Systems and methods for monitoring vascular function - Patents.com

Abstract

A method for displaying data on a patient's arm, comprising the steps of taking an image of the patient's arm, analyzing the image to thereby obtain information about the blood vessels in the patient's arm, and displaying the information by projecting a light pattern onto the patient's arm. A system for displaying data on a patient's arm, comprising a light source for illuminating the patient's arm, a sensor for taking an image of the patient's arm, a computer for analyzing the image to thereby obtain information about the blood vessels in the patient's arm, and a projector for displaying the information by projecting a light pattern onto the patient's arm. Related apparatus and methods are also described.

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 441,892, filed January 30, 2023, the contents of which are incorporated herein by reference in their entirety.

[0002] The present invention relates generally to the field of vascular monitoring in patients. Some aspects relate more particularly to early diagnosis of impaired vascular function, and even more particularly to early detection of impaired vascular access in patients undergoing hemodialysis treatment. Some aspects relate more particularly to measuring fistulas. [Background technology]

[0003] Dialysis vascular access (VA, fistula or graft) allows for life-saving hemodialysis treatment but is prone to access-related problems.

[0004] The term "VA" or "vascular access" is used throughout this specification in all its grammatical forms and is intended to mean any type of vascular access structure, both synthetic and biologic, including, as some non-limiting examples, arteriovenous fistulas (AVs), synthetic grafts, and intravenous catheters.

[0005] One type of long-term access is an AV fistula. A surgeon creates an AV fistula by connecting an artery, usually in the arm or leg, to a vein. When the surgeon connects the artery to the vein, the vein develops, increasing in width and thickness, making it easier to insert a dialysis needle. An AV fistula also has a larger diameter, which allows blood to quickly drain out and return to the body. The goal of an AV fistula is to allow a high blood flow rate so that a large volume of blood can pass through the dialysis machine.

[0006] VA function and patency are essential for optimal management of HD patients. Low VA flow and loss of patency can limit hemodialysis delivery, prolong treatment times, and lead to underdialysis, which increases morbidity and mortality. In long-term VAs, especially grafts, thrombosis is the primary cause of loss of VA patency, increasing healthcare costs.

[0007] The basic concept of VA monitoring and management is that progressive stenosis develops in the majority of VAs over a variable period of time, but if detected and corrected (corrective procedures such as percutaneous transluminal angioplasty (PTA)), underdialysis can be minimized or avoided (dialysis volume conservation) and the rate of thrombosis can be reduced. Several monitoring and management methods are available, including sequential VA flow, sequential dynamic or static pressure, recirculation measurements, and physical examination.

[0008] Surveillance is the examination and evaluation of the VA to diagnose VA dysfunction using physical examination, usually in the HD suite, to detect dysfunction or the presence of correctable pathology before VA is lost.

[0009] Physical examination can be used as a surveillance tool to rule out low flow associated with impending fistula and graft failure. Typically, the VA examination has three components: inspection, palpation, and auscultation.

[0010] A simple visual inspection can reveal the presence of enlarged ischemic fingers, aneurysms, and abundant collateral veins. A strong pulse and weak thrill from the central vein to the anastomosis suggests outflow venous stenosis. The stenosis can be palpated, and the intensity and character of the bruit can suggest the location of the stenosis. A focal increase in the bruit over the graft or venous anastomosis compared with the adjacent segment suggests a stenosis or stenosis. The physical examination may also include a lifting test, which consists of elevating the limb containing the VA and examining the access for normal collapse. This test is considered normal if the fistula collapses after the organ is elevated above the level of the patient's heart.

[0011] Additional background art includes: U.S. Patent Application Publication No. 2021 / 0015991 to Drori et al.

[0012] The disclosures of all references cited above and throughout this specification, as well as all references cited within those references, are hereby incorporated by reference. Summary of the Invention

[0013] The present invention relates generally to the diagnosis of impaired vascular function, and more particularly to the early detection of impaired vascular access in patients undergoing hemodialysis treatment.

[0014] According to an aspect of some embodiments of the present disclosure, there is provided a method of displaying data on a patient's arm, the method including taking an image of the patient's arm, analyzing the image to thereby obtain information about the blood vessels in the patient's arm, and displaying the information by projecting a light pattern onto the patient's arm.

[0015] According to some embodiments of the present disclosure, the projecting step includes projecting using a digital light processing (DLP) projector.

[0016] According to some embodiments of the present disclosure, the information includes a mapping of skin vibrations on the patient's arm.

[0017] According to some embodiments of the present disclosure, the information includes a mapping of the blood vessels in the patient's arm.

[0018] According to some embodiments of the present disclosure, the information includes a mapping of the pulsatility of the patient's arm.

[0019] According to some embodiments of the present disclosure, the information includes a proposed location of an inflow needle puncture point on the patient's arm.

[0020] According to some embodiments of the present disclosure, the information includes a proposed location of an outflow needle puncture point on the patient's arm.

[0021] According to some embodiments of the present disclosure, the information includes suggested no needle insertion locations.

[0022] According to some embodiments of the present disclosure, the information includes treatment instructions.

[0023] According to some embodiments of the present disclosure, the information includes numerical data generated as a result of the analysis.

[0024] According to some embodiments of the present disclosure, the information includes a puncture plan.

[0025] According to some embodiments of the present disclosure, the puncture plan is based on an analysis of two or more images, at least two of the images used for the analysis being taken at different times.

[0026] According to some embodiments of the present disclosure, the puncture plan suggests locations for the inflow and outflow needle puncture points based on historical information about previous puncture points.

[0027] According to some embodiments of the present disclosure, the step of taking an image of the patient's arm includes taking a plurality of images of the patient's arm, and the step of analyzing the images includes analyzing the plurality of images.

[0028] According to an aspect of some embodiments of the present disclosure, there is provided a system for displaying data on a patient's arm, the system including a light source for illuminating the patient's arm, a sensor for capturing images of the patient's arm, a computer for analyzing the images and thereby obtaining information regarding the blood vessels in the patient's arm, and a projector for displaying the information by projecting a light pattern onto the patient's arm.

[0029] According to some embodiments of the present disclosure, the light source includes a laser illuminator positioned to illuminate an area of ​​the patient's arm.

[0030] According to some embodiments of the present disclosure, the light source includes a laser illuminator positioned to illuminate an area of ​​the patient's arm with a pattern of spots.

[0031] According to some embodiments of the present disclosure, the light source includes a source of structured light.

[0032] According to some embodiments of the present disclosure, the projector includes a source of structured light.

[0033] According to some embodiments of the present disclosure, the projector includes a digital light processing (DLP) projector.

[0034] According to some embodiments of the present disclosure, the source of structured light includes a DLP projector similar to the projector described above.

[0035] According to an aspect of some embodiments of the present disclosure, there is provided a method of mapping areas of vibration on a patient's arm, the method comprising the steps of illuminating the patient's arm, taking an image of the patient's arm, analysing the image to thereby obtain information about the vibrations on the skin of the patient's arm, and displaying a mapping of the areas of vibration on the patient's arm based on the analysis.

[0036] According to some embodiments of the present disclosure, the illuminating step includes illuminating using coherent light.

[0037] According to some embodiments of the present disclosure, the illuminating step includes illuminating an area of ​​the patient's arm.

[0038] According to some embodiments of the present disclosure, the illuminating step includes illuminating using structured light.

[0039] According to some embodiments of the present disclosure, the illuminating step includes illuminating with a digital light processing (DLP) projector.

[0040] According to some embodiments of the present disclosure, the information includes a mapping of skin vibrations on the patient's arm.

[0041] According to some embodiments of the present disclosure, further comprising displaying the information by projecting a light pattern onto the patient's arm.

[0042] According to some embodiments of the present disclosure, the step of displaying the information includes displaying a mapping of the information about the vibrations on the skin of the patient's arm.

[0043] According to some embodiments of the present disclosure, displaying the mapping includes displaying where vibrations on the skin of the patient's arm exceed a threshold level of vibration.

[0044] According to some embodiments of the present disclosure, displaying the mapping includes displaying the mapping in alignment with the patient's arm.

[0045] According to some embodiments of the present disclosure, the step of taking images of the patient's arm includes taking a plurality of images of the patient's arm, and the step of analyzing the images includes analyzing the plurality of images.

[0046] According to an aspect of some embodiments of the present disclosure, there is provided a system for mapping areas of vibration on a patient's arm, the system including a light source for illuminating the patient's arm, a sensor for taking images of the patient's arm, and a computer for analyzing the images to thereby obtain information regarding the vibrations of the patient's arm.

[0047] According to some embodiments of the present disclosure, the light source includes a laser illuminator positioned to illuminate an area of ​​the patient's arm.

[0048] According to some embodiments of the present disclosure, the light source includes a laser illuminator positioned to illuminate an area of ​​the patient's arm with a pattern of spots.

[0049] According to some embodiments of the present disclosure, the light source includes a source of structured light.

[0050] According to some embodiments of the present disclosure, a projector is included for displaying information by projecting a light pattern onto the patient's arm.

[0051] According to some embodiments of the present disclosure, the projector includes a source of structured light.

[0052] According to some embodiments of the present disclosure, the projector includes a digital light processing (DLP) projector.

[0053] According to some embodiments of the present disclosure, the source of structured light includes a DLP projector similar to the projector described above.

[0054] According to an aspect of some embodiments of the present disclosure, there is provided a method for displaying a puncture plan on a patient's arm, the method including the steps of providing historical information regarding needle puncture points on the patient's arm, taking an image of the patient's arm, analyzing the image and the historical information to thereby obtain information regarding the blood vessels of the patient's arm, generating a puncture plan, and displaying the puncture plan by projecting a light pattern on the patient's arm.

[0055] According to some embodiments of the present disclosure, the historical information includes an image of the patient's arm taken prior to the step of taking an image of the patient's arm.

[0056] According to some embodiments of the present disclosure, the historical information includes an image of the patient's arm taken more than two days before the step of taking an image of the patient's arm.

[0057] According to aspects of some embodiments of the present disclosure, there is provided a method for indicating locations on a patient's arm where a needle should not be inserted, the method comprising the steps of providing historical information regarding needle insertion points on the patient's arm, taking images of the patient's arm, analyzing the images and the historical information to thereby obtain derived information regarding blood vessels in the patient's arm, determining locations on the patient's arm where it is not recommended to insert a needle based on the derived information, and indicating the locations on the patient's arm where it is not recommended to insert a needle.

[0058] According to some embodiments of the present disclosure, the step of indicating locations on the patient's arm where needle insertion is not recommended includes by projecting a light pattern onto the patient's arm.

[0059] Unless otherwise specified, all technical and / or scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains.Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, exemplary methods and / or materials are described below.In the event of conflict, the present patent specification, including definitions, will prevail.In addition, the materials, methods, and examples are for illustrative purposes only and are not necessarily intended to be limiting.

[0060] As will be appreciated by those skilled in the art, some embodiments of the present invention may be embodied as a system, a method, or a computer program product. Accordingly, some embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which may be collectively referred to herein as a "circuit," "module," or "system." Furthermore, some embodiments of the present invention may take the form of a computer program product embodied in one or more computer-readable medium(s) having computer-readable program code embodied therein. Implementation of the methods and / or systems of some embodiments of the present invention may involve performing and / or accomplishing selected tasks manually, automatically, or a combination thereof. Furthermore, depending on the actual equipment and implementation of some embodiments of the methods and / or systems of the present invention, some selected tasks may be implemented by hardware, software, or firmware, and / or a combination thereof, for example, using an operating system.

[0061] For example, hardware for performing selected tasks according to some embodiments of the present invention may be implemented as a chip or circuit. As software, selected tasks according to some embodiments of the present invention may be implemented as a plurality of software instructions executed by a computer using any suitable operating system. In exemplary embodiments of the present invention, one or more tasks according to some exemplary embodiments of the methods and / or systems described herein are performed by a data processor, such as a computing platform, that executes a plurality of instructions. Optionally, the data processor includes volatile memory for storing instructions and / or data, and / or non-volatile storage, e.g., a magnetic hard disk and / or removable media, for storing instructions and / or data. Optionally, a network connection may also be provided. Optionally, a display and / or a user input device, such as a keyboard or mouse, may also be provided.

[0062] Any combination of one or more computer-readable media may be utilized in some embodiments of the present invention. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (non-exhaustive list) of computer-readable storage media may include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), fiber optics, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can hold or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0063] A computer-readable signal medium may include a propagated data signal in which computer-readable program code is embodied, for example, in baseband of or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium is not a computer-readable storage medium but may be any computer-readable medium that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

[0064] The program code embodied in the computer readable medium and / or data used thereby may be transmitted using any suitable medium, including but not limited to wireless, wireline, fiber optic cable, RF, etc., or any suitable combination of the foregoing.

[0065] Computer program code for carrying out operations of some embodiments of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" programming language or similar programming languages. The program code may run entirely on the user's computer, partly on the user's computer, partly on the user's computer and partly on a remote computer, or entirely on a remote computer or server, as a standalone software package. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (e.g., through the Internet using an Internet Service Provider).

[0066] Some embodiments of the present invention may be described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce machine-readable means for implementing the functions / acts specified in the flowchart and / or block diagram blocks.

[0067] These computer program instructions may be stored on a computer-readable storage medium that can direct a computer, other programmable data processing apparatus, or other device, or combination thereof, to function in a particular manner, such that the instructions stored on the computer-readable medium produce an article of manufacture that includes instructions that implement aspects of the functions / operations specified in the flowchart and / or block diagram blocks.

[0068] Computer program instructions may be loaded into a computer, other programmable data processing apparatus, or other device to cause a series of operational steps on the computer, other programmable apparatus, or other device to generate a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide a process that implements the functions / operations specified in the flowchart and / or block diagram blocks.

[0069] Some of the methods described herein are generally designed for computer use only and may not be feasible or practical for purely manual performance by a human expert. A human expert wishing to manually perform a similar task, such as monitoring a patient's blood vessels, may be expected to use an entirely different method, e.g., leveraging specialized knowledge and / or the pattern recognition capabilities of the human brain, which is much more efficient than manually performing the steps of the methods described herein.

[0070] Some embodiments of the present invention are herein described, by way of example only, with reference to the accompanying drawings and images. With specific reference now to the drawings, it is emphasized that the details shown are by way of example and for the purpose of illustratively discussing embodiments of the invention. In this regard, the description read in conjunction with the drawings will make apparent to those skilled in the art how embodiments of the invention may be practiced. [Brief explanation of the drawings]

[0071] [Figure 1] 1 is a simplified diagram of a system for measuring blood vessels, according to an exemplary embodiment of the present invention; [Figure 2] 1 is a simplified block diagram of a system for measuring blood vessels, in accordance with an exemplary embodiment of the present invention; [Figure 3] 1 is a simplified block diagram of a system for measuring blood vessels, in accordance with an exemplary embodiment of the present invention; [Figure 4] 1 is a table showing the steps a medical professional takes to examine a patient for vascular stenotic lesions or thrombi. [Figure 5] FIG. 1 is a simplified flowchart diagram of a method for testing a patient, according to an exemplary embodiment of the present invention. [Figure 6] FIG. 2 is a simplified flowchart diagram of a method for converting data from a stream of images into a frequency spectrum, according to an exemplary embodiment of the present invention. [Figure 7] 1 is a graph showing the power spectrum of vibrations measured by analysis of images produced by laser speckle imaging. [Figure 8]1 is a simplified diagram of a system for measuring blood vessels, according to an exemplary embodiment of the present invention; [Figure 9] 1 is a simplified diagram of optional lighting modes and optional captured images according to an exemplary embodiment of the present invention. [Figure 10] FIG. 1 is a simplified diagram of laser vibrometry used to “listen” to the fistula, according to an exemplary embodiment of the present invention. [Figure 11] 1 is a simplified diagram of laser speckle vibrometry used to assess vibrations, according to an exemplary embodiment of the present invention; [Figure 12] 1 is a simplified diagram of various projections onto a patient's arm, in accordance with an exemplary embodiment of the present invention; [Figure 13] 1 is a graph illustrating a Receiver Operator Characteristic (ROC) curve for a stenosis detection model in accordance with an example embodiment. [Figure 14] FIG. 1 is a simplified flowchart diagram of a method for displaying data on a patient's arm, according to an exemplary embodiment of the present invention. [Figure 15] FIG. 1 is a simplified flowchart diagram of a method for mapping areas of vibration on a patient's arm, according to an exemplary embodiment of the present invention. [Figure 16] FIG. 1 is a simplified flowchart diagram of a method for displaying a puncture plan on a patient's arm, according to an exemplary embodiment of the present invention. [Figure 17] FIG. 1 is a simplified flowchart diagram of a method for indicating where on a patient's arm a needle should not be inserted, according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0072] The present invention relates generally to the field of vascular monitoring in patients. Some aspects relate more particularly to early diagnosis of impaired vascular function, and even more particularly to early detection of impaired vascular access in patients undergoing hemodialysis treatment. Some aspects relate more particularly to measuring fistulas.

[0073] Introduction Physical examination surveillance is a cost-effective and proven method for detecting VA abnormalities. Unfortunately, nephrologists and HD staff generally have limited availability and are not very knowledgeable. Consequently, routine VA physical examinations are not typically performed in HD suites.

[0074] Therefore, there is a need for a monitoring solution capable of early detection of developing stenoses and predicting thrombus formation that overcomes at least some of the shortcomings of existing monitoring practices, including: dialysis centers failing to adequately adhere to prescribed VA physical examinations outlined in the guidelines; the inherent inaccuracies associated with a single physical examination or pressure / flow measurements of the VA; the inherent inaccuracy of single parameters such as flow rate and pressure; The results of routine measurements may be influenced by unrelated hemodynamic events; Measurements by different human caregivers may result in inconsistencies.

[0075] An aspect of some embodiments of the present invention relates to replacing or supplementing a physical examination performed by a medical professional or nurse.

[0076] When a nurse or doctor examines a patient's blood vessels, they typically use a three-step process: see, listen, and feel.

[0077] Aspects of some embodiments relate to "seeing, hearing, feeling" through instrumental measurements and computerized analysis.

[0078] In some embodiments, the systems described herein "see, hear, and feel" based on illuminating and imaging a patient's extremity and analyzing the data gathered from the imaging. In some embodiments, the system teaches how to predict fistula conditions, potentially allowing for early prevention of damage.

[0079] In some embodiments, the methods described herein "see, hear, and feel" based on illuminating and imaging a patient's extremity and analyzing the data gathered from the imaging. In some embodiments, the system teaches how to predict fistula conditions, potentially allowing for early prevention of damage.

[0080] In some embodiments, blood flow is measured non-invasively based on image processing of images of blood vessels within the human body. Physiological parameters known to affect vascular access (VA) are measured, and the measurements are optionally used to determine whether the patient should be scheduled for corrective treatment or proceed to undergo dialysis.

[0081] Aspects of some embodiments relate to performing the "feel" through instrumental measurements and computerized analysis, as described herein.

[0082] In some embodiments, the "listening" described herein is performed by a device, optionally the same device.

[0083] In some embodiments, "seeing" as described herein is performed by a device, optionally the same device.

[0084] An aspect of some embodiments of the present invention relates to the automatic detection and / or monitoring of AV fistulas in vascular images.

[0085] In some embodiments, images of blood vessels are analyzed to determine the location where the artery joins the vein, optionally as the location of the AV fistula.

[0086] In some embodiments, images of blood vessels are analyzed to determine locations where arteries appear to join veins, optionally as sites of AV fistulas.

[0087] In some embodiments, images of blood vessels are analyzed and, optionally, AV fistulas are measured to estimate geometric properties.

[0088] An aspect of some embodiments of the present invention relates to the automatic, non-invasive measurement of parameters related to blood flow.

[0089] In some embodiments, the non-invasive measurement involves imaging blood vessels through the skin using reflected and / or transmitted light.

[0090] In some embodiments, the probability of vascular access failure is optionally estimated, hi some embodiments, the estimation is based on one or more of the measured parameters.

[0091] In some embodiments, the probability of occlusion formation is optionally estimated, hi some embodiments, the estimation is based on one or more of the measured parameters.

[0092] In some embodiments, the probability of thrombus formation is optionally estimated, hi some embodiments, the estimation is based on one or more of the measured parameters.

[0093] In some embodiments, the degree of stenosis is optionally estimated, hi some embodiments, the estimation is based on one or more of the measured parameters.

[0094] In some embodiments, the rate of stenosis formation is optionally estimated, hi some embodiments, the estimation is based on one or more of the measured parameters.

[0095] In some embodiments, the degree of VA maturation is optionally estimated, hi some embodiments, the estimation is based on one or more of the measured parameters.

[0096] In some embodiments, the rate of VA maturation is optionally estimated, hi some embodiments, the estimation is based on one or more of the measured parameters.

[0097] An aspect of some embodiments of the present invention relates to providing a visual report to a caregiver.

[0098] Listed below are attributes, one or more of which may be relevant to some embodiments of the present invention: 1. One or more of the patient-related parameters, including images, are readily available for measurement, potentially in a cost-effective and / or non-invasive (optionally non-contact) manner and / or integrated into routine dialysis appointments. 2. Inputs to the algorithms described herein optionally include one or more patient-related parameters for estimating the probability of vascular access failure, each parameter may be available at one measurement or at multiple measurements along a time axis. 3. Some of the patient-related parameters are obtained using objective measurements, potentially requiring less skill on the part of the user, such as the patient and / or medical professional. 4. Some of the patient-related parameters are optionally taken from the patient's specific medical record and include elements such as demographic information (e.g., age, sex, weight and height), results of clinical tests, imaging tests (e.g., X-ray, MRI) and physical examinations. It will be apparent to one skilled in the art that the parameters can be extracted in many ways, for example, by typing test results directly into a keyboard connected to the system described herein, by a computer process accessing electronic medical records using a unique patient ID, by speech-to-text conversion, by speech recognition algorithms applied to personnel language analysis, by OCR of printed / written documents.

[0099] Measurement of VA maturation: VAs have a unique tissue structure compared to veins and arteries. The structure changes during the VA maturation and stenosis process.

[0100] Structural changes affect the mechanical and optical properties of the VA, and therefore monitoring of the changes can, in some embodiments, potentially be measured by one or more of the following: Imaging: by measuring, as a non-limiting example, changes in contrast or intensity of reflected and / or transmitted light; - Non-imaging: reflected or transmitted light intensity; - Measurement of scattering and absorption rates (e.g., two-distance steady-state photon transfer measurements).

[0101] For example, in some embodiments, the system is configured to detect veins, and monitoring the VA during the maturation period potentially changes the detection results. In an example of optical sensing, the VA's response to light (one or more of transmission, reflection, absorption, and scattering) potentially changes throughout the maturation period. Monitoring maturation is potentially beneficial for increasing the success rate of VA maturation by suggesting timely and proactive corrections. Measuring vascular layers, or ratios between vascular layers, or changes in the ratios between layers, or changes in the absolute values ​​of layers, during the maturation or stenosis process.

[0102] The accuracy of estimating maturation (degree, stage, rate, completion) or probability of vascular access failure, occlusion formation, and thrombus formation can be improved by using one or more parameters generated from noninvasive measurements. The parameters used can be measured directly or can be the result of preprocessing applied to the measurements. Such preprocessing can involve the application of various algorithms and combinations of several parameters and the use of multiple measurements over time.

[0103] Examples of indicators or phenomena that may optionally be extracted and used in some embodiments of the present invention include: 1. Pulse wave velocity. In some embodiments, reflection or absorption of optical radiation from at least two points in an image frame is detected. In some embodiments, the change in electrical impedance along the vessel or tissue area is measured by electrodes placed between and / or along the two points. Optionally, the two points include a section known to be more prone to stenosis. More commonly, at least one point is used to measure pulse wave shape (e.g., pulse wave amplitude, full width at half maximum (FWHM), etc.).

[0104] In some embodiments, pulse wave amplitude is optionally measured. An optional method for measuring pulse wave amplitude includes measuring a first measurement of the area of ​​a location along the vein identified as vascular dilation due to the pulse wave. A second measurement also measures the area of ​​the same location in another image when the pulse wave is not present at that location. The difference between the first and second measurements is optionally related to the pulse wave amplitude. In some embodiments, pulse wave amplitude is considered a feature corresponding to the mechanical properties of the vein and / or the maturity of the AV through which the pulse wave travels.

[0105] In some embodiments, pulse wave analysis (PWA) is optionally performed to assess variances related to vascular stiffness associated with additional risk factors, such as cardiovascular disease or atherosclerosis, that may affect VA survivability over time. Pulse quality is optionally scored, and in some embodiments, changes over time and between different intervals are optionally included in the analysis.

[0106] In some embodiments, the field of view (FoV) of the camera is positioned to be equal to or greater than the distance traveled by the pressure pulse during the time between successive captured images.

[0107] In some embodiments, the illuminated area of ​​the patient's arm is positioned to be equal to or greater than the distance traveled by the pressure pulse during the time between successive captured images.

[0108] 2. The appearance and development of collateral veins and their characteristics, such as density, size, distance from the VA, orientation, and fullness, can be determined by imaging and / or other detection methods, such as measuring contrast through light absorption in visible or near-IR wavelengths or emission in far-IR wavelengths. Other measurement options include measuring changes in absorption in the visible and near-IR, and emission in the far-IR. Another optional means of measuring collateral development optionally measures temperature changes around the VA. In some embodiments, detection of collateral vein appearance and development optionally uses reference images or measurements taken from previous tests. In some embodiments, trend analysis of the rate of collateral vein development optionally uses frequent testing. Testing is optionally performed daily, with each dialysis session, weekly, biweekly, or monthly.

[0109] In some embodiments, collateral veins are detected by comparing a new image with a previous image and counting the veins, and an increase in the number of veins is optionally interpreted to mean that the new vein is a collateral vein.

[0110] In some embodiments, the appearance and / or development of collateral veins is detected by extracting features from a single image or measurement.

[0111] Rationale: Detection of collateral vessels may indicate flow-limiting (hemodynamically significant) lesions. Collateral vessels may develop and enlarge to dissipate increased intra-access pressure in the setting of outflow stenosis.

[0112] 3. Minimum diameter of blood vessel (location of stenosis) determined by image processing.

[0113] 4. Detection of stenosis points by estimation of mechanical reflected waves or local pressure / flow changes by measuring, for example, electrical impedance changes.

[0114] 5. Maximum diameter of vessel by imaging (appearance and size of aneurysm).

[0115] 6.Detection of blood vessel collapse when lifting an arm or leg.

[0116] 7. Use of reflectance and / or transmission near-infrared (NIR) (700-1000 nm) spectroscopy to measure the amount of oxygenated and deoxygenated hemoglobin (Hb).

[0117] 8. Spectroscopic analysis of oxygenated and deoxygenated hemoglobin (Hb).

[0118] 9. Audible VA (vascular bruit).

[0119] 10. Palpation pulsation (thrill) of VA.

[0120] 11. Analysis of electrical impedance changes in the VA using signal processing methods known in the art.

[0121] 12. In some embodiments where multiple measurements of the same parameter are taken over time, the measurements may be synchronized according to the detected respiratory cycle and categorized for the detection algorithm with respect to their relative time along the respiratory cycle. Such synchronization and categorization may be beneficial, for example, in assessing changes in oxygen mixing over time, but may also improve the accuracy of other measurements, such as pulse wave velocity.

[0122] The output of the systems described herein may be in the form of an audible warning, a visual warning, an image, a sequence of images, or a video that provides the clinician with guidance regarding rapid and precise intervention (e.g., giving the clinician recommendations regarding the best location for intervention). The system may recommend treatment to the patient (PTA, no intervention, thrombectomy). Recommendations are optional and based on information collected by the system.

[0123] According to aspects of some embodiments of the present invention, the output of the system during the test is optionally analyzed and / or optionally used to guide the patient throughout the test to perform the test correctly. As a non-limiting example, the lifting test ensures that the limbs are lifted / positioned correctly. In some embodiments, there is also an alert to the nurse / technician if the patient does not perform the test correctly or needs help.

[0124] In some embodiments, the above-described outputs are optionally used to assist a patient in performing a physical exam remotely, while the system provides feedback on the correct performance of the exam and / or notifies a remote support person, such as a nurse or technician, that additional guidance is needed.

[0125] In some embodiments, the system output is optionally provided differently to different consumers of the data, for example: a dialysis nurse is optionally provided with a general interpretation regarding the likelihood of clinically significant stenosis formation, an interventional radiologist is optionally provided with warnings along with annotated images, and / or a report is optionally provided highlighting parameters such as the location, severity, and rate of stenosis formation.

[0126] According to an aspect of some embodiments of the present invention there are provided systems and methods for measuring parameters related to a fistula.

[0127] In some embodiments, a system is provided that includes an optical device that acquires one or more images of a fistula in the same patient over a management period.

[0128] In some embodiments, one or more measurements and / or features are optionally extracted from the images and their changes over time are optionally monitored, hi some embodiments, the features are derivatives along a timeline of parameters measured or estimated in the images, such as, by way of non-limiting example, changes in the number, branching, and size of collateral veins over a period of days / weeks / months, etc.

[0129] In some embodiments, machine learning derived methods are used to identify patterns in these changes that may lead to significant clinical endpoints (e.g., fistula stricture) before the onset of clinical signs or symptoms that a human nurse can identify.

[0130] In some embodiments, a system is provided for measuring a parameter related to a fistula by optical means.

[0131] In some embodiments, structured light is projected onto a patient's body or limb and the body is imaged. In some embodiments, the structured light may include horizontal and / or vertical stripes of equal or different widths and / or various light patterns other than stripes.

[0132] In some embodiments, structured light imaging is used to provide information about the extent of the fistula, for example, the length of the long axis of the fistula along the body, the extent of the short axis of the fistula along the body, the shape of the fistula as seen in the image, the segmentation of the fistula periphery, the eccentricity and / or aspect ratio of each segment, the smoothness and / or roughness of the fistula contour.

[0133] In some embodiments, a structured light pattern is projected onto the patient's body or limb and the body is imaged to provide information about the three-dimensional shape of the fistula or organ.

[0134] In some embodiments, the system identifies changes in the shape of the fistula and / or organs near the fistula. In some embodiments, a projector is used to project one or more light patterns (e.g., structured light). In some embodiments, the method measures and / or estimates how the patterns deform on the patient's organ to measure the organ's shape and shape changes over time.

[0135] In some embodiments, a structured light pattern is projected onto the patient's body or limb and the body is imaged to provide information about the three-dimensional shape of the fistula, some non-limiting examples being the volume of the entire fistula or a segment of the fistula (e.g., needle puncture point), the characteristics and / or variance of curvature, changes in shape and / or volume of the underlying arm / organ section near the fistula, and three-dimensional surface features such as smoothness and / or roughness.

[0136] In some embodiments, laser speckle interferometry (LSI) is used to record and observe vibrations on the fistula surface that correlate with internal blood flow and turbulence. Changes in blood flow and turbulence generally correlate with stenotic events and the potential development of clinical conditions.

[0137] In some embodiments, speckle light imaging is used to provide information about dynamic effects within the fistula, such as heartbeat, blood flow turbulence, and optionally to generate a spectrogram of fistula vibrations.

[0138] In some embodiments, images of the body are taken at some time interval, and the differences between the images are optionally used to determine differences in the shape of the fistula.

[0139] In some embodiments, images are taken days, weeks, months, or years apart, and the differences between the images are optionally used to measure and / or monitor changes in the size or shape of the fistula.

[0140] In some embodiments, images are taken one second or one minute apart while the limb, e.g., the hand, is held horizontally and then the hand is held vertically, and the difference between the images is optionally used to measure and / or monitor one or more of: whether at least some of the blood in the fistula is able to exit the fistula; the rate of blood drainage; the extent of blood drainage from the fistula and / or particular portions of the fistula; and collapse of one or more needle puncture points.

[0141] In some embodiments, images are taken as video clips or movies spaced a fraction of a second apart, and the differences between image frames are optionally used to measure and / or monitor dynamic parameters related to the fistula, such as heart rate, blood flow turbulence, and optionally to generate a spectrogram of fistula vibrations.

[0142] In some embodiments, the spectrogram is optionally generated by selecting one or more pixels in the image frame that exhibit large or even maximum intensity variations over time. In some embodiments, the number of pixels selected is optionally in the range of 1 to 100 pixels. In some embodiments, the pixel intensity values ​​of the pixels are used to calculate a function of light intensity over time. In some embodiments, a frequency spectrum of light intensity is optionally generated by converting from the time domain to the frequency domain, for example, by a Fast Fourier Transform (FFT).

[0143] In some embodiments, changes in dynamic parameters related to the fistula between imaging sessions are analyzed to monitor changes in the fistula and patient condition.

[0144] In some embodiments, doing the above in conjunction with near-IR imaging may allow for the collection of data that correlates to tests that need to be performed by nurses and / or physicians and has already been clinically proven to have predictive value in identifying stenosis events.

[0145] According to an aspect of some embodiments of the present invention, there are provided systems and methods for implementing and recording two or more techniques or modalities using a single imaging device, for example, one or more of the following modalities: structured light, laser speckle interferometry, image analysis, and near-IR imaging.

[0146] In some embodiments, the system includes a processor and an imaging device including a digital light processing (DLP) projector and a near-IR camera.

[0147] According to an aspect of some embodiments of the present invention there are provided systems and methods for analyzing vibrations of light reflected from a patient's body.

[0148] In some embodiments, the pulsatility of the heart is monitored.

[0149] In some embodiments, the pattern of vibrations caused by flow through or near the fistula is analyzed to optionally detect complete or partial blockage of either the inflow or outflow pathways.

[0150] In some embodiments, complete or partial blockage of either the inflow or outflow pathways is optionally detected by applying local pressure to either the inflow or outflow pathways while analyzing the pattern of vibrations caused by flow through or near the fistula.

[0151] In some embodiments, the vibrations are analyzed to optionally detect the onset of flow through the fistula associated with normal cardiac activity (diastole or systole of the cardiac cycle).

[0152] In some embodiments, the vibrations are analyzed to detect the onset of flow through the fistula, optionally associated with sudden release (partial or complete collapse or dilation of the fistula).

[0153] In some embodiments, the vibrations are analyzed to detect periods of blood flowing into the fistula, optionally followed by a sudden release of the blockage that allows blood to flow out of the fistula. Such release may occur during the high pressure of a cardiac contraction. In some embodiments, the sudden release is referred to as hammering. In some embodiments, hammering is detected by measuring the amplitude of the vibrations, optionally compared to the amplitude at other times, for example, during a heartbeat.

[0154] In some embodiments, for any or all types of initiation, the oscillations related to the initiation of flow are analyzed, optionally to measure a parameter value or a change in a parameter value or a change in a characteristic parameter value, or a variance in the parameter value, where the parameter may be one or more of intensity, energy, onset steepness (derivative of value), relaxation time, time width, duty cycle, spectral content, spectral width, or any combination thereof.

[0155] In some embodiments, the oscillations associated with the onset of flow are analyzed to optionally measure parameter values ​​related to the time delay or phase delay between onsets associated with sudden ejection and onsets associated with normal cardiac activity.

[0156] In some embodiments, the oscillations associated with flow initiation are analyzed to optionally measure parameter values ​​related to the regularity or self-similarity of successive initiations of the same cause.

[0157] Overview An aspect of some embodiments of the present invention relates to providing a non-contact machine vision based monitoring system built with illumination by a coherent light source and a high-speed image sensor for capturing images of structural changes in the fistula for early detection of fistula stenosis, sensing subcutaneous information, and reading data related to vascular assessment. The present invention is designed to streamline workflow in dialysis centers, improve the quality of care for dialysis patients, and provide a means to assist care staff. In some embodiments, the system is optionally suitable for home use.

[0158] An aspect of some embodiments of the present invention relates to the automatic, non-invasive collection of imaging information and the analysis of the imaging information.

[0159] In some embodiments, the imaging information is mapped or registered to blood vessels and / or fistulas within the patient's organ being imaged. In some embodiments, the patient's organ is the patient's arm.

[0160] In some embodiments, the information is optionally projected onto an organ of the patient, for example onto the patient's arm.

[0161] The projected information may be one or more of the following: analytically based numerical data; one or more correctly aligned locations on the patient's organs, e.g., the location of a fistula, and / or a vibration map and / or a pulsatility map, and / or a map showing the results of an analysis of one or more images of the patient's arm; instructions to patients or caregivers regarding treatment suggestions based on the analysis; Puncture planning, as a non-limiting example, based on information obtained from different information taken at different times, proposing the location of the inflow and / or outflow needle puncture points taking into account historical information about previous puncture points; Information to assist with specific puncture methods, such as rope ladder and buttonhole.

[0162] It is noted that historical data, i.e. records of previous puncture locations, potentially allow the creation of new puncture plans. A good puncture plan potentially allows: a. Minimize damage to the AV access during puncture. b. Minimize possible complications from puncture. c. Minimize pain and anxiety associated with the needle.

[0163] In some embodiments, the system includes software that tracks the patient's arm to accurately align it and project information onto the patient's arm.

[0164] In some embodiments not shown in FIG. 8, the detector or camera 802 and the illumination source 804 optionally share the same line of sight toward the patient's arm, for example, by both viewing the patient's arm through a semi-transparent mirror with at least one of the camera 802 and illumination source 804 at a 45-degree angle to the line of sight.

[0165] The term "pulsatility" is used throughout this specification and claims to mean a value measured and / or calculated by the systems and methods described herein based on one or more of vibration, pulse wave shape properties, pulse wave amplitude, vibration amplitude, pulse wave slope, a map of vibration, a map of vibration difference from previous measurements, a map of the slope of the 3D shape of the arm, and a map of changes in the 3D shape of the arm.

[0166] The pulsatility values ​​mentioned above can be calculated based on image analysis, optionally registered to the patient's arm, and optionally projected onto the patient's arm.

[0167] An aspect of some embodiments of the present invention relates to displaying the puncture plan on the patient's arm.

[0168] In some embodiments, historical information about previous needle puncture points on the patient's arm is used to provide the puncture plan.

[0169] In some embodiments, a current image of the patient's arm is provided or taken and used to provide a puncture plan.

[0170] In some embodiments, a vibration map is generated and used to provide a puncture plan. In some embodiments, the vibration map may be generated based on analysis of one or more images of the patient's arm.

[0171] In some embodiments, the historical information optionally includes historical images of the patient's arm.

[0172] In some embodiments, the puncture plan is based on analyzing one or more of the current image and the historical image.

[0173] In some embodiments, historical images may be images taken more than two days prior to the analysis and provision of the puncture plan.

[0174] In some embodiments, the historical images may include previous images taken hours, days, weeks, or even months before the image of the patient's arm was taken, from previous puncture treatments, or even previous images taken during a previous unsuccessful puncture attempt.

[0175] Before describing at least one embodiment of the present invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of components and / or methods set forth in the following description and / or illustrated in the drawings and / or examples. The invention is capable of other embodiments or of being practiced or being carried out in various ways.

[0176] Reference is now made to FIG. 1, which is a simplified diagram of a system for measuring blood vessels in accordance with an exemplary embodiment of the present invention.

[0177] FIG. 1 shows a top-level configuration of an exemplary system 100 for measuring blood vessels.

[0178] In some embodiments, the system 100 may include at least one illumination source 104 and at least one detector 102, such as a camera.

[0179] In some embodiments, the system 100 comprises: It may further include an optional control unit 106 that operates the illumination source 104 and the camera 102 , and an optional processor 108 that optionally receives and analyzes images produced by the camera 102 .

[0180] In some embodiments, the generated images and / or data generated after analysis of the images may be displayed on an optional display 110 connected to the processor 108 wirelessly or via a wired connection.

[0181] In some embodiments, the processor 108 and the display 110 may be implemented in a single device, such as a laptop, tablet, or smartphone. In some embodiments, a scanning system may be applied, optionally moving the detection unit (automatically or manually) to scan the organ, optionally at two or more points. Figure 1 depicts the system 100 applied to an arm 112.

[0182] The systems and methods can be implemented with other organs without limitation.

[0183] Reference is now made to FIG. 2, which is a simplified block diagram of a system for measuring blood vessels in accordance with an exemplary embodiment of the present invention.

[0184] FIG. 2 shows a top-level block diagram of an exemplary system.

[0185] In some embodiments, the system may include at least two main units: a detection unit 202 and a software unit 206 .

[0186] The system may include additional units such as a workstation 204 and an optional cloud infrastructure 208.

[0187] In some embodiments, the software unit 206 includes at least two sub-units: an embedding unit 230 and an algorithm unit 234. The software unit 206 may include additional blocks, such as a graphical user interface (GUI) unit 232.

[0188] Detection Unit In some embodiments, the detection unit 202 optionally uses: 1. Visual / optical detection to obtain an image containing information for further analysis. 2. Speckle Imaging. When an object is illuminated with laser light, the backscattered light forms an interference pattern consisting of dark and bright areas. This pattern is called the speckle pattern. If the illuminated object is stationary, the speckle pattern is static. If the object is moving, such as red blood cells in tissue, the speckle pattern changes over time. The speckle image contains information related to changes in blood vessels, which can optionally be analyzed and extracted by image processing. 3. Dark field / side illumination a. Specular reflections that do not reach the camera b. Only diffuse scattered light is captured by the camera c. Reduction of surface reflection d. The contrast profile changes as the angle between the source and detector is changed. 4. Trans-illumination - Illuminates the backside of the sample. The sample is placed between the illumination source and the sensor device. Trans-illumination potentially improves image contrast and / or potentially increases the depth to which blood vessels can be imaged. 5. Photoacoustic imaging potentially enhances contrast between media due to differences in the variations in optical properties of different media. Photoacoustic imaging averages out refractive index gradients in tissue components, potentially reducing scattering within tissue and consequently increasing the penetration depth of light.

[0189] In some embodiments, the detection unit 202 optionally includes one or more of the following components: 1. One or more detectors / sensors / cameras 210 (e.g., CCD or CMOS, InGaAs sensors, microbolometers) sensitive to one or more of visible, near-infrared, and short-wave infrared (SWIR) light. In some embodiments, the sensor frame rate can range from a single frame to a high frame rate. The sensor frame rate is optionally in the range of, for example, 5, 10, 16, 24, 30, 50, 60, 100, 165, 200, or even up to 300 frames per second (fps). 2. One or more lenses 212 (zoom or fixed focal length) and / or filters 3. One or more illuminators 214 or emitters (e.g., coherent or non-coherent, narrow spectrum or broadband, UV, visible, SWIR, far IR, NIR, e.g., NIR LED or green (532 nm) laser illumination sources). The emitters may be coaxial with the detector 210 and VA or at different angles. The mode of operation can be still or video. 4. One or more projectors 225 configured to project colored dots, lines, shapes, text, and similar colored marks onto the patient's arm. 5. One or more polarizing filters (elliptical and / or linear) 6. One or more optical bandpass filters 7. The detection unit optionally includes a scanning system or a moving bar scanner.

[0190] In some embodiments, the detection unit 202 optionally uses an audio / sound detection sensor 216 instead of or in addition to visual / optical detection, and the detection unit 202 may optionally include one or more audio sensors.

[0191] In some embodiments, the detection unit 202 may include a vital signs sensor.

[0192] Software Unit In some embodiments, the software unit 206 may include one or more of the following components: 1. A GUI (Graphical User Interface) / application 232 for one or more of: operating the examination procedure, displaying images and / or results, and / or inserting or importing patient clinical information, and / or controlling one or more projectors 225 to project colored dots, lines, shapes, text, and similar colored marks onto the patient's arm. 2. An embedded unit 230 for controlling the detection unit 202. 3. Algorithm unit 234. The algorithm unit optionally includes algorithms or software modules for image processing and / or artificial intelligence (AI), such as machine learning (ML). The terms artificial intelligence (AI), machine learning (ML), and other similar terms known in the art are interchangeable.

[0193] In some embodiments, the input of the ML algorithm is optionally images and / or data captured by the detection unit 202.

[0194] In some embodiments, the input may also include clinical information and / or vital signs of the patient.

[0195] In some embodiments, the workstation 204 optionally includes a computer, a screen, a keyboard, one or more knob controls, a mechanical interface for the imaging unit, and an interface with a power source or power source. In some embodiments, the workstation 204 may also include an "organ fixation surface."

[0196] In some embodiments, the workstation 204 optionally includes one or more of the following: a control unit 220 for controlling the operation of the detection unit 202 and / or one or more components of the detection unit 202; Computer 220; Display 224; an optional organ fixation surface or device 226 for optionally positioning the organ in a specific position relative to the illumination 214 and / or detector 210; and A stand 228 for placing the components of the system in a specific position relative to the patient's organs.

[0197] In some embodiments, the cloud infrastructure 208 optionally includes one or more of the following cloud services: storage (database) server 240; web application server 236; Machine learning, such as refining algorithms based on new data, and / or analytics to provide users with measures and indicators of function, and / or computing services to provide insights that provide indicators regarding the current or predicted future clinical state of the VA.

[0198] The machine learning algorithms may be supervised or unsupervised and train based on images and / or patient parameters generated by embodiments of the present invention and / or a database of patient metadata, such as disease, vital signs, parameters from the dialysis machine, and / or other data available in the electronic medical record, optionally including previous interventions for the patient, additional risk factors, comorbidities, etc.

[0199] The steps include one or more of the following: 1. Feature extraction from images 2. Feature trend calculation 3. Perform ML on the feature vectors and / or trends in the feature vectors.

[0200] In some embodiments, the result of the ML is a statistical classification model that distinguishes between less than 50% AV patency and greater than or equal to 50% AV patency.

[0201] In some embodiments, analysis and insights are performed on the metadata and patient records to calculate AV failure statistics based on the patient profile (metadata and medical health records).

[0202] In some embodiments, an analysis of clinic performance is optionally performed, for example, how many stenosis events occur per year.

[0203] Scaling Algorithm In some embodiments, a scaling algorithm calculates the image scale (e.g., scaling pixels to mm), which may be used to calculate absolute or relative values ​​for one or more of the vessel radius, pulse wave velocity, collateral vessel size, collateral vessel density, and collateral vessel distance from the VA.

[0204] Alignment Algorithm In some embodiments, a registration algorithm may perform automatic or semi-automatic registration between two or more consecutive images.

[0205] The registration algorithm may align and / or scale two or more images containing the same object at different positions or viewing angles or different fields of view.

[0206] In some embodiments, the input to the alignment algorithm includes at least two images and, in the case of semi-automatic alignment, optionally one or more points marked by a user on the two images.

[0207] The registration algorithm potentially allows the system to measure the variation between at least two exams, regardless of how the arm or other examined organ is positioned during the different exams.

[0208] In some embodiments, alignment of at least two images of the same patient containing VA objects is optionally performed by detecting (e.g., segmenting) the VA and fitting the VA image in the first image to the VA image in the second image by a geometric transformation.

[0209] Algorithm for detecting vascular access (VA) bodies In some embodiments, automatic or semi-automatic detection of the location of the vascular access body in the image is performed.

[0210] In some embodiments, the input to the algorithm for detecting the vascular access body includes at least one image that includes the vascular access body within an image frame.

[0211] In some embodiments, an optional input is a set of one or more points along the blood vessel containing the VA body, optionally marked by a doctor / nurse on an image containing the VA body.

[0212] The output of the algorithm may be a set of pixels of the vascular access body in the image.

[0213] In some embodiments, the computerized detection of the VA body is based on the unique VA shape, size, orientation, position, and the like.

[0214] In some embodiments, a device such as, by way of non-limiting example, the "ELY-1000 Vascular Imaging Device for Arterial Puncture" developed by ELYNNSH MEDICAL is used, which, according to the manufacturer, can assist medical personnel in identifying the underlying artery during arterial puncture and conveniently and quickly display the exact location and orientation of the artery.

[0215] In some embodiments, locations where arteries and veins are likely to join or converge are detected in the image.

[0216] In some embodiments, the blood vessels supplying the VA are surgically elevated toward the skin surface. Due to the difference in depth of the blood vessel segments, the VA often appears as the center of gravity of a closed contour in an image covering a field of view (FOV) that includes the VA. The tissue surrounding the VA body is often deeper beneath the skin than the VA body itself.

[0217] In some embodiments, the difference in depth is optionally detected by the VA body appearing as an area that is potentially darker than the natural or surrounding blood vessels. For example, if NIR illumination is used, NIR light is absorbed by blood Hgb, causing blood vessels closer to the surface to appear darker than deeper blood vessels.

[0218] Exemplary Embodiments - System Description The system may measure one or more of the following exemplary phenomena: vessel diameter, pulse wave velocity, NIR (e.g., 700-1000 nm) reflectance spectroscopy, the appearance of collateral veins and their characteristics, such as density, size, distance from the vascular access, and oxygen concentration at the vascular access.

[0219] In some embodiments, the NIR spectral range is used for vascular imaging. The spectral window lies from approximately 700 nm to approximately 900 nm, where light can penetrate deep into tissue and where more radiation is absorbed by venous blood vessels than by surrounding tissue.

[0220] Reference is now made to FIG. 3, which is a simplified block diagram of a system for measuring blood vessels in accordance with an exemplary embodiment of the present invention.

[0221] 3 shows a top-level block diagram of an exemplary embodiment of a system 300. The system 300 may include an imaging / detection unit 302 and a software / computing unit 306.

[0222] The imaging / detection unit 302 optionally includes one or more sensors 310 , one or more lenses 312 , one or more filters 313 , one or more illuminators 314 , 316 , and one or more optional projectors 325 .

[0223] In some embodiments, the sensor 310 may be a CMOS sensor.

[0224] In some embodiments, the sensor 310 may be a multispectral and / or hyperspectral camera.

[0225] In some embodiments, the sensor 310 may be a NIR sensor or a camera.

[0226] In some embodiments, lens 312 may optionally be a fixed focal length lens.

[0227] In some embodiments, lens 312 may optionally be a zoom lens.

[0228] In some embodiments, the filter 313 may optionally include a bandpass or longpass filter.

[0229] In some embodiments, the illuminators 314, 316 may optionally include NIR LEDs, optionally in the 700-1200 nm spectral range.

[0230] In some embodiments, the illuminators 314, 316 may optionally include broadband NIR LEDs.

[0231] In some embodiments, the illuminators 314, 316 may optionally include one or more laser sources, optionally in the near-IR spectral range of 850 nm to 910 nm.

[0232] In some embodiments, the illuminators 314, 316 may optionally include narrowband illumination, optionally in the 900 nm spectral range.

[0233] In some embodiments, the illuminators 314, 316 may optionally include an array of illuminators.

[0234] In some embodiments, the optional projector 325 is configured to project colored dots, lines, shapes, text, and similar colored marks onto the patient's arm.

[0235] In some embodiments, the software / computing unit 306 optionally includes one or more of a GUI 334 , an image processing unit 335 , a computer vision unit 336 , and a machine learning algorithm unit 337 .

[0236] In some embodiments, the algorithm unit 337 optionally includes one or more of an image processing algorithm, a vein segmentation algorithm, a collateral vein detection and / or segmentation algorithm, a pulse wave detection algorithm, and a classifier algorithm, optionally a machine learning algorithm.

[0237] The system 300 may include additional units such as a workstation 304 and an optional cloud infrastructure 308 .

[0238] In some embodiments, cloud infrastructure 308 optionally includes one or more of a web application 338 , a database 340 (optionally including big data analytics capabilities), and an analytics unit 342 .

[0239] In some embodiments, the workstation 304 optionally includes one or more of the following: a control unit 320 for controlling the operation of the imaging / detection unit 302 and / or one or more components of the imaging / detection unit 302; Computer 322; Display 324; an optional organ fixation surface or device 326 for optionally positioning the organ in a specific position relative to the lights 314, 316 and / or sensor 310; and A stand 328 for placing the components of the system in a specific position relative to the patient's organs.

[0240] When a healthcare caregiver (eg, a family member, nurse, or physician) examines a patient's blood vessels, they typically use a three-step procedure: see, listen, and feel.

[0241] In some embodiments, the systems described herein "see, hear, and feel" based on illuminating and imaging a patient's extremity and analyzing the data gathered from the imaging.

[0242] In some embodiments, the methods described herein "see, hear, and feel" based on illuminating and imaging a patient's extremity and analyzing the data collected from the imaging.

[0243] Reference is now made to Figure 4, which is a table illustrating the steps a medical professional would take to screen a patient for vascular stenotic lesions or thrombi.

[0244] Figure 4 shows what humans are instructed to do, but it is known that inter-human variability is expected to affect such testing.

[0245] It is noted that automated testing may provide better reproducibility for such testing.

[0246] It is noted that automated testing may provide faster testing with less intervention from medical personnel.

[0247] Reference is now made to FIG. 5, which is a simplified flowchart illustration of a method for testing a patient in accordance with an exemplary embodiment of the present invention.

[0248] The method of FIG. 5 includes: The device views the patient's body by taking one or more images of the body and using image analysis on the images (502); The device listens to the patient's body by capturing body vibrations and analyzing the vibrations at frequencies audible to humans (504); and The device senses the patient's body by analyzing body vibrations below human audible frequencies (506).

[0249] In some embodiments, taking one or more images of the body is optionally done by taking images at near-IR wavelengths.

[0250] In some embodiments, capturing the vibrations of the body is optionally done by laser speckle imaging as described elsewhere herein.

[0251] In some embodiments, capturing the body vibrations is optionally performed by a microphone in contact with the patient's body and / or a microphone attached to a stethoscope in contact with the patient's body.

[0252] In some embodiments, capturing the vibrations of the body is optionally done by analyzing the "smearing" or expansion of the size of one or more spots of light on the body compared to the size of other spots of light on the body.

[0253] It is noted that automated testing, in some embodiments, may enable such testing to be provided without human contact with the patient, and may be used in situations where medical distancing is required, such as when the patient may have a contagious disease.

[0254] In some embodiments, the systems and methods described herein optionally "see," i.e., analyze images of blood vessels, "listen," i.e., analyze vibrations of the patient's body at frequencies audible to humans, and "feel," i.e., analyze vibrations of the patient's body at low frequencies below typical audio frequencies.

[0255] In some embodiments, a non-contact management tool is provided that supplements and / or replaces physical examination of vascular access (VA), potentially allowing for early detection of stenosis, potentially earlier than human examination.

[0256] In some embodiments, the management tool does not contact the patient's fistula and / or the patient's limb while the limb is optionally placed on the device, which can place the fistula within the device's field of view.

[0257] In some embodiments, the recording and monitoring of administratively measured parameters may allow for early detection and / or prediction of stenosis, potentially earlier than human inspection.

[0258] In some embodiments, administration is enabled without human contact, for example, at a distance greater than 10, 20, 30, 40, 50 centimeters from the location of the VA.

[0259] In some embodiments, the systems and methods optionally allow for the acquisition of all parameters that are typically acquired by human physical examination by "seeing, hearing and feeling."

[0260] In some embodiments, it may be easier to train a person to operate VA monitoring using the embodiments described herein than using human senses.

[0261] Using the embodiments described herein may add value by recording and using historical data from the same patient and tracking changes.

[0262] Use of the embodiments described herein allows for pre- and / or post-visit testing in a clinic, potentially without physical contact.

[0263] Use of the embodiments described herein may aid in medical care in the context of COVID-19.

[0264] Use of the embodiments described herein allows for care potentially in a home environment, possibly operated by the patient.

[0265] In some embodiments, a projector (e.g., projectors 225 and / or 325 of FIGS. 2 and 3, respectively, or other projectors described herein) optionally projects light at a location of interest to allow the user to correctly position the patient's body.

[0266] In some embodiments, the location of interest is a fistula in a patient.

[0267] In some embodiments, two or more spots are illuminated simultaneously.

[0268] In some embodiments, one location of interest at which a spot is illuminated is the patient's fistula, and another location of interest at which a spot is illuminated is a location adjacent to the patient's fistula but which is not the fistula.

[0269] In some embodiments, one location of interest at which a spot is illuminated is the fistulizing aneurysm, and another location of interest at which a spot is illuminated is a location adjacent to the fistulizing aneurysm but is not the fistulizing aneurysm.

[0270] In some embodiments, the projector is a digital light processing (DLP) projector.

[0271] In some embodiments, the projector is a laser projector.

[0272] In some embodiments, a location of interest, such as a fistula, aneurysm, or body dilation, is identified, optionally using structured illumination and image analysis, and a projector is controlled, optionally automatically controlled, to illuminate the location of interest. In some embodiments, a DLP and / or laser projector is optionally controlled to illuminate the location of interest.

[0273] In some embodiments, a doctor or nurse controls the lighting to the location of interest.

[0274] In some embodiments, a doctor or nurse controls the laser illumination to the location of interest.

[0275] In some embodiments, the projector is optionally capable of projecting light in multiple modes, including two or more of the following: Project uniform (or approximately uniform) illumination onto an area or limited spot on the patient's body, potentially sufficient to image collateral veins; Projecting structured lighting, optionally including stripes or other patterns of specific, equal, or unequal programmed widths; and For example, laser speckle interferometry projects one or more areas of coherent laser light, potentially useful for measuring one or more of vibration, microtremor, and pulse.

[0276] In some embodiments, the projector is switchable between one of three different lighting modes: uniform, various line patterns, and various spot patterns.

[0277] In some embodiments, the projector can provide one or more spots, each ranging in size from 0.2 mm to 0.5, 1, 2, 6, 9, 12, 15, or 18 mm in diameter on the patient's limb. For example, a spot size of approximately 1 mm. In some embodiments, multiple spots are provided in an area of ​​the patient's arm. In some embodiments, this area is optionally determined by a user of the system for projection onto an area of ​​interest, such as an AV fistula. In some embodiments, this area optionally spans the patient's entire arm. In some embodiments, this area spans the patient's entire arm, along a length ranging from 3 cm to 30 cm.

[0278] In some embodiments, the projector includes one or more LED and / or laser light sources, optionally in near-IR wavelengths.

[0279] In some embodiments, the projector is optionally a digital light processing (DLP) projector.

[0280] In some embodiments, the projector optionally includes nanomirrors for shaping the light.

[0281] In some embodiments, the projector optionally includes Micro-Electro-Mechanical System (MEMS) mirrors for shaping the light.

[0282] In some embodiments, the projector optionally includes a digital mirror driver (DMD).

[0283] In some embodiments, the projector and camera are packaged in one package.

[0284] Reference is now made to FIG. 6, which is a simplified flowchart illustration of a method for converting data from a stream of images into a frequency spectrum, in accordance with an exemplary embodiment of the present invention.

[0285] The method of FIG. 6 includes: receiving a stream of images of a patient's body (602); Optionally, selecting one or more pixels with a high variance in intensity over the duration of the stream of images (604); Generate a vector of intensities over time durations (606); The vector of intensities is converted into a vector of frequency spectra (608).

[0286] In some embodiments, the transformation is performed by a Fast Fourier Transform.

[0287] In some embodiments, the power spectrum is optionally normalized before analyzing it. As some non-limiting examples, the normalization factor is optionally calculated from the total spectral energy, the peak value, the peak-to-baseline ratio, the energy in a particular bandwidth, etc.

[0288] In some embodiments, a reference spectrum measured at a remote location (far from the fistula, e.g., the opposite hand) is used as a reference. Both spectra may or may not be normalized, and the measured spectrum is replaced by the difference between the spectra at the different locations.

[0289] In some embodiments, the skewness or kurtosis of the measured power spectrum or differential power spectrum is optionally used to estimate flow rate.

[0290] In some embodiments, the measured power spectrum is first fitted to a model, and in some embodiments, one or more hidden model mixtures, a non-limiting example being a Poisson-Gaussian mixture, are assumed, and the model parameters are used as correlators with flow rate.

[0291] In some embodiments, energy in a particular frequency range is used to estimate flow rate.

[0292] Reference is now made to FIG. 7, which is a graph illustrating the power spectrum of vibrations measured by analysis of images produced by laser speckle imaging.

[0293] FIG. 7 shows a graph 700 where the X-axis 702 shows frequency ranges or bins and the Y-axis 704 shows the relative power spectrum in measured units.

[0294] Two patient groups were sampled to generate this graph: a first group 706 with a blood flow rate (FV) greater than 500 mL / min, and a second group 708 with an FV less than 500 mL / min.

[0295] Graph 700 shows that the maximum of the power spectrum is located at approximately 140 Hz for both groups. This leads us to believe that listening to the pitch of the blood flow in both groups may not be a good way to differentiate them. However, analysis of the power spectrum of both groups shows the following differences: The first group 706 appears to have a higher amplitude at its maximum than the second group 708; The second group 708 may have a flatter or wider curve than the first group 706 .

[0296] The vibrations analyzed in the power spectrum shown in Figure 7 appear to be caused by blood flow and / or turbulence through the blood vessels.

[0297] It should be understood that the graph shown in Figure 7 is an example provided to enable those skilled in the art to understand the present invention. For example, although the frequencies shown in Figure 7 reach approximately 250 Hz, the present invention is not limited to this number. In some embodiments, the system is configured to generate frequencies up to approximately 1000 Hz, and optionally even higher.

[0298] Flow rate and turbulence change over time and are influenced by the local physical conditions within and around the vessel where the flow occurs, possibly including pressure gradients, vessel diameter, vessel wall compliance, vessel inner surface properties, etc.

[0299] The power spectrum of blood flow measured at VA / fistula locations potentially relates to the physical and / or clinical flow conditions at those locations. Changes in such power spectrum characteristics over time potentially correlate with a decline in fistula health. Analyzing changes in power spectra obtained from VA / fistula locations potentially predicts early stages of fistula deterioration.

[0300] With regard to the early stage prediction described herein, it is noted that such prediction potentially allows percutaneous transluminal angioplasty (PTA) to be performed earlier than would be possible based on medical testing of the pre-existing condition.

[0301] In some embodiments, the power spectrum is measured by measuring the intensity of light reflected from the patient's body, which is expected to vary with frequencies related to the frequency of the body's vibrations.

[0302] In some embodiments, the power spectrum is measured by measuring the intensity of light reflected from an illuminated area of ​​the patient's body, and in such embodiments, the vibrations are actually measured specifically at the illuminated area.

[0303] In some embodiments, the power spectrum is measured by measuring the difference between successive images of the body, for example, small shifts in a pattern on the body, which may be a mole on the skin, structured lighting, a moving spot of light, two or more moving spots of light, moving laser speckles, and similar movements.

[0304] "See, hear, feel" Some aspects of the present invention are further described in terms of the "see, hear, feel" procedures used by medical personnel.

[0305] In some embodiments, the "see, hear, feel" procedure is optionally performed by system embodiments described herein.

[0306] In some embodiments, the systems described herein "see, hear, and feel" based on illuminating and imaging a patient's extremity and analyzing the data gathered from the imaging.

[0307] In some embodiments, the methods described herein "see, hear, and feel" based on illuminating and imaging a patient's extremity and analyzing the data collected from the imaging.

[0308] Fistula bruit, also called vascular murmur, is an indicator of how well the dialysis access is functioning.

[0309] An arteriovenous fistula is a type of access created by connecting an artery to a vein, usually under the skin of the upper or lower arm or leg. The high blood flow from the artery through the vein allows the fistula to grow large and strong. A healthy AV fistula has a bruit (a rumbling sound that a person can hear), a thrum (a rumbling sensation that a person can feel), and good blood flow.

[0310] In some embodiments, the "seeing" aspect is optionally performed by imaging the body or limb and analyzing one or more images to quantify vascular and / or fistula structures.

[0311] In some embodiments, the "seeing" aspect is performed by imaging the body or limb, optionally using structured light, to generate a 3D shape of the fistula.

[0312] In some embodiments, the "listening" aspect is optionally performed by measuring body or limb vibrations and analyzing the vibrations to quantify parameter values ​​related to the medical condition of the fistula. In some embodiments, the "listening" aspect includes analyzing vibrations in a frequency range within the human hearing range.

[0313] In some embodiments, the "sensing" aspect is optionally performed by measuring body or limb vibrations and analyzing the vibrations to quantify parameter values ​​related to the medical condition of the fistula. In some embodiments, the "sensing" aspect optionally includes analyzing vibrations in frequency ranges above and / or below the range of human hearing.

[0314] In some embodiments, the analysis of vibrations is optionally performed in a frequency range below 1,000 Hz. In some embodiments, the analysis of vibrations is optionally performed in a frequency range below a typical human voice, for example below 4,000 Hz.

[0315] As some non-limiting examples, aspects of "feeling" include one or more of the following:

[0316] To measure a human pulse, which is typically in the range of 40 beats per minute or more, such measurements must analyze frequency vibrations at and slightly below 1 hertz. If such analysis is performed by analyzing image frames of a video sequence, it is sufficient to analyze the image frames at approximately twice the rate of the frequency to be measured, i.e., for example, approximately 2 frames per second or more.

[0317] Thrill measurements are typically in the range of 50 to 250 Hz or 50 to 750 Hz. When such analysis is performed by analyzing image frames of a video sequence, it is generally sufficient to analyze the image frames at about twice the rate of the frequency being measured, i.e., about 100 frames per second or more.

[0318] For example, analysis and quantification of the power spectrum of the vibrations as described above with reference to Figures 6 and 7.

[0319] In some embodiments, "seeing, hearing, and feeling" is accomplished without physically touching the patient by image analysis and / or by using specific modes of lighting.

[0320] Reference is now made to FIG. 8, which is a simplified diagram of a system for measuring blood vessels, in accordance with an exemplary embodiment of the present invention.

[0321] FIG. 8 shows a system 800 that includes at least one illumination source 804 and / or projection component 804, and at least one detector 802, such as a camera.

[0322] FIG. 8 also illustrates some optional functions performed by the system 800.

[0323] A first optional feature 810 is illumination with near-IR, which potentially allows imaging of subcutaneous organs such as veins and / or AV fistulas.

[0324] A second optional feature 820 is structured light illumination, which potentially allows for determination of the 3D structure of the surface of the patient's hand 822 .

[0325] A third optional feature 830 is the optional projection of colored dots, lines, shapes, text, and similar color marks 834 onto the patient's arm 832. In some embodiments, such projection serves as a graphical user interface projected onto the patient's arm. In some embodiments, the optional marks 834 include data, such as numbers and / or text, projected onto the patient's arm, e.g., the results of a reading. In some embodiments, the optional marks 834 include suggested treatment instructions, optionally based on analysis of images collected by the detector 802. In some embodiments, the optional marks 834 include a mark of the location of an AV fistula. In some embodiments, the optional marks 834 include a mark of an area of ​​the arm detected to vibrate in an optical image analysis corresponding to a skin movement analysis, e.g., a vibration analysis corresponding to a "seeing" or "listening" or "feeling" action performed by a caregiver.

[0326] A fourth optional function 840 is optional analysis of vibrations using laser speckle illumination. The laser speckles move as a result of blood flow-induced vibrations of the patient's skin at various frequencies. Some of the frequencies correspond to actions that humans "hear," i.e., they are frequencies audible to humans. Some of the frequencies correspond to actions that humans "feel," i.e., they are below typical human hearing frequencies. It is noted that a vibration map may be projected onto the patient's body, optionally at a location precisely aligned with the patient's body, to display where vibrations of the patient's skin are detected. In some embodiments, the vibration map indicates where vibrations of the patient's skin exceed a threshold. In some embodiments, the vibration map indicates where vibrations of the patient's skin are below a threshold. The threshold is optionally set to range between zero (indicating all locations where vibrations are detected) and 90% or even 99% of the maximum vibration value. In some embodiments, a non-contact machine vision based surveillance system is provided, as shown by way of non-limiting example in Figures 1, 2, 3, and 8.

[0327] In some embodiments, the system includes one or more illumination sources 804 and / or projection components 804, optionally using a digital light processor (DLP) architecture.

[0328] In some embodiments, detector 802 is optionally a camera, and by way of non-limiting example, is a high-speed CMOS sensor configured to capture imaging, optionally using multi-mode imaging such as 3D imaging (e.g., using structured light illumination), 2D imaging, near-IR imaging, visible light imaging, laser speckle imaging, etc.

[0329] In some embodiments, the light source includes wavelengths in the near IR and visible wavelengths.

[0330] In some embodiments, the detector or camera 802 and the illumination source 804 observe and illuminate the same area.

[0331] Depending on the distance of this area from the system 800, the angle between the detector or camera 802 and the illumination source 804 may be adjusted. In some embodiments, one or more of the detector or camera 802 and the illumination source 804 may be adjustably, optionally automatically, mounted to observe and illuminate the same area.

[0332] Reference is now made to FIG. 9, which is a simplified illustration of optional lighting modes and optional captured images, in accordance with an exemplary embodiment of the present invention.

[0333] Figure 9 shows: A first image 910 shows a patient's arm 912 illuminated with near-IR illumination. The near-IR illumination allows for the capture and analysis of images that may enable the detection and measurement of veins, including optionally collateral veins. The first image 910 also shows a fistula 914; A second image 920 shows the patient's arm 922 illuminated with structured light. The structured light allows for images to be taken and analyzed, which may allow for 3D analysis of the shape of the arm and may allow for detection of vibrations and / or pulsations of the arm or fistula. The second image 920 also shows the fistula 924; a third image 930 showing the 3D shape of the patient's arm 932. The representation of the 3D shape is, by way of non-limiting example, a point cloud image and / or equal height contours; a fourth image 940 showing a 3D contour of the patient's arm 942, e.g., showing a ridge 944 of the patient's arm 942; and A fifth image 950 showing a projection 952 of the shape change projected onto the patient's arm.

[0334] Monitoring the shape of a patient's fistula allows for the potential detection of aneurysms and / or edema.

[0335] In some embodiments, the image analysis and shape change detection is performed on at least two images taken at different stages during the arm lifting test, hi some embodiments, alignment of arm shape features potentially allows for comparison of two images taken at different arm lifting times.

[0336] Reference is now made to FIG. 10, which is a simplified diagram of laser vibrometry used to "listen" to the fistula, according to an exemplary embodiment of the present invention.

[0337] Figure 10 shows: A first image 1010 in which vibration measurements are used on a patient's arm 1012. An area 1014 of the patient's arm 1012 is illuminated with coherent light, which potentially allows for accurate vibration measurements of specific areas of the patient's arm and / or accurate detection of changes in blood flow in specific areas of the patient's arm. A second image 1020 in which a pattern is projected onto the patient's arm 1022, potentially allowing for area vibration measurements, vibration and / or pulsatility and / or mapping of measurements obtained by analyzing one or more images to an area of ​​the patient's arm. Monitoring such an area potentially allows for the detection of potential locations for inserting a needle into the patient's arm; A third image 1030 showing optional pulsatility or vibration mapping 1032 of the patient's arm. In some embodiments, the mapping includes projecting spots with different intensities and / or different colors based on calculated values ​​for pulsatility and / or vibration at the location of the spots. A fourth image 1040 showing an optional projection of pulsatility or vibration mapping 1044 onto the patient's arm, optionally marking areas where pulsatility or vibration is greater than a threshold level.

[0338] Reference is now made to FIG. 11, which is a simplified diagram of laser speckle vibrometry used to assess vibrations, according to an exemplary embodiment of the present invention.

[0339] Figure 11 shows: a first image 1100 showing a system 1104, such as system 100 shown in FIG. 1 and / or system 800 shown in FIG. 8, being used to assess a patient's arm by projecting light onto an area 1102 of the patient's arm; a second image 1110 showing a speckle-acquired image of area 1112; a third image 1120 showing a micro-vibration 1122 of the area 1112 of the second image 1110; A fourth image 1130 shows spectral analysis graphs 1134, 1136, 1144, and 1146. The fourth image 1130 shows two spectral analysis graphs 1134, 1136 in the high-frequency region corresponding to spectral analysis in the pitch region, typically at frequencies of 50 Hz or higher, or even 100 Hz, which may enable blood flow analysis, and two spectral analysis graphs 1144, 1146 in the low-frequency region corresponding to spectral analysis in the pulse region, typically at frequencies of 100 Hz or lower, or even 50 Hz, which may enable analysis of the patient's pulse. In some embodiments, the aforementioned pitch region corresponds to frequencies in the vascular noise range. In some embodiments, the aforementioned pulse region corresponds to frequencies in the thrill range.

[0340] Laser speckle vibrometry potentially allows for the assessment of one or more of tremors, pitch (flow and / or bruits), pulsatility, pulse strength and / or thrill.

[0341] In some embodiments, features extracted from one or more of the imaging modalities mentioned above are optionally used to train a machine learning algorithm to assess the likelihood of stenosis.

[0342] In some embodiments, a visible light source built into the hybrid DLP platform is optionally used to assist the caregiver and / or patient by projecting a layer of information and / or GUI elements onto the patient's arm.

[0343] Reference is now made to FIG. 12, which shows a simplified diagram of various projections onto a patient's arm, in accordance with an exemplary embodiment of the present invention.

[0344] Figure 12 shows: A first image 1210 showing a sample GUI projection onto a patient's arm. The first image 1210 shows a first candidate area 1212 for using the needle for inflow, a second candidate area 1216 for using the needle for outflow, a third area 1214 marked "Do Not Needle", and a fourth area onto which suggested treatment instructions will be projected; A second image 1220 in which multiple light spots are projected onto the patient's arm 1222, marking areas 1224 analyzed as having pulsatility or vibration or other calculations described herein greater than a specified threshold. In some embodiments, the light spots are optionally projected with an intensity and / or color corresponding to the value of the pulsatility / vibration / calculation. A third image 1230 shows vascular mapping projected onto the patient's arm. The vascular mapping potentially assists needle insertion into the vascular access location. The mapping may include annotations; A fourth image 1240 in which real-time physiological monitoring data is projected onto the patient's arm.

[0345] It is noted that area 1224 may be a good candidate for puncture and is potentially the area selected for puncture planning. Area 1224 may also indicate where the fistula is located.

[0346] In some embodiments, one or more of the first candidate area for using a needle for inflow 1212, the second candidate area for using a needle for outflow 1216, and the third area marked "do not puncture" 1214 are optionally determined automatically based on one or more of the following: the distance from one candidate area to another; the distance from where the fistula is located on the patient's arm based on historical or previous data; A plan to allocate candidate locations for future needle punctures; and Optionally, plan to reuse previous fistula location.

[0347] It is noted that candidate areas to be marked for puncture, such as first candidate area 1212 and second candidate area 1216 in image 1201, may be marked by illuminating the candidate area, by illuminating a line outlining the area, by illuminating an area surrounding the candidate area, by a symbol such as an "X" at or near the proposed location for needle insertion, and by other means of indicating the area by illumination.

[0348] Reference is now made to FIG. 13, which is a graph illustrating a receiver operating characteristic (ROC) curve for a stenosis detection model in accordance with an exemplary embodiment.

[0349] FIG. 13 shows a graph 1300 with an X-axis 1310 showing specificity and a Y-axis 1320 showing sensitivity, an ROC curve 1332, a singularity point 1334, and a line 1336 corresponding to the 50 / 50 chance that any model will get the correct result.

[0350] The singularity point 1334 in FIG. 13 is located at the specificity-sensitivity position corresponding to the best possible physical examination.

[0351] FIG. 13 shows an ROC curve 1332 of a stenosis detection model in accordance with an exemplary embodiment compared to a stenosis detected by Doppler ultrasonography.

[0352] The stenosis detection model was trained on 1139 observations (obtained from 44 patients) in a 5-fold cross-validation.

[0353] It is noted that the area under the curve (AUC) = 0.83.

[0354] Reference is now made to FIG. 14, which is a simplified flowchart illustration of a method for displaying data on a patient's arm, in accordance with an exemplary embodiment of the present invention.

[0355] The method of FIG. 14 includes: taking an image of the patient's arm (1402); analyzing the image, thereby obtaining information about the blood vessels in the patient's arm (1404); The information is displayed by projecting a light pattern onto the patient's arm (1406).

[0356] Reference is now made to FIG. 15, which is a simplified flowchart illustration of a method for mapping areas of vibration on a patient's arm, in accordance with an exemplary embodiment of the present invention.

[0357] The method of FIG. 15 includes: Illuminating the patient's arm (1502); taking an image of the patient's arm (1504); analyzing the image to obtain information about vibrations on the skin of the patient's arm (1506); and Based on the analysis, a mapping of the area of ​​vibration is displayed on the patient's arm (1508).

[0358] Reference is now made to FIG. 16, which is a simplified flowchart illustration of a method for displaying a puncture plan on a patient's arm, according to an exemplary embodiment of the present invention.

[0359] The method of FIG. 16 includes: providing historical information about the needle puncture point on the patient's arm (1602); taking an image of the patient's arm (1604); analyzing the image and historical information, thereby obtaining information about the blood vessels in the patient's arm (1606); Generate a puncture plan (1608); and The puncture plan is displayed by projecting a light pattern onto the patient's arm (1610).

[0360] Reference is now made to FIG. 17, which is a simplified flowchart illustration of a method for indicating where on a patient's arm a needle should not be inserted, in accordance with an exemplary embodiment of the present invention.

[0361] The method of FIG. 17 includes: providing historical information about the needle puncture point on the patient's arm (1702); taking an image of the patient's arm (1704); analyzing the image and historical information, thereby obtaining derived information about the blood vessels in the patient's arm (1706); determining, based on the derived information, locations on the patient's arm where needle insertion is not recommended (1708); and Indicate the areas on the patient's arm where needle insertion is not recommended (1710).

[0362] In some embodiments, the indication of locations on the patient's arm where needle insertion is not advisable is by projecting a light pattern onto the patient's arm.

[0363] Various embodiments and aspects of the present invention as described above and as claimed in the claims section below are supported by experimental and computational support in the following examples. [Example]

[0364] Illustrative general information regarding acquisition. In some embodiments, there is an optional step of calibrating the system, which is performed periodically (e.g., once a day or once a month) without the patient being present.

[0365] In some embodiments, there are generally two acquisition steps: a vibration measurement and a 3D generation step. In some embodiments, the vibration measurement is performed once per visit, and the 3D measurement is optionally performed twice: once while the hand is placed parallel to the floor, and a second time while the hand is elevated at an angle above the heart (also called the "elevation test"). In some embodiments, the elevation is performed above the heart at a height that may or may not empty the fistula.

[0366] In some embodiments, the acquisition process can be divided into subtasks that are completed to generate raw information.

[0367] The following table summarizes an example process divided by subtasks:

[0368] [Table 1]

[0369] In some embodiments, specific requirements are used for each subtask, for example, in connection with the subtask of photographing vibrations (described elsewhere herein), the lens is configured to have a large focal length.

[0370] In some embodiments, another hardware-related feature is the CCD region of interest (ROI). In some embodiments, a full ROI may limit the frame rate, whereas a limited ROI may allow for a higher frame rate.

[0371] Below are some exemplary descriptions of tasks and subtasks.

[0372] Acquisition process: Vibration: Subtask - Return to previous measurement point: The laser marks the center point, and simultaneously a picture of the fistula with the previous center point marked appears on the screen. In some embodiments, the image is the full FOV and includes both the fistula and its surroundings.

[0373] The central point is oriented on the patient's hand so that it lights up in approximately the same place as before.

[0374] The system then takes several pictures to provide a photograph of the hand and the previously targeted points, so that at the next visit there will be a record of where the measurements were taken.

[0375] Subtask - Find ROI: The lens then changes its focal length to its maximum. The laser projector continues to be pointed at the same location. The camera takes several pictures and the software, using image processing tools, identifies where the laser illumination falls within the pixel space of the image.

[0376] Subtask - Vibration Photography: The ROI may be changed from a full ROI to a restricted ROI. Reducing the number of pixels allows for photography at a higher rate.

[0377] A projector then illuminates a collection of dots, and a camera photographs them together over the course of a few seconds.

[0378] Option to move the point slightly on both axes and repeat this process.

[0379] Acquisition process: 3D modeling.

[0380] Subtask - Calibration: Occasionally (e.g., once a day or once a month, but not during the consultation itself), the system is calibrated using a calibration board. For example, a checkerboard-shaped board is used. In some embodiments, the calibration saves internal data (e.g., center or focal length) and external data (e.g., angle to the outside world) of the camera and projector.

[0381] Subtask - Structured Light: Optionally performed twice during the examination: once when the hand is parallel to the floor, and a second time when the hand is raised and the fistula is empty (or partially empty, or not empty).

[0382] During the examination itself, the patient places their hand under a projector, which takes several photographs of vertical and horizontal stripes. Using triangulation calculations and with the help of a calibration provider, depth reconstruction can be performed to extract a point cloud of the photographed hand, i.e., a collection of XYZ points in space. In some embodiments, these point clouds are used to generate a 3D object of the hand with a fistula.

[0383] In some embodiments, the entire process is fully automated.

[0384] In some embodiments, the procedure is repeated after elevating the hand above heart level to allow the blood in the fistula to drain.

[0385] In some embodiments, a potential advantage of the inventive system is that it uses both vibration photography and structured light photography, all within one unique system, while leveraging the flexibility of mechanized lenses and controlling the ROI and imaging rate.

[0386] In some embodiments, additional acquisition steps are optionally performed, such as taking three-dimensional photographs, collecting historical information, and projecting it onto the patient.

[0387] Exemplary raw data acquired during the acquisition process In some embodiments, the raw data information is obtained directly from a camera or using a processing step, hi some embodiments, the raw data information is used to generate processed information that is presented to a healthcare caregiver (e.g., a nurse) and / or used to train an ML system.

[0388] The following table summarizes exemplary raw data information obtained during different subtasks, for example.

[0389] [Table 2]

[0390] Exemplary post-processing information displayed to the user and / or ML In some embodiments, the system has two modes: a manual monitoring system mode in which a medical caregiver views post-processing information and makes decisions about the patient, and an automated monitoring system mode in which the ML system provides recommendations without the need for external human interaction.

[0391] In some embodiments, in either case, raw data information is used in both modes.

[0392] Exemplary Use of Raw Data Information in a Process

[0393] [Table 3-1]

[0394] [Table 3-2]

[0395] [Table 3-3]

[0396] [Table 3-4]

[0397] [Table 3-5]

[0398] [Table 3-6]

[0399] Exemplary System Features It should be understood that the following features are exemplary features, and that additional and / or alternative features, such as those relating to predicting stenosis using ML and displaying information by projecting light patterns onto the patient's arm, are within the scope of the present invention.

[0400] Illustrative features in "miru" Grayscale images of AVF - Two grayscale images collected from infrared laser illumination. Infrared illumination enhances vascular features compared to the human visible spectrum.

[0401] Grayscale images are taken during one visit before an arm-raising test with the arm parallel to the floor and after an arm-raising test with the arm above heart level, after a few seconds have elapsed to prevent rapid changes in the AVF.

[0402] The caregiver can view the grayscale images before and after the arm lift test on two different screens, for example by using the buttons on the main menu to toggle between the screens.

[0403] A caregiver can view and compare grayscale images of the AVF from a previous visit on a previous day. The comparison may be performed by viewing a grayscale image from the current visit for one image with a grayscale image from a previous visit for another image. The images may be displayed side by side on a single screen, for example.

[0404] Alternatively, the grayscale image obtained in the current visit and the grayscale image obtained in the previous visit may be displayed in one view.

[0405] 3D Shape of AVF - 3D contour images of the arm and fistula before and after the arm lift test. The 3D image can be freely rotated and specified in the XY, XZ, or YZ plane.

[0406] 3D images obtained in previous examinations can be compared as described in grayscale images.

[0407] Illustrative features of "listen": Vibration Spectrum: The vibration spectrum graph displays the FFT transform of the temporal vibration signal as described in "Recordings." In an exemplary embodiment, the x-axis of the signal may be limited to between 20 Hz and 1000 Hz. Spectra from previous visits may also be displayed.

[0408] In some embodiments, additional measurements (listed below) may be provided. Each measurement may be in the form of a plot, with the x-axis being the consultation time and the y-axis being the corresponding value. Trends in changing values ​​may be observed. Optionally, the system may provide recommendations based on the measurements.

[0409] Such measurements can be, for example: A maximum frequency index above a minimum index, such as 250 Hz. An increase in the maximum frequency index may indicate a stenosis. The ratio of the maximum value above a minimum index, such as 250 Hz, to the maximum value below a minimum index, such as 50 Hz. In other words, the energy at high abnormal frequencies is normalized to the energy at low normal frequencies. An increase in this value may indicate a stenosis. The FWHM (width corresponding to half the value) of the maximum frequency index, as described herein above. A decrement in this value may indicate a narrowing.

[0410] Recording: The optical vibrometry is converted into an audible form, allowing you to listen to recordings of the vibrations from the current visit and previous visits by toggling between them.

[0411] Illustrative features of "feel": Heart rate estimates from the current visit and previous visits may be compared on a graph, with the x-axis being the visit date and the y-axis being the heart rate in beats per minute (bpm), which is limited to human bpm values, such as 30-150 bpm.

[0412] [Table 4-1]

[0413] [Table 4-2]

[0414] [Table 4-3]

[0415] While particular implementations have been disclosed in detail herein, this has been done by way of example for purposes of illustration only and is not intended to be limiting with respect to the scope of the following claims. In particular, it is contemplated that various substitutions, alterations, and modifications may be made therein without departing from the spirit and scope of the present disclosure, as defined by the claims. Other aspects, advantages, and modifications are believed to be within the scope of the following claims. The claims presented are representative of implementations and features disclosed herein. Other unclaimed implementations and features are also contemplated. Accordingly, other implementations are within the scope of the following claims.

[0416] It is anticipated that many related image processing algorithms will be developed during the life of the patent arising from this application, and the scope of the term image processing is intended to pre-emptively include all such new techniques.

[0417] When used herein in connection with a quantity or value, the word "approximately" means "within ±15% of."

[0418] The words "comprise," "include," "have," and their conjugations mean "including, but not limited to."

[0419] The word "consisting of" is intended to mean "including, but not limited to."

[0420] The phrase "consisting essentially of" means that a composition, method, or structure may include additional ingredients, steps, and / or parts, provided that the additional ingredients, steps, and / or parts do not materially alter the basic and novel characteristics of the claimed composition, method, or structure.

[0421] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. For example, the word "a unit" or "at least one unit" may include a plurality of units, including combinations thereof.

[0422] The words "example" and "exemplary" are used herein to mean "serving as an example, instance, or illustration." An embodiment described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments and / or as excluding the inclusion of features from other embodiments.

[0423] The word "optionally" is used herein to mean "provided in some embodiments and not provided in other embodiments." Particular embodiments of the invention may include multiple "optional" features unless such features conflict.

[0424] Throughout this application, various embodiments of the present invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and intermittency and should not be construed as an inflexible limitation on the present invention. Accordingly, the description of a range should be considered to have specifically disclosed all possible subranges as well as individual numerical values ​​within that range. For example, the description of a range such as 1 to 6 should be considered to have specifically disclosed subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., as well as individual numbers within that range, e.g., 1, 2, 3, 4, 5, and 6. This is true regardless of the broadness of the range.

[0425] When a numerical range is given herein (e.g., "10-15," "10 to 15," or any pair of numbers joined by these range designators), it is intended to include any number (decimal or integer) within the stated range limits, inclusive of the range limits, unless the context clearly dictates otherwise. The phrase "ranging between" a first designated number and a second designated number, and the phrase "ranging from" a first designated number to a second designated number "up to," "up to," or "through" (or another similar range term), are used interchangeably herein and are intended to include the first designated number and the second designated number and all decimals and integers therebetween.

[0426] Unless otherwise indicated, numbers and numerical ranges used herein are approximations within the accuracy of reasonable measurement and rounding errors, as will be understood by those skilled in the art.

[0427] It will be appreciated that certain features of the invention that are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as appropriate in other described embodiments of the invention. A particular feature described in the context of various embodiments should not be construed as an essential feature of those embodiments, unless the embodiment cannot function without that element.

[0428] While this disclosure has been described in conjunction with specific embodiments thereof, it is evident that many alterations, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alterations, modifications, and variations that fall within the spirit and broad scope of the appended claims.

[0429] It is the intention of the applicant that all publications, patents, and patent applications referenced in this specification, when stated to be incorporated herein by reference, are incorporated herein by reference in their entirety to the same extent as if each individual publication, patent, and patent application was specifically and individually indicated to be incorporated herein by reference. Furthermore, citation or identification of a reference in this application should not be construed as an admission that such reference is available as prior art to the present invention. To the extent section headings are used, they should not be construed as necessarily limiting. Additionally, the priority documents of this application are incorporated herein by reference in their entirety. [Explanation of symbols]

[0430] 100 systems 102 detectors, cameras 104 Illumination source 106 Control Unit 108 processors 110 Display 112 Arm 202 Detection Unit 204 workstations 206 Software Unit 208 Cloud Infrastructure 210 Detectors, sensors, cameras 212 Lens 214 Lighting 216 Audio / Sound Detection Sensor 220 Computer 224 Display 226 Organ Fixation Surface or Device 228 Stand 230 Embedded Unit 232 GUI Unit 234 Algorithm Unit 236 Web Application Server 240 servers 300 System 302 Imaging / Detection Unit 304 workstations 306 Software / Calculation Unit 308 Cloud Infrastructure 310 Sensors 312 Lens 313 Filters 314, 316 Illuminators 322 Computer 324 Display 325 Projector 326 Organ Fixation Surfaces and Devices 328 Stand 334 GUI 335 Image Processing Unit 336 Computer Vision Unit 337 Machine Learning Algorithms Unit 338 Web Applications 340 databases 342 Analysis Unit 702, 704 axes 706, 708 Group 800 System 802 detector 804 Illumination Sources, Projection Components 810, 820, 830, 840 Features 832 Patient's arm 834 Color Mark 910, 920, 930, 940, 950 images 912, 922, 932, 942 Patient's arms 914, 924 Fistula 952 Projection 1010, 1020, 1030, 1040 images 1012, 1022 Patient's arm 1014 Area 1032, 1044 mapping 1104 System 1100, 1120, 1130 images 1102, 1112 area 1122 Microvibration 1134, 1136, 1144, 1146 Spectral analysis graph 1210, 1220, 1230 images 1212, 1214, 1216, 1224 areas 1222 Patient's arm 1300 graphs 1310, 1320 axes 1332 ROC curve 1334 Singularity 1336 line

Claims

1. 1. A method for displaying data on a patient's arm, comprising: taking an image of the patient's arm; analyzing the image to thereby obtain information regarding the blood vessels of the patient's arm; and displaying the information by projecting a light pattern onto the patient's arm.

2. The method of claim 1 , wherein the projecting step includes projecting using a digital light processing (DLP) projector.

3. 3. The method of claim 1, wherein the information comprises a mapping of skin vibrations on the patient's arm.

4. The method of claim 1 , wherein the information includes a mapping of blood vessels in the patient's arm.

5. The method of claim 1 , wherein the information comprises a mapping of the pulsatility of the patient's arm.

6. The method of claim 1 , wherein the information includes a proposed location of an inflow needle puncture point on the patient's arm.

7. The method of claim 1 , wherein the information includes a proposed location of an outflow needle puncture point on the patient's arm.

8. The method of claim 1 , wherein the information includes suggested no needle insertion locations.

9. The method of claim 1 , wherein the information comprises a treatment indication.

10. The method of claim 1 , wherein the information comprises numerical data generated as a result of the analysis.

11. The method of claim 1 , wherein the information comprises a puncture plan.

12. The method of claim 11 , wherein the puncture planning is based on an analysis of two or more images, at least two of the images used in the analysis being taken at different times.

13. The method of claim 12 , wherein the puncture plan suggests locations for inflow and outflow needle puncture points based on historical information about previous puncture points.

14. the step of capturing an image of the patient's arm includes capturing a plurality of images of the patient's arm; The method of claim 1 , wherein the step of analysing the image comprises analysing the plurality of images.

15. 1. A system for displaying data on a patient's arm, comprising: a light source for illuminating the patient's arm; a sensor for taking an image of the patient's arm; a computer for analyzing the images to thereby obtain information regarding the blood vessels of the patient's arm; a projector for displaying the information by projecting a light pattern onto the patient's arm.

16. 16. The system of claim 15, wherein the light source comprises a laser illuminator positioned to illuminate an area of ​​the patient's arm.

17. 16. The system of claim 15, wherein the light source comprises a laser illuminator positioned to illuminate an area of ​​the patient's arm with a pattern of spots.

18. 18. The system of claim 15, wherein the light source comprises a source of structured light.

19. 19. The system of claim 15, wherein the projector includes a source of structured light.

20. 20. The system of claim 15, wherein the projector comprises a digital light processing (DLP) projector.

21. 20. The system of claim 18, wherein the source of structured light comprises a DLP projector identical to the projector of claim 20.

22. 1. A method of mapping areas of vibration on a patient's arm, comprising: illuminating the patient's arm; taking an image of the patient's arm; analyzing the images to obtain information about vibrations on the skin of the patient's arm; and displaying a mapping of areas of vibration on the patient's arm based on the analysis.

23. 23. The method of claim 22, wherein the illuminating step comprises illuminating using coherent light.

24. 24. The method of any one of claims 22 to 23, wherein the illuminating step includes illuminating an area of ​​the patient's arm.

25. 25. The method of any one of claims 22 to 24, wherein the illuminating step comprises illuminating using structured light.

26. 26. The method of any one of claims 22 to 25, wherein the illuminating step comprises illuminating with a digital light processing (DLP) projector.

27. 27. The method of any one of claims 22 to 26, wherein the information comprises a mapping of skin vibrations on the patient's arm.

28. 28. The method of any one of claims 22 to 27, further comprising displaying the information by projecting a light pattern onto the patient's arm.

29. 30. The method of claim 28, wherein the step of displaying the information includes displaying a mapping of the information relative to vibrations on the skin of the patient's arm.

30. 30. The method of claim 29, wherein displaying the mapping includes displaying where the vibrations on the skin of the patient's arm exceed a threshold level of vibration.

31. 31. The method of any one of claims 29 to 30, wherein displaying the mapping comprises displaying the mapping in registration with the patient's arm.

32. the step of capturing an image of the patient's arm includes capturing a plurality of images of the patient's arm; 32. The method of any one of claims 22 to 31, wherein the step of analysing the image comprises analysing the plurality of images.

33. 1. A system for mapping areas of vibration on a patient's arm, comprising: a light source for illuminating the patient's arm; a sensor for taking an image of the patient's arm; a computer for analyzing the images to thereby obtain information regarding vibrations of the patient's arm.

34. 34. The system of claim 33, wherein the light source comprises a laser illuminator positioned to illuminate an area of ​​the patient's arm.

35. 34. The system of claim 33, wherein the light source comprises a laser illuminator positioned to illuminate an area of ​​the patient's arm with a pattern of spots.

36. 35. The system of any one of claims 33 to 34, wherein the light source comprises a source of structured light.

37. 37. The system of any one of claims 33 to 36, further comprising a projector for displaying the information by projecting a light pattern onto the patient's arm.

38. 38. The system of claim 37, wherein the projector includes a source of structured light.

39. 39. The system of any one of claims 37 to 38, wherein the projector comprises a digital light processing (DLP) projector.

40. 40. The system of claim 36, wherein the source of structured light comprises a DLP projector identical to the projector of claim 39.

41. A method for displaying a puncture plan on a patient's arm, comprising: providing historical information regarding needle puncture points on the patient's arm; taking an image of the patient's arm; analyzing the images and the historical information to thereby obtain information about the blood vessels of the patient's arm; generating a puncture plan; and displaying the puncture plan by projecting a light pattern onto the patient's arm.

42. 42. The method of claim 41, wherein the historical information includes an image of the patient's arm taken before the step of taking the image of the patient's arm.

43. 43. The method of any one of claims 41 to 42, wherein the historical information includes an image of the patient's arm taken more than two days before the step of taking the image of the patient's arm.

44. 1. A method for indicating where on a patient's arm a needle should not be inserted, comprising: providing historical information regarding needle puncture points on the patient's arm; taking an image of the patient's arm; analyzing the images and the historical information to thereby obtain derived information regarding the blood vessels of the patient's arm; determining, based on the derived information, locations on the patient's arm where needle insertion is not recommended; and indicating locations on the patient's arm where needle insertion is not recommended.

45. 45. The method of claim 44, wherein the step of indicating locations on the patient's arm where needle insertion is not recommended comprises by projecting a light pattern onto the patient's arm.

Images