Vascular and fluid detection and imaging device

Abstract

A detection and imaging device may include a sensor having a plurality of electrodes for circumferential disposition around or proximate to the exterior of a target anatomy. At least one of the electrodes may deliver a stimulation current to the target anatomy and one or more other electrodes may collect a resulting impedance signal. The device may also include circuitry in communication with the sensor and that may generate and deliver the stimulation current and may sense the resulting impedance signal. The device may also include a processing unit to evaluate the impedance signal based on differential impedance to detect a clinically significant condition and to generate a tomographic image of the monitored anatomy representative of the detected condition. The device may also include a power source.

Description

2238-23001TAMUS 6213VASCULAR AND FLUID DETECTION AND IMAGING DEVICECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application 63 / 776,922 filed March 24, 2025, and entitled “Post-Vascular Surgery Event Detection and Imaging Device,” and to U.S. Provisional Application 63 / 776,941 filed March 24, 2025, and entitled “Fluid Detection and Imaging Device,” each of which is hereby incorporated herein by reference in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.TECHNICAL FIELD

[0003] The present disclosure relates generally to medical detection and imaging devices, and more particularly to a vascular and fluid detection and imaging device for monitoring vascular perfusion and fluid accumulation in patients using electrical impedance tomography.BACKGROUND

[0004] A primary challenge in post-operative vascular care is ensuring the continued function of operative structures and organs following surgical intervention. Blood flow through areas of surgical trauma can spontaneously constrict as a result of inflammatory or infectious processes attendant to the post-operative state, compromising perfusion of downstream tissuesand organsand potentially threatening their viability. Surgeons must consequently devote considerable time and resources to repeated, in-person evaluation of post-operative patients to confirm the continuous perfusion of surgical sites. This monitoring burden extends hospital stays, consumes clinical resources, and introduces potential delays in the identification of clinically significant changes in perfusion that can arise between evaluation intervals.

[0005] Existing technologies for post-operative vascular monitoring present meaningful limitations. General bedside patient monitoring systems do not specifically assess perfusion through individual vessels or operative sites. Peripheral perfusion metrics, such as those measured at the extremity, do not account for muscle oxygen consumption or regional blood flow, and thus may fail to identify early-stage vascular2238-23001TAMUS 6213compromise localized to the operative site. While various implantable and non-invasive sensing modalities have been investigated for vascular monitoring applications, no currently available device provides continuous, real-time, radiation-free monitoring and imaging of perfusion through a specific vasculature in the postoperative patient in a manner that reduces the need for repeated in-person clinical evaluation.

[0006] Separately, there exists a significant clinical need for continuous, non-invasive monitoring of patients who are prone to or at risk for fluid accumulation in or around the lungs or within the peritoneal cavity. Pulmonary edema occurs in more than one million patients per year in the United States, often secondary to cardiac causes, with associated treatment costs ranging from approximately $2,000 to $20,000 per patient. Pneumonia represents an even larger market burden, with the pneumonia diagnostics and therapeutics market estimated at $11.9 billion in 2021. Acute respiratory distress syndrome (ARDS), a severe form of diffuse lung injury characterized by widespread fluid accumulation, has seen increased clinical presentation in recent years.

[0007] Conventional detection of fluid accumulation within or around the lungs relies primarily upon radiographic imaging, which requires discrete imaging events, exposes the patient to ionizing radiation with repeated studies, and generally necessitates a clinical visit or hospital admission, making it poorly suited for continuous monitoring in the outpatient or home setting. Laboratory testing may assist in identifying a causative pathogen but likewise cannot provide real-time, continuous monitoring of fluid burden. While various non-invasive sensing modalities have been investigated for fluid detection applications, no single integrated platform has yet emerged that is capable of continuous, real-time, radiation-free monitoring and imaging of fluid accumulation within or around the lungs or within the peritoneal cavity. Because existing technologies do not allow for continuous data collection, it is difficult to identify the early onset of fluid accumulation and to intervene before a patient’s condition deteriorates.

[0008] Accordingly, there is a need for a device and related methods that can continuously and non-invasively monitor vascular perfusion and fluid accumulation in patients, generate real-time tomographic images of the monitored anatomy without the use of ionizing radiation, and communicate clinically relevant data and imaging to care providers — reducing the need for repeated clinical visits and enabling earlier intervention in patients who need it most.2238-23001TAMUS 6213BRIEF SUMMARY OF THE DISCLOSURE

[0009] These and other needs in the art are addressed in one or more of the embodiments disclosed herein.

[0010] Disclosed herein are one or more embodiments of a detection and imaging device. The device may comprise a sensor comprising a plurality of electrodes configured for circumferential disposition around or proximate to the exterior of a target anatomy. At least one of the plurality of electrodes may be configured to deliver a stimulation current to the target anatomy and one or more other electrodes are configured to collect a resulting impedance signal. The device may also comprise signal circuitry in electrical communication with the sensor and configured to generate and deliver the stimulation current via the at least one electrode and to sense the resulting impedance signal via the one or more other electrodes. The device may also comprise a processing unit configured to evaluate the impedance signal based on differential impedance to detect a clinically significant condition and to generate a tomographic image of the monitored anatomy representative of the detected condition. The device may also comprise a power source configured to provide power to the signal circuitry and the processing unit.

[0011] Also disclosed herein are one or more embodiments of a system for detection and imaging. The system may comprise a detection and imaging device. The device may comprise a sensor comprising a plurality of electrodes configured for circumferential disposition around or proximate to the exterior of a target anatomy. At least one of the plurality of electrodes may be configured to deliver a stimulation current to the target anatomy and one or more other electrodes are configured to collect a resulting impedance signal. The device may also comprise signal circuitry in electrical communication with the sensor and configured to generate and deliver the stimulation current via the at least one electrode and to sense the resulting impedance signal via the one or more other electrodes. The device may also comprise a processing unit configured to evaluate the impedance signal based on differential impedance to detect a clinically significant condition and to generate a tomographic image of the monitored anatomy representative of the detected condition. The device may also comprise a power source configured to provide power to the signal circuitry and the processing unit. The system may also comprise an external device in wireless communication with the processing unit, the external device comprising a user interface configured to allow a user to monitor and control the detection and imaging2238-23001TAMUS 6213device, to view real-time impedance data and tomographic images generated by the detection and imaging device, and to receive alerts regarding clinically significant conditions detected by the detection and imaging device.

[0012] Also disclosed herein are one or more embodiments of a method of detecting a clinically significant condition in a patient. The method may comprise positioning a sensor comprising a plurality of electrodes circumferentially around or proximate to the exterior of a target anatomy of the patient. The method may also comprise delivering a stimulation current to the target anatomy via at least one of the plurality of electrodes. The method may also comprise collecting a resulting impedance signal via one or more other electrodes of the plurality of electrodes. The method may also comprise evaluating the impedance signal based on differential impedance to detect a clinically significant condition. The method may also comprise generating a tomographic image of the target anatomy representative of the detected condition.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] For a detailed description of exemplary embodiments of the disclosure, reference will now be made to the accompanying drawings in which:

[0014] Figure 1 is a schematic block diagram illustrating the architecture of a detection and imaging device according to one or more embodiments disclosed herein.

[0015] Figure 2 is a schematic view of a sensor of a post-vascular surgery event detection and imaging device according to one or more embodiments disclosed herein.

[0016] Figure 3 is a schematic block diagram of a fluid detection and imaging device showing the sensor deployed proximate to the lungs or within the peritoneal cavity according to one or more embodiments disclosed herein.

[0017] Figure 4 is an example of a tomographic image as may be generated via operation of the vascular and fluid detection and imaging device according to one or more embodiments disclosed herein.DETAILED DESCRIPTION

[0018] The following discussion is directed to various exemplary embodiments. However, one skilled in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.2238-23001TAMUS 6213

[0019] Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.

[0020] In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to...” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., the central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis.

[0021] Disclosed herein are various embodiments of detection and imaging devices, for example, a vascular and fluid detection and imaging device (VFDID). Generally, such devices may be configured to utilize electrical impedance to monitor anatomical structures within a patient and to detect clinically significant changes therein. Electrical impedance tomography (EIT) is an imaging technique that relies upon differences in impedance measurements between multiple electrodes circumferentially disposed in a plane to identify differences in tissue composition and anatomy based on differential impedance. Devices as disclosed herein may be capable of generating real-time tomographic images of the monitored anatomy without the use of ionizing radiation and, in some embodiments, of communicating clinically relevant data and imaging to a patient’s physician or healthcare provider.

[0022] In various embodiments, the VFDID may be configured for monitoring different anatomical targets and detecting different clinically significant conditions using EIT, depending upon the intended application. Generally, the various embodiments may share a common architecture comprising a sensor, signal circuitry, a processing unit,2238-23001TAMUS 6213and a power source, as disclosed herein below.

[0023] For example, in some embodiments, disclosed herein is a post-vascular surgery event detection and imaging device (VSEDID) having a sensor that is disposed around or proximate to the exterior of a vasculature of interest so as to monitor blood flow and detect changes in perfusion overtime, as may result from postoperative inflammation, infection, or other vascular events. For example, and not intending to be bound by theory, the impedance exhibited by a vasculature with diminished perfusion may differ sufficiently from that of a normally-perfused vasculature, for example, as a result of detectable changes in vessel wall characteristics attendant to post-operative inflammation or infection, as to allow for detection and monitoring of perfusion changes on the basis of impedance differential.

[0024] Additionally, in some embodiments, disclosed herein is a fluid detection and imaging device (FDID) having a sensor disposed on the skin proximate to the lungs, attached directly to the lung tissue, or placed within the peritoneal cavity, so as to detect and monitor fluid accumulation within or around the lungs or within the peritoneal cavity. For example, and not intending to be bound by theory, the impedance exhibited by lung tissue ora peritoneal cavity containing accumulated fluid may differ sufficiently from that of the normal anatomy as to allow for detection and monitoring of fluid accumulation on the basis of impedance differential.

[0025] Referring now to Figure 1, the VFDID 100 generally comprises a sensor 110 including a plurality of electrodes 112, signal circuitry 120, a processing unit 130, and a power source 140. This common architecture may underlie various embodiments of the VFDID as disclosed herein, for example, the VSEDID and the FDID.

[0026] In various embodiments, the sensor 110 may comprise a medical-grade and / or biocompatible electrically-conductive material, for example, a medical-grade and / or biocompatible metal. Generally, the term “medical-grade” may refer to a material that is not toxic or injurious with respect to biological tissue. In some embodiments, the medical-grade material may be or comprise those electrically-conductive materials as may be employed in conventional implantable medical devices, examples of which may include metals such as nitinol, cobalt-chromium alloys, medical- and / or implantgrade stainless steel (316L), and combinations thereof. Additionally, at least a portion of the sensor 110 may comprise a medical-grade and / or biocompatible polymer. Examples of suitable polymers may include, but are not limited to, synthetic polymers such as polyvinyl alcohol, polyethylene glycerol, poly-vinyl pyrrolidone (PVP),2238-23001TAMUS 6213polyolefins, fluoropolymers, hydropolymers of vinyl esters, vinyl ethers, carboxy vinyl monomers, meth(acrylic) acid, acrylamide, N-vinyl pyrrolidone, acrylamidopropane, polyalkoxylated alcohols, alkyl or dialkyl polyglycerol compounds, polyethyloxylated alcohols, homopolymers and copolymers of acrylamide (e.g., N-(2-hydroxypropyl)methacrylamide (HPMA)), silicone, polyether block amides, polyetherpolyester block polymers, polyurethanes, and combinations thereof.

[0027] In various embodiments, the sensor 110 may be configured as a plurality of electrodes 112 circumferentially disposed around or proximate to the exterior of the target anatomy. More particularly, at least one of the plurality of electrodes 112 may be configured to apply a stimulation or injection current, for example, an electrical signal such as an alternating current (A / C) or a direct current (D / C), and one or more other electrodes 112 may be configured to collect the resulting impedance signal, for example, to collect impedance data such as current and / or voltage that can be used to calculate the impedance.

[0028] The sensor 110 may further comprise a plurality of leads connected thereto. In some embodiments, the electrical leads may comprise or be made from a suitable signal-conducting material, for example, MP-35N and / or MP-35N with titanium, platinum, or platinum-iridium alloys.

[0029] The sensor 110 may take any suitable form generally adapted for placement around or proximate to the exterior of the anatomy to be monitored. In some embodiments, the sensor 110 may be integrated into a non-conductive mesh. The non-conductive mesh may be configured for placement around or proximate to the exterior of a vasculature or within or proximate to a body cavity, thereby facilitating stable positioning of the electrodes 112 at the target anatomy. In some embodiments, the non-conductive mesh may be generally flexible and conformable so as to accommodate varying anatomical geometries and configurations.

[0030] In various embodiments, the non-conductive mesh may comprise a medicalgrade and / or biocompatible material suitable for implantation or prolonged contact with biological tissue. For example, the non-conductive mesh may comprise one or more biocompatible polymers, examples of which may include those polymers as disclosed herein with respect to the sensor 110, or other suitable biocompatible materials, for example, expanded polytetrafluoroethylene (ePTFE), polyethylene terephthalate (PET), or combinations thereof. In various embodiments, the non-conductive mesh may be configured to be generally resistant to degradation in the in vivo environment2238-23001TAMUS 6213so as to maintain its structural integrity and electrode positioning over the intended monitoring period.

[0031] In various embodiments, the signal circuitry 120 may generally be configured to generate and deliver a stimulation current to be applied via at least one electrode 112 of the sensor 110 and to sense an impedance signal via one or more other electrodes 112. In various embodiments, a plurality of electrical leads connected to the sensor 110, for example in electrical communication with each of the one or more electrodes 112, may provide signal communication between the sensor 110 and the signal circuitry 120.

[0032] In various embodiments, the signal circuitry 120 may comprise any components suitable to yield the desired functionality, for example, integrated circuits, transistors, multiplexors, LEDs, copper wires, tin-lead solder, ETFE coating, or combinations thereof.

[0033] Generally, the signal circuitry 120 may be in electrical communication with the one or more electrodes 112 of the sensor 110. The signal circuitry 120 may be configured to generate one or more stimulation currents, for example, an A / C signal or a D / C signal. In some embodiments, the signal circuitry 120 may be in electrical communication with the power source so as to generate the stimulation current utilizing power from the power source. Additionally, the signal circuitry 120 may include one or more capacitors, which may be charged via the power source, to generate the stimulation current. In some embodiments, the signal circuitry 120 may be configured to selectively connect one or more of the electrodes 112, for example, via a suitable configuration of switches or the like, such that the one or more electrodes 112 that deliver the stimulation current is selectable. For example, in some embodiments, the signal circuitry 120 may be configured to alter the state of a single electrode to act as the source electrode and to configure the other electrodes as ground electrodes, such that a controlled current is injected into the source electrode and the resulting voltage / impedance is measured at the remaining electrodes. This procedure may be repeated for each electrode in succession such that the collected data may be transformed into a tomographic representation of a cross-sectional area of the sensor 110.

[0034] Additionally, in some embodiments, the signal circuitry 120 may be configured to monitor and control various parameters associated with the generated stimulation current, for example, current, voltage, and waveform. For example, in some2238-23001TAMUS 6213embodiments, the signal circuitry 120 may be configured to generate an A / C stimulation current having a frequency from about 1 hertz (Hz) to about 10 kHz, or from about 50 Hz to about 500 Hz, and a peak-to-peak voltage (Vpp) from about 3 volts (V) to about 9V, or from about 4V to about 8V. Additionally or alternatively, the signal circuitry 120 may be configured to generate a D / C stimulation current of about 3V to about 9V, or from about 4V to about 8V. In various embodiments, the stimulation current may be characterized as exhibiting any suitable signal propagation parameters and / or reconstruction qualities, and may also be characterized as exhibiting a suitable waveform, for example, a sinusoidal wave, a square wave, a triangular wave, or a complex wave. Additionally, in some embodiments, the signal circuitry 120 may also comprise an oscillator (for example, to provide for generation of a sinusoidal output signal) and / or one or more digital-to-analog converters (DAC) (for example, to provide a controllable output signal in a desired form).

[0035] Also, the signal circuitry 120 may be configured to sense one or more aspects of an impedance signal. In some embodiments, the signal circuitry 120 may receive, via two or more of the electrodes 112, the resulting impedance data so as to provide electrical signals indicative of the detected condition. The signal circuitry 120 may also be configured to be adjustable with respect to various parameters associated with impedance sensing, for example, sampling rate, frequency band, slew rate, sensitivity, and / or dynamic range. In some embodiments, the signal circuitry 120 may include one or more analog-to-digital converter sub-circuits and / or sample / hold circuitry for use in sampling the sensed signal and converting the sensed signal to a form that can be processed via the processing unit 130. Although the signal circuitry 120 and processing unit 130 may be disclosed as distinct components, in some embodiments the signal circuitry 120 and the processing unit 130 may be integrated.

[0036] The processing unit 130 may be configured to control the overall operation of the VFDID. Generally, the processing unit 130 may be configured to cause the VFDID to implement processes for the generation, delivery, sensing, and evaluation of an impedance signal, for example, based on impedance differentials within the monitored anatomy.

[0037] In various embodiments, the processing unit 130 may comprise a microcontroller or microprocessor, suitable memory, and wireless communications modules (e.g., microchips or circuits), for example, suitable for communication via a desired communication interface. Additionally or alternatively, in some embodiments,2238-23001TAMUS 6213the processing unit 130 may comprise one or more integrated circuits comprising a suitable arrangement of transistors, LEDs, wires (e.g., copper wires), tin-lead solder, ETFE coatings, or combinations thereof.

[0038] In some embodiments, the processing unit 130 may be configured to carry out a desired functionality by executing instructions stored in memory. The memory can include computer system readable media in the form of volatile memory, such as random-access memory (RAM) and / or cache memory. The memory may further include other removable / non-removable, volatile / non-volatile computer system storage media. In some embodiments, the memory may include at least one application configured to carry out the disclosed functionalities, for example, evaluation of an impedance signal and / or communication with an external device. The application program modules may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages such as C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages.

[0039] Additionally, in some embodiments, the processing unit 130 may be configured for communication with an external device such as a mobile device (e.g., a smartphone), a tablet, ora computer. In various embodiments, the processing unit 130 may comprise one or more communication modules configured to provide communication via a wireless connection such as radiofrequency (RF) signals (e.g., Bluetooth, Wi-Fi), inductive coupling, optical signaling, acoustic signaling, conducted communication signals, and / or any other signals suitable for communication.

[0040] In some embodiments, the external device may comprise a user interface that allows a user to control and monitor the VFDID via communication over the wireless connection. For example, the user interface may comprise a graphical user interface (GUI) displayed on a mobile device, tablet, or computer. In some embodiments, the user interface may be modifiable to meet the needs of different users or medical professionals, for example, including different languages or font sizes to accommodate users with different backgrounds or visual impairments. The user interface may also include different modes or profiles for different types of functions or different users, and may include security features, such as passwords or biometric authentication, to2238-23001TAMUS 6213ensure that only authorized users can access the device. Additionally, the user interface may allow a user to monitor the VFDID, to adjust settings, and to view realtime data from the VFDID. The user interface may also provide alerts or notifications when the VFDID requires attention, such as a low battery alarm, or when certain conditions are met, such as when a change in perfusion or fluid accumulation is detected.

[0041] In some embodiments, the processing unit 130 may be configured to cause a stimulation current to be generated and delivered. For example, the processing unit 130 may include instructions that cause the signal circuitry 120 to generate the stimulation current and to cause the sensor 110 to deliver the stimulation current via one or more of the electrodes 112. Additionally, the processing unit 130 may include instructions that cause the stimulation current to exhibit desired parameters, for example, an A / C stimulation current having a frequency from about 1 Hz to about 10 kHz, or from about 50 Hz to about 500 Hz, and a peak-to-peak voltage (Vpp) from about 3V to about 9V, or from about 4V to about 8V, or a D / C stimulation current of about 3V to about 9V, or from about 4V to about 8V.

[0042] In some embodiments, the processing unit 130 may include instructions that cause the stimulation current to be generated and delivered at a predetermined interval, for example, about once every 10 minutes, alternatively about every 30 minutes, alternatively about every 60 minutes, alternatively about every 2 hours, alternatively about every 4 hours, alternatively about every 8 hours, alternatively about every 12 hours, alternatively about every 24 hours, alternatively about every 36 hours, or alternatively about every 48 hours. Additionally or alternatively, the processing unit 130 may cause the stimulation current to be generated and delivered upon receipt of a prompt from the external device via wireless communication. For example, the processing unit 130 may be configured to receive one or more inputs, such as via the user interface, to control the operation of the VFDID, including the frequency with which the stimulation current is generated and delivered.

[0043] Additionally, the processing unit 130 may be configured to cause an impedance signal to be collected and to evaluate the impedance data, for example, to detect a change in vascular perfusion or to detect fluid accumulation. For example, the processing unit 130 may receive, via the sensor 110 and the signal circuitry 120, one or more impedance signals resultant from the stimulation current delivered via the one or more electrodes 112. The processing unit 130 may then evaluate the one or more2238-23001TAMUS 6213resultant impedance signals based upon differential impedance to detect the condition of interest.

[0044] Additionally, in some embodiments, where the processing unit 130 determines that a clinically significant condition is present, the processing unit 130 may further generate a tomographic image representative of the detected condition based on the impedance differential. Generally, the tomographic image may indicate various characteristics associated with the detected condition, for example, the location, extent, and disposition of a perfusion change or fluid accumulation. In some embodiments, the processing unit 130 may generate the tomographic image via suitable software, an example of which is publicly available as Electrical Impedance and Diffuse Optical Tomography Reconstruction Software (EIDORS). An example of a tomographic image as may be generated by the VFDID is illustrated with respect to Figure 4.

[0045] In some embodiments, the processing unit 130 may be configured to establish a baseline impedance profile upon initial deployment and activation of the VFDID 100. The baseline impedance profile may represent the impedance characteristics of the monitored anatomy under normal conditions and may serve as a reference against which subsequent impedance measurements are evaluated. For example, the processing unit 130 may collect and average impedance measurements over an initial monitoring period so as to establish the baseline impedance profile, and may thereafter compare subsequent impedance measurements to the baseline to identify deviations indicative of a clinically significant change. In some embodiments, the processing unit 130 may be configured to periodically update the baseline impedance profile, for example, to account for gradual physiological changes over time that may otherwise be misidentified as clinically significant events. The processing unit 130 may also be configured to apply one or more threshold values to the comparison of subsequent impedance measurements to the baseline, such that only deviations exceeding the applicable threshold are identified as clinically significant, thereby reducing the occurrence of false-positive detections.

[0046] Also, in various embodiments, the processing unit 130 may be configured to communicate electrical impedance data to the external device. For example, in some embodiments, upon detecting a clinically significant condition, the processing unit 130 may communicate an indication of the result of such determination to the external device; for example, a visual, tactile, and / or audible alert may be sent to the external2238-23001TAMUS 6213device. Additionally or alternatively, upon generating a tomographic image, the processing unit 130 may communicate the tomographic image to the external device. Additionally or alternatively, in some embodiments, the processing unit 130 may be configured to communicate the one or more impedance signals resultant from the stimulation current to the external device, such that the external device may evaluate the impedance signals to determine the condition of interest and / or to generate a tomographic image accordingly.

[0047] In some embodiments, the processing unit 130 may be further configured to detect dislodgement of the sensor 110 from its intended position. Generally, and not intending to be bound by theory, dislodgement of the sensor 110 may result in one or more electrodes 112 losing adequate contact with the surrounding tissue, which may produce a characteristic change in the impedance readings that is distinguishable from a true clinical event. For example, dislodgement may result in an anomalous or asymmetric impedance signal, a loss of signal continuity across one or more electrodes 112, or impedance values falling outside an expected physiological range. The processing unit 130 may be configured to identify such patterns and to distinguish them from impedance changes attributable to a clinically significant condition. Upon detection of a potential dislodgement event, the processing unit 130 may be configured to communicate an appropriate alert to the external device, for example, via the user interface as disclosed herein, so as to prompt clinical evaluation of device positioning. In some embodiments, the processing unit 130 may be configured to suspend clinical monitoring and alerting functions upon detection of a dislodgement event, so as to avoid generation of false clinical alerts pending confirmation of correct sensor positioning.

[0048] In some embodiments, the power source 140 may generally be configured to provide power for the operation of the VFDID 100. For example, the power source 140 may comprise a battery and / or a battery management system. In some embodiments, the battery may comprise a rechargeable battery, such as a lithium-ion battery. In some alternative embodiments, the VFDID 100 may be powered via an external power source. In some embodiments, the power source 140 may be configured to provide wireless charging capability, for example, via inductive coupling, so as to allow for recharging of the battery without requiring a physical connection to an external charging device. The power source 140 may further be configured to communicate power status information to the processing unit 130, for example, to enable generation2238-23001TAMUS 6213of a low battery alert to the external device via the user interface as disclosed herein.

[0049] Referring now to Figure 2, in some embodiments the VFDID 100 may be configured as a VSEDID 200. Generally, the VSEDID 200 may be configured for continuous or scheduled post-operative monitoring of vascular perfusion in patients who have recently undergone vascular surgery. The VSEDID 200 may utilize the common architecture disclosed above, for example, comprising a sensor 110, signal circuitry 120, a processing unit 130, and a power source 140. The VSEDID 200 may be configured for implantation and operation in the post-operative vascular monitoring context as described herein.

[0050] Generally, and not intending to be bound by theory, the impedance exhibited by a vasculature with normal perfusion may differ from that of a vasculature with diminished perfusion, such as may result from post-operative inflammation, infection, or other vascular compromise, for example, as a result of changes in vessel wall characteristics attendant to such conditions. The VSEDID 200 may exploit these differences in impedance to detect and monitor changes in perfusion over time, and to generate a tomographic image of the vasculature, thereby providing information about the perfusion status of the vessel upon detection of a clinically significant change.

[0051] Referring to the embodiment of Figure 2, the VSEDID 200 may be configured for placement around or proximate to the exterior of a vasculature of interest. In the embodiment of Figure 2, the sensor 110 of the VSEDID 200 may be integrated into a non-conductive mesh 215, for example, such that the electrodes 112 of the sensor 110 are circumferentially disposed around or proximate to the exterior of the vasculature. The non-conductive mesh 215 may comprise any suitable non-conductive, biocompatible material and may be generally flexible and conformable so as to accommodate varying vasculature diameters and anatomical configurations. In various embodiments, the VSEDID 200 may be configured for deployment with respect to vasculature of varying sizes, for example, large veins or arteries such as the superior vena cava, the inferior vena cava, the hepatic portal vein, or other vessels of clinical interest.

[0052] In some embodiments, a VSEDID 200 as disclosed herein may be implanted in a patient who has recently undergone vascular surgery. Generally, a procedure for placement of the VSEDID 200 may include pre-procedural imaging, such as MRI or CT angiography, to determine an intended deployment site. Upon deployment, the2238-23001TAMUS 6213sensor 110 may be positioned around or proximate to the target vasculature, with the signal circuitry 120, processing unit 130, and power source 140 implanted at an appropriate subcutaneous or intracavitary location, for example, in a manner similar to placement of a cardiac rhythm management device, such as within the patient's chest. The leads may be of sufficient length to extend between the intended site of deployment for the sensor 110 and the location of the remaining components. After confirming correct function and electrical connections, the processing unit 130 may be programmed and tested to confirm signal communication with the sensor 110.

[0053] Once implanted, the VSEDID 200 may monitor vascular perfusion continuously or at predetermined intervals as disclosed herein. Upon detection of a clinically significant change in perfusion, the VSEDID 200 may be configured to notify the patient and / or healthcare provider, for example, via wireless communication to an external device as disclosed herein. Upon notification, the patient and / or provider may request the device to generate a tomographic image of the vasculature providing information about the perfusion status of the vessel. Additionally, in some embodiments, the VSEDID 200 may also be configured to detect dislodging of the sensor 110, thereby enabling early detection of device-related events.

[0054] Referring now to Figure 3, in some embodiments the VFDID 100 may be configured as a fluid detection and imaging device (FDID) 300. Generally, the FDID 300 may be configured for continuous or scheduled monitoring of fluid accumulation, such as within or around the lungs or within the peritoneal cavity. The FDID 300 may utilize the common architecture disclosed above, for example, comprising a sensor 110, signal circuitry 120, a processing unit 130, and a power source 140. The FDID 300 may be configured for operation in the fluid detection and monitoring context as described herein.

[0055] Generally, and not intending to be bound by theory, the impedance exhibited by lung tissue or a peritoneal cavity containing accumulated fluid may differ sufficiently from that of the normal anatomy as to allow for detection and monitoring of fluid accumulation on the basis of impedance differential. The FDID 300 may exploit this impedance differential to detect and monitor fluid accumulation over time, and to generate a tomographic image of the monitored anatomy, thereby providing information about the location, extent, and disposition of any detected fluid accumulation upon detection of a clinically significant change.

[0056] Referring to the embodiment of Figure 3, the FDID 300 may be configured for2238-23001TAMUS 6213placement on the skin proximate to the lungs, for attachment directly to the exterior of the lung tissue, or for placement within the peritoneal cavity such that the sensor is positioned proximate and external to the target anatomy therein, depending upon the intended clinical application. In the embodiment of Figure 3, the sensor 110 of the FDID 300 may be integrated into a non-conductive mesh configured for placement around or proximate to the exterior of the target anatomy, for example, such that the electrodes 112 of the sensor 110 are circumferentially disposed so as to monitor the region of interest. The non-conductive mesh may comprise any suitable non-conductive, biocompatible material and may be generally flexible and conformable so as to accommodate varying anatomical geometries and configurations.

[0057] In some embodiments, placement of the FDID 300 may include pre-procedural imaging to determine an intended deployment site. Upon deployment, the sensor 110 may be positioned at or proximate to the target anatomy, with the signal circuitry 120, processing unit 130, and power source 140 positioned at an appropriate location, for example, subcutaneously or at another suitable site. The leads may be of sufficient length to extend between the intended site of deployment for the sensor 110 and the location of the remaining components. After confirming correct function and electrical connections, the processing unit 130 may be programmed and tested to confirm signal communication with the sensor 110.

[0058] In various embodiments, the FDID 300 may be employed to monitor patients who are prone to or at risk for pulmonary edema, pneumonia, acute respiratory distress syndrome (ARDS), or peritoneal fluid accumulation. The FDID 300 may monitor fluid accumulation continuously or at predetermined intervals as disclosed herein. Upon detection of a clinically significant accumulation of fluid, the FDID 300 may be configured to notify the patient and / or healthcare provider, for example, via wireless communication to an external device as disclosed herein, and to generate a tomographic image of the monitored anatomy as illustrated with respect to Figure 4. Additionally, in some embodiments, the FDID 300 may also be configured to detect dislodging of the sensor 110, thereby enabling early detection of device-related events.

[0059] Referring now to Figure 4, an example of a tomographic image as may be generated via operation of the VFDID 100 is illustrated. Generally, the tomographic image may provide a visual representation of the cross-sectional impedance distribution of the monitored anatomy, for example, identifying regions of altered2238-23001TAMUS 6213impedance that may be indicative of a clinically significant condition such as a change in vascular perfusion or fluid accumulation. The tomographic image may indicate various characteristics associated with the detected condition, including the location, extent, and disposition of the identified change relative to the surrounding anatomy. In some embodiments, the tomographic image may be generated by the processing unit 130 and communicated to an external device for display via the user interface as disclosed herein, thereby providing the patient’s physician or healthcare provider with real-time, actionable imaging data without the use of ionizing radiation.

[0060] The devices and methods disclosed herein offer a number of meaningful advantages over existing technologies for post-operative vascular monitoring and fluid detection. By providing continuous or scheduled, real-time monitoring and imaging of the target anatomy without the use of ionizing radiation, the VFDID 100 may enable earlier detection of clinically significant changes in perfusion or fluid accumulation than is achievable through discrete imaging events or periodic in-person clinical evaluation. The ability to communicate alerts and tomographic imaging data directly to an external device may reduce the need for repeated clinical visits, shorten or obviate prolonged hospital stays attributable to monitoring requirements, and enable more timely clinical intervention. These capabilities may reduce healthcare costs and focus clinical resources on the patients who need them most.

[0061] In various additional embodiments, a similar device may be configured for implantation about, around, or otherwise proximate and external to various other target anatomy. For example, a device may be deployed about, around, or otherwise proximate and external to organs, body cavities, or other anatomical structures of clinical interest.

[0062] While embodiments of the disclosure have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim2238-23001TAMUS 6213may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.

Claims

2238-23001TAMUS 6213CLAIMSWhat is claimed is:

1. A detection and imaging device comprising:a sensor comprising a plurality of electrodes configured for circumferential disposition around or proximate to the exterior of a target anatomy, wherein at least one of the plurality of electrodes is configured to deliver a stimulation current to the target anatomy and one or more other electrodes are configured to collect a resulting impedance signal; signal circuitry in electrical communication with the sensor and configured to generate and deliver the stimulation current via the at least one electrode and to sense the resulting impedance signal via the one or more other electrodes;a processing unit configured to evaluate the impedance signal based on differential impedance to detect a clinically significant condition and to generate a tomographic image of the monitored anatomy representative of the detected condition; anda power source configured to provide power to the signal circuitry and the processing unit.

2. The device of claim 1, wherein the sensor comprises a medical-grade and / or biocompatible electrically-conductive material comprising one or more of nitinol, cobalt-chromium alloys, medical-grade stainless steel, and combinations thereof.

3. The device of claim 1 , wherein the sensor is integrated into a non-conductive mesh configured for placement around or proximate to the exterior of a vasculature or around or proximate to the exterior of a body cavity, the non-conductive mesh comprising a medical-grade and / or biocompatible material.

4. The device of claim 1, wherein the signal circuitry is configured to generate a stimulation current comprising one or more of an alternating current (A / C) stimulation current having a frequency from about 1 Hz to about 10 kHz and a peak-to-peak voltage from about 3V to about 9V, and a direct current (D / C) stimulation current of about 3V to about 9V.2238-23001TAMUS 62135. The device of claim 1 , wherein the processing unit is configured to establish a baseline impedance profile upon initial deployment and activation of the device and to compare subsequent impedance measurements to the baseline impedance profile to identify deviations indicative of a clinically significant condition.

6. The device of claim 1, wherein the processing unit is configured to detect dislodgement of the sensor by identifying one or more of an anomalous or asymmetric impedance signal, a loss of signal continuity across one or more electrodes, and impedance values falling outside an expected physiological range.

7. The device of claim 1, wherein the processing unit comprises one or more wireless communication modules configured to communicate with an external device via one or more of radiofrequency (RF) signals, inductive coupling, optical signaling, acoustic signaling, and conducted communication signals.

8. The device of claim 1, wherein the device is configured as a post-vascular surgery event detection and imaging device (VSEDID), wherein the sensor is configured for placement around or proximate to the exterior of a vasculature of interest so as to monitor vascular perfusion and detect changes in perfusion over time resulting from one or more of post-operative inflammation, infection, and other vascular compromise.

9. The device of claim 8, wherein the vasculature of interest comprises one or more of the superior vena cava, the inferior vena cava, and the hepatic portal vein.

10. The device of claim 1 , wherein the device is configured as a fluid detection and imaging device (FDID), wherein the sensor is configured for placement on the skin proximate to the lungs, for attachment directly to lung tissue, or for placement within the peritoneal cavity, so as to detect and monitor fluid accumulation associated with one or more of pulmonary edema, pneumonia, acute respiratory distress syndrome (ARDS), and peritoneal fluid accumulation.

11. The device of claim 1, wherein the power source comprises a rechargeable2238-23001TAMUS 6213battery configured to provide wireless charging capability via inductive coupling.

12. A system comprising:the detection and imaging device of claim 1 ; andan external device in wireless communication with the processing unit, the external device comprising a user interface configured to allow a user to monitor and control the detection and imaging device, to view real-time impedance data and tomographic images generated by the detection and imaging device, and to receive alerts regarding clinically significant conditions detected by the detection and imaging device.

13. The system of claim 12, wherein the external device comprises one or more of a smartphone, a tablet, and a computer, and wherein the user interface comprises a graphical user interface (GUI) configured to display tomographic images generated by the processing unit.

14. The system of claim 12, wherein the external device is configured to receive one or more impedance signals from the processing unit and to generate a tomographic image based thereon.

15. A method of detecting a clinically significant condition in a patient, the method comprising:positioning a sensor comprising a plurality of electrodes circumferentially around or proximate to the exterior of a target anatomy of the patient; delivering a stimulation current to the target anatomy via at least one of the plurality of electrodes;collecting a resulting impedance signal via one or more other electrodes of the plurality of electrodes;evaluating the impedance signal based on differential impedance to detect a clinically significant condition; andgenerating a tomographic image of the target anatomy representative of the detected condition.

16. The method of claim 15, further comprising establishing a baseline impedance2238-23001TAMUS 6213profile upon initial deployment of the sensor and comparing subsequent impedance measurements to the baseline impedance profile to identify deviations indicative of a clinically significant condition.

17. The method of claim 15, further comprising detecting dislodgement of the sensor by identifying one or more of an anomalous or asymmetric impedance signal, a loss of signal continuity across one or more electrodes, and impedance values falling outside an expected physiological range.

18. The method of claim 15, further comprising communicating one or more of an alert and the tomographic image to an external device for display via a user interface upon detection of the clinically significant condition.

19. The method of claim 15, wherein the target anatomy comprises a vasculature of interest, and wherein the clinically significant condition comprises a change in vascular perfusion resulting from one or more of post-operative inflammation, infection, and other vascular compromise.

20. The method of claim 15, wherein the target anatomy comprises lung tissue or a peritoneal cavity, and wherein the clinically significant condition comprises fluid accumulation associated with one or more of pulmonary edema, pneumonia, acute respiratory distress syndrome (ARDS), and peritoneal fluid accumulation.

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