Volumetric interventional tool tracking and patient monitoring method and apparatus

Abstract

An interventional tool tip tracking system includes a sensor support structure; a plurality of ultrasound elements attached to the sensor support structure and arranged in an array pattern, each ultrasound element of the plurality of ultrasound elements being configured to receive an acoustic signal generated from an acoustic source proximate an interventional tool tip within a volume of interest and to provide a corresponding plurality of detection signals; and a data processing device configured to receive the corresponding plurality of detection signals from the plurality of ultrasound elements and to determine a position of the interventional tool tip in the volume of interest from the plurality of detection signals. Each ultrasound element of the plurality of ultrasound elements has a diameter and an arrangement in the array pattern to provide a combined detection coverage corresponding to the volume of interest.

Description

Att’y Ref. : 2240-615468 Applicant Ref.: Pl 7912-02VOLUMETRIC INTERVENTIONAL TOOL TRACKING ANDPATIENT MONITORING METHOD AND APPARATUSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present patent application claims priority benefit to U.S. Provisional Patent Application No. 63 / 689,340, filed on August 30, 2024, the entire content of which is incorporated herein by reference. All references cited anywhere in this specification, including the Background and Detailed Description sections, are incorporated by reference as if each had been individually incorporated.BACKGROUND1. Technical Field

[0002] The currently claimed embodiments of the present invention relate to systems and methods for interventional tool tracking and patient monitoring.2. Discussion of Related ArtClinical needs

[0003] Vascular access is the most common medical procedure in the world, with over a billion insertions performed annually. [1], [2] In the United States, over 350 million peripheral intravenous (IV) catheters are sold yearly, in addition to millions of central and arterial lines. [3] Peripheral IV placement often requires several attempts at insertion, which is painful, time consuming, and associated with increased complications. Furthermore, there is a high rate of early failure related to peripheral IV insertion, which can lead to further complications, including extravasation, thrombophlebitis, and compartment syndrome (which can be limb and life threatening), as well as delays in delivery of therapeutic medications. [4], [5] Improving the success rate for vascular access will have a huge impact on patient care and patient safety both for peripheral and central vascular access, as well as during cardiac catheterization, interventional radiology, cardiac surgery, and during ECMO cannulation. Accurate needle, catheter and tool trackingAtt’y Ref.: 2240-615468Applicant Ref.: Pl 7912-02 during medical procedures is a crucial task that directly affects the safety and effectiveness of many interventional procedures, including vascular access. Also, the clinical procedures have been heavily based on trained clinicians, which has caused accuracy deviations dependent on the user’s proficiency. There is also an urgent need for technology assisted devices that can learn the necessary intracorporeal tool trajectory and desired outcome, enabling increasing automation to progressively lower the user dependency. This direction may eventually enhance the procedural success rate while lowering clinicians’ workload. The target to be tracked would span a specific vessel or other endogenous target a clinician specified or is ultimately learned and automated by the device, no longer restricted to an intracorporeal tool.Available clinical modalities for tool tracking

[0004] With improving quality, decreasing cost, and an ever-smaller size, point-of-care ultrasound (US) has emerged as an indispensable tool for procedural guidance. In fact, US is becoming the new standard for procedures such as tissue biopsy, thoracentesis, regional anesthesia, and central vascular access. [6]-[9] US-guided peripheral intravenous catheter placement is also expanding and has been shown to improve cannulation success over palpation and visualization, reduce the need for central line placement, and is associated with higher patient satisfaction.

[0010] -

[0013] US-guided peripheral vascular access is now being taught in medical school.

[0014] ,

[0015]

[0005] In addition to improving peripheral and central vascular access success rates, US-guided vascular access has also been shown to decrease cannulation time for emergent veno-arterial extracorporeal membrane oxygenation VA-ECMO cannulation in refractory cardiac arrest.

[0016] Increased utilization of US imaging has been shown to reduce complications vascular access for vascular surgical procedures.

[0017] Despite the increasingly widespread use of US for procedural guidance, reliable, accurate tracking of the device can be challenging even for practitioners with years of experience; needle tip tracking is especially difficult and is critical for avoiding vital structures that can cause catastrophe.

[0018] —

[0020] At best, inability to track the needle tip can lead to procedural failure, which increases discomfort and pain for patients, wastes equipment and time, and increases cost. At worst, it can lead to such complications as bleeding, infection, pseudoaneurysm, pneumothorax, pericardial tamponade, and death.

[0021] ,

[0022] While utilization of US imaging for procedural guidance is appropriately increasing, there is clearly room for improvement as meta-analysis for US-guided peripheral IV showed only an 81% success rate.

[0010]

[0006] Specifically, conventional US techniques suffer from the following issues: (a) Reduced visualization of interventional tools (i.e., needle tips and catheters) or endogenous targets due to low contrast resolution. The echo signal strength determines object visualization. Needles and catheters areAtt’y Ref.: 2240-615468Applicant Ref.: Pl 7912-02 typically made of homogenous materials and their echo appearance mainly comes from reflection, which depends on acoustic impedance mismatch and the relative orientation between the tool and the insonification direction. As a result, the tool is visible in the US image only when the reflection is directed to the probe. In most clinical conditions, the needle is inserted with an angle with respect to the probe lateral direction. Obviously smaller needles with smaller localized reflection are harder to detect. Also, endogenous targets (e.g., arterial / venous vessels) do not have high contrast resolution over the surrounding targets, and tracking should involve sophisticated image-based tracking algorithms, (b) Lack of off-plane tracking. From the most used 2D US images, clinicians cannot determine the interventional tool trajectory or endogenous target positions before it intersects with the US image plane, (c) Image plane thickness. The US image plane has a thickness of a few millimeters to over a centimeter, depending on the probe type and depth. As a result, any reflected signal within this thickness will be shown in the image, leading to a localization uncertainty equals to half of the beam thickness. However, such an error can be too large for applications with large gauge needles and small targets, (d) Difficulty of tip identification of curved tools or endogenous targets tracking. Large gauge needles and catheters and endogenous tissue compartments are not rigid and can bend during insertion, making it difficult to track with in-plane US imaging approach. Also, endogenous targets usually have complex structure and deformable features in volume, which makes challenges for naive or less trained users. Software may provide tracking but requires sophisticated processing disadvantageous in cost-efficient form factors for vendor-independency or wearable form factor. There is active research and US-guidance technologies to address some of these limitations, which we describe in more detail in the innovation section with comparison to our proposed invention.Available methods to localize tools in US image

[0007] Accurate tool / catheter tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures including vascular access. Before describing concepts of the current invention, it is important to summarize the state-of-the-art and highlight deficiencies. In recent years, several approaches have been proposed to enable tool visualization and pose recovery under US guidance including beam steering, electromagnetic (EM) tracking, and passive markers.

[0008] The beam steering approach has been developed and validated by several research groups and currently is integrated into a commercial ultrasound scanner from SonoSite Inc. The basic principle is to steer the imaging beam directions to get the optimized reflection from the catheter / tool. It has been proven effective when the tool is rigid, is in-plane, and has acoustic impedance mis-match with surrounding tissue. For cases where catheters simply intersect the imaging plane in- and out-of-plane with a large angle, this image enhancement method doesn’t work.Att’y Ref. : 2240-615468 Applicant Ref.: Pl 7912-02

[0009] Electro-magnetic (EM) tracking approach was recently introduced and integrated into several commercial ultrasound scanners (GE LOGIQ E9, Ultrasonix GPS, etc.). In this approach, an EM field is generated by an EM emitter; EM sensors are implanted in both the catheter and the imaging probe. The relative pose of the catheter is estimated and injected as a graphic overlay to the B-mode image. However, several disadvantages limit its applications to all interventions: the overall navigation accuracy can easily be worse than 3~5mm; it requires specially designed imaging equipment to accommodate the extra H / W from the tracking system; it has an intrusive setup that interrupts the clinical workflow; it is an expensive setup that requires frequent calibration; and any ferromagnetic object in the operation region may affect the system accuracy. This technology failed to penetrate the vascular access market but has been useful for tool tracking, especially in electrophysiology suites where the equipment is fixed and incorporated into the table and fluoroscopy system.

[0010] Some researchers and companies focus on the visualization enhancement of the coded catheter in B-mode US images. One approach is to improve image quality by using passive US markers. In this method, US markers, sometimes in the form of scattering coatings, are integrated into the tool to improve the echo amplitude. The major issue of this approach is that the visualization enhancement by scattering coating is limited and is affected by the insonification angle, size of the tool, depth, and surrounding medium. These echogenic catheters exist in the regional anesthesia market but are not commonly used for vascular access. However, it is impossible to identify the relative location of the tip with respect to the midplane of the probe. Additionally, doctors are dissatisfied with this passive technology as it only shines under specific imaging conditions.

[0011] Consequently, there remains a need for improved systems and methods for interventional tool tracking and patient monitoring.SUMMARY

[0012] An interventional tool tip tracking system according to an embodiment of the current invention includes a sensor support structure; a plurality of ultrasound elements attached to the sensor support structure and arranged in an array pattern, each ultrasound element of the plurality of ultrasound elements being configured to receive an acoustic signal generated from an acoustic source proximate an interventional tool tip within a volume of interest and to provide a corresponding plurality of detection signals; and a data processing device configured to receiveAtt’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02 the corresponding plurality of detection signals from the plurality of ultrasound elements and to determine a position of the interventional tool tip in the volume of interest from the plurality of detection signals. Each ultrasound element of the plurality of ultrasound elements has a diameter and an arrangement in the array pattern to provide a combined detection coverage corresponding to the volume of interest.

[0013] An interventional tool tip tracking and tissue typing system according to an embodiment of the current invention includes a multi wavelength light source; an optical fiber optically coupled to the multi wavelength light source, the optical fiber being suitable to be attached to an interventional tool with a light emission end arranged at a tool tip of the interventional tool to emit light therefrom to interact with tissue within a volume of interest; a sensor support structure that includes a plurality of ultrasound elements attached thereto and arranged in an array pattern, wherein each of the plurality of ultrasound elements is configured to receive photoacoustic signals when generated by the emitted light from the light emission end of the optical fiber and provide a corresponding plurality of detection signals; and a data processing device configured to receive the corresponding plurality of detection signals from the plurality of ultrasound elements by photoacoustic signals generated from a plurality of wavelengths from the multi wavelength light source. The data processing device is further configured to determine a position of the tool tip, and the data processing device is further configured to determine a tissue type within the volume of interest.

[0014] An ultrasound system according to an embodiment of the current invention includes an ultrasound probe, an ultrasound image processor configured to receive ultrasound signals from the ultrasound probe and to provide ultrasound image signals, an image display configured to receive the ultrasound image signals and to display an ultrasound image based thereon, and at least one of an interventional tool tip tracking system according to any one of embodiments of the current invention or an interventional tool tip tracking and tissue typing system according to any one of the current invention. The image display is configured to communicate with the data processing device and to display information concerning the interventional tool tip position and a tissue type along with the ultrasound image.Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Embodiments of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.

[0016] FIG. 1 is a schematic illustration of an interventional tool tip tracking system according to an embodiment of the current invention. The tool tip tracking system is a wearable system.

[0017] FIGS. 2A and 2B are schematic illustrations of an interventional tool tip tracking system according to another embodiment of the current invention, allowing flexible placement of tracking elements on top of patient body under the optical tracking camera. Any number of modules, more than 3, will allow the volumetric triangulation of the tool tip.

[0018] FIGS. 3A and 3B are schematic illustrations showing an example of a wearable tool tip tracking and tissue typing system according to an embodiment of the current invention.

[0019] FIGS. 4A-4D are schematic illustrations to explain a vendor-independent tool tip tracking and tissue typing system according to an embodiment of the current invention. This is also referred to as a vendor-independent 5T (tool tip tracking + tissue typing)-IV guidance system for vascular access. FIG. 4A: (a) Illustrates a system configuration in a conventional US-based vascular access guidance. FIG. 4B: (b) Illustrates a bracket system to triangulate needle tip position while hijacking imaging sequence of the clinical US system according to an embodiment of the current invention. FIG. 4C: (c) Is an example of an image display for real-time needle tip localization with in-pane indicator and concurrent tissue typing according to an embodiment of the current invention. FIG. 4D: (d) Is a schematic illustration of a universal bracket system design to be used in various US transducer dimension according to an embodiment of the current invention.Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02

[0020] FIGS. 5-8 illustrate some embodiments of trigger hijackers according to the current invention.

[0021] FIG. 9A shows a field-of-view simulation setup for single tracking element and FIG. 9B is a fitted Gaussian curve in radial direction for the design of an interventional tool tip tracking system according to an embodiment of the current invention.

[0022] FIGS. 10A-10B show that overlapped width (w) indicate the effective tracking FOV at the target depth, and width of the shared effective tracking area of two PA receivers at various depths and various PA receiver separations, respectively, according to an embodiment of the current invention.

[0023] FIG. HA shows elliptic tracking contour with different number of tracking elements and angular offset according to an embodiment of the current invention. (Left) Three tracking elements with 30-degree offset, (middle) Four tracking elements with 45-degree offset, (right) Four tracking elements with 0-degree offset. FIG. 11B shows target configuration for each depth.

[0024] FIGS. 12A-12C show tracking error of each PA source at various depth and SNR of (FIG. 12A) 4 dB, (FIG. 12B) 6 dB, and (FIG. 12C) 8 dB, according to an embodiment of the current invention.DETAILED DESCRIPTION

[0025] Some embodiments of the current invention are discussed in detail below. In describing embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. A person skilled in the relevant art will recognize that other equivalent components can be employed, and other methods developed, without departing from the broad concepts of the present invention. All references cited anywhere in this specification are incorporated by reference as if each had been individually incorporated.Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02

[0026] The phrase “window defined by the acoustic coupling structure” is intended to refer to a space or a gap that is suitable for the tip of the interventional tool to pass through into the volume of interest.

[0027] The terms “optical” and “light” are intended to have broad meanings that can include visible and non-visible regions of the electromagnetic spectrum, such as, but not limited to, infrared and ultraviolet light in addition to visible light.

[0028] The term “optical” fiber is intended to include any type of light guide that has appropriate dimensions to be attached to, and used with, the interventional tool of interest.

[0029] Some embodiments of the current invention are directed to volumetric tool tracking technology and the corresponding design process to guarantee the tracking accuracy in practical clinical circumstances. This technology can be implemented in multiple ways. For example, current ultrasound (US) image-guidance systems can be augmented to track the tool in volume. Also, a wearable device can be implemented for robotic assisted or autonomous intervention, as well as patient monitoring.

[0030] An embodiment of the current invention can include a guidance device that has multiple elements to estimate an exact position of an intracorporeal tool (e.g., needle, biopsy device, catheter, etc.) with considerations in tracking accuracy and field-of-view (FOV) for appropriate guidance of the clinical interventions. Mutual communication between tool and the guidance system can be implemented in different configurations: (a) tool talking, guidance system listening; (b) tool listening, guidance system talking; (c) tool talking / listening, guidance system listening / talking. To implement the guidance systems according to some embodiments, several parameters are specifically considered: Individual multiple element sizes and volumetric position / angle in the system would determine the overall FOV by changing the overlap in the target volume among the element directivity angle; distance among elements will decide the tracking accuracy; the number of elements will decide the overall signal sensitivity and system complexity. Such a versatile and effective design process can support a wide range of system form factors, including assistive or autonomous interventional, as well as patient monitoring devices.Att’y Ref.: 2240-615468Applicant Ref.: Pl 7912-02

[0031] Some embodiments address unmet needs for tool tip tracking and tissue typing, referred to as ‘5T-IV’ platform here. Two different types of embodiments can either (a) to augment the currently existing US imaging devices with a peripheral system that can be attached to the clinical US transducer or (b) to implement a wearable device for continuous patient monitoring or instant autonomous vascular access either within hospital or at patient’s home. However, the general concepts of the current invention are not limited to only those embodiments.

[0032] Some embodiments can be implemented using common system compartments. 1) multi-element ultrasound system either peripheral to the commercial US device or standalone, 2) design process to secure appropriate target tracking performance (e.g., FOV, spatial accuracy, signal sensitivity), 3) mutual communication with target (tool or target), 4) software to continuously track the target region. There is an optional feature for tissue characterization using photoacoustic (PA) sensing either by extracorporeal light source for wide FOV or by intracorporeal light guide, fed by external light source, embedded in the injection tool for specific optical biopsy. In this case, integration of additional system compartments to the injection tool will be needed: 4) multi -wavelength light source and light guide optimized in spectral ranges for hemoglobin oxygen & quantity and / or exogenous contrast agent; 5) software to analyze a range of tissue properties for tissue typing using acoustic and optical properties of the target. For example, the software may analyze multi-parametric features to differentiate diseased tissue (contrast agent or low oxygenation) or to differentiate the status of target region whether it is solid (tissue) or liquid (blood). These differentiations may be used to guide the vascular access or biopsy procedures or analyze the patient condition. On the other hand, hardware synchronization between light source and US imaging device is needed for target tracking by calculating time-of- flight (TOF) to multiple tracking elements, but it might not be available in some clinical US imaging systems. In this case, 6) a trigger hijacker can be introduced to detect the US transmittance from the clinical US device and to understand the timing of the first scanline scanning and the time interval to the next scanline. It can be done with different modalities in acoustic and electromagnetic modalities. This information can be used to run the light source to implement the synchronization to the US imaging device, which makes entire workflow vendor independent.

[0033] There are several general parameters to be considered when designing the guidance system: Individual multiple element sizes would determine the overall FOV by changing theAtt’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02 overlap in the target volume among the element directivity angle; distance among elements will decide the tracking accuracy; the number of elements will decide the overall signal sensitivity and system complexity. Such a versatile and effective design process will support wide range of system form factors, including assistive or autonomous interventional or patient monitoring devices.

[0034] Mutual communication between tool and the guidance system can be implemented in different configurations: (a) tool talking, guidance system listening; (b) tool listening, guidance system talking; (c) tool talking / listening, guidance system listening / talking. The idea of toolimager communication can be seen in the following patents issued to the same assignee as the current application (US 11,229,418 in 2022; 10,932,751 in 2021; 10,806,346 in 2020; 10,105,186 in 2018; 9,723,995 in 2017; 9,636,083 in 2017, all of which are incorporated herein by reference).

[0035] The tool for injection (e.g., needle or catheter) can be implemented through either wired or wireless communication to the imaging module for synchronization to calculate the acoustic time-of-fhght to tracking elements in the guidance system, for example.

[0036] FIG. 1 is a schematic illustration of an interventional tool tip tracking system 100 according to an embodiment of the current invention. The interventional tool tip tracking system 100 includes a sensor support structure 102 and a plurality of ultrasound elements 104 attached to the sensor support structure 102 and arranged in an array pattern. Each ultrasound element, e.g., ultrasound element 106, of said plurality of ultrasound elements 104 are configured to receive an acoustic signal generated from an acoustic source proximate an interventional tool tip when it is within a volume of interest. The plurality of ultrasound elements 104 provide a corresponding plurality of detection signals. The interventional tool tip tracking system 100 further includes a data processing device 108 that is configured to receive the corresponding plurality of detection signals from the plurality of ultrasound elements 104 and is further configured to determine a position of the interventional tool tip in the volume of interest from the plurality of detection signals. Each ultrasound element of the plurality of ultrasound elements 104 has a diameter and an arrangement in the array pattern to provide a combined detection coverage corresponding to the volume of interest, as will be discussed in more detail below.Att’y Ref.: 2240-615468Applicant Ref.: Pl 7912-02

[0037] In the embodiment of FIG. 1, the sensor support structure 102 is also referred to as an acoustic coupling layer and the plurality of ultrasound elements 104 are referred to as tracking elements with one labeled as an example. The remaining plurality of ultrasound elements 104 (tracking elements in this embodiment) are represented as small circles as is self-evident from FIG. 1.

[0038] In some embodiments, each ultrasound element, such as 106, of the plurality of ultrasound elements 104 is flat and has a diameter less than 2 mm. In some embodiments, the number of the plurality of ultrasound elements is selected to provide a minimum sensitivity.

[0039] The sensor support structure 102 is configured to make contact with a portion of a subject’s body, such as, but limited to a person’s arm 110 in this example. In this embodiment, the sensor support structure 102 can be rigid with a size and shape to conform to the portion of the person’s body or could have at least some flexibility. In the case of a rigid sensor support structure 102, known relative positions of the ultrasound elements can be used by the data processing device 108. In other embodiments, the sensor support structure 102 can be flexible such as in the example of FIG. 2 A, for example. In FIG. 2 A, the positions of each of the plurality of ultrasound elements 104 can be determined using a tracking and / or imaging device, such as, but limited to, an optical tracker. FIG. 2B shows one of the potential designs for the tracking element module to support acoustic sensing by a limited number of elements per module, tissue attachment, and cascaded data / power transfer to minimize the number of the lines to external controller, data acquisition system, and drivers, etc. Multi-module integration is not limited to this embodiment. For example, the most straightforward approach could be to have wired modules. Use of other tracking methods could be options: electromagnetic field, iterative optimization using transmit / receive interrogation and analysis, etc.

[0040] In some embodiments, sensor support structure 102 defines a window 112 through which the interventional tool tip can pass into the volume of interest. In the example of FIG. 1, the volume of interest is within the person’s arm. In the example of FIG. 2, the volume of interest is within the torso region of the person. The volume of interest is not limited to these examples.

[0041] FIGS. 3A and 3B are schematic illustrations of other examples in which the system 100 can be used, for example with other mechanical scanning and / or robotic devices.Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02

[0042] In some embodiments, sensor support structure 102 can be a bracket configured to be attachable to an ultrasound probe (FIGS. 4A, 4D).

[0043] In some embodiments, the interventional tool tip tracking system 100 can include a trigger hijacker configured to be attachable to or arranged proximate an ultrasound probe and configured to communicate with the data processing device 108. (See, for example, FIGS. 4B, 4D, and 5-8.)

[0044] Some embodiments of the current invention can include tissue typing in addition to an interventional tool tip tracking system such as system 100 to provide a combined interventional tool tip tracking and tissue typing system as is illustrated in the example of FIGS. 4A-4D. These figures also schematically illustrate an example of a complete ultrasound system that includes a interventional tool tip tracking and tissue typing system according to an embodiment of the current invention.

[0045] The following describes some embodiments in more detail. The general concepts of the current invention are not limited to only these examples.Peripheral guidance system connected to clinical US device

[0046] The guidance system can be a peripheral device to clinical 2D US imaging device to expand the guidance performance to 3D area using tracking elements distributed in a plane perpendicular to the imaging plane. FIGS. 4A-4B illustrate an example of such a peripheral guidance system which assumes vascular access with a needle with an embedded optical fiber for multi-spectral PA signal generation for tool tracking and tissue typing. The peripheral guidance system could be in a bracket form factor that can be installed on an US transducer. The system can be a clip-on bracket to any US transducer to be vendor-independent in this embodiment. The trigger hijacker would recognize the image formation sequence and synchronize the light excitation timing with the data acquisition events.

[0047] The example FIGS. 4A-4D has four subsystems: (1) small-caliber IV needle subsystem with embedded fiberoptic cable (FIG. 4B); (2) coupled to the 5T-IV board containing a fiber coupled light source (e.g., pulsed laser diodes and drivers) (FIG. 4A); (3) a 5T-IV bracket (FIG. 4D) that attaches to any clinical US probe and contains multiple piezoelectric receiving elementsAtt’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02 for needle tip tracking; and (4) a compact host subsystem to control subsystems and collect, analyze multi-channel and multi -wavelength PA data, and display to clinicians. The 5T-IV bracket attached to the probe monitors the imaging US signals and signals the fiberoptic stylet when to pulse the signal, thus 2) allowing for triangulation to identify the precise location of the needle tip in volume (FIG. 4C); 2) creating the beacon pulse that is perceived as a flashing dot on the imaging US representing the needle tip (FIG. 4C (left)); and 3) enabling tissue typing (FIG. 4C (right)) contains additional processing power for tool tip guidance.

[0048] The design of the bracket system should consider the field-of-view (FOV) of individual tracking elements in the bracket system. In the simulation using K-wave simulator, several PA sources radially posed to the tracking element with variable width (£>) (FIG. 9A). The maximum magnitude of each PA source and fit a 1st order Gaussian curve to the data. The field-of-view was represented by the full-width-half-maximum (FWHM) of the fitted Gaussian curve (FIG. 9B).

[0049] Table 1 summarizes the FOV measured in different D. As expected, the wider D resulted narrowed the potential single-element FOV from 83 to 64 degree. The overall FOV for tool tracking only effective in the overlapped FOVs among the tracking elements, in which singleelement FOV takes a critical role to define the FOV with considerations of element distribution and tracking depth.

[0050] Table 1. Single-element field-of-view (FOV) with different element widths from 1 to 5 mm.

[0051] The design process uses the single-element FOV to estimate the tracking FOV. FIG. 10A shows the representative example when two 5-mm wide tracking elements are separated by variable distance (5). At a specific depth, we compute the width of effective tracking FOV where the two tracking elements can sense the PA source at the same time.

[0052] We further explored tracking accuracy and field-of-view of the tracking system in 3D space, which is essentially the expansion of the 2D simulation, but will represent moreAtt’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02 comprehensive performance. Point tracking element was first assumed to sorely observe the effect of element distribution. Based on the design of most commercial US linear array transducers, commonly used in vascular access, we set the dimensions of the tracking system as 2cm in width and 4cm in height. The elliptic shape was preserved while changing the number of tracking element: 3 & 4 (FIG. 11 A).

[0053] We analyze the tracking accuracy of the system by comparing the estimated spatial location using triangulation with ground truth. The distance between one source and one PA receiver is obtained by multiplying the simulation medium propagation speed with the time-of- flight, which is determined by finding the temporal location of the maximum magnitude of the Hilbert-transformed receiver data. Once distance from one source to each PA receiver has been determined, we find the spatial location of the source using triangulation by applying a nonlinear solver.

[0054] In addition, we investigated the robustness of the tracking system by adding noise to PA receiver measurements. The noise, denoted as N, is generated based on Gaussian white noise, the magnitude of which is first normalized to between 0 and 1. For each source, we further scale the normalized noise with the maximum signal magnitude measured among all sensors.

[0055] Finally, we apply attenuation to the noise magnitude scaling factor in various dB ( ai / nuaUfjn ------ e ■ ■ )anc[original sensor measurement. We denote n as SNR. The process is repeated ten times so that different Gaussian white noises can be added to the measurement.

[0056] FIGS. 12A-12C show the box plots of tracking errors at various depths when SNR is 4 dB, 6 dB, and 8 dB. Configuration number stands for the corresponding PA source location inAtt’y Ref.: 2240-615468Applicant Ref.: Pl 7912-02 the 2D plane at one specific depth. The tracking error is averaged at each PA source for different noise. The box plot suggests that the tracking system has submillimeter tracking accuracy at depth of 32.4mm and 40mm when SNR is above 4dB.

[0057] We also validated the implementation of the trigger hijacker (FIG. 4D). An electromagnetic trigger hijacker can be used. The timing of each ultrasound firing event in each scanline can be recovered by attaching a small antenna close to the transducer head or the cable, for example. The antenna is a shielded loop antenna that is sensitive to H field and rejects E field. The antenna can be made on a conventional flexible circuit board. A low noise amplifier (LNA) amplifies the signal. The signal can be converted to digital by an adaptive comparator circuit, and digitally filtered by a field programmable gate array (FPGA) or microcontroller to recover the trigger signals. The antenna and processing circuit can be integrated as a part of the bracket or clip on the transducer cable.

[0058] FIG. 6 A shows the signal path for the electromagnetic trigger hijacker in this embodiment. FIG. 6B show the placement of the electromagnetic trigger hijacker. FIG. 6C shows a proof-of-concept experiment for the electromagnetic trigger hijacker. An H-field antenna was placed near the ultrasound transducer. The signal was amplified by an LNA and captured by an oscilloscope. Each transmit pulse in each A line produces a spike detectable by the antenna. Simple time-domain signal processing can be used to recover the frame and line triggers.Guidance system for autonomous vascular access or patient monitoring

[0059] The guidance system and design process have a full potential to support wearable form factor to enable autonomous vascular access or continuous monitoring of patient vasculatures. FIG. 1 shows an example design of the device. The rigid part of the device will have multiple tracking elements for tool tip tracking through the window at the center. The opposite part of the device will be fastened by a stretchable fabric on patient’s body to be fastened. The FOV and tracking accuracy of this embodiment can be designed in the same design process as shown above. The tool injection window can be on any position or shape within the guidance platform.

[0060] The use cases can be either manual tool injection using the system similar to the scenario being a peripheral to the clinical US device as in the embodiment above or with a standalone form factor. The first configuration supports the light excitation for PA imaging,Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02 manual vascular access, or simply to do US imaging using tracking elements. The target for tracking can be either tool for interventions or endogenous objects including vessels or any other lesion needed to be monitored in US and / or PA modalities.

[0061] The second configuration will have the ‘modular’ system that can be clipped onto the tool injection window. The module can perform anything related to the needed procedures. For example, the module may include a tool maneuvering submodule, a mechanical scanner module, and / or an US and / or PA imaging module to automate the vascular access procedures. The system may localize the target based on US / PA modalities using the imaging module and maneuver the tool to put a tool (e.g., needle or catheter) using the mechatronics embedded. It may allow remote control by clinician using apps in workstation or personal devices. The imaging module may have 2D or ID US transducer for volumetric imaging and signal reception from the tool. A mechatronic module may maneuver both tool and imaging transducer for better 5T functionalities.

[0062] Some embodiments of a wearable 5T-IV device can be include blood pressure measurement with PA imaging as in the published PCT application WO2023033983Alassigned to the same assignee as the current application, the entire contents of which are incorporated herein by reference.

[0063] Other possible features and applications• The communication between extracorporeal tracking elements and intracorporeal tool enables absolute TOF measurements in the biological sample. This information can be used to further elaborate the whole framework in either (1) to correct inhomogeneous sound propagation speed in US / PA imaging within the same FOV for more accurate morphological mapping and (2) to reconstruct a quantitative US map of sound propagation speed, attenuation, and density.• External US imaging component could be a non-contact US imaging module.• All the other US imaging techniques not mentioned here can be applied as a part of the embodiments (e.g., elastography, B-flow, vector Doppler, etc.)Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02• Using the spectral Doppler and vascular morphology information, blood pressure may be estimated in real-time for patient monitoring purpose.• The system use for vascular access can be used for preclinical applications in a standalone table-top system form factor. For example, a smaller implementation of the above may allow autonomous IV catheterization on rodent tail vein, which is an essential task in preclinical investigation of drug or contrast agents.• The framework can be implemented wirelessly by having wireless needle.

[0064] References[1] C. M. Rickard, N. M. Marsh, J. Webster, N. C. Gavin, M. R. McGrail, E. Larsen, A. Corley, D. Long, J. R. Gowardman, M. Murgo, J. F. Fraser, R. J. Chan, M. C. Wallis, J. Young, D. McMillan, L. Zhang, M. A. Choudhury, N. Graves, and E. G. Playford, “Intravascular device administration sets: replacement after standard versus prolonged use in hospitalised patients — a study protocol for a randomised controlled trial (The RSVP Trial),” Bmj Open, vol. 5, no. 2, p. e007257, 2015.[2] P. J. Carr, N. S. Higgins, M. L. Cooke, G. Mihala, and C. M. Rickard, “Vascular access specialist teams for device insertion and prevention of failure,” Cochrane Db Syst Rev, vol. 2019, no. 3, p. CD011429, 2018.[3] L. Steere, C. Ficara, M. Davis, and N. Moureau, “Reaching One Peripheral Intravenous Catheter (PIVC) Per Patient Visit With Lean Multimodal Strategy: the PIV5RightsTM Bundle,” J Assoc Vase Access, vol. 24, no. 3, pp. 31-43, 2019.[4] S. S. Dychter, D. A. Gold, D. Carson, and M. Haller, “Intravenous Therapy: A Review of Complications and Economic Considerations of Peripheral Access,” J Infusion Nurs, vol. 35, no. 2, pp. 84-91, 2012.[5] R. E. Helm, J. D. Klausner, J. D. Klemperer, L. M. Flint, and E. Huang, “Accepted but Unacceptable: Peripheral IV Catheter Failure,” J Infusion Nurs, vol. 42, no. 3, pp. 151-164, 2019.Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02[6] L. Nicosia, A. Bozzini, F. Addante, G. Renne, A. Latronico, L. Meneghetti, O. Paia, S. Frassoni, V. Bagnardi, E. Cassano, and M. G. Mastropasqua, “Wireless ultrasound-guided vacuum-assisted breast biopsy: Experience in clinical practice at European Institute of Oncology,” Breast J, vol. 27, no. 6, pp. 514-520, 2021.[7] R. Krackov and D. Rizzolo, “Real-time ultrasound-guided thoracentesis,” J Am Acad Physician Assistants, vol. 30, no. 4, pp. 32-37, 2017.[8] H. J. Gelfand, J.-P. P. Ouanes, M. R. Lesley, P. S. Ko, J. D. Murphy, S. M. Sumida, G. R. Isaac, K. Kumar, and C. L. Wu, “Analgesic efficacy of ultrasound-guided regional anesthesia: a meta-analysis,” J Clin Anesth, vol. 23, no. 2, pp. 90-96, 2011.[9] “AIUM Practice Parameter for the Use of Ultrasound to Guide Vascular Access Procedures: AIUM Practice Parameter for the Use of Ultrasound to Guide Vascular Access Procedures,” J Ultras Med, vol. 38, no. 3, pp. E4-E18, 2019.

[0010] F. H. J. van Loon, M. P. Buise, J. J. F. Claassen, A. T. M. D. Daele, and A. R. A. Bouwman, “Comparison of ultrasound guidance with palpation and direct visualisation for peripheral vein cannulation in adult patients: a systematic review and meta-analysis,” Brit J Anaesth, vol. 121, no. 2, pp. 358-366, 2018.

[0011] J. R. Pare, S. E. Pollock, J. H. Liu, M. M. Leo, and K. P. Nelson, “Central venous catheter placement after ultrasound guided peripheral IV placement for difficult vascular access patients,” Am J Emerg Medicine, vol. 37, no. 2, pp. 317-320, 2019.

[0012] B. T. Galen and W. N. Southern, “Ultrasound-Guided Peripheral Intravenous Catheters to Reduce Central Venous Catheter Use on the Inpatient Medical Ward,” Qual Manag Health Ca, vol. 27, no. 1, pp. 30-32, 2018.

[0013] E. Schoenfeld, H. Shokoohi, and K. Boniface, “Ultrasound-Guided Peripheral Intravenous Access in the Emergency Department: Patient-Centered Survey,” West J Emerg Medicine, vol. 12, no. 4, pp. 475-477, 2011.

[0014] R. J. Adrian, A. Choi, S. Lamba, I. Ostrovsky, C. Ramdin, C. Traba, S. Chen, A. Sudyn, and S. Alerhand, “Teaching Module on Ultrasound-Guided Venous Access Using a HomemadeAtt’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02Gel Model for Fourth-Year Medical Students,” Mededportal J Teach Learn Resour, vol. 18, p. 11222, 2022.

[0015] S. R. Osborn, J. Borhart, and M. S. Antonis, “Medical students benefit from the use of ultrasound when learning peripheral IV techniques,” Critical Ultrasound J, vol. 4, no. 1, pp. 2-2, 2012.

[0016] S. Voicu, P. Henry, I. Malissin, D. Jean-Guillaume, A. Koumoulidis, N. Magkoutis, D. Yannopoulos, D. Logeart, S. Manzo-Silberman, N. Peron, N. Deye, B. Megarbane, and G. Sideris, “Improving cannulation time for extracorporeal life support in refractory cardiac arrest of presumed cardiac cause - Comparison of two percutaneous cannulation techniques in the catheterization laboratory in a center without on-site cardiovascular surgery,” Resuscitation, vol. 122, pp. 69-75, 2018.

[0017] M. D. Balceniuk, A. Sebastian, A. C. Schroeder, B. C. Ayers, K. Raman, J. L. Ellis, A. J. Doyle, R. J. Glocker, and M. C. Stoner, “Regional Variation in Usage of Ultrasound-Guided Femoral Access in the Vascular Quality Initiative,” Ann Vase Surg, vol. 72, pp. 544-551, 2021.

[0018] P. Beigi, S. E. Salcudean, G. C. Ng, and R. Rohling, “Enhancement of needle visualization and localization in ultrasound,” Int J Comput Ass Rad, vol. 16, no. 1, pp. 169-178, 2021.

[0019] C. H. Hovgesen, J. E. Wilhjelm, P. Vilmann, and E. Kalaitzakis, “Echogenic Surface Enhancements for Improving Needle Visualization in Ultrasound: A PRISMA Systematic Review.,” J Ultrasound Medicine Official J Am Inst Ultrasound Medicine, vol. 41, no. 2, pp. 311-325, 2021.

[0020] K. J. Chin, A. Perlas, V. W. S. Chan, and R. Brull, “Needle Visualization in Ultrasound- Guided Regional Anesthesia: Challenges and Solutions,” Region Anesth Pain M, vol. 33, no. 6, pp. 532-544, 2008.

[0021] C. R. Peabody and D. Mandavia, “Deep Needle Procedures: Improving Safety With Ultrasound Visualization,” J Patient Saf, vol. 13, no. 2, pp. 103-108, 2017.

[0022] T. Hoffman, M. D. Plessis, M. P. Prekupec, J. Gielecki, A. Zurada, R. S. Tubbs, and M. Loukas, “Ultrasound-guided central venous catheterization: A review of the relevant anatomy,Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02 technique, complications, and anatomical variations,” Clin Anat, vol. 30, no. 2, pp. 237-250, 2017.

[0065] While various embodiments of the present invention have been described above, they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described illustrative embodiments but should instead be defined only in accordance with the following claims and their equivalents.

[0066] The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art how to make and use the invention. In describing embodiments of the disclosure, specific terminology is employed for the sake of clarity. However, the disclosure is not intended to be limited to the specific terminology so selected. The above-described embodiments of the disclosure may be modified or varied, without departing from the invention, as appreciated by those skilled in the art considering the above insights. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described. For example, it is to be understood that the present disclosure contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.

Claims

Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-02WE CLAIM:

1. An interventional tool tip tracking system, comprising: a sensor support structure; a plurality of ultrasound elements attached to said sensor support structure and arranged in an array pattern, each ultrasound element of said plurality of ultrasound elements being configured to receive an acoustic signal generated from an acoustic source proximate an interventional tool tip within a volume of interest and to provide a corresponding plurality of detection signals; and a data processing device configured to receive said corresponding plurality of detection signals from said plurality of ultrasound elements and to determine a position of said interventional tool tip in said volume of interest from said plurality of detection signals, wherein each ultrasound element of said plurality of ultrasound elements has a diameter and an arrangement in said array pattern to provide a combined detection coverage corresponding to said volume of interest.

2. The system according to claim 1, wherein each of said plurality of ultrasound elements is flat and has a diameter less than 2 mm.

3. The system according to claim 1 or 2, wherein a number of said plurality of ultrasound elements is selected to provide a minimum sensitivity.

4. The system according to any one of claims 1-3, wherein said sensor support structure is configured to contact a portion of a subject’s body.Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-025. The system according to claim 4, wherein said sensor support structure is flexible to be able to conform to said portion of said subject’s body.

6. The system according to any one of claims 1-5, wherein said sensor support structure defines a window through which said interventional tool tip can pass into said volume of interest.

7. The system according to any one of claims 1-3, wherein said sensor support structure is a bracket configured to be attachable to an ultrasound probe.

8. The system according to claim 7, further comprising a trigger hijacker configured to be attachable to or arranged proximate said ultrasound probe and configured to communicate with said data processing device.

9. The system according to claim 8, wherein said trigger hijacker comprises: an antenna at least one of attached to or proximate at least one of said ultrasound probe, an electrical cable connected to said ultrasound probe, or an electrical connector attached to said electrical cable; and a processing circuit configured to receive a signal from said antenna.

10. The system according to claim 8, wherein said trigger hijacker comprises: an ultrasound sensor attached to said ultrasound probe so as to receive an ultrasound signal therefrom; and a processing circuit configured to receive a signal from said ultrasound sensor.Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-0211. The system according to claim 8, wherein said trigger hijacker comprises: a probe connector configured to be connected to an electrical connector of said ultrasound probe so as to receive an ultrasound signal therefrom; and a processing circuit configured to receive a signal from said probe connector.

12. An interventional tool tip tracking and tissue typing system, comprising: a multi wavelength light source; an optical fiber optically coupled to said multi wavelength light source, said optical fiber being suitable to be attached to an interventional tool with a light emission end arranged at a tool tip of said interventional tool to emit light therefrom to interact with tissue within a volume of interest; a sensor support structure comprising a plurality of ultrasound elements attached thereto and arranged in an array pattern, wherein each of said plurality of ultrasound elements is configured to receive photoacoustic signals when generated by said emitted light from said light emission end of said optical fiber and provide a corresponding plurality of detection signals; and a data processing device configured to receive said corresponding plurality of detection signals from said plurality of ultrasound elements by photoacoustic signals generated from a plurality of wavelengths from said multi wavelength light source, wherein said data processing device is further configured to determine a position of said tool tip, and wherein said data processing device is further configured to determine a tissue type within said volume of interest.Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-0213. The system according to claim 12, wherein said plurality of ultrasound elements attached to said sensor support structure are of a size and at fixed relative positions to provide a pattern of coverage for said volume of interest.

14. The system according to claim 12 or 13, wherein said sensor support structure is configured to conform to a portion of a subject’s body.

15. The system according to claim 14, wherein said sensor support structure defines a window through which said interventional tool can pass into said volume of interest.

16. The system according to claim 14 or 15, further comprising a flexible support configured to hold said sensor support structure in contact with said portion of said patient’s body.

17. The system according to claim 12, wherein said sensor support structure is a bracket configured to be attachable to an ultrasound probe.

18. The system according to claim 17, further comprising a trigger hijacker configured to be attachable to or arranged proximate said ultrasound probe and configured to communicate with said electronic system.

19. The system according to claim 18, wherein said trigger hijacker comprises an antenna and a processing circuit.Att’y Ref.: 2240-615468 Applicant Ref.: Pl 7912-0220. The system according to any one of claims 12-19, wherein said multi wavelength light source is a tunable pulsed laser.

21. The system according to any one of claims 12-20, wherein said plurality of ultrasound elements attached to said sensor support structure are at least three ultrasound elements arranged in a nonlinear array.

22. The system according to any one of claims 1-21, further comprising said interventional tool, wherein said optical fiber is attached to said interventional tool.

23. An ultrasound system, comprising: an ultrasound probe; an ultrasound image processor configured to receive ultrasound signals from said ultrasound probe and to provide ultrasound image signals; an image display configured to receive said ultrasound image signals and to display an ultrasound image based thereon; and at least one of an interventional tool tip tracking system according to any one of claims 1-11 or an interventional tool tip tracking and tissue typing system according to any one of claims 12-22, wherein said image display is configured to communicate with said data processing device and to display information concerning said interventional tool tip position and a tissue type along with said ultrasound image.

Images