, 2008 disposed through a sidewall 2010, and a plurality of electrodes 2012, 2014, one associated with each of the plurality of holes. The medical device 2000 further includes an electronics cartridge 2016 located at least partially within the lumen 2004 of the cannula-like structure 2002. The electronics cartridge 2016 includes electronics, such as an antenna, an ASIC, a power source, etc. The electronics cartridge 2016 further includes a plurality of electrical contacts 2018, 2020, each associated with a respective one of the holes 2006, 2008 to provide electrical coupling between the cartridge electronics and each of the electrodes 2012, 2014, respectively.

[0147] The cannula-like structure 2002 has a substrate 2024 with an outer surface 2026 and an inner surface 2028. A first electrode 2012 of the plurality of electrodes is disposed on the outer surface 2026 of the substrate, the first electrode having a feedthrough 2030 that extends through a first hole 2006 of the plurality of holes to the inner surface 2028 of the substrate. A second electrode 2014 of the plurality of electrodes is also disposed on the outer surface 2026 of the substrate, the second electrode having a feedthrough 2032 that extends through a second hole 2008 of the plurality of holes to the inner surface 2028 of the substrate.

[0148] In some embodiments, the substrate 2024 is formed of an insulating material. In some embodiments, the substrate 2024 is made of a conductive material coated with an insulating material 2034. As shown in Figure 20B, the substrate 2024 can be treated or coated to electrically insulate the outer surface 2026, the inner surface 2028, and the inner walls 2036, 2038 of each hole 2006, 2008. For example, the titanium substrate 2024 can be anodized to provide an insulating surface.

[0149] The electrodes 2012, 2014 may be formed by coating or treating the outer surface 2026 of the substrate 2024 to create the outer portions of the electrodes. The inner walls 2036, 2038 of the holes 2006, 2008 and adjacent portions of the inner surface 2028 of the substrate 2024 are similarly coated or treated. The coating or treatment may be performed, for example, by electroplating or silk screening. After the electrodes 2012, 2014 are formed, for example, by electroplating, the holes 2040, 2042 formed through the electrodes may be filled with a material to strengthen the sidewall 2010 of the cannula-like structure 2002, or the electrodes may be made without holes in order to control the electrode plating process to strengthen the sidewall.

[0150] The electrodes 2012, 2014 may be custom plated profiles, as shown in FIG. 20B, or may be profiled ends of conductive pins that penetrate the sidewall 2010 of the cannula-like structure 2002. These fabrication techniques allow for any number, size, and shape of electrodes to be added to the surface of the screw. The electrodes 2012, 2014 are separated from each other by an insulating seal 2046. The insulating seal 2046 prevents harmful electrical contact between the electrodes, even when the space between them is filled with a conductive fluid. The insulating seal 2046 may be an O-ring or a compliant overmolded silicone wiper.

[0151] 20A and 20B , in one configuration, the electronics cartridge 2016 has a connecting leg 2048 that extends down the lumen 2004 of the cannula-like structure 2002. The connecting leg 2048 has a conductive center peg 2050 with a distal end that forms the first electrical contact 2018, an insulating core 2052, and a conductive jacket that surrounds a portion of the insulating core to form the second electrical contact 2020. Thus, the electronics cartridge 2016 has the first electrical contact 2018 positioned to contact the feedthrough 2030 of the first electrode 2012 on the inner surface 2028 of the substrate, thereby providing an electrical coupling between the electronics and the first electrode, and the second electrical contact 2020 positioned to contact the feedthrough 2032 of the second electrode 2014 on the inner surface of the substrate, thereby providing an electrical coupling between the electronics and the second electrode.

[0152] 21A and 21B, in some embodiments, a preloaded smart medical device 2100 includes a cannula-like structure 2102 configured to be at least partially implanted within a body. The cannula-like structure 2102 has a lumen 2104 extending therethrough, a plurality of holes 2106a-2106d extending through a sidewall 2110, and a plurality of pin electrodes 2112a-2112d, each associated with a respective one of the plurality of holes. The medical device 2100 further includes an electronics cartridge 2116 located at least partially within the lumen 2104 of the cannula-like structure 2102. The electronics cartridge 2116 includes electronics, such as an antenna, an ASIC, a power source, etc. The electronics cartridge 2116 further has a plurality of electrical trace lines 2114a-2114d, each with a distal end 2116a-2116d that align with a corresponding one of the holes 2106a-2106d, thereby providing electrical coupling between the cartridge electronics and each of the pin electrodes 2112a-2112d.

[0153] The cannula tubular structure 2102 includes a substrate 2124 having an outer surface 2126 and an inner surface 2128. In some embodiments, the substrate 2124 is formed of an insulating material. In some embodiments, the substrate 2124 is formed of a conductive material coated with an insulating material 2134. As shown in FIG. 21B, the substrate 2124 may be treated or coated to insulate the outer surface 2126, the inner surface 2128, and the inner walls of each of the holes 2106a-2106d. For example, the titanium substrate 2124 may be anodized to render these surfaces electrically insulating.

[0154] The pin electrodes 2112a-2112d can be bonded or force-fit into the holes 2106a-2106d to contact the corresponding distal ends of the distal ends 2116a-2116d. The pin electrodes 2112a-2112d can be rigid or can be spring-loaded pogo-style pins biased to extend radially outward from the holes 2106a-2106d. In configurations where the substrate 2124 of the cannula tubular structure 2102 is conductive but not coated with an insulating material, the pin electrodes 2112a-2112d have insulating outer surfaces and conductive cores. The pin electrodes 2112a-2112d can also be bonded into the holes 2106a-2106d using an insulating bonding agent. The pin electrodes 2112a-2112d may be riveted into the holes 2106a-2106d, and the ends of the pins may be flattened into electrodes in the riveting process. The pin electrodes 2112a-2112d may be formed together by filling the holes 2106a-2106d with a solidifying conductive material (e.g., conductive epoxy). This can help increase the strength of the sidewall 2110 of the cannula-like structure 2102 in the vicinity of the holes 2106a-2106d.

[0155] Electrical Elements and Features Thus, having disclosed example cartridge configurations and example smart medical device pre-integration configurations, as well as the mechanical, material, and other structural details of these various embodiments, the electrical and operational elements and features of the two example configurations will now be described.

[0156] 22A, an example configuration of a smart medical device includes an implantable reporting processor (IRP) 2203. The IRP 2203 includes a power supply 2212, a sensing electrode 2221, an electronics assembly 2210, an antenna 2230, communication electrodes 2231 and 2233, and an acoustic transducer 2236.

[0157] The circuitry of the electronics assembly 2210 may include one or more sensors 2222, an electrode switch 2223, and a detection circuit / module 2227. As disclosed further below, in some embodiments, the detection electrodes 2221, the electrode switch 2223, and the detection circuit / module 2227 function together as a sensor 2229 configured to monitor an electrical property of tissue. For example, the sensor 2229 may be an impedance sensor.

[0158] The circuitry of the electronics assembly 2210 may include a fuse 2214, one or more power switches 2216, 2218, a clock oscillator, a power management unit 2220, a memory 2224, a controller 2232, and communications circuitry 2225. The communications circuitry 2225 may include one or more of a radio frequency (RF) transceiver 2226 and filter 2228 coupled to the antenna 2230, tissue conduction communication (TCC) circuitry 2238 coupled to the set of communications electrodes 2231, 2233, or data-over-sound circuitry 2240 coupled to the acoustic transducer 2236. Examples of some or all of these components are described elsewhere in this application or in U.S. patent application Ser. No. 16 / 084,544, which is incorporated by reference in its entirety and incorporated by reference in all jurisdictions. In one embodiment, the electronics assembly 2210 may be an ASIC chip with the possibility of recharging via a 2mF to 8mF capacitor for processing and transmitting data packages.

[0159] As noted above, the IRP 2203 includes one or more sensors 2222, 2229. "Sensor" refers to a combination of components that form a device or sensor that can be used to one or more of the following: 1) detect, measure, and / or monitor one or more aspects of the state or function of the body or body segment / joint (fracture healing, movement including measuring position, angle, velocity, and acceleration of body segments and joints), 2) detect, measure, and / or monitor one or more distinct aspects of body tissue (anatomy, physiology, metabolism, and / or function), and / or 3) detect, measure, and / or monitor one or more aspects of an orthopedic device or implant.

[0160] Referring to FIG. 22B, as described above, in some embodiments, the IRP 2203 includes a detection electrode 2221, an electrode switch 2223, and an impedance sensor 2229 having a detection circuit / module 2227. The detection electrode 2221 may include multiple individual electrodes 2231a-2231n. In some embodiments, the number of electrodes 2231a-2231n may be at least two and may be up to eight or more. Referring to FIGS. 1A-1C, in some embodiments, the detection electrode 2221 may correspond to the electrodes 128, 130 associated with the cannulated screw 102. Referring to FIGS. 13A-13D, in some embodiments, the detection electrode 2221 may correspond to the electrodes 1328, 1330 associated with the electronics cartridge 1306. 14A-14D, in some embodiments, the detection electrodes 2221 may correspond to the array of electrodes 1414 associated with the electronics cartridge 1406.

[0161] 22B, in some embodiments, the detection circuit / module 2227 of the impedance sensor 2229 includes a switch controller 2234, a signal generator 2235, an impedance calculator 2237, a digital-to-analog converter (DAC) 2239, a digital transconductance amplifier (GMC) 2241, and an analog-to-digital converter (ADC) 2243. In this example configuration, the impedance sensor 2229 functions as an EIS sensor that measures frequency-dependent impedance through the body anatomy for the purposes of characterizing the fracture and assessing the healing or pathology of the fracture. EIS sensors in this context are described, for example, in Monica C. Lin et al., "New Opportunities for Fracture Healing Detection: Impedance Spectroscopy Measurements Correlate to Tissue Composition in Fractures," Journal of Orthopaedic Research, published December 2017, which is incorporated herein by reference.

[0162] 22B, the medical device may include a sensor system 2229, such as an impedance sensor or an EIS sensor, including one or more sensing electrodes 2231a-2231n and one or more components 2223, 2227 electrically coupled to the one or more sensing electrodes for monitoring electrical properties of tissue for purposes of characterizing fracture healing. Two structural embodiments of such a medical device are envisioned: one embodiment in which the sensor components of the sensor system 2229 are included in a single medical device, and another example in which the sensor components are distributed across various structures of the medical device.

[0163] 24A and 24B, in a first embodiment, multiple sensing electrodes 2420 are associated with a single medical device 2400 having a structure configured to be implanted in a bone 2410 to bridge a fracture 2408. In this embodiment, the length of the medical device 2400 is selected to allow for positioning of a first sensing electrode 2428 on a first side of the fracture 2408 and a second sensing electrode 2430 on a second side of the fracture opposite the first side.

[0164] 24C , in a second embodiment, a first sensing electrode 2428 of a medical device 2400 is associated with a first implant or structure 2402 configured to be implanted on a first side of a fracture 2408, and a second sensing electrode 2430 of the medical device is associated with a second implant or structure 2404 configured to be implanted on a second side of the fracture. In this embodiment, the medical device 2400 includes a third implant or plate 2406 configured to straddle the structures 2402, 2404. The plate 2406 serves as a means for electrically coupling the two sensing electrodes 2428, 2430 to a common sensing component. The common sensing component can be located in one or more of the first structure 2402, the second structure 2404, and the plate 2406.

[0165] In either embodiment, impedance measurements can be obtained across the bone fracture 2408 and analyzed over time as a means of monitoring the healing process from an inflammatory stage to a repair stage, e.g., from hematoma to callus, as the fracture transitions to bony callus / spongy. To this end, changes in impedance measurements as a function of time can be obtained by the medical device 2400. Measurements can be obtained periodically, e.g., hourly, every six hours, etc., to collect a dataset of impedance measurements over time. In some embodiments, the dataset of impedance measurements can be analyzed on-board by the medical device 2400 to provide an outcome that is indicative of the healing condition of the fracture. In some embodiments, the dataset can be transmitted to an external device for analysis to provide an outcome that is indicative of the healing status of the fracture.

[0166] In either case, such visualization may include one of the following: "union" (meaning the fracture 2408 has healed; e.g., the magnitude of impedance before and after the fracture has increased above baseline by a threshold amount, e.g., a percentile); "suspected non-union" (meaning healing has not progressed to a level consistent with union; e.g., the magnitude of impedance before and after the fracture has increased relative to baseline, but the increase is too small and the rate of increase is too slow as a function of time); or "non-union" (meaning healing has not occurred; e.g., the magnitude of impedance before and after the fracture remains the same over time).

[0167] In some embodiments, an outcome of the analysis is obtained based on a comparison of a measure derived from a patient's dataset of impedance measurements to a measure derived from a reference dataset of impedance measurements across an entire patient population. For example, a measure of change in impedance over a period of time derived from the patient's dataset can be compared to a measure of change in impedance over the same period of time derived from the reference dataset to determine whether the patient's measurements are within an acceptable range of the reference measurements. If the patient's measurements are determined to be outside the acceptable range, the smart medical device 2400 can issue an alert. For example, an alert can be issued if the patient's measurements deviate from the reference measurements by a threshold measure, e.g., one percentile less than the reference measurements.

[0168] In some embodiments, measurements corresponding to different stages or modalities of bone healing over time can be defined based on a reference data set. For example, with reference to FIG. 23 , the reference data set can define the expected change in impedance at 7 days post-implant, representing a “cartilage” healing state; the expected change in impedance at 13 days post-implant, representing a “C and C” healing state (where “C and C” represent cartilage and cancellous bone); the expected change in impedance at 19 days post-implant, representing a “cancellous” healing state; and the expected change in impedance at 28 days post-implant, representing a “cortical” healing state. Comparing patient measurements at approximately the same time post-implant with the reference measurements can track the patient's healing status and provide alerts if the patient's measurements fall outside the acceptable range of the corresponding reference measurements.

[0169] With respect to obtaining impedance measurements, and with reference to FIG. 22B , as described above, the impedance sensor 2229 can function as an EIS sensor. To this end, in some embodiments, the impedance sensor 2229 employs a two-point impedance sensing technique, where the sensing electrode 2221 includes a first electrode and a second electrode. The first electrode and the second electrode can be selected from a plurality of available sensing electrodes 2231a-2231n. The sensing circuit / module 2227 is configured to enable the first electrode and the second electrode to function in either an application mode or a detection mode. During the application mode, a signal, e.g., a current, is applied to the first electrode and the second electrode. For example, the signal can be applied to the first electrode while the second electrode is grounded. During the detection mode, the impedance between the first electrode and the second electrode is sensed based on a change in potential between the electrodes.

[0170] With regard to the application mode, in some embodiments, the signal generator 2235 generates a digital representation 2245 of a temporal sinusoidal wave at a first frequency and provides this sinusoidal signal to both the DAC 2239 and the impedance calculator 2237. The DAC 2239 receives the digital representation 2245, converts it to an analog sinusoidal voltage 2247, and provides it to the GMC 2241. The GMC 2241 converts the analog sinusoidal voltage 2247 to a sinusoidal current 2249. The GMC 2241 outputs the sinusoidal current 2249 to the electrode switch 2223, which applies the sinusoidal current to the first electrodes 2231a-2231n of the sensing electrodes 2221. The sinusoidal current 2249 is applied to body tissue by a voltage that is the potential difference between the first and second electrodes 2231a-2231n of the sensing electrodes 2221 where they are located.

[0171] During the detection mode, a voltage 2251 across the first and second electrodes and through the body tissue is detected by ADC 2243, which has an input coupled to the first electrode via electrode switch 2223. ADC 2243 converts voltage 2251 to a digital voltage 2253 and provides this voltage to signal generator 2235. The signal generator converts digital voltage 2253 to a digital sine wave voltage 2255 and provides this to impedance calculator 2237. Impedance calculator 2237 calculates the impedance based on digital representation 2245 of a temporal sine wave at a first frequency and generates the resulting digital sine wave voltage 2255.

[0172] The above can be repeated for different frequencies in the frequency range. Different impedance measurements at different frequencies allow for the collection of different measurements that can indicate different fracture healing responses. Analysis of measurements at different frequencies reveals that the impedance change at a particular frequency or subset of frequencies best correlates with the stage of healing. For each frequency, the impedance calculator 2237 processes the corresponding digital representation of the sinusoidal wave over time 2245 and the digital sinusoidal voltage 2255 to calculate the complex impedance (Z) of the anatomical structure. As described above, these impedances are collected over time into a data set and analyzed to provide an outcome corresponding to the healing state of the fracture.

[0173] With regard to obtaining impedance measurements, and continuing to refer to FIG. 22B , in some embodiments, the impedance sensor 2229 employs a four-point impedance detection method, where the detection electrodes 2221 include a first electrode, a second electrode, a third electrode, and a fourth electrode, which are switchably coupled to the detection module via the electrode switch 2223. The first and second electrodes can be selected from a plurality of available detection electrodes 2231a-2231n. The detection circuit / module 2227 is configured such that the first and second electrodes can function in an application mode, and the third and fourth electrodes can function in a detection mode. During the application mode, a signal, e.g., a current, is applied to the first and second electrodes. For example, the signal can be applied to the first electrode while the second electrode is grounded. During the detection mode, the impedance between the third and fourth electrodes is detected based on the potential between the third and fourth electrodes.

[0174] In some embodiments, changes in impedance indicate healing progress. For example, referring to FIG. 23 , a graph 2300 of impedance magnitude 2302 measured before and after a fracture is shown as a function of time 2304 using a pair of sensing electrodes spaced 27 mm apart based on EIS measurements at a frequency of 5000 Hz. The progress of different fracture characterizations or healing states, including cartilage and cancellous bone (C and C), trabecular bone, and cortical bone, is indicated by the corresponding increase in impedance magnitude between days 5 and 35. In this example, given the increase in impedance magnitude over time, the data analysis outcome at day 35 indicates “union,” meaning the fracture is healed.

[0175] The impedance sensor 2229 of the smart medical device 2400 offers various advantages over other bone healing monitoring methods. For example, the monitoring capabilities of the medical device 2400 eliminate the need for intermediate x-ray transmissions, thereby reducing medical care costs and the patient inconvenience of having to visit an imaging facility. In the case of suspected nonunion, the monitoring capabilities of the medical device 2400 identify delayed healing sooner than image monitoring and allow for additional patient care and complementary and / or alternative treatment options. In the case of nonunion, the monitoring capabilities of the medical device 2400 identify non-healing fractures sooner than image monitoring, thereby allowing for consideration of other options for the patient, such as new surgery, e.g., hip replacement. The medical device 2400 also provides improved clinician workflow by providing useful information relatively automatically and by providing relevant remote patient monitoring (RPM) data over a period of time, which may meet minimal requirements for organization.

[0176] 22A, 22B, and 24B, considering an embodiment of a smart medical device in which the sensor components of the sensor system 2229 are included in a single medical device, in one particular configuration the medical device 2400 can have multiple electrodes 2420 along its shaft. In this configuration, the switch controller 2243 can be configured to control the electrode switch 2223 to select a first electrode 2428 and a second electrode 2430 from among the multiple electrodes 2420 by testing various electrode pairs to first locate the fracture 2408 and then select an electrode on a first side 2460 of the fracture to serve as the first electrode 2428 and an electrode on a second side 2462 of the fracture to serve as the second electrode 2430.

[0177] To locate the location of a fracture, impedance measurements may be taken between adjacent pairs of electrodes along the shaft of the medical device 2400, ultimately resulting in a measurement indicative of the fracture. For example, the fracture 2408 may be determined to be located between the pair of electrodes with the highest impedance measurement. With regard to the selection of the first 2428 and second 2430 electrodes, any electrodes on either side may be selected, although closely spaced electrodes tend to provide more accurate impedance measurements. Thus, generally speaking, the electrodes closest to, but opposite, the fracture 2408 are selected as the first 2428 and second 2430 electrodes.

[0178] Initial electrode selection may be performed during implantation of the medical device by a physician interface, e.g., a programmer, configured to detect the location of the fracture relative to the paired electrodes based on impedance measurements. To this end, the external programmer may control the implanted switch controller 2234 to perform the electrode selection process described above.

[0179] 22A, 22B, and 24B, in another example configuration of a smart medical device in which the sensor components of the sensor system 2229 are included in a single medical device, the medical device 2400 can further include a third electrode 2448 and a fourth electrode 2450 located at an exterior surface of the structure 2402, where the one or more electrical components include a signal generator and an impedance sensor. The first electrode 2428 and the second electrode 2430 are coupled to the signal generator to enable an application mode in which a signal, e.g., a current, is applied to the first and second electrodes. The third electrode 2448 and the fourth electrode 2450 are coupled to the impedance sensor to enable a detection mode in which a potential between the third electrode and the fourth electrode is measured, and the impedance is calculated based on the current applied to the first and second electrodes.

[0180] 22A, 22B, and 24C , considering an embodiment of a smart medical device in which sensor components of a sensor system are disposed across various structures of the medical device, in one particular configuration, a medical device 2400 includes a first structure 2402 configured to be at least partially implanted in a bone 2410 and including at least one electrode 2428, a second structure 2404 configured to be at least partially implanted in the bone and having at least one second electrode 2430, and a third implant or structure 2406 configured to be positioned on the bone across a fracture 2408 and secured in place by the first structure and the second structure. One or more electrical components are associated with one or more of the first structure 2402, the second structure 2404, and the third implant or structure 2406. The electrical components include a sensor configured to enable measurement of tissue impedance between the first electrode 2428 and the second electrode 2430.

[0181] 22A, as noted above, in some embodiments, the IRP 2203 may include one or more other sensors 2222 in addition to the impedance sensor 2229. Representative examples of other sensors 2222 suitable for use in the IRP 2203 include ultrasonic sensors, fluid pressure sensors, fluid volume sensors, contact sensors, position sensors, pulse pressure sensors, blood volume sensors, blood flow sensors, chemical sensors (e.g., for blood and / or other fluids), metabolic sensors (e.g., for blood and / or other fluids), impedance sensors, conductivity sensors, optical sensors, acoustic sensors, accelerometers, gyroscopes, mechanical stress sensors, and temperature sensors.

[0182] A wide variety of sensors (also known as microelectromechanical systems or "MEMS", or nanoelectromechanical systems or "NEMS", and BioMEMS or BioNEMS, see generally https: / / en.wikipedia.org / wiki / MEMS) are available. Representative patents and published patent applications include U.S. Patent Nos. 7,383,071, 7,450,332, 7,463,997, 7,924,267, and 8,634,928, and U.S. Patent Application Publication Nos. 2010 / 0285082 and 2013 / 0215979. Representative publications include Albert Foch, "Introduction to BioMEMS," CRC Press, 2013; Marc J. Madou, "From MEMS to Bio-MEMS and Bio-NEMS: Manufacturing Techniques and Applications," CRC Press, 2011; Simona Badilescu, "Bio-MEMS: Science and Engineering Perspectives," CRC Press, 2011; and Steven S. Soliterman. Saliterman), "Fundamentals of BioMEMS and Medical Microdevices", The International Society of Optical Engineering (SPIE), 2006, Wanjun Wang, Steven A. SoperSoper, co-editors, "Bio-MEMS: Technologies and Applications," CRS Press, 2012; Volker Kempe, "Inertial MEMS: Principles and Practice," Cambridge University Press, 2011; Polla, DL et al., "Microdevices in Medicine," Ann. Rev. Biomed. Eng., 2000, Vol. 2, pp. 551-576; Yun, K. S., et al. al.), "A Surface-Tension Driven Micropump for Low-Voltage and Low-Power Operations", 11:5, J. Microelectromechanical Sys., October 2002, pp. 454-461. Yeh, R., et al., "Single Mask, Large Force, and Large Displacement Electrostatic Linear Inchworm Motors", 11:4, J. Microelectromechanical Sys., August 2002, pp. 330-336. Loh, N.C., et al. al.), "Sub‐10 cm. 3"Sub-10cm³ Interferometric Accelerometer with Nano-g Resolution," 11:3, J. Microelectromechanical Sys., June 2002, pp. 182-187, all of the above-mentioned patent and non-patent documents are incorporated by reference in their entirety.

[0183] The sensor 2222 may be located on the printed circuit board of the electronics assembly 2210 or in or on another structure of the smart medical device spaced from the IRP 2203, but is electrically coupled to the electronics assembly. In certain embodiments, the sensor 2222 may include a processor or may be coupled to a processor located on the printed circuit board of the electronics assembly 2210. In other embodiments, the sensor may be a wireless sensor. In another embodiment, one or more (including all) of the sensors may have a unique sensor identification (USI) number that specifically identifies the sensor.

[0184] The sensor 2222 may be an ultrasonic sensor utilized to characterize fracture healing based on known ultrasonic techniques. To this end, an ultrasonic sensor of appropriate size and with power requirements that can be supported by the medical device may be located within a structure of the medical device, such as a cannulated screw or electronics cartridge, that places the sensor at or near the fracture site upon implantation of the medical device. Ultrasound measurements of the tissue at the fracture site may be obtained over time and may be processed to provide one or more of a characterization of the fracture and a characterization of the tissue within a region of the structure.

[0185] The sensor 2222 may be a strain sensor utilized to characterize fracture healing based on known mechanical stress / strain techniques. To this end, the strain sensor may be located within a structure of the medical device, such as a trocar or electronics cartridge, that places the sensor at or near the fracture site upon implantation of the medical device. Strain measurements at the fracture site may be obtained over time and processed to provide one or more of a characterization of the fracture and a characterization of the tissue within a region of the structure.

[0186] Sensor 2222 can be a glucose detector or oxygen sensor utilized to characterize tissue inflammation based on known techniques. To this end, the glucose detector or oxygen sensor can be located within a structure of the medical device, such as a tubular screen or electronics cartridge, that places the sensor at or near the fracture site at the time of implantation of the medical device. Sensor measurements at the tissue at the fracture site can be obtained over time and processed using known techniques to provide an indication of inflammatory fluid, interstitial fluid, or other biological fluids, such as blood, within a region of the medical device.

[0187] The sensors 2222 can be used to detect, measure, and / or monitor information regarding the state of the medical device after implantation. The state of the medical device can include the health of the medical device (device fracture), the motion of the medical device (device backout), the forces exerted on the medical device, and other information regarding the implanted medical device. Examples of these types of sensors 2222 include gyroscopes, accelerometers, temperature sensors, and pressure sensors.

[0188] The sensors 2222 can be used to detect, measure, and / or monitor information regarding the state of the body or body segment after implantation of the medical device, including kinematic information of the body or body segment. Examples of these types of sensors 2222 include gyroscopes, accelerometers, temperature sensors, and pressure sensors coupled to a processor. In some embodiments, the sensors 2222 can include an inertial measurement unit (IMU), such as an accelerometer or gyroscope, configured to output signals corresponding to movement of the medical device 100 and, by association, movement of the bony structures in which the device is implanted, and corresponding to the movement or activity of a patient in which the device is implanted.

[0189] Sensors 2222 can be used to detect, measure, and / or monitor information about body tissue after implantation of the medical device. Body tissue monitoring can include blood pressure, pH levels. Examples of such sensors 2222 include fluid pressure sensors, fluid volume sensors, pulse pressure sensors, blood volume sensors, blood flow sensors, chemical sensors (e.g., for blood and / or other fluids), and metabolic sensors (e.g., for blood and / or other fluids). Sensors 2222 can be used to monitor temperature within an area of ​​the medical device for the purpose of detecting infection.

[0190] Power supply 2212 is configured to generate a regulated supply signal approximately within the range of 1 volt (V) to 24 volts (V) to power the components of IRP 2203. Power supply 2212 may include one or more of a battery, a rechargeable power device (e.g., a rechargeable battery or a supercapacitor), and an energy harvesting device.

[0191] In some embodiments, the power supply 2212 of the IRP 2203 may be any suitable battery, such as a lithium carbon monofluoride (LiCFx) battery, or other storage battery configured to store energy to power the components of the electronics assembly 2210 for the expected life of the smart medical device (e.g., 5-25+ years).

[0192] The size of the power supply 2212 is generally constrained by the size of the medical device structures, e.g., the cannulated screw, electronics cartridge shell. For example, with reference to FIGS. 13C and 13D, the diameter of the power supply 1354 is limited by the diameter of the inner lumen 1304 of the cannulated screw 1302. In another embodiment, with reference to FIGS. 17A-17C, the diameter of the power supply 1754 is limited by the diameter of the shaft 1726 of the electronics cartridge 1706. In yet another embodiment, with reference to FIGS. 19A and 19B, the diameter of the power supply 1954 is limited by the diameter of the lower cavity of the structure 1902. In an exemplary design, the diameter of the battery can be greater than 1 mm, typically in the range of 1 to 5 mm. The length of the battery can be greater than 1 mm, typically a minimum of 3 mm. The volume of the battery can be less than 2 mm. 2 The battery capacity should be greater than 1 mAh, although based on measurements and communications, more energy may be required, for example, about 100 mAh. The power required to fully charge in 1 hour should be greater than 5 mW, and generally speaking, should be in the range of 5 mW to 150 mW.

[0193] In some embodiments, the power supply 2212 of the IRP 2203 may be a supercapacitor. Supercapacitors are attractive due to their rapid charge / discharge characteristics; for example, a 2.8 mAh battery is rated at 0.2 C charge / discharge and a 5 hour charge time. Supercapacitors also have a high current delivery capability compared to batteries. The supercapacitor may be an electrochemical double layer capacitor (EDLC) supercapacitor or a wire-like supercapacitor. Commercially available EDLCs have only half the volumetric energy density of the "new" wire-like supercapacitors. Therefore, wire-like supercapacitors may be preferred.

[0194] Example properties and specifications for a wire supercapacitor are: form factor (2 x 0.5 mm OD wire), 153.3 Wh kg -1 Gravimetric energy density: 8810Wkg (1 / 3 of LiCFx) -1 Exemplary properties and specifications for EDLCs include a form factor (3.2 x 2.5 x 0.9 mm), single-digit μAh, and a power density of 2.3 mWhcm. -3 Includes.

[0195] In some embodiments, the power supply 2212 of the IRP 2203 may be a hybrid solution, where the IRP includes a first power supply for measurements, such as a primary battery, and a second power supply, such as a supercapacitor, for temporarily buffering energy while exchanging data.

[0196] The power supply 2212 of the IRP 2203 may be a rechargeable power device, such as a lithium-ion battery or a supercapacitor. In this case, the power supply 2212 and / or the electronics assembly 2210 include additional components for charging the power source by an external recharging unit. These additional components include a power coil configured to generate a voltage and current in response to a magnetic field generated by the external recharging unit. Possible energy transmission modes include far-field RF, near-field RF, and ultrasonic.

[0197] An example configuration for far-field energy transmission has operating parameters of power 0.24 / 32mW, frequency 2.34 / 1GHz, efficiency 12 / 0.2%, and antenna size 9 / 2160mm. 2 , range 20 / 150 cm, and permissible Specific Absorption Rate (SAR) limits (1.6 W / kg) limit power transmission. Far-field energy transmission can be directed by multiple antennas. Furthermore, far-field energy transmission can be performed using the antenna used for communication. For example, antenna 144b in FIG. 9B can be used for both RF energy transmission and RF communication.

[0198] In an exemplary configuration for near-field RF energy transmission, the operating parameters are: power 0.2 / 15.7 mW, frequency 10 MHz / 1.5 GHz, efficiency 15.2 / 0.5%, and antenna size 2.3 / 6 mm. 2 , and a depth of 0.5 / 3 cm. Near-field energy transmission requires precise tuning and alignment as well as intimate contact with the skin.

[0199] In an example configuration for ultrasonic energy transmission, the operating parameters are: power 0.36mW @ 1MHz, efficiency up to 5.6%, transducer size 1x1mm 2, a minimum depth of 5 mm or greater relative to the maximum thickness for people with a BMI (Body Mass Index) of up to 45. In this configuration, it is possible to transmit energy to a skin depth of over 10 cm. Ultrasonic energy transmission may be less efficient when traveling through many tissue types, and such ultrasonic energy transmission requires direct contact with the skin.

[0200] The energy harvesting device is configured to convert environmental stimuli into energy for charging the rechargeable power device. For example, the harvesting device can convert one or more of body heat from a subject in which the IRP2203 is implanted, kinetic energy generated by movement of the subject, pressure changes (e.g., atmospheric pressure or pressure inside the subject's body, such as the subject's blood pressure), energy generated by electrochemical reactions inside the subject's body, radio frequency (RF) fields, light, electro-mechanical conversion (e.g., piezoelectric), or electro-magnetic conversion into a current or voltage for charging a battery or a supercapacitor charge.

[0201] Fuse 2214 can be any suitable fuse (e.g., permanent) or circuit breaker (e.g., resettable) configured to prevent current flowing from power supply 2212 or the battery from causing injury to the patient or damaging the battery and one or more components of electronics assembly 2210. For example, fuse 2214 can be configured to prevent power supply 2212 from generating enough heat to cause burns to the patient, damage electronics assembly 2210, damage the battery, or damage structural components of the smart implantable implant.

[0202] The first power switch 2216 is configured to couple or decouple the power supply 2212 to or from one or more sensors 2222 in response to a control signal from the controller 2232. For example, the controller 2232 can be configured to generate a control signal having an open circuit state that causes the switch 2216 to open, thus disconnecting power from one or more sensors 2222, during a sleep mode or other low power mode to conserve power, thereby extending the life of the power supply 2212. Similarly, the controller 2232 can also be configured to generate a control signal having a closed circuit state that causes the switch 2216 to close, thus coupling power to one or more sensors 2222, upon “waking up” from a sleep mode or exiting another low power mode. Such a low power mode can be for only one or more sensors 2222, or for the sensors and one or more components of the electronics assembly 2210.

[0203] The second power switch 2218 is configured to couple or decouple the power supply 2212 to the memory 2224 in response to a control signal from the controller 2232. For example, the controller 2232 can be configured to generate a control signal having an open circuit state that causes the switch 2218 to open, thus disconnecting power from the memory 2224, during a sleep mode or other low power mode to conserve power, thereby extending the life of the power supply 2212. Similarly, the controller 2232 can also be configured to generate a control signal having a closed circuit state that causes the switch 2218 to close, thus coupling power to the memory 2224, upon “waking up” from a sleep mode or exiting another low power mode. Such a low power mode can be for only the memory 2224, or for the memory and one or more components of the electronics assembly 2210.

[0204] Clock and power management unit 2220 may be configured to generate clock signals for one or more of the other components of electronics assembly 2210, and may be configured to generate periodic commands or other signals (e.g., interrupt requests) in response to which controller 2232 causes one or more components of IRP 2203 to enter or exit a sleep mode or other low-power mode. Clock and power management unit 2220 may also be configured to regulate the voltage from power supply 2212 and provide the regulated power supply voltage to some or all of the other components of electronics assembly 2210.

[0205] Memory 2224 may include volatile or non-volatile memory. For example, the volatile memory may be configured to store an operating system and one or more applications executed by controller 2232. The non-volatile memory may be configured to store configuration information for IRP 2203, store data written by controller 2232, and provide data in response to read commands from the controller.

[0206] The IRP2203 of the medical device includes a communications interface that facilitates communications between the medical device and another device. The other device may be, for example, an external device, such as a base station, located outside or remote from the patient receiving the medical device, or it may be an internal device located within the patient receiving the medical device. In either case, communication between the implanted medical device and another device, whether internal or external, is referred to as intrabody communication. One or more modes of intrabody communication may be enabled by the communications interface of the IRP2203. As discussed above, possible intrabody communication modes include: 1) RF telemetry communication; 2) tissue-conducted communication, such as galvanic coupling communication; and 3) data-over-sound communication, such as ultrasound or acoustic communication.

[0207] The communications interface typically includes communications circuitry 2225, although not necessarily associated with the electronics assembly 2210 of the IRP 2203. The communications circuitry 2225 may include any hardware, firmware, software, or any combination thereof suitable for enabling one or more modes of intrabody communication. To this end, the communications circuitry 2225 may include, for example, voltage regulators, current generators, oscillators, or other signal generating circuitry, resistors, capacitors, inductors, and other filtering circuitry for processing received signals, and circuitry for modulating and / or demodulating signals in accordance with a communications protocol.

[0208] Depending on the intrabody communication mode, the communications circuitry 2225 can further include transistors or other switching circuitry for selectively coupling the transmitted signal to or receiving signals from a desired transceiver, such as an antenna 2230 (which can be used for electromagnetic communication, e.g., RF telemetry communication), or electrodes 2231, 2233 (which can be used for tissue-conducted communication), or an acoustic transducer 2236 (which can be used for data-over-sound communication). Under the control of the controller 2232, the communications circuitry 2225 can receive downlink communications signals from an external device or another implanted device and send uplink communications signals to such an external device or implanted device. Additionally, the communications circuitry 2225 can communicate with external devices and computer networks, such as the Medtronic CareLink® network developed by Medtronic Public Limited Company (Medtronic, plc) of Dublin, Ireland, and networked computing devices.

[0209] Additional details for each of the RF telemetry, tissue-conducted, and data-over-sound modes of intrabody communication are provided below.

[0210] The RF telemetry mode of intrabody communication is enabled by an RF communication interface including an antenna 2230 and RF telemetry circuitry, such as an RF transceiver 2226 and a filter 2228. Possible RF communication modes include far-field RF and near-field RF. The RF transceiver 2226 may be a conventional transceiver configured to enable the controller 2232 (and optionally a fuse 2214) to communicate with another implanted medical device (not shown in FIG. 22A ) or a base station (not shown in FIG. 22A ) configured for a smart implantable device. For example, the RF transceiver 2226 may be any suitable type of transceiver (e.g., Bluetooth, Bluetooth Low Energy (BTLE)), and WiFi®) and may be configured to operate according to any suitable protocol (e.g., MICS, ISM, Bluetooth, Bluetooth Low Energy (BTLE), and WiFi®) and may be configured to operate in a frequency band ranging from 1 MHz to 5.4 GHz, or any other suitable range. In exemplary configurations for far-field RF communication, the frequency band may be 401-406 MHz or 2.4 GHz. For some embodiments, different frequencies may be used for different purposes. For example, in one configuration, 2.4 GHz may be used to wake up the device, while 400 MHz is used for communication.

[0211] For far-field RF communication, the antenna 2230 can be a monopole, dipole, folded dipole, serpentine load, loop, small loop, MEMS on-chip, or helical antenna. Additionally, far-field RF communication can be implemented using the antenna used for energy transmission. For example, antenna 144b in FIG. 9B can be used for both RF energy transmission and RF communication.

[0212] Filter 2228 may be any suitable bandpass filter, such as a surface acoustic wave (SAW) filter or a bulk acoustic wave (BAW) filter. Antenna 2230 may be any antenna suitable for the frequency bands at which signals are generated by RF transceiver 2226 for transmission by the antenna and at which signals are generated by a base station (not shown in FIG. 22A ) for reception by the antenna.

[0213] The tissue conduction communication (TCC) mode of intrabody communication is enabled by a TCC interface including TCC circuitry 2238 and a pair of electrodes 2231, 2233. The pair of electrodes 2231, 2233 may be selected from the sensing electrodes 2221 and may be coupled to the TCC circuitry 2238 via an electrode switch 2223. Alternatively, the pair of electrodes may be electrodes 2231, 2233 that are also the sensing electrodes 2221. The TCC interface allows the controller 2232 to communicate with another device having the same TCC interface as the IRP 2203. The other device may be an implanted medical device (not shown in FIG. 22A ) or a base station (not shown in FIG. 22A ) configured for a medical device.

[0214] Tissue-conductive communication relies on the ionic content of the bodily tissue of the patient in which the smart medical device 2202 is implanted, and is thus often referred to as galvanic communication. The ionic content of the bodily tissue provides an electrical communication medium for transmitting information to and receiving information from the smart medical device. To communicate in a transmit mode, the TCC circuitry 2238 applies a voltage to the electrodes 2231, 2233, causing a current to flow between the electrodes and a corresponding electrical signal to propagate through the bodily tissue. The propagated current can be detected by a receiving device (not shown in FIG. 22A ) by measuring the voltage developed between the two electrodes. To communicate in a receive mode, the TCC circuitry 2238 measures the voltage across the electrodes 2231, 2233.

[0215] When tissue-based communication is employed to facilitate communication, the sensing attachment and other devices that send and receive information to the sensing attachment have associated hardware, firmware, software, or any combination thereof suitable for enabling such communication. TCC transmission and associated hardware, firmware, and software are described and may be included in the smart implantable devices of the present invention. See, e.g., U.S. Patent Application Publication Nos. 2016 / 213939, 2018 / 207429, 2019 / 160290, 2019 / 160291, 2019 / 160292, and 2019 / 184181. For example, in one aspect, TCC circuitry 2238 may be coupled to one or more electrodes 2231, 2233 and may include circuitry that enables the TCC interface to switch between a transmit mode for transmitting TCC signals and a receive mode for receiving TCC signals from another similarly configured device.

[0216] The data-over-sound mode of intrabody communication is enabled by a data-over-sound communication interface that includes data-over-sound circuitry 2240 and at least one acoustic transducer 2236. The data-over-sound communication interface allows the controller 2232 to communicate with another device that has the same data-over-sound communication interface as the IRP 2203. The other device may be an implanted medical device or a base station configured for a smart implantable device.

[0217] When data-over-sound communication is employed to facilitate communication, the smart medical device and other devices that send and receive information to the smart medical device have associated hardware, firmware, software, or any combination thereof suitable for enabling such communication. Data-over-sound communication transmissions and associated hardware, firmware, and software have been described and may be included in the smart implantable medical device of the present invention. See, e.g., U.S. Pat. No. 7,489,967 and U.S. Patent Application Publication Nos. 2010 / 0249882(A1) and 2013 / 0033966(A1). For example, in one aspect, data-over-sound circuitry 2240 may be coupled to acoustic transducer 2236 and may include circuitry that enables the data-over-sound communication interface to switch between a transmit mode for transmitting ultrasound signals and a receive mode for receiving ultrasound signals from another similarly configured device.

[0218] Controller 2232 may be any suitable microcontroller or microprocessor, configured to control the configuration and operation of one or more of the other components of electronics assembly 2210. For example, controller 2232 may be configured to control one or more sensors 2222, 2229 to detect associated measurement data and to store the measurement data generated by the one or more sensors in memory 2224. Controller 2232 may also be configured to generate messages for communication over one or more types of communication interfaces. For example, in the case of RF telemetry communication, controller 2232 may create messages containing the stored data as a payload, packetize such messages, and provide the message packets to RF transceiver 2226 for transmission to a base station (not shown in FIG. 22A ). Controller 2232 may also be configured to execute commands received from a base station (not shown in FIG. 22A ) via a communication interface, e.g., antenna 2230, filter 2228, and RF transceiver 2226. For example, controller 2232 may be configured to receive configuration data from a base station and to provide setting data to components of electronics assembly 2210 to which the base station has directed the setting data. When the base station directs the setting data to controller 2232, the controller is configured to configure itself in response to the setting data.

[0219] In one aspect, the medical devices of the present invention are sterile. In another aspect, the medical devices of the present invention have undergone a sterilization procedure to provide a sterile medical device. In various options, the medical devices may be sterilized using an alcoholic solution by exposing the medical device to ethylene oxide, ionizing radiation, autoclaving, ultraviolet radiation, or dry heat. Alcoholic solutions that can be used include, but are not limited to, methanol, ethanol, isopropanol, and aqueous solutions thereof. Ionizing radiation used may include gamma radiation and electron beam radiation. The dose of ionizing radiation used for sterilization may be greater than 20 kGy, greater than 25 kGy, greater than 30 kGy, greater than 35 kGy, or greater than 40 kGy. For devices sterilized using ethylene oxide, the sterilized devices preferably comply with ISO 10993-7 for residual ethylene oxide and ethylene chlorohydrin.

[0220] The medical devices of the present invention may be in a non-sterile form. In one aspect, the non-sterile medical devices are <1111> In one aspect, the non-sterile device has a total aerobic microbial count (cfu / g or cfu / mL) of 10 or less. In one aspect, the non-sterile device has a total fungal count (cfu / g or cfu / mL) of less than 10. In one aspect, the non-sterile device has a total aerobic microbial count (cfu / g or cfu / mL) of 10 or less and a total fungal count (cfu / g or cfu / mL) of 10 or less. The non-sterile device is not susceptible to contamination with Pseudomonas aeruginosa, Staphylococcus aureus, or Candida albicans.

[0221] Implant placement location 24A and 24B, in some embodiments, the structure 2402 of the medical device 2400 is configured to be implanted to bridge a fracture 2408 in a bone 2410. For example, in FIG. 24A, the medical device 2400 can be one of two devices arranged parallel to one another to bridge a femoral neck fracture 2408. In another embodiment, shown in FIG. 24B, the medical device 2400 can be one of three devices that form a triangle and are implanted to bridge a femoral head hip fracture 2408, with the other two devices 2422, 2424 simply being cannulated screws. In this example, the medical device 2400 is implanted at the apex of the triangle, at the location of the three that experiences the least amount of stress. In another embodiment, the medical device 2400 may be implanted solely for the purpose of monitoring bone healing, and does not perform any support or load-bearing functions associated with orthopedic treatment provided by the other devices. To this end, the medical device 2400 may be implanted at the center of the surrounding orthopedic support devices, for example at the center of a triangle, with orthopedic support devices implanted at each vertex of the triangle.

[0222] Referring to FIG. 24C, in some embodiments, a medical device 2400 includes a pair of smart structures 2402, 2404, each configured to be implanted through a corresponding hole in a bone 2410, e.g., a plate 2406 bridging a fracture 2408, e.g., a humeral shaft fracture, of the bone 2410.

[0223] 24D and 24E, in some embodiments, medical device 2400 is a structure 2402, such as a rod or pin, configured to be implanted to bridge a fracture 2408 in a bone 2410. For example, in FIG. 24D, structure 2402 of medical device 2400 is a push rod bridging a distal fibular fracture. In FIG. 24E, structure 2402 of medical device 2400 is one of four percutaneous pins bridging a humeral neck fracture.

[0224] Fracture characterization instruments and methods 25A and 25B are a flow chart and a schematic illustration, respectively, of a method for characterizing a fracture, which may be performed by one of the smart medical instruments configured as disclosed herein and further described below.

[0225] In block 2502, a smart medical device 2520 comprising multiple electrodes is implanted in bone tissue 2522 to position a first electrode 2524 and a second electrode 2526 on opposite sides of a fracture 2528. In some methods, the multiple electrodes are implanted by implanting a cannula-like structure with a lumen into the bone tissue and across the fracture. After implanting the cannula-like structure, an electronics cartridge comprising a detection module and other electronics is inserted into the lumen. In some methods, the cannula-like structure comprises multiple electrodes that couple to the detection module upon insertion of the electronics cartridge into the lumen. In some methods, the multiple electrodes are disposed within the electronics cartridge and interface with the bone tissue through holes in a sidewall of the cannula-like structure or through openings at the end of the cannula-like structure. In some methods, the multiple electrodes are implanted by implanting a preloaded medical device comprising a structure comprising multiple electrodes, a detection module, and other electronics coupled to the multiple electrodes.

[0226] In block 2504, multiple measurements of electrical properties of the tissue are obtained over time by a first electrode 2524 and a second electrode 2526 located on opposite sides of the fracture 2528. The electrical properties of the tissue may correspond to impedance measurements, which are obtained by applying signals of different frequencies to the first electrode 2524 and measuring the tissue impedance according to EIS techniques.

[0227] At block 2506, the measurements are processed to determine the healing status of the fracture, for example, union, risk of non-union, and a characterization of the fracture 2528 corresponding to non-union.

[0228] In block 2508, the measurements of the electrical properties of the tissue or characterization of the fracture 2528 are communicated to an external device.

[0229] 26A and 26B are a flow chart and a schematic illustration, respectively, of a method for characterizing a fracture, which may be performed by one of the smart medical instruments configured as disclosed herein and further described below.

[0230] In block 2602, a smart medical device 2620 including multiple electrodes is implanted in a bone 2622 to position each of a first electrode 2624 and a second electrode 2626 within a gap 2630 of a fracture 2628. In some methods, the multiple electrodes are implanted by implanting a cannula-like structure with a lumen into bone tissue at the fracture. After implanting the cannula-like structure, an electronics cartridge including a detection module and other electronics is inserted into the lumen. In some methods, the cannula-like structure includes multiple electrodes that couple to the detection module upon insertion of the electronics cartridge into the lumen. In some methods, the multiple electrodes are disposed within the electronics cartridge, and the multiple electrodes interface with bone tissue through holes in a sidewall of the cannula-like structure. In some methods, the multiple electrodes are implanted by implanting a preloaded medical device including a structure including multiple electrodes, a detection module, and other electronics coupled to the multiple electrodes.

[0231] In block 2604, multiple measurements of electrical properties of the tissue are obtained over time by a first electrode 2624 and a second electrode 2626 positioned within the gap 2630 of the fracture 2628. The electrical properties of the tissue may correspond to impedance measurements, which are obtained by applying signals of different frequencies to the first electrode 2624 and measuring the tissue impedance according to EIS techniques.

[0232] At block 2606, the measurements are processed to determine the healing status of the fracture, for example, union, risk of non-union, and a characterization of the fracture 2628 corresponding to non-union.

[0233] In block 2608, the measurements of the electrical properties of the tissue or characterization of the fracture 2628 are communicated to an external device.

[0234] Referring to FIG. 26B , a smart medical device 2620 has a first set of electrodes located on a first side of the device's shaft 2632 and a second set of electrodes located on a second side of the shaft spaced from the first side. This embodiment of the medical device may be based, for example, on the embodiment of FIGS. 21A and 21B , but modified to have two sets of four pin electrodes. Continuing with reference to FIG. 26B , the smart medical device 2620 is placed in a patient's bone 2622 such that the first and second sets of electrodes span the fracture 2628, with at least one electrode from each set located within the gap 2630. The electrodes are positioned on the shaft 2632 such that the first electrode 2624 is on one side of the shaft and the second electrode 2626 is on the other side of the shaft. The shaft 2632 may be insulated (e.g., anodized titanium). This creates an electrical path 2634 from the first electrode 2624 to the second electrode 2626 through the healing bone in the gap 2630. This results in a large change in impedance as the fracture site heals. However, the electrical path 2634 may be localized to the area located immediately around the shaft 2632. Therefore, to better understand healing throughout the fracture site, multiple medical devices 2620a, 2620b, 2620c of this style can be employed to position multiple paired electrodes within the gap 2630 at multiple locations across the gap, thereby collecting sets of impedance measurements at different locations across the gap.

[0235] 27A and 27B are a flow chart and a schematic illustration, respectively, of a method for characterizing a fracture, which may be performed by one of the smart medical instruments configured as disclosed herein and further described below.

[0236] In block 2702, a smart medical device 2720 including multiple electrodes is implanted in a bone 2722, with a first linear electrode 2724 and a second linear electrode 2726 each positioned such that each linear electrode spans a gap 2730 in a fracture 2728. The linear electrodes 2724, 2726 are at least 1 mm in length. In some methods, the multiple electrodes are implanted by implanting a cannula-like structure with a lumen into bone tissue at the fracture. After implanting the cannula-like structure, an electronics cartridge including a detection module and other electronics is inserted into the lumen. In some methods, the cannula-like structure includes multiple electrodes that couple to the detection module upon insertion of the electronics cartridge into the lumen. In some methods, the multiple electrodes are disposed within the electronics cartridge, and the multiple electrodes interface with bone tissue through slots in a sidewall of the cannula-like structure. In some methods, multiple electrodes are implanted by implanting a preloaded medical device having a structure with multiple electrodes, a sensing module, and other electronics coupled to the multiple electrodes.

[0237] In block 2704, multiple measurements of electrical properties of the tissue are obtained over time with a first linear electrode 2724 and a second linear electrode 2726 spanning a gap 2730 in a fracture 2728. The electrical properties of the tissue may correspond to impedance measurements, which are obtained by applying signals of different frequencies to the first linear electrode 2724 and measuring the tissue impedance according to EIS techniques.

[0238] At block 2706, the measurements are processed to determine the healing status of the fracture, for example, union, risk of non-union, and a characterization of the fracture 2728 corresponding to non-union.

[0239] At block 2708, the measurements of the electrical properties of the tissue or characterization of the fracture 2728 are communicated to an external device.

[0240] Referring to FIG. 27A, a smart medical device 2720 has a first linear electrode 2724 located on a first side of a shaft 2732 of the medical device and a second linear electrode 2726 located on a second side of the shaft spaced from the first side. This embodiment of the medical device may be based, for example, on the embodiment of FIGS. 13A-13D, but modified to include two linear electrodes, each configured to pass through respective slots on opposite sides of a cannular structure. Continuing with FIG. 27B, the smart medical device 2720 is placed in a patient's bone 2722 such that the first linear electrode 2724 and the second linear electrode 2726 straddle the fracture 2628. The linear electrodes 2724, 2726 are positioned on the shaft 2732 such that they are on opposite sides of the shaft. The shaft 2632 may be insulated (e.g., anodized titanium). This creates a current path 2734 from the first linear electrode 2724 to the second linear electrode 2726 through a localized area around the shaft 2732. Because the linear electrodes 2724, 2726 contact the bone 2722 on either side of the fracture site, the current path 2734 passes through the healing bone at the fracture site as well as through the bone on either side of the fracture site.

[0241] Example circuit diagrams are shown for the initial state 2729 of the fracture 2728 and the healed state 2731 of the fracture. As the bone heals, the impedance of the gap 2730 of the fracture 2728 changes from a low resistance R G in the fractured state to a high resistance R G′ in the healed state, allowing the smart medical device 2720 to determine if healing has occurred in a localized region around the shaft 2732. If two linear electrodes 2724, 2726 are placed on each side of the shaft 2732, a four-wire impedance measurement method is used to remove the effect of electrode contact resistance from this measurement. This embodiment tends to measure healing in only the localized region around the shaft 2732. Therefore, to better understand healing throughout the fracture site, multiple medical devices of this style can be employed with multiple pairs of linear electrodes spanning the gap 2730 at multiple locations across the gap cross-section, thereby collecting sets of impedance measurements at different locations in the gap.

[0242] In one aspect, the present invention provides a method of treating a fracture in bone tissue, the method comprising the steps of identifying a fracture in the bone tissue and inserting a medical device disclosed herein into the bone tissue, the medical device being inserted across the fracture. The fracture may be identified, for example, by x-ray. In one embodiment, the medical device is a screw. The medical device may be inserted into the bone tissue according to standard techniques used to insert cannulated screws into fractured bones. Optionally, the method further includes the step of characterizing the fracture with the medical device.

[0243] In one aspect, the present invention provides a method for characterizing a fracture in bone tissue, the method comprising the steps of identifying a fracture in bone tissue and inserting a medical device as disclosed herein into the bone tissue, the medical device being inserted across the fracture, the method further comprising characterizing the fracture with a sensor disposed within the medical device. The fracture may be identified, for example, by x-ray. In one embodiment, the medical device is a screw. The medical device may be inserted into the bone tissue according to standard techniques used to insert cannulated screws into fractured bone.

[0244] Communication with smart medical devices The smart medical device may be part of an environment with which it communicates. An exemplary environment is an operating room, where the smart medical device is implanted in a patient by a healthcare professional. Another exemplary environment is a patient's home, where the smart medical device has already been implanted in the patient. Yet another exemplary environment is a doctor's office, where a patient with an implanted smart medical device is present in the office, for example, for an evaluation. The following is a detailed description of an exemplary environment in a patient's home. However, the described features and connectivity are analogously present in other environments where a patient with an implanted smart medical device is present, such as an operating room or a doctor's office, and are also described herein, but in less detail.

[0245] FIG. 28 is a related diagram of a smart medical device environment 2800, including features present in a patient's home. In this environment, a smart medical device 2802 having an implantable reporting processor (IRP) 2803 is implanted within the patient (not shown). The sensing capabilities and associated electronics assembly of the smart medical device of the present invention may collectively be referred to as the implantable reporting processor (IRP). The IRP is a component of the smart medical device of the present invention, in which case the smart medical device includes the IRP. The antenna may or may not be a component of the IRP. Similarly, the power supply may or may not be a component of the IRP. The implantable reporting processor 2803 is positioned and configured to collect data, including, for example, medical and health data regarding the patient with which the smart medical device is associated, as well as operational data for the smart medical device 2802 itself. The smart medical device 2802 communicates with one or more home base stations 2804 or one or more external smart devices 2805 during different monitoring phases of the patient.

[0246] The smart medical device 2802 has one or more sensors that collect information and data, including medical and health data about the patient with which it is associated, as well as operational data about the smart medical device 2802 itself. The smart medical device 2802 collects data at different times and at different rates during the patient monitoring process, and the smart medical device can optionally store such data in memory until it is transmitted outside the patient's body. In some embodiments, the smart medical device 2802 can operate in multiple different stages throughout patient monitoring, with a large amount of data collected soon after the smart medical device 2802 is implanted in the patient's body, and less data collected as the patient is healing and thereafter.

[0247] The amount and type of data collected by the smart medical device 2802 may vary from patient to patient, and the amount and type of data collected may vary for a single patient. For example, a medical professional studying the data collected by the smart medical device 2802 for a particular patient may be able to adjust or otherwise control how the smart medical device 2802 collects future data.

[0248] The amount and type of data collected by the smart medical device 2802 may vary for different body parts, different types of patient conditions, different patient demographics, or other differences. Alternatively or additionally, the amount and type of data collected may change over time based on other factors, such as how the patient is healing or feeling, how long the monitoring process is estimated to last, how much power is remaining in the smart medical device 2802 and how much power should be conserved, the type of movement being monitored, the body part being monitored, etc. In some cases, the collected data is supplemented with personal descriptive information provided by the patient, such as subjective pain data, quality of life metric data, co-morbidities, the patient's perceptions or expectations related to the smart medical device 2802, etc.

[0249] Once the smart medical device 2802 is implanted in the patient and the patient returns home, the smart medical device can begin communicating outside the patient's body in the home environment. Communication can occur with, for example, a home base station 2804, an external smart device 2805 (e.g., the patient's smartphone), a connected personal assistant 2807, or two or more of the home base station, external smart device, and connected personal assistant that can communicate with the smart medical device 2802. The smart medical device 2802 can collect data at a defined rate and time, a variable rate and time, or another controllable rate and time. Data collection can begin when the smart medical device 2802 is initialized in the operating room, when directed by medical personnel, or at some later time.

[0250] At least some data collected by the smart medical device 2802 can be transmitted directly to the home base station 2804, directly to the external smart device 2805, directly to the connected personal assistant 2807, via one or both of the smart device and the connected personal assistant to the base station, via one or both of the base station and the connected personal assistant to the smart device, or via one or both of the smart device and the base station to the connected personal assistant. In this context, "one" and "both" mean via one item alone and via both items serially or in parallel. For example, data collected by the implanted smart medical device 2802 can be transmitted to the home base station 2804 via the external smart device 2805 alone, via the connected personal assistant 2807 alone, serially via the external smart device and the connected personal assistant, serially via the connected personal assistant and the external smart device, and directly, or in some cases via both the external smart device and the connected personal assistant simultaneously.

[0251] Similarly, data collected by implanted smart medical device 2802 can be transmitted via home base station 2804 alone, via connected personal assistant 2807 alone, serially via the home base station and connected personal assistant, serially via the connected personal assistant and home base station, directly via both the home base station and connected personal assistant, possibly simultaneously, to external smart device 2805. Further by way of example, data collected by implanted smart medical device 2802 can be transmitted via external smart device 2805 alone, via home base station 2804 alone, serially via the external smart device and home base station, serially via the home base station and external smart device, directly via both the external smart device and home base station, possibly simultaneously, to connected personal assistant 2807.

[0252] In various embodiments, one or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807 periodically, at predetermined or other times, perform network connectivity checks on the implanted smart medical device 2802 to determine whether the implanted smart medical device 2802 is within communication range of one or more of the home base station, external smart device, and connected personal assistant. Based on a response from the implanted smart device 2802, one or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807 confirm that the implanted smart medical device 2802 is within communication range and can issue requests, commands, or otherwise direct the implanted smart medical device 2802 to transmit data collected by the smart medical device to one or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807.

[0253] One or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807 may each include a corresponding optional user interface in some cases. The user interface may be configured as a multimedia interface that provides one-way or two-way streaming of one or more types of multimedia information (e.g., video, audio, tactile, etc.). The patient (not shown in FIG. 28 ) or a friend of the patient (not shown in FIG. 28 ) may enter other data to complement data collected by the implanted smart medical device 2802 via the respective user interfaces of one or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807. The user may enter, for example, personal descriptive information (e.g., age change, weight change), changes in medical condition, comorbidities, pain level, quality of life, indicators of how the implanted smart medical device 2802 “feels,” other subjective metric data, personal messages for healthcare professionals, etc. In these embodiments, the personal descriptive information may be entered via a keyboard, mouse, touch screen, microphone, wired or wireless computing interface, or some other input means. When personal descriptive information is collected, it may include or otherwise be associated with one or more identifiers that associate the information with a unique identifier for the implanted smart medical device 2802, the patient, an associated medical professional, an associated medical facility, etc.

[0254] For some of these cases, the respective optional user interface of one or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807 may also be arranged to send information associated with the implanted smart medical device 2802 to a user, e.g., from a medical professional. In these cases, the information sent to the user may be sent via a video screen, an audio output device, a tactile transducer, a wired or wireless computing interface, or some other similar means.

[0255] In embodiments in which one or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807 include a user interface, the user interface may comprise an internal user interface arranged to enable communicative coupling to a patient portal device. The patient portal device may be a smartphone, tablet, wearable device, weight or other health measurement device (e.g., thermometer, scale, etc.), or some other computing device capable of wired or wireless communication. In these cases, the user may enter personal descriptive information and the user may also receive information associated with the implanted smart medical device 2802.

[0256] The home base station 2804 transmits the collected data to the cloud 2808 using the patient's home network 2806. The home network 2806 may be a local area network that allows access to a wide area network, such as the Internet, from the patient's home. In some embodiments, the home base station 2804 may connect to the home network 2806 using a Wi-Fi connection to access the Internet. In other embodiments, for example, the home base station 2804 may connect to the patient's home computer (not shown in FIG. 28 ) via a USB connection that is itself connected to the home network 2806.

[0257] The external smart device 2805 can communicate directly with the implanted smart medical device 2802, for example, via a Bluetooth® compliant signal, and can transmit collected data to the cloud 2808 using the patient's home network 2806 or can communicate directly with the cloud, for example, via a cellular network. Alternatively, the external smart device 2805 is configured to communicate directly with one or both of the home base station 2804, the connected personal assistant 2807, for example, via a Bluetooth® compliant signal, and such external smart device is not configured to communicate directly with the implanted smart medical device 2802.

[0258] Additionally, the connected personal assistant 2807 may communicate directly with the implanted smart medical device 2802, e.g., via a Bluetooth®-compliant signal, and may utilize the patient's home network 2806 to transmit collected data to the cloud 2808 or may communicate directly with the cloud, e.g., via a modem / internet connection or a cellular network. Alternatively, the connected personal assistant 2807 may be configured to communicate directly with one or both of the home base station 2804 and the external smart device 2805, e.g., via a Bluetooth®-compliant signal, and such connected personal assistant 2807 is not configured to communicate directly with the implanted smart medical device 2802.

[0259] One or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807 can also transmit collected data to the cloud 2808 and obtain data, commands, or other information from the cloud 2808 directly or via the home network 2806. One or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807 can provide some or all of the received data, commands, or other information to the implanted smart medical device 2802. Examples of such information include, but are not limited to, configuration update information, diagnostic requests to determine whether the implanted smart medical device 2802 is functioning properly, data collection requests, and other information.

[0260] The cloud 2808 may include one or more server computers or databases for collecting data collected from the implanted smart medical device 2802, possibly data collected from other assemblies (not shown), as well as personal descriptive information collected from the patient (not shown in FIG. 28 ), and possibly personal descriptive information collected from other patients. In this manner, the cloud 2808 may generate a variety of metrics related to the collected data from each of multiple assemblies implanted in different patients. This information may be useful in determining whether the assemblies are functioning properly. The collected information may also be useful for other purposes, such as determining which particular device is not functioning properly, determining whether a procedure or condition associated with the smart medical device is helping the patient (e.g., whether a knee replacement is working properly and reducing the patient's pain), and determining other medical information.

[0261] 28 , alternative embodiments are contemplated. For example, one or more of the home base station 2804, the external smart device 2805, and the connected personal assistant 2807 can be omitted from the smart medical device environment 2800. Furthermore, each of the home base station 2804, the external smart device 2805, and the connected personal assistant 2807 can be configured to communicate with one or both of the implanted smart medical device 2802 and the cloud 2808 via another one or more of the base station, the smart device, and the connected personal assistant. Furthermore, the external smart device 2805 can temporarily sign on as an interface to the implanted smart medical device 2802, and the external smart device can be any suitable device other than a smartphone, such as a smart watch, a smart patch, or any IoT device capable of acting as an interface to the implanted smart medical device 2802, such as a coffee pot.

[0262] Additionally, one or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807 can act as a communications hub for multiple prostheses implanted within one or more patients. Furthermore, one or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807 can automatically order or reorder prescriptions or medical supplies (e.g., knee braces) in response to patient or implantable prosthesis input (e.g., pain level, instability level), provided that a medical professional or insurance company has pre-authorized such an order or reorder; alternatively, one or more of the base station, smart device, and connected personal assistant may be configured to request permission from a medical professional or insurance company to place an order or reorder. Furthermore, one or more of the home base station 2804, external smart device 2805, and connected personal assistant 2807 may include a personal assistant, such as Alexa® or Siri®.

[0263] While the smart medical device environment has been described with reference to FIG. 28 in the context of a patient's home, the same principles apply when the environment is an operating room or a physician's office. For example, an implanted smart medical device 2802 can be implanted within a patient in an operating room environment in connection with a medical procedure. The implanted smart medical device 2802 communicates with an operating room base station (similar to a home base station) concurrent with the medical procedure. The patient then returns home after sufficiently recovering from the medical procedure, after which the implanted smart medical device 2802 is configured to communicate with the home base station 2804. Later, at another point in time, the implanted smart medical device 2802 is configured to communicate with a physician's office base station when the patient visits the physician for a follow-up appointment. In either case, the implanted smart medical device 2802 communicates with each base station via a short-range network protocol, such as Medical Instrument Communication Service (MICS), Medical Instrument Radio Communication Service (MedRadio), or any other wireless communication protocol suitable for use with the smart medical device 2802.

[0264] For example, implantation of the implantable smart medical device 2802 into a patient may occur in an operating room. As used herein, an operating room includes any clinic, room, building, or facility where a smart medical device 2802 is implanted into a patient. For example, an operating room may be a typical operating room in a hospital, an operating room in a surgical clinic or doctor's office, or any other surgical site where a smart medical device 2802 is implanted into a patient.

[0265] The operating room (similar to the home base station in FIG. 28) is utilized to configure and initialize the implanted smart medical device 2802 in association with the smart medical device 2802 implanted in the patient. A communication relationship is established between the smart medical device 2802 and the operating room base station, for example, based on polling signals transmitted by the operating room base station and response signals transmitted by the smart medical device 2802.

[0266] During communication establishment, which often occurs prior to implantation of the smart medical device 2802, the operating room base station transmits initialization information to the smart medical device 2802. This initialization information may include, but is not limited to, a time stamp, a date stamp, identification of the type and location of the smart medical device 2802, information about other implants associated with the smart medical device, information about the surgeon, patient identification, operating room information, etc.

[0267] In some embodiments, the initialization information flows unidirectionally, while in other embodiments, the initialization information flows bidirectionally. The initialization information can define at least one parameter associated with the collection of data by the smart medical device 2802. For example, the configuration information can specify settings for one or more sensors on the smart medical device 2802 for each of one or more operational modes. The configuration information can also include other control information, such as the initial operational mode of the smart medical device 2802, specific events that trigger a change in operational mode, wireless settings, data collection information (e.g., how much data the smart medical device 2802 wakes up to collect, how much data the smart medical device collects, and how much data to collect), identities of the home base station 2804, smart device 2805, connected personal assistant 2807, and other control information associated with the implantation or operation of the smart medical device 2802. Examples of connected personal assistants 2807, which may also be referred to as smart speakers, include Amazon Echo®, Amazon Dot®, Google Home®, Phillips® patient monitors, Comcast health tracking speakers, and Apple HomePod®.

[0268] In some embodiments, the configuration information may be pre-stored on the operating room base station or the patient's computing device. In other embodiments, a surgeon, surgical technician, or some other medical personnel may input control information and other parameters into the operating room base station for transmission to the smart medical instrument 2802. In at least one such embodiment, the operating room base station may be in communication with an operating room configuration computing device. The operating room configuration computing device includes an application with a graphical user interface that allows medical personnel to input configuration information for the smart medical instrument 2802. In various embodiments, the application running on the operating room configuration computing device may have some default configuration information that may or may not be adjustable by medical personnel.

[0269] The operating room configuration computing device communicates the configuration information to the operating room base station via a wired or wireless network connection method (e.g., a USB connection method, a Bluetooth connection method, a Bluetooth Low Energy (BTLE) connection method, or a Wi-Fi connection method), which then transmits the configuration information to the smart medical instrument 2802.

[0270] The procedure setting computing device can also display information about the smart medical instrument 2802 or procedure room base station to the surgeon, surgical technician, or medical personnel. For example, the procedure setting computing device can display error information if the smart medical instrument 2802 is unable to or cannot access its configuration information, if the smart medical instrument 2802 is unresponsive, if the smart medical instrument 2802 is undergoing an initial self-test, if it identifies a problem with one of its sensors or radios, if the procedure room base station is unresponsive or malfunctioning, or for other reasons.

[0271] Although the operating room base station and operating room configuration computing device are described as separate devices, embodiments are not so limited; instead, the functionality of the operating room configuration computer device and operating room base station may be included in a single computing device as shown, or in separate devices, which in one embodiment allows medical personnel to enter configuration information directly into the operating room base station.

[0272] After a smart medical device is implanted in a patient, the patient may periodically visit a physician's office for follow-up evaluations. In one aspect, the present invention can provide a physician's office environment (similar to the home environment described herein) where the implanted smart medical device communicates with the office environment. During these visits, data stored in memory can be accessed and / or specific data can be requested and obtained as part of the monitoring process.

[0273] For example, at various times throughout the monitoring process, the patient may be required to visit a medical professional for a follow-up appointment. This medical professional may be the surgeon who implanted the smart medical device 2802 in the patient or another medical professional overseeing the monitoring process, physical therapy, and the patient's recovery. For various reasons, the medical professional may want to collect real-time data from the smart medical device 2802 in a controlled environment. In some cases, the request to visit the medical professional may be sent through a respective optional interactive user interface of one or more of the home base station 2804, the external smart device 2805, and the connected personal assistant 2807.

[0274] The medical practitioner uses a doctor's office base station (similar to the home base station shown in FIG. 28) in communication with the smart medical device 2802 to stream additional data between the doctor's office base station and the smart medical device 2802. Alternatively or additionally, the medical practitioner uses a doctor's office base station (not shown in FIG. 28) to communicate commands to the smart medical device 2802. In some embodiments, the doctor's office base station commands the smart medical device 2802 to enter a high-resolution mode to temporarily increase the rate or type of data collected in a short period of time. The high-resolution mode commands the smart medical device 2802 to collect a different amount (e.g., a larger amount) of data during an activity in which the medical practitioner is also monitoring the patient.

[0275] In some embodiments, the physician office base station allows a medical practitioner to input event or pain markers and synchronize such event or pain markers with the high-resolution data collected by the smart medical device 2802. For example, a medical practitioner can have a patient walk on a treadmill with the smart medical device 2802 in high-resolution mode. As the patient is walking, the patient may complain of pain. The medical practitioner can click a pain marker button on the physician office base station to indicate the patient's discomfort. The physician office base station records the marker and the time the marker was entered. By synchronizing the timing of this marker with the timing of the collected high-resolution data, the medical practitioner can analyze the data to investigate and determine the cause of the pain.

[0276] In other embodiments, the doctor's office base station can provide updated configuration information to the smart medical device 2802. The smart medical device 2802 stores this updated configuration information, which can be used to adjust parameters associated with data collection. For example, if the patient is improving, the medical practitioner can instruct the smart medical device 2802 to collect data less frequently. Conversely, if the patient is experiencing unexpected pain, the medical practitioner can instruct the smart medical device 2802 to collect additional data over a defined period of time (e.g., several days). The medical practitioner can use the additional data to diagnose and address specific problems. In some cases, the additional data can include personal descriptive information provided by the patient after the patient leaves the medical practitioner's care, when such additional data is no longer within range of the doctor's office base station. In these cases, the personal descriptive information can be collected via or sent from one or more of the home base station 2804, the external smart device 2805, and the connected personal assistant 2807. Firmware within the smart medical device and / or base station provides safeguards that limit the period of enhanced monitoring to ensure the smart medical device 2802 maintains enough power to last the lifecycle of the patient's implant.

[0277] In various embodiments, the physician office base station can communicate with a physician office-configured computing device (similar to an operating room computing device). The physician office-configured computing device includes an application with a graphical user interface that allows medical personnel to input commands and data. Some or all of the commands, data, and other information can then be transmitted to the smart medical instrument 2802 via the physician office base station. For example, in some embodiments, medical personnel can use the graphical user interface to issue commands to the smart medical instrument 2802, thereby entering its high-resolution mode. In other embodiments, medical personnel can use the graphical user interface to enter or modify configuration information for the smart medical instrument 2802. The physician office-configured computing device transmits information (e.g., commands, data, or other information) to the physician office base station via a wired or wireless network connection (e.g., a USB connection, a Bluetooth connection, or a Wi-Fi connection), and the physician office base station transmits some or all of the configuration information to the smart medical instrument 2802.

[0278] The doctor office setting computing device can also display other information to the medical professional about the smart medical device 2802, about the patient (e.g., personal descriptive information), or about the doctor office base station. For example, the doctor office setting computing device can display high-resolution data collected by the smart medical device 2802 and transmitted to the doctor office base station. The doctor office setting computing device can also display error information if the smart medical device 2802 is unable to store or access configuration information, if the smart medical device 2802 is unresponsive, if the smart medical device 2802 identifies a problem with one of its sensors or radios, if the doctor office base station is unresponsive or malfunctioning, or for other reasons.

[0279] In some embodiments, the doctor office set up computing device can have access to the cloud 2808. In at least one embodiment, a medical professional can utilize the doctor office set up computing device to access data stored in the cloud 2808 that was previously collected by the smart medical device 2802 via one or both of the home base station 2804 and the external smart device 2805 and transmitted to the cloud 2808. Similarly, the doctor office set up computing device can transmit high resolution data obtained from the smart medical device 2802 to the cloud 2808 via the doctor office base station. In some embodiments, the doctor office base station can have internet access, allowing the doctor office base station to transmit high resolution data directly to the cloud 2808 without utilizing the doctor office set up computing device.

[0280] In various embodiments, a medical practitioner can update the configuration information of the smart medical instrument 2802 when the patient is not in the medical practitioner's office. In these cases, the medical practitioner can utilize a doctor's office configuration computing device (not shown in FIG. 28 ) to transmit the updated configuration information to the smart medical instrument 2802 via the cloud 2808. One or more of the home base station 2804, the external smart device 2805, and the connected personal assistant 2807 can obtain the updated configuration information from the cloud 2808 and send the updated configuration information to the cloud. This allows the medical practitioner to remotely adjust the operating state of the smart medical instrument 2802 without the patient having to visit the medical practitioner's office. This also allows the medical practitioner to send messages to the patient, for example, in response to personal descriptive information provided by the patient and sent to the doctor's office base station (not shown in FIG. 28 ) via one or more of the home base station 2804, the external smart device 2805, and the connected personal assistant 2807. For example, if a patient says to the connected personal assistant 2807 that they are in pain, a healthcare professional can write a prescription for a pain medication, whereby the connected personal assistant can notify the patient by "speaking" that the doctor has called the patient's preferred pharmacy with a prescription for Vicodin® and that the prescription is ready for pickup at 4:00 PM.

[0281] Although the physician office base station (not shown in FIG. 28) and the physician office setup computing device (not shown in FIG. 28) are described as separate devices, embodiments are not limited thereto; instead, the functionality of the physician office setup computing device and the physician office base station may be included in a single computing device or in separate devices (as shown). In this manner, in one embodiment, a medical professional may enter setup information or markers directly into the physician office base station and then view high resolution data (and synchronized marker information) from a display on the physician office base station.

[0282] Certain exemplary embodiments of the present invention, numbered for convenience, include the following: [Embodiment 1] A medical device, a structure configured to be at least partially implanted within a body, the structure having a lumen extending at least partially therethrough; an electronics cartridge containing electronics and configured to be inserted into the lumen after implantation of the structure. [Embodiment 2] and a sensor for measuring an electrical property of the tissue, said sensor comprising: A plurality of electrodes; 2. The medical device of embodiment 1, further comprising a detection module of the electronics cartridge, the detection module being coupled to the plurality of electrodes. [Embodiment 3] the plurality of electrodes includes a first electrode and a second electrode; The medical device of embodiment 2, wherein the detection module is configured to enable the first electrode and the second electrode to function in either an application mode in which a signal is applied across the electrodes, or a detection mode in which impedance between the electrodes is detected. [Embodiment 4] 4. The medical device of embodiment 3, wherein the detection module includes a signal generator configured to apply signals at different frequencies to measure tissue impedance according to an electrical impedance spectroscopy (EIS) method. [Embodiment 5] The sensor further comprises an electrode switch; the plurality of electrodes includes a first electrode, a second electrode, a third electrode, and a fourth electrode switchably coupled to the detection module via the electrode switch; The medical device of embodiment 2, wherein the detection module is configured to enable an application mode in which a signal is applied to the first electrode and the second electrode, and a detection mode in which impedance between the third electrode and the fourth electrode is detected. [Embodiment 6] The medical device of embodiment 5, wherein the detection module includes a signal generator configured to apply signals at different frequencies to measure tissue impedance according to an electrical impedance spectroscopy (EIS) method. [Embodiment 7] The medical device of embodiment 2, wherein the electrical properties of the tissue include impedance measurements, and the medical device further comprises a controller configured to process the impedance measurements over time to determine a characterization of the fracture, the characterization corresponding to a healing state of the fracture. [Embodiment 8] The medical device of embodiment 7, wherein the healing status corresponds to one of union, suspected non-union, and non-union. [Embodiment Item 9] the plurality of electrodes are associated with the structure and spaced apart to permit placement of a first electrode and a second electrode on opposite sides of the fracture; 3. The medical device of embodiment 2, wherein the electronics cartridge has a plurality of electrical contacts arranged to electrically couple to the plurality of electrodes when the electronics cartridge is inserted into the lumen of the structure. [Embodiment 10] 3. The medical device of embodiment 2, wherein the plurality of electrodes are associated with the electronics cartridge and spaced apart to allow placement of a first electrode and a second electrode on opposite sides of the fracture. [Embodiment 11] the structure has at least one hole extending through the sidewall; 11. The medical device of embodiment 10, wherein the plurality of electrodes are positioned on the electronics cartridge so as to align with the at least one hole when the electronics cartridge is inserted into the lumen of the structure. [Embodiment 12] the structure has a distal end opening and a proximal end opening; The medical device of embodiment 10, wherein the plurality of electrodes includes a first electrode disposed on the electronics cartridge so as to be positioned adjacent to the distal end opening and a second electrode positioned on the electronics cartridge so as to be positioned adjacent to the proximal end opening when the electronics cartridge is inserted into the lumen of the structure. [Embodiment 13] the structure has a distal end opening; The medical device of embodiment 10, wherein the plurality of electrodes includes a first electrode and a second electrode positioned on the electronics cartridge such that when the electronics cartridge is inserted into the lumen of the structure, each electrode is positioned distal to the distal end opening of the structure. [Embodiment 14] 14. The medical device of any one of embodiments 1 to 13, wherein the lumen is configured to receive an implant tool during implantation of the structure. [Embodiment 15] 15. The medical device of embodiment 14, wherein the structure has a head with a recessed pocket forming a head portion of the lumen configured to receive a portion of the implant tool to enable transmission of torque applied to the implant tool to the structure. [Embodiment 16] The medical device according to any one of embodiments 1 to 15, wherein the structure is configured to be implanted in bone. [Embodiment 17] 17. The medical device of embodiment 16, wherein the structure is configured to be implanted to bridge a fracture in the bone. [Embodiment 18] 17. The medical device of embodiment 16, wherein the structure is configured to be implanted through a hole in a plate bridging the fracture in the bone. [Embodiment 19] 19. The medical device according to any one of embodiments 1 to 18, wherein the structure is a screw, pin, rod, nail, part of a joint replacement implant, part of a spinal fixation device, or part of another orthopedic device. [Embodiment 20] 20. The medical device according to any one of embodiments 1 to 19, wherein the structure has a shaft with an outer diameter in the range of 4 mm or more. [Embodiment 21] The medical device of any one of embodiments 1 to 20, wherein the lumen has a shaft portion with a diameter sized to receive at least a portion of the electronics cartridge. [Embodiment 22] 22. The medical device of any one of embodiments 1 to 21, wherein the electronics cartridge and the lumen each have respective form factors that are substantially identical. [Embodiment 23] 23. The medical device of embodiment 22, wherein the form factors of each of the electronics cartridge and the lumen include a head portion and a shaft portion, the head portion having a larger diameter than the shaft portion. [Embodiment 24] 24. The medical device of any one of claims 1 to 23, wherein the structure and the electronics cartridge include mechanical features capable of securely securing the electronics cartridge within the lumen. [Embodiment 25] 25. The medical device of embodiment 24, wherein the mechanical feature comprises one of a difference in form factor between the head of the electronics cartridge and the head portion of the lumen of the structure, a protrusion associated with the electronics cartridge and a recess associated with the lumen of the structure, and an interlocking feature associated with the shaft of the electronics cartridge that receives adhesive and an inner wall of the structure that engages the adhesive. [Embodiment 26] The medical device of any one of embodiments 1 to 25, wherein the structure and the electronics cartridge have mechanical features that allow the electronics cartridge to be removed from the lumen without damaging the structural integrity of either the electronics cartridge or the structure. [Embodiment 27] 27. The medical device of embodiment 26, wherein the mechanical features comprise complementary threads. [Embodiment 28] The medical device of any one of embodiments 1 to 27, wherein the electronics cartridge has a head and a shaft, and at least a portion of the electronics is included in an electronics assembly disposed within the head.

[0283] [Embodiment 29] The medical device of any one of embodiments 1 to 28, wherein the electronics cartridge has a head and a shaft, and at least a portion of the electronics is included in an electronics assembly disposed within the shaft. [Embodiment 30] the structure has an outer surface, and one or more electrodes are located at the outer surface; The medical device of any one of claims 1 to 29, wherein the electronics cartridge has an exterior surface and one or more electrical contacts disposed at the exterior surface and configured to electrically couple to the one or more electrodes when the electronics cartridge is inserted into the lumen. [Embodiment 31] 31. The medical device of embodiment 30, wherein the structure has a conductive substrate, the one or more electrodes correspond to conductive material associated with a sidewall of the conductive substrate, and the one or more electrodes are electrically insulated from the conductive substrate by insulating material. [Embodiment 32] 32. The medical device of embodiment 31, further comprising a feedthrough for the one or more electrodes, the feedthrough extending through the sidewall of the conductive substrate and providing an electrical connection between the one or more electrodes and the interior of the structure. [Embodiment 33] The structure has a conductive substrate at least partially coated with an insulating material, and the one or more electrodes are an area of ​​the conductive substrate that is not covered with the insulating material; and 31. The medical device of embodiment 30, wherein the medical device corresponds to one or more of the conductive materials overlying the insulating material. [Embodiment 34] 31. The medical device of embodiment 30, wherein the structure comprises a substrate, and the one or more electrodes correspond to conductive material on the substrate. [Embodiment 35] 35. The medical device of embodiment 34, wherein the substrate is made of a non-conductive material. [Embodiment 36] the substrate is made of a conductive material; 35. The medical device of embodiment 34, wherein the one or more electrodes correspond to a conductive material disposed over an insulating material. [Embodiment 37] The medical device of embodiment 30, wherein the structure has a proximal end and a distal end, and the one or more electrodes comprise one or more of a distal electrode located near the distal end, a proximal electrode located near the proximal end, a plurality of distal electrodes located near the distal end, a plurality of proximal electrodes located near the proximal end, and a plurality of electrodes located between the proximal end and the distal end. [Embodiment 38] 31. The medical device of embodiment 30, wherein the one or more electrodes are electrically isolated from each other and from the structure. [Embodiment 39] the structure having one or more holes extending through the sidewall; The medical device of any one of embodiments 1 to 38, wherein the electronics cartridge has one or more electrodes positioned to align with the one or more holes when the electronics cartridge is inserted into the lumen of the structure. [Embodiment 40] The medical device of embodiment 39, wherein each of the structure and the electronics cartridge is configured to align each of the one or more electrodes with a corresponding one of the one or more holes when the electronics cartridge is inserted into the lumen. [Embodiment 41] 40. The medical device of embodiment 39, wherein the electronics cartridge has a proximal end and a distal end, and the one or more electrodes comprise one or more of a distal electrode located near the distal end, a proximal electrode located near the proximal end, a plurality of distal electrodes located near the distal end, a plurality of proximal electrodes located near the proximal end, and a plurality of electrodes located between the proximal end and the distal end. [Embodiment 42] 40. The medical device of embodiment 39, wherein the one or more electrodes are electrically isolated from each other. [Embodiment 43] the one or more holes correspond to slots; 40. The medical device of embodiment 39, wherein the electronics cartridge has a form factor that extends outward from a surface of the electronics cartridge and fits into the slot, and the electrode assembly includes the one or more electrodes. [Embodiment 44] 44. The medical device of embodiment 43, wherein the electrode assembly is biased against the surface of the electronics cartridge such that the electronics cartridge can transition between a compressed state in which the outer surface of the electrode assembly is substantially flush with the surface of the electronics cartridge, and an expanded state in which the outer surface of the electrode assembly rests against the surface of the electronics cartridge so as to pass through the slot. [Embodiment 45] 40. The medical device of embodiment 39, wherein the electrode is associated with the shaft of the electronics cartridge, and the electrode includes an electrode surface that is recessed relative to the surface of the shaft such that, when inserted into the lumen of the structure, an empty space in communication with the hole is formed between the electrode surface and the inner wall of the structure. [Embodiment 46] the structure has a distal end opening and a proximal end opening; The medical device of any one of embodiments 1 to 45, wherein the electronics cartridge has a first electrode positioned to be adjacent to the distal end opening and a second electrode positioned to be adjacent to the proximal end opening when the electronics cartridge is inserted into the lumen of the structure. [Embodiment 47] the structure has a distal end opening; The medical device of any one of embodiments 1 to 46, wherein the electronics cartridge has a plurality of electrodes positioned thereon so as to be located distal to the distal end opening when the electronics cartridge is inserted into the lumen of the structure. [Embodiment 48] The medical device according to any one of embodiments 1 to 47, wherein the electronics includes an antenna. [Embodiment 49] the electronics cartridge having a proximal end, a distal end, a head at the proximal end, and a shaft extending from the head toward the distal end; 49. The medical device of embodiment 48, wherein the antenna is associated with the shaft. [Embodiment 50] 50. The medical device of embodiment 49, wherein the antenna comprises a conductive wire or trace extending along the length of the shaft. [Embodiment 51] 51. The medical device of embodiment 50, wherein the antenna extends in a helical pattern around the shaft. [Embodiment 52] 52. The medical device of embodiment 51, wherein the antenna is electrically insulated from the outer surface of the shaft to avoid contact with the structure when the electronics cartridge is inserted into the lumen of the structure. [Embodiment 53] the electronics cartridge having a proximal end, a distal end, a head at the proximal end, and a shaft extending from the head toward the distal end; 49. The medical device of embodiment 48, wherein the antenna is associated with the head. [Embodiment 54] 54. The medical device of embodiment 53, wherein the antenna comprises a conductive wire or trace extending along a plane parallel to the base of the head. [Embodiment 55] The medical device according to any one of embodiments 1 to 54, wherein the electronics include one or more power sources. [Embodiment 56] the electronics cartridge having a proximal end, a distal end, a head at the proximal end, and a shaft extending from the head toward the distal end; 56. The medical device of embodiment 55, wherein the one or more power sources are associated with the shaft. [Embodiment 57] the electronics cartridge having a proximal end, a distal end, a head at the proximal end, and a shaft extending from the head toward the distal end; 56. The medical device of embodiment 55, wherein the one or more power sources are associated with the head. [Embodiment 58] 56. The medical device of embodiment 55, wherein the one or more power sources include one or more of a battery and a capacitor. [Embodiment 59] The medical device of embodiment 55, wherein the one or more power sources include an energy extraction device configured to extract energy by one of electrostatic energy, wireless energy transmission, electromechanical transduction, electromagnetic transduction, and IR radiation. [Embodiment 60] The medical device of any one of embodiments 1 to 59, wherein the electronics include one or more communication components that enable communication between the medical device and another device either implanted within the body or located outside the body. [Embodiment 61] The one or more communication components are: Antennas, and 61. The medical device of embodiment 60, further comprising a radio frequency (RF) transceiver coupled to the antenna and configured to transmit and receive RF signals. [Embodiment 62] The one or more communication components: a transmitter constructed and arranged to be coupled to an electrode associated with the medical device and to be placed in contacting relationship with tissue; and 61. The medical device of embodiment 60, comprising a receiver configured and arranged to be coupled to an electrode associated with said medical device and to be placed in contacting relation with tissue.

[0284] [Embodiment 63] The one or more communication components are: enabling capacitive coupling between the medical device and the other device; or The medical device of embodiment 60, configured to at least one of: enable galvanic coupling between the medical device and the other device. [Embodiment 64] The medical device according to any one of embodiments 1 to 63, wherein the electronics includes one or more sensors. [Embodiment 65] 65. The medical device of embodiment 64, wherein the one or more sensors include an accelerometer configured to output a signal corresponding to movement of the structure. [Embodiment 66] 66. The medical device of embodiment 65, wherein the accelerometer comprises one of a one-dimensional accelerometer and a three-dimensional accelerometer. [Embodiment 67] The medical device of embodiment 65, wherein the electronics further includes a processor coupled to the accelerometer to receive the signal and configured to process the signal to provide an indication of one or more of patient activity, health of the structure, and movement of the structure relative to the implant location. [Embodiment 68] 65. The medical device of embodiment 64, wherein the one or more sensors include a temperature sensor configured to output a signal corresponding to the temperature of the structure at the implant location. [Embodiment 69] The medical device of embodiment 64, wherein the one or more sensors include a strain sensor configured to output a signal corresponding to a motion, force, tension, velocity, or other mechanical force associated with the structure. [Embodiment 70] The medical device of embodiment 69, wherein the electronics further includes a processor coupled to the strain sensor to receive signals from the strain sensor over time and configured to process the signals to provide a characterization of the fracture, the characterization corresponding to a healing state of the fracture. [Embodiment 71] 65. The medical device of embodiment 64, wherein the one or more sensors include an ultrasonic transducer configured to output a signal corresponding to ultrasonic energy detected within an area of ​​the structure. [Embodiment 72] The medical device of embodiment 71, wherein the electronics further includes a processor coupled to the ultrasound transducer to receive signals from the ultrasound transducer and configured to process the signals to provide one or more of: characterization of the fracture, characterization of tissue within the area of ​​the structure, and healing area glucose. [Embodiment 73] The medical device of embodiment 64, wherein the one or more sensors include one or more of a glucose detector and an oxygen sensor configured to output a signal corresponding to one of a glucose level and an oxygen level, respectively. [Embodiment 74] The medical device of embodiment 73, wherein the electronics further includes a processor coupled to one or more of a glucose detector and an oxygen sensor to receive the signal and configured to process the signal to provide an indication of inflammatory fluid within a region of the medical device. [Embodiment 75] The medical device of any one of embodiments 1 to 74, wherein the electronics cartridge further comprises a mechanism configured to deliver a catalytic material that chemically reacts to produce a gaseous oxygen reaction at the implant site. [Embodiment 76] The mechanism is a reservoir that releases the catalytic material one or more times after implantation under the control of a sustained release controller; and 76. The medical device of embodiment 75, comprising one or more coatings of catalytic material applied to the electronics cartridge. [Embodiment Item 77] A medical device, a cannula-like structure having a lumen extending therethrough and a plurality of electrodes disposed at an outer surface of the cannula-like structure, the cannula-like structure being configured to be at least partially implanted within a body; A medical device having an electronics cartridge containing electronics, the electronics cartridge configured to be inserted into the lumen and to establish one or more electrical connections between the electronics and the plurality of electrodes upon such insertion. [Embodiment 78] 78. The medical device of embodiment 77, wherein the cannula-like structure has a shaft, and the plurality of electrodes comprises a single set of electrodes spaced apart along the length of the shaft. [Embodiment 79] 78. The medical device of embodiment 77, wherein the cannula-like structure has a shaft, and the plurality of electrodes comprises a first set of electrodes spaced apart from one another along the length of a first side of the shaft, and a second set of electrodes spaced apart from one another along the length of a second side of the shaft spaced apart from the first side. [Embodiment 80] The medical device of embodiment 77, wherein the cannula-like structure has a shaft, and the plurality of electrodes comprises a first linear electrode provided on a first side of the shaft and a second linear electrode provided on a second side of the shaft spaced apart from the first side. [Embodiment 81] The cannula-like structure includes: a conductive body having an outer surface at least partially coated with an insulating material; a first electrode of the plurality of electrodes corresponding to the exposed portion of the conductive body; 78. The medical device of embodiment 77, further comprising a second electrode of the plurality of electrodes located on a portion of the insulating material. [Embodiment 82] The electronics cartridge is a first electrical contact positioned to contact an inner surface of the conductive body, thereby providing an electrical coupling between the electronics and the first electrode; 82. The medical device of embodiment 81, further comprising a second electrical contact positioned to contact a portion of the second electrode, thereby establishing an electrical connection between the electronics and the second electrode. [Embodiment 83] 83. The medical device of embodiment 82, wherein the electronics cartridge further comprises an insulating seal between the first electrical contact and the second electrical contact. [Embodiment 84] 83. The medical device of embodiment 82, wherein the second electrode is partially coated with an insulating material, and the portion of the second electrode that contacts the second electrical contact corresponds to the uncoated portion of the second electrode. [Embodiment Item 85] The medical device of embodiment 84, wherein the uncoated portion of the second electrode is disposed within a head portion of the lumen located at the proximal end of the cannula-like structure. [Embodiment 86] The cannula-like structure includes: a head and a body having an outer surface at least partially coated with an insulating material; a first portion of conductive material disposed on the insulating material forms a first electrode of the plurality of electrodes, a first electrical contact located near the head, and a first conductive path between the first electrode and the first electrical contact; 78. The medical device of embodiment 77, wherein a second portion of conductive material disposed on the insulating material forms a second electrode of the plurality of electrodes, a second electrical contact located near the head, and a second conductive path between the second electrode and the second electrical contact. [Embodiment 87] The electronics cartridge is a first electrical contact established to contact the first contact of the cannula-like structure, thereby achieving an electrical coupling between the electronics and the first electrode; and 87. The medical device of embodiment 86, having a second electrical contact established to contact the second contact of the cannula-shaped structure, thereby achieving an electrical coupling between the electronics and the second electrode. [Embodiment Item 88] The cannula-like structure includes: a distal component including a first electrode of the plurality of electrodes; 78. The medical device of embodiment 77, further comprising a proximal component including a second electrode of the plurality of electrodes. [Embodiment 89] 89. The medical device of embodiment 88, wherein each of the distal component and the proximal component has a conductive substrate with an outer surface at least partially coated with an insulating coating. [Embodiment Item 90] 89. The medical device of embodiment 88, wherein the distal component and the proximal component each have a mechanical feature that enables mechanical coupling between the distal component and the proximal component. [Embodiment Item 91] 78. The medical device of embodiment 77, wherein the cannula-like structure and the electronics cartridge have mechanical features that enable the electronics cartridge to be securely fixed within the lumen. [Embodiment Item 92] The medical device of embodiment 91, wherein the mechanical feature comprises one of a difference in form factor between the head of the electronics cartridge and the head portion of the lumen of the cannular structure, a protrusion associated with the electronics cartridge and a recess associated with the lumen of the cannular structure, and an interlocking feature associated with the shaft of the electronics cartridge that receives adhesive and the inner wall of the cannular structure that engages the adhesive. [Embodiment Item 93] The medical device of embodiment 77, wherein the cannula-like structure and the electronics cartridge have mechanical features that allow the electronics cartridge to be removed from the lumen without damaging the structural integrity of either the electronics cartridge or the cannula-like structure. [Embodiment Item 94] 94. The medical device of embodiment 93, wherein the mechanical features comprise complementary threads.

[0285] [Embodiment Item 95] A medical device, a cannula-like structure having a lumen extending therethrough and at least one aperture extending through a sidewall of the cannula-like structure, the cannula-like structure being configured to be at least partially implanted within a body; A medical device having an electronics cartridge including a plurality of electrodes and electronics electrically coupled to the electrodes, the electronics cartridge configured to be inserted into the lumen and to provide alignment of the plurality of electrodes with the at least one hole upon such insertion. [Embodiment Item 96] the at least one hole corresponds to a slot; 96. The medical device of embodiment 95, wherein the electronics cartridge extends outward from a surface of the electronics cartridge, has a form factor that fits into the slot, and includes an electrode assembly including the plurality of electrodes. [Embodiment Item 97] The medical device of embodiment 96, wherein the electrode assembly is biased against the surface of the electronics cartridge such that the electronics cartridge can transition between a compressed state in which the outer surface of the electrode assembly is substantially flush with the surface of the electronics cartridge, and an expanded state in which the outer surface of the electrode assembly is positioned above the surface of the electronics cartridge so as to pass through the slot. [Embodiment Item 98] the at least one hole corresponds to a plurality of holes; 96. The medical device of embodiment 95, wherein the electronics cartridge has a corresponding plurality of electrodes. [Embodiment Item 99] The medical device of embodiment 98, wherein the plurality of electrodes are ring electrodes recessed relative to the surface of the electronics cartridge, such that when inserted into the lumen of the cannular structure, an annular space in communication with the hole is formed between the electrode surface and the inner wall of the cannular structure. [Embodiment 100] 99. The medical device of embodiment 98, wherein the plurality of electrodes includes a distal electrode and a proximal electrode. [Embodiment 101] 99. The medical device of embodiment 98, wherein the plurality of electrodes includes three or more electrodes arranged in an array between a distal electrode and a proximal electrode. [Embodiment 102] A medical device, a cannula-like structure having a lumen extending therethrough and a distal end opening and a proximal end opening, the cannula-like structure being configured to be at least partially implanted within a body; A medical device having an electronics cartridge including a plurality of electrodes and electronics electrically coupled to the electrodes, the electronics cartridge configured to be inserted into the lumen and to position a first electrode of the plurality of electrodes at the distal end opening and a second electrode of the plurality of electrodes at the proximal end opening upon such insertion. [Embodiment 103] The medical device of embodiment 102, wherein the first electrode is a ring electrode recessed relative to the surface of the electronics cartridge, such that when inserted into the lumen, an annular space communicating with the distal end opening is formed between the surface of the first electrode and the inner wall of the cannula-like structure. [Embodiment 104] 103. The medical device of embodiment 102, wherein the cannula-like structure has a head with an outer periphery, and the second electrode extends from the electronics cartridge and beyond the outer periphery. [Embodiment 105] A medical device, a cannula-like structure having a lumen extending therethrough and a distal end opening and a proximal end opening, the cannula-like structure being configured to be at least partially implanted within a body; A medical device having an electronics cartridge including a plurality of electrodes and electronics electrically coupled to the electrodes, the electronics cartridge configured to be inserted into the lumen and to position the plurality of electrodes distal to the distal end opening upon such insertion. [Embodiment 106] The medical device of embodiment 105, wherein the electronics cartridge has a shaft with a length and at least two portions along the length with different stiffnesses. [Embodiment 107] 107. The medical device of embodiment 106, wherein the plurality of electrodes are associated with the less rigid of the at least two portions. [Embodiment 108] 107. The medical device of embodiment 106, wherein the electronics are associated with the more rigid of the at least two portions. [Embodiment 109] 1. A medical device configured to be at least partially implanted within a body, the medical device comprising: a structure having a head and a shaft, each having a head cavity and a shaft cavity, respectively; electronics disposed within one or more of the head cavity and the shaft cavity; at least one electrode associated with the shaft and electrically coupled to the electronics. [Embodiment 110] The medical device of embodiment 109, wherein the structure has a shaft, and the at least one electrode comprises a single set of electrodes spaced apart from one another along the length of the shaft. [Embodiment 111] The medical device of embodiment 109, wherein the structure has a shaft, and the at least one electrode comprises a first set of electrodes spaced apart from one another along the length of a first side of the shaft and a second set of electrodes spaced apart from one another along the length of a second side of the shaft spaced apart from the first side. [Embodiment 112] The medical device of embodiment 109, wherein the structure has a shaft, and the at least one electrode comprises a first linear electrode disposed on a first side of the shaft and a second linear electrode disposed on a second side of the shaft spaced apart from the first side. [Embodiment 113] The method further comprises a sensor for measuring an electrical property of the tissue, the sensor comprising: A plurality of electrodes; The medical device of embodiment 109, further comprising a detection module coupled to the plurality of electrodes. [Embodiment 114] the plurality of electrodes includes a first electrode and a second electrode; The medical device of embodiment 113, wherein the detection module is configured to enable the first electrode and the second electrode to function in either an application mode in which a signal is applied across the electrodes, or a detection mode in which impedance between the electrodes is detected. [Embodiment 115] The medical device of embodiment 114, wherein the detection module includes a signal generator configured to apply signals at different frequencies to measure tissue impedance according to an electrical impedance spectroscopy (EIS) method. [Embodiment 116] The sensor further comprises an electrode switch; the plurality of electrodes includes a first electrode, a second electrode, a third electrode, and a fourth electrode switchably coupled to the detection module via the electrode switch; The medical device of embodiment 113, wherein the detection module is configured to enable an application mode for applying a signal to the first electrode and the second electrode, and a detection mode for detecting impedance between the third electrode and the fourth electrode. [Embodiment Item 117] The medical device of embodiment 116, wherein the detection module includes a signal generator configured to apply signals at different frequencies to measure tissue impedance according to an electrical impedance spectroscopy (EIS) method. [Embodiment Item 118] The medical device of embodiment 113, wherein the electrical properties of the tissue include impedance measurements, and the medical device further comprises a controller configured to process the impedance measurements over time to determine a characterization of the fracture, the characterization corresponding to a healing state of the fracture. [Embodiment 119] The medical device of embodiment 118, wherein the healing status corresponds to one of union, suspected non-union, and non-union. [Embodiment 120] The medical device of embodiment 109, wherein the structure is configured to be implanted in bone. [Embodiment Item 121] 121. The medical device of embodiment 120, wherein the structure is configured to be implanted to bridge a fracture in the bone. [Embodiment 122] 121. The medical device of embodiment 120, wherein the structure is configured to be implanted through a hole in a plate bridging the fracture in the bone. [Embodiment 123] 110. The medical device of embodiment 109, wherein the structure is a screw, pin, rod, nail, part of a joint replacement implant, part of a spinal fixation device, or part of other orthopedic device. [Embodiment Item 124] 110. The medical device of embodiment 109, wherein the structure has a shaft with an outer diameter in the range of 4 millimeters or greater. [Embodiment Item 125] 110. The medical device of embodiment 109, wherein the structure has an outer surface and one or more electrodes disposed at the outer surface and electrically coupled to the electronics.

[0286] [Embodiment 126] The medical device of embodiment 125, wherein the structure has a substrate, and the one or more electrodes correspond to conductive structures extending from the outer surface along the sidewall of the substrate to the electronics. [Embodiment Item 127] The medical device of embodiment 125, wherein the structure has a substrate, and the one or more electrodes correspond to conductive structures passing through holes formed through a sidewall of the substrate. [Embodiment Item 128] 128. The medical device of embodiment 127, wherein the conductive structure has a layer of conductive material extending from the outer surface of the structure along the sidewalls of the holes to the inner surface of the structure. [Embodiment 129] 128. The medical device of embodiment 127, wherein the conductive structure comprises a conductive pin passing through the hole. [Embodiment 130] 130. The medical device of embodiment 129, wherein the conductive pins are pogo-style pins that are normally biased outward from the holes. [Embodiment Item 131] 130. The medical device of embodiment 129, wherein the conductive structure comprises a conductive material filling the holes. [Embodiment 132] 130. The medical device of embodiment 129, wherein the substrate is made of a conductive material at least partially coated with an insulating material. [Embodiment 133] 133. The medical device of embodiment 132, wherein the holes have sidewalls coated with an insulating material. [Embodiment 134] The medical device of embodiment 129, wherein the substrate is made of a non-conductive material. [Embodiment 135] The medical device of embodiment 125, wherein the structure has a proximal end and a distal end, and the one or more electrodes comprise one or more of a distal electrode located near the distal end, a proximal electrode located near the proximal end, a plurality of distal electrodes located near the distal end, a plurality of proximal electrodes located near the proximal end, and a plurality of electrodes located between the proximal end and the distal end. [Embodiment 136] The medical device of embodiment 135, wherein the one or more electrodes are electrically isolated from each other. [Embodiment Item 137] The medical device of embodiment 109, wherein the electronics include an antenna. [Embodiment Item 138] The medical device of embodiment 137, wherein the antenna is associated with the shaft of the structure. [Embodiment 139] 139. The medical device of embodiment 138, wherein the antenna comprises a conductive wire or trace extending along the length of the shaft. [Embodiment Item 140] 140. The medical device of embodiment 139, wherein the antenna extends in a spiral pattern around the shaft. [Embodiment 141] The medical device of embodiment 138, wherein the antenna is associated with the head of the structure. [Embodiment 142] 142. The medical device of embodiment 141, wherein the antenna comprises a conductive wire or trace extending along a plane parallel to the base of the head. [Embodiment Item 143] The medical device of embodiment 109, wherein the electronics include one or more power sources. [Embodiment Item 144] The medical device of embodiment 143, wherein the one or more power sources are associated with the shaft of the structure. [Embodiment Item 145] The medical device of embodiment 143, wherein the one or more power sources are associated with the head of the structure. [Embodiment 146] The medical device of embodiment 143, wherein the one or more power sources include one or more of a battery and a capacitor. [Embodiment Item 147] The medical device of embodiment 143, wherein the one or more power sources include an energy extraction device configured to extract energy by one of electrostatic energy, wireless energy transmission, electromechanical transduction, electromagnetic transduction, and IR radiation. [Embodiment Item 148] The medical device of embodiment 109, wherein the electronics include one or more communication components that enable communication between the medical device and another device either implanted within the body or located outside the body. [Embodiment Item 149] The one or more communication components are: Antennas, and The medical device of embodiment 148, further comprising a radio frequency (RF) transceiver coupled to the antenna and configured to transmit and receive RF signals. [Embodiment Item 150] The one or more communication components: a transmitter constructed and arranged to be coupled to an electrode associated with the medical device and to be placed in contacting relationship with tissue; and The medical device of embodiment 148, comprising a receiver configured and arranged to be coupled to an electrode associated with the medical device and arranged to be in contact with tissue. [Embodiment Item 151] The one or more communication components are: enabling capacitive coupling between the medical device and the other device; or The medical device of embodiment 150, configured to at least one of enable galvanic coupling between the medical device and the other device. [Embodiment Item 152] The medical device of embodiment 109, wherein the electronics include one or more sensors. [Embodiment Item 153] The medical device of embodiment 152, wherein the one or more sensors include an accelerometer configured to output a signal corresponding to movement of the structure. [Embodiment Item 154] The medical device of embodiment 153, wherein the accelerometer comprises one of a one-dimensional accelerometer and a three-dimensional accelerometer. [Embodiment Item 155] The medical device of embodiment 153, wherein the electronics further includes a processor coupled to the accelerometer to receive the signal and configured to process the signal to provide an indication of one or more of patient activity, health of the structure, and movement of the structure relative to the implant location. [Embodiment Item 156] The medical device of embodiment 152, wherein the one or more sensors include a temperature sensor configured to output a signal corresponding to the temperature of the structure at the implant location. [Embodiment Item 157] The medical device of embodiment 152, wherein the one or more sensors include a strain sensor configured to output a signal corresponding to a motion, force, tension, velocity, or other mechanical force associated with the structure. [Embodiment Item 158] The medical device of embodiment 157, wherein the electronics further includes a processor coupled to the strain sensor to receive signals from the strain sensor over time and configured to process the signals to provide a characterization of the fracture, the characterization corresponding to a healing state of the fracture. [Embodiment Item 159] The medical device of embodiment 152, wherein the one or more sensors include an ultrasonic transducer configured to output a signal corresponding to ultrasonic energy detected within an area of ​​the structure. [Embodiment 160] The medical device of embodiment 159, wherein the electronics further includes a processor coupled to the ultrasonic transducer to receive signals from the ultrasonic transducer and configured to process the signals to provide one or more of: characterization of a fracture, characterization of tissue within the area of ​​the structure, and glucose levels. [Embodiment Item 161] The medical device of embodiment 152, wherein the one or more sensors include one or more of a glucose detector and an oxygen sensor configured to output a signal corresponding to one of a glucose level and an oxygen level, respectively. [Embodiment 162] The medical device of embodiment 161, wherein the electronics further includes a processor coupled to one or more of a glucose detector and an oxygen sensor to receive the signal and configured to process the signal to provide an indication of inflammatory fluid within an area of ​​the medical device. [Embodiment 163] The medical device of embodiment 109, further comprising a mechanism configured to deliver a catalytic material that chemically reacts to produce a gaseous oxygen reaction at the implant site. [Embodiment Item 164] The mechanism is a reservoir that releases the catalytic material one or more times after implantation under the control of a sustained release controller; and The medical device of embodiment 163, comprising one or more coatings of catalytic material disposed on the structure. [Embodiment Item 165] A medical device, a cannula-like structure having a lumen extending therethrough, a plurality of holes formed through a sidewall, and a plurality of electrodes, each electrode associated with a respective one of the plurality of holes, the cannula-like structure being configured to be at least partially implanted within a body; The medical device has an electronics cartridge containing electronics, the electronics cartridge being at least partially disposed within the lumen, the electronics cartridge having a plurality of electrical contacts each aligned with one of the holes to achieve electrical coupling between the electronics and each of the plurality of electrodes.

[0287] [Embodiment 166] The cannula-like structure has a shaft, the plurality of holes comprises a single set of holes spaced apart from one another along the length of the shaft; The medical device of embodiment 165, wherein the plurality of electrodes comprises a single set of electrodes spaced apart from one another along the length of the shaft. [Embodiment Item 167] The cannula-like structure has a shaft, the plurality of holes comprising a first set of holes spaced apart from one another along the length of a first side of the shaft and a second set of holes spaced apart from one another along the length of a second side of the shaft spaced apart from the first side of the shaft; The medical device of embodiment 165, wherein the plurality of electrodes comprises a first set of electrodes spaced apart from one another along the length of a first side of the shaft, and a second set of electrodes spaced apart from one another along the length of a second side of the shaft, the second side being spaced apart from the first side. [Embodiment Item 168] The cannula-like structure has a shaft, the plurality of holes comprising a first linear slot disposed at a first side of the shaft and a second linear slot disposed at a second side of the shaft spaced from the first side; The medical device of embodiment 165, wherein the plurality of electrodes comprises a first linear electrode disposed at the first side of the shaft and a second linear electrode disposed at the second side of the shaft spaced apart from the first side. [Embodiment Item 169] the cannula-like structure includes a substrate having an outer surface and an inner surface; The plurality of electrodes are a first electrode having a feedthrough disposed at the outer surface and extending through a first hole of the plurality of holes to the inner surface of the substrate; The medical device of embodiment 165, further comprising: a second electrode disposed at the outer surface and having a feedthrough extending through a second hole of the plurality of holes to the inner surface of the substrate. [Embodiment Item 170] The medical device of embodiment 169, wherein the substrate is made of an insulating material. [Embodiment Item 171] The medical device of embodiment 169, wherein the substrate is made of a conductive material coated with an insulating material. [Embodiment Item 172] The electronics cartridge is a first electrical contact of the plurality of electrical contacts positioned to contact the feedthrough of the first electrode on the inner surface of the substrate, thereby achieving electrical coupling between the electronics and the first electrode; The medical device of embodiment 169, further comprising a second electrical contact of the plurality of electrical contacts positioned to contact the feedthrough of the second electrode on the inner surface of the substrate, thereby establishing an electrical connection between the electronics and the second electrode. [Embodiment Item 173] The plurality of electrodes are a first conductive structure passing through a first hole of the plurality of holes; 166. The medical device of embodiment 165, further comprising a second conductive structure extending through a second hole of the plurality of holes to the inner surface of the body. [Embodiment Item 174] The medical device of embodiment 173, wherein the first conductive structure corresponds to a first conductive pin and the second conductive structure corresponds to a second conductive pin. [Embodiment Item 175] The medical device of embodiment 174, wherein each of the first conductive pin and the second conductive pin is a pogo-type pin normally biased outward from the first hole or the second hole. [Embodiment Item 176] The medical device of embodiment 173, wherein each of the first conductive structure and the second conductive structure corresponds to the conductive material filling the first hole or the second hole. [Embodiment Item 177] 1. An implantable medical device for characterizing a fracture in a bone, the medical device comprising: an implant configured to be implanted at least partially within the bone and across the fracture; an impedance sensor contained within the implant, the impedance sensor comprising: a first electrode and a second electrode, and a detection module configured to obtain impedance measurements between the first electrode and the second electrode; a controller with memory disposed within the implant and configured to process and store the impedance measurements; A medical device comprising communication circuitry disposed within the implant and configured to transmit the impedance measurements to an external device. [Embodiment Item 178] The medical device of embodiment 177, wherein the detection module is configured to enable the first electrode and the second electrode to function in either an application mode in which a signal is applied across the electrodes, or a detection mode in which impedance between the first electrode and the second electrode is detected. [Embodiment Item 179] The medical device of embodiment 178, wherein the detection module includes a signal generator configured to apply signals at different frequencies to measure tissue impedance according to an electrical impedance spectroscopy (EIS) method. [Embodiment Item 180] the impedance sensor further includes a third electrode and a fourth electrode; The medical device of embodiment 177, wherein the detection module is configured to enable an application mode in which a signal is applied to the first electrode and the second electrode, and a detection mode in which impedance between the third electrode and the fourth electrode is detected. [Embodiment Item 181] The medical device of embodiment 180, wherein the detection module includes a signal generator configured to apply signals at different frequencies to measure tissue impedance according to an electrical impedance spectroscopy (EIS) method. [Embodiment Item 182] The medical device of embodiment 177, wherein the controller is further configured to process impedance measurements over time to determine a characterization of the fracture, the characterization corresponding to a healing state of the fracture. [Embodiment Item 183] The medical device of embodiment 182, wherein the healing status corresponds to one of union, suspected non-union, and non-union. [Embodiment Item 184] The medical device of embodiment 177, wherein the first electrode and the second electrode are spaced apart from each other on the implant to allow placement of the first electrode and the second electrode on opposite sides of the fracture. [Embodiment Item 185] The medical device of embodiment 177, wherein the impedance sensor has a plurality of electrodes including the first electrode, the second electrode, and at least one additional electrode, and the detection module is configured to select the first electrode and the second electrode from the plurality of electrodes based on the impedance measurement value so that the first electrode and the second electrode are located on opposite sides of the fracture. [Embodiment Item 186] The medical device of embodiment 177, wherein the communication circuitry comprises a tissue-conductive communication circuitry coupled to the first electrode and the second electrode and configured to enable capacitive coupling between the medical device and another device or to enable galvanic coupling between the medical device and the other device. [Embodiment Item 187] The above implants are a structure having a lumen extending at least partially therethrough, the structure configured to be implanted at least partially within the bone and across the fracture; The medical device of embodiment 177 has an electronics cartridge including at least a portion of the impedance sensor, the controller, the memory, and at least a portion of the communication circuitry, the electronics cartridge being configured to be inserted into the lumen after implantation of the structure. [Embodiment Item 188] The medical device of embodiment 187, wherein the structure has an outer surface, and the first electrode and the second electrode are located at the outer surface. [Embodiment Item 189] the structure has at least one hole extending through the sidewall; The medical device of embodiment 187, wherein the electronics cartridge has an outer surface, and the first electrode and the second electrode are located on the outer surface and positioned to align with the at least one hole when the electronics cartridge is inserted into the lumen of the structure. [Embodiment Item 190] The medical device of embodiment 187, wherein the structure is a screw, pin, rod, nail, part of a joint replacement implant, part of a spinal fixation device, or part of other orthopedic device. [Embodiment Item 191] The medical device of embodiment 177, wherein the implant consists of a single structure. [Embodiment Item 192] The medical device of embodiment 191, wherein the unitary structure is a screw, pin, rod, nail, part of a joint replacement implant, part of a spinal fixation device, or part of other orthopedic device. [Embodiment Item 193] The method of characterizing the fracture, the method comprising: obtaining a plurality of measurements of tissue electrical properties over time via a plurality of electrodes positioned within the bone tissue and across the fracture, the plurality of electrodes including a first electrode and a second electrode located on opposite sides of the fracture; processing the measurements to determine a characterization of the fracture, the characterization corresponding to a healing state of the fracture; Optionally, the plurality of measurements are obtained using a medical device according to any one of embodiments 1-192, 226-238, and 262 and 263.

[0288] [Embodiment Item 194] The method of embodiment 193, wherein the healing status corresponds to one of union, suspected nonunion, and nonunion. [Embodiment Item 195] The method of embodiment 193, further comprising the step of communicating the plurality of measurements of the electrical properties of the tissue or the characterization of the fracture to an external device. [Embodiment Item 196] The electrical property of the tissue includes impedance, and obtaining a plurality of measurements includes: The method of embodiment 193, comprising the step of applying signals to the first electrodes at different frequencies to measure tissue impedance according to electrical impedance spectroscopy (EIS). [Embodiment Item 197] The method of embodiment 196, wherein the signal is applied by an implanted detection module. [Embodiment Item 198] The method of embodiment 193, further comprising the step of implanting the plurality of electrodes such that the first electrode and the second electrode are positioned on opposite sides of the fracture. [Embodiment Item 199] The step of implanting the plurality of electrodes comprises: implanting at least one cannula-like structure into the bone tissue across the fracture, the cannula-like structure having a lumen extending at least partially therethrough; The method of embodiment 198, further comprising the step of inserting an electronics cartridge into the lumen after implantation of the cannulated structure, the electronics cartridge including a detection module. [Embodiment 200] The method of embodiment 199, wherein the plurality of electrodes are carried by the cannula-like structure and are coupled to the detection module upon insertion of the electronics cartridge into the lumen. [Embodiment 201] The method of embodiment 199, wherein the plurality of electrodes are carried by the electronics cartridge and interface with bone tissue through a plurality of holes provided in the sidewall of the cannular structure. [Embodiment 202] The method of embodiment 199 further comprises the step of securing the electronics cartridge to the cannula-like structure. [Embodiment 203] The step of implanting the plurality of electrodes comprises: The method of embodiment 198, comprising the step of implanting a medical device having a structure carrying the plurality of electrodes and electronics disposed within the structure and coupled to the plurality of electrodes. [Embodiment 204] The method of characterizing the fracture, the method comprising: obtaining a plurality of measurements of electrical properties of the tissue over time via a plurality of electrodes disposed within the bone tissue, the plurality of electrodes including a first electrode and a second electrode each located within the fracture gap; The method includes processing the measurements to determine a characterization of the fracture, the characterization corresponding to a healing state of the fracture. [Embodiment 205] The method of embodiment 204, wherein the healing status corresponds to one of union, suspected non-union, and non-union. [Embodiment 206] The method of embodiment 204, further comprising transmitting a plurality of said measurements of electrical properties of tissue or characterization of bone fracture to an external device. [Embodiment 207] The electrical properties of the tissue include impedance, and obtaining the plurality of measurements comprises: The method of embodiment 204, comprising the step of applying signals at different frequencies to the first electrodes to measure tissue impedance according to electrical impedance spectroscopy (EIS). [Embodiment 208] The method of embodiment 207, wherein the signal is applied by an implanted detection module. [Embodiment 209] The method of embodiment 204, further comprising the step of implanting the plurality of electrodes such that the first electrode and the second electrode are positioned within the gap of the fracture. [Embodiment 210] The step of implanting the plurality of electrodes comprises: implanting at least one cannula-like structure into the bone tissue and across the gap of the fracture, the cannula-like structure having a lumen extending at least partially therethrough; The method of embodiment 209, further comprising the step of inserting an electronics cartridge into the lumen after implantation of the cannulated structure, the electronics cartridge including a detection module. [Embodiment 211] The method of embodiment 210, wherein the plurality of electrodes are carried by the cannula-like structure and are coupled to the detection module upon insertion of the electronics cartridge into the lumen. [Embodiment 212] The method of embodiment 210, wherein the plurality of electrodes are carried by the electronics cartridge and interface with bone tissue through a plurality of holes provided in the sidewall of the cannular structure. [Embodiment 213] The method of embodiment 210, further comprising the step of securing the electronics cartridge to the cannula-like structure. [Embodiment 214] The step of implanting the plurality of electrodes comprises: The method of embodiment 209, comprising the step of implanting a medical device having a structure carrying the plurality of electrodes and electronics disposed within the structure and coupled to the plurality of electrodes. [Embodiment 215] 1. A method for characterizing a fracture, the method comprising: obtaining a plurality of measurements of electrical properties of the tissue over time via a plurality of electrodes disposed within the bone tissue, the plurality of electrodes including a first electrode and a second electrode each spanning the fracture gap; processing the measurements to determine a characterization of the fracture, the characterization corresponding to a healing state of the fracture; Optionally, the plurality of measurements are obtained using a medical device according to any one of embodiments 1-192, 226-238, and 262 and 263. [Embodiment 216] The method of embodiment 215, wherein the healing status corresponds to one of union, suspected nonunion, and nonunion. [Embodiment 217] The method of embodiment 215, further comprising transmitting the plurality of measurements of electrical properties of tissue or characterization of bone fracture to an external device. [Embodiment Item 218] The electrical properties of the tissue include impedance, and obtaining the plurality of measurements comprises: The method of embodiment 215, comprising the step of applying signals to the first electrodes at different frequencies to measure tissue impedance according to electrical impedance spectroscopy (EIS). [Embodiment 219] The method of embodiment 218, wherein the signal is applied by an implanted detection module. [Embodiment 220] The method of embodiment 215, further comprising the step of implanting the plurality of electrodes such that the first electrode and the second electrode span the fracture gap. [Embodiment 221] The step of implanting the plurality of electrodes comprises: implanting at least one cannula-like structure into the bone tissue and across the gap of the fracture, the cannula-like structure having a lumen extending at least partially therethrough; The method of embodiment 220, further comprising the step of inserting an electronics cartridge into the lumen after implantation of the cannulated structure, the electronics cartridge including a detection module. [Embodiment 222] The method of embodiment 221, wherein the plurality of electrodes are carried by the cannula-like structure and are coupled to the detection module upon insertion of the electronics cartridge into the lumen. [Embodiment 223] The method of embodiment 221, wherein the plurality of electrodes are carried by the electronics cartridge and interface with bone tissue through a plurality of holes provided in the sidewall of the cannular structure. [Embodiment 224] The method of embodiment 221, further comprising the step of securing the electronics cartridge to the cannula-like structure. [Embodiment 225] The step of implanting the plurality of electrodes comprises: The method of embodiment 220, comprising the step of implanting a medical device having a structure carrying the plurality of electrodes and electronics disposed within the structure and coupled to the plurality of electrodes.

[0289] [Embodiment 226] 1. An implantable medical device for characterizing a fracture in a bone, the medical device comprising: a first implant configured to be at least partially implanted within the bone, the first implant having a first electrode;...

Claims

1. A medical device, a structure configured to be at least partially implanted within a body, the structure having a lumen extending at least partially therethrough; an electronics cartridge containing electronics and configured to be inserted into the lumen after implantation of the structure; a sensor for measuring electrical properties of tissue, the sensor comprising a plurality of electrodes and a sensing module of the electronics cartridge, the sensing module coupled to the plurality of electrodes; the plurality of electrodes are disposed on an exterior surface of the electronics cartridge and are spaced apart to allow placement of a first electrode and a second electrode on opposite sides of a fracture; the electronics cartridge includes a plurality of electrical contacts disposed on an exterior surface of the electronics cartridge, the plurality of electrical contacts being spaced apart to electrically couple to the plurality of electrodes when the electronics cartridge is inserted into the lumen of the structure; the structure includes a plurality of holes extending through a sidewall, the plurality of electrodes being disposed on an outer surface of the structure and spaced apart to permit placement of a first electrode and a second electrode on opposite sides of a fracture and to permit alignment between the plurality of electrodes and the plurality of holes when the electronics cartridge is inserted into the lumen of the structure.

2. the plurality of electrodes includes a first electrode and a second electrode; 2. The medical device of claim 1, wherein the detection module is configured to enable the first electrode and the second electrode to function in either an application mode in which a signal is applied across the plurality of electrodes, or a detection mode in which impedance between the plurality of electrodes is detected.

3. The medical instrument of claim 2 , wherein the detection module includes a signal generator configured to apply signals at different frequencies in the detection mode to measure tissue impedance according to an electrical impedance spectroscopy (EIS) method.

4. the sensor further comprises an electrode switch; the plurality of electrodes includes a first electrode, a second electrode, a third electrode, and a fourth electrode switchably coupled to the detection module via the electrode switch; 2. The medical device of claim 1, wherein the detection module is configured to enable an application mode in which a signal is applied to the first electrode and the second electrode, and a detection mode in which an impedance between the third electrode and the fourth electrode is detected.

5. 5. The medical instrument of claim 4, wherein the detection module includes a signal generator configured to apply signals at different frequencies in the detection mode to measure tissue impedance according to an electrical impedance spectroscopy (EIS) method.

6. 10. The medical device of claim 1, wherein the electrical properties of the tissue include impedance measurements, and the medical device further comprises a controller configured to process the impedance measurements over time to determine a characterization of the fracture, the characterization corresponding to a healing state of the fracture.

7. The medical device of claim 6 , wherein the healing status corresponds to one of union, suspected non-union, and non-union.

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