Systems and methods for automated peripheral vascular catheterization - Patents.com

Abstract

The device for catheterization includes a catheter sheath support mounted on the catheterization device and holding a catheter sheath, a carriage supporting a guide needle, and a connector for removably engaging the catheter sheath support to the carriage. When the carriage is disengaged from the connector, it translates along an insertion axis of the guide needle independent of the catheter sheath support. An actuator controls the separation of the carriage from the catheter sheath support at a uniform speed in response to disengagement of the connector. The translation and separation may be automated. In response to detection of a vessel wall puncture, the carriage is automatically released from the catheter sheath support and retracts along the insertion axis at a uniform speed relative to the catheter sheath support, and the catheter sheath is automatically advanced along the insertion axis at a uniform speed into the target vessel while the carriage is retracted.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of the filing date of U.S. Provisional Application No. 63 / 293,406, filed December 23, 2021, entitled "Systems And Methods For Automated Peripheral Vessel Catheterization," the disclosure of which is incorporated herein by reference.

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with Government support under R01EB020036 and F31HL149219 awarded by the National Institutes of Health. The Government has certain rights in this invention. [Background technology]

[0003] Percutaneous peripheral catheterization procedures are typically performed manually by trained physicians. The physician visually locates or palpates a tissue target, such as a blood vessel, and then introduces a cannula, often in a blind fashion, aiming to reach the center of the target. In general, finding a suitable target is difficult, especially in young children, elderly or obese patients, or patients with comorbidities. It can also be difficult to predict the depth or to insert the instrument accurately in the presence of tissue motion. For these reasons, the success of the cannulation procedure is highly dependent on the patient's physiology and the physician's skill. For vascular access in particular, failure rates are known to be greater than 25% overall and can increase up to 70% in difficult patients. Difficulty in finding a vessel or inserting a needle or catheter increases the likelihood of pain, bruising, and access-related complications. Such difficulties also lead to significant delays in procedures, resulting in unnecessary costs to medical facilities.

[0004] A control scheme for a handheld automated cannulation device can respond quickly and efficiently to real-time sensor data while not having to rely on a fixed frame of reference external to the device itself. While known control schemes allow physicians to perform cannulation procedures for routine blood draw venipuncture, they are not sufficient to perform peripheral catheterization procedures for intravenous or intravascular therapy. Peripheral catheterization involves guiding a catheter sheath and guide needle into a blood vessel and retracting the guide needle after the puncture while the catheter sheath remains in place. This is more complicated than simply puncturing a vessel to draw blood. Summary of the Invention

[0005] The present disclosure is directed to a handheld automated device capable of performing percutaneous peripheral catheterization, as well as blood sampling. The device combines the imaging, positioning, and continuous image-based feedback techniques of known control schemes for handheld automated cannulation devices with additional features for safely guiding a catheter sheath and guide needle into a blood vessel and for retracting the guide needle after puncture while the catheter sheath remains in place. The additional features may include both hardware components for stabilizing the catheter sheath and guide needle during puncture and withdrawal, as well as routines for stable control of the hardware components.

[0006] One aspect of the present disclosure is directed to an automated cannulation method, which may include receiving, by one or more processors, imaging data of a target location including one or more target vessels for insertion of a cannula under a patient's skin; identifying, by the one or more processors, a plurality of candidate vessel segments from among the one or more vessels; determining, by the one or more processors, a plurality of characteristics of each of the candidate vessel segments based on the imaging data, where at least one of the plurality of characteristics is a vessel cross-sectional area; assigning, by the one or more processors, a respective plurality of values ​​for each of the identified candidate vessel segments based on the determined plurality of characteristics, each value corresponding to a respective feature; calculating, by the one or more processors, a total score for each of the identified candidate vessel segments based on the respective plurality of values; selecting, by the one or more processors, a highest scoring candidate vessel segment based on the calculated total score; and outputting, by the one or more processors, the selected highest scoring candidate vessel segment.

[0007] In some examples, the method may further include assigning a respective predefined weight to each of the plurality of values ​​for each of the plurality of identified candidate vascular segments. For each identified candidate vascular segment, a total score for the identified candidate vascular segment may be a weighted sum of its corresponding plurality of values.

[0008] In some examples, the plurality of features may include a distance of the identified candidate vessel segment from an artery of the patient. The distance of the identified candidate vessel segment from an artery of the patient may be determined based on the imaging data.

[0009] In some examples, the features may include a quality of blood flow through the identified candidate vessel segment, which may be determined based on Doppler signal strength derived from the imaging data.

[0010] In some examples, identifying the candidate vessel segments from among the one or more vessels may be performed using a machine learning model. The features may include a confidence level output by the machine learning model. In some examples, the machine learning model may be a convolutional neural network.

[0011] Another aspect of the present disclosure is directed to a method for automated catheterization, which may include detecting, by a sensor, a vessel wall puncture of a target vessel by a needle supporting a catheter sheath; in response to detecting the vessel wall puncture, automatically releasing the needle carriage from a catheter sheath support to which the catheter sheath is mounted; automatically retracting the carriage along the needle insertion axis at a uniform speed relative to the catheter sheath support; and automatically advancing the catheter sheath into the target vessel along the needle insertion axis at a uniform speed while the carriage is automatically retracted such that the position of the needle relative to the target vessel is maintained.

[0012] In some examples, automatically retracting the carriage may involve applying a constant force to the carriage in a direction along the needle insertion axis away from the target vessel, the constant force may be controlled to not exceed a predefined threshold.

[0013] In some examples, the sensor may be a force sensor. Automatically releasing the carriage may involve actuating a solenoid latch in response to detection of a vessel wall puncture by the force sensor.

[0014] In some examples, the method may further include receiving an indication of success of the catheterization procedure separate from the indication of vessel wall puncture. Automatically releasing the carriage may be performed further in response to both the detection of the vessel wall puncture and the indication of success of the catheterization procedure.

[0015] In some examples, an indication of the success of the catheter procedure may be determined from at least one of an infrared emitter and collector sensor to detect blood flush, or a force profile of force data collected at a force sensor during needle insertion into the target blood vessel.

[0016] In some examples, the method may further include receiving, by the one or more processors, imaging data of the target location under the patient's skin; identifying, by the one or more processors, a plurality of candidate vascular segments from among the one or more blood vessels; assigning, by the one or more processors, a respective likelihood of success value for each of the identified candidate vascular segments, the likelihood of success value indicating a likelihood of success of the cannulation procedure using the corresponding candidate vascular segment; determining, by the one or more processors, a cross-sectional area of ​​each of the candidate vascular segments based on the imaging data; assigning, by the one or more processors, a respective size value for each of the identified candidate vascular segments; calculating, by the one or more processors, a total score for each of the identified candidate vascular segments based on the respective likelihood of success values ​​and the respective size values; selecting, by the one or more processors, the highest scoring candidate vascular segment based on the calculated total score; and advancing, by the one or more processors, the guide needle and the catheter toward the selected highest scoring candidate vascular segment of the target vessel.

[0017] Yet another aspect of the present disclosure is directed to a device for automated catheterization including a catheter sheath support configured to be mounted to a catheterization device, the catheter sheath support configured to hold a catheter sheath, a carriage configured to support a guide needle, a connector configured to removably engage the catheter sheath support to the carriage, the carriage configured to translate along an insertion axis of the guide needle independent of the catheter sheath support when the carriage is disengaged from the connector, and a constant force actuator configured to control separation of the carriage from the catheter sheath support at a uniform velocity in response to disengagement of the connector.

[0018] In some examples, the constant force actuator may be a spring.

[0019] In some examples, the constant speed may be equal to the speed of insertion of the catheter sheath controlled by an injection motor of a handheld catheter treatment device.

[0020] In some examples, the device may further include a rotational speed limiter configured to limit the magnitude of the constant speed to a predetermined threshold.

[0021] In some examples, the device may further include a force sensor positioned along the insertion axis of the guide needle, the force sensor configured to detect a vessel wall puncture and to transmit a vessel wall puncture signal in response to detecting the vessel wall puncture.

[0022] In some examples, the connector can be configured to disengage in response to a vessel wall puncture signal.

[0023] In some examples, the connector may be a solenoid latch and the vessel wall puncture signal may be a voltage to activate the solenoid latch.

[0024] In some examples, the device may further include a blood flush sensor configured to detect successful insertion of the guide needle. The connector may be configured to disengage further in response to a signal indicative of detection of successful insertion of the guide needle by the blood flush sensor.

[0025] The devices and methods disclosed herein are advantageous for patients, physicians, and medical facilities. For patients, the devices and workflows ensure rapid, first-attempt cannulation success, especially in difficult-to-access patients. For physicians, the devices have the potential to eliminate the risk of accidental sharps injury by automating the instrument installation and disposal process. Finally, for medical facilities, the devices have the potential to reduce costs due to complexity and delays, and potentially allow procedures to be performed by less trained personnel. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a side view of an example catheter treatment device according to aspects of the present disclosure. [Diagram 2] FIG. 2 is a functional block diagram of the catheter treatment device of FIG. 1. [Diagram 3] 2(a)-(c) are perspective views of a portion of the catheter procedure device of FIG. 1 during retraction of the guide needle from the catheter sheath after successful insertion into the target vessel. [Figure 4A] FIG. 2 is a further perspective view of the catheter treatment device of FIG. 1. [Figure 4B] FIG. 2 is a side view of the example catheter treatment device of FIG. 1. [Figure 5A] FIG. 2 is a side view of another example of the catheter treatment device of FIG. 1. [Figure 5B] FIG. 2 is a side view of another example of the catheter treatment device of FIG. 1. [Figure 5C] FIG. 2 is a side view of another example of the catheter treatment device of FIG. 1. [Figure 6A]FIG. 2 is a side view of yet another example of the catheter treatment device of FIG. 1. [Figure 6B] FIG. 2 is a side view of yet another example of the catheter treatment device of FIG. 1. [Figure 7] FIG. 1 is a block diagram of a workflow for operating a catheter treatment device according to aspects of the present disclosure. [Figure 8] FIG. 1 is a flow diagram of an automated catheterization protocol according to aspects of the present disclosure. [Figure 9] FIG. 13 is a flow diagram of a target vessel selection protocol according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] 1 illustrates an example catheterization device 100. The device 100 may be handheld and may be automated to improve the accuracy of the catheterization process. The device 100 includes both an imaging unit 110 for imaging a target area for catheterization and a positioning unit 120 for steering a needle toward the target area based at least in part on information from the imaging unit 110.

[0028] The imaging unit 110 may include an ultrasound probe for acquiring images of a target area beneath the patient's skin, such as one or more blood vessels. The probe may be attached to an end of the unit 110 such that the unit 110 is configured to acquire ultrasound (US) images of a portion of the patient positioned opposite the probe. The probe may be made of a flexible material designed to bend and conform to an imaging portion of the patient (e.g., the patient's arm). In some examples, the probe may further include a gel compartment configured to contain ultrasound gel to enhance acquisition of US images.

[0029] The positioning unit 120 may be attached to the imaging unit 110 and may include a robotic arm configured to control the positioning of the needle. In the case of a catheter treatment device, the robotic arm may further control the positioning of the catheter sheath. Each of the needle and the catheter sheath may be supported by a respective attachment to the positioning unit 120. In some cases, the attachments may be engaged with each other such that the movement of the needle and the catheter sheath are coordinated. In some cases, the attachments may be disengaged such that each can move independently of the other, such as during disengagement of the guide needle from the catheter sheath after successful puncture of the target vessel. The positioning unit 120 may be capable of movement along multiple degrees of freedom to manipulate the needle and the catheter sheath individually or in coordination.

[0030] Exemplary imaging and positioning units are described in co-pending U.S. application Ser. No. 17 / 284,018, the disclosure of which is incorporated herein by reference in its entirety. For example, near-infrared (NIR) light imaging may be used in place of or in addition to ultrasound imaging.

[0031] 2 is a block diagram illustrating a control scheme of a device 200 according to the present disclosure. The catheter treatment device 200 includes a main processor 210, a microcontroller 220, a display 230, and a number of motor controllers 240a, 240b each for controlling various axes of freedom of a catheter treatment instrument 250, such as a guide needle, a catheter sheath, or both. The main processor 210 can be any processing device known in the art that has sufficient processing power to receive, process, and output image data at video frame rates. The microcontroller 220 can be an integrated chip or other processing device known in the art that has sufficient processing power to control a robotic arm, including processing and relaying sensor inputs and instructions to control motor activity.

[0032] The microcontroller 220 may be configured to receive analog and / or digital inputs from various sensors, process those inputs, and relay the inputs to the main processor via a controller area network (CAN) connection. In some cases, the main processor 210 may include different connections, for example, in the case of a universal serial bus (USB) connection, the sensor data may be relayed via a CAN-USB connection. Conversely, instructions relayed from the main processor 210 through the microcontroller 220 may be provided via a USB-CAN connection.

[0033] The display 230 may be configured to provide a two-dimensional or three-dimensional image of the cannulation target location and the cannulation instrument. A cannulation trajectory, e.g., a predicted trajectory of the cannulation instrument until it reaches the target vessel, may be superimposed on the image. The image may be updated or refreshed in real time or at the video frame rate. The display may be further configured to allow the clinician to identify a location within the image presented on the display, such as to identify a target location.

[0034] The display 230 may further be configured to initialize image processing routines. For example, automatic segmentation of a vessel boundary may be initiated by a user's interaction with the device 200 through the display 430. For example, the ultrasound transducer may be moved around until the target vessel is centered within the ultrasound image (the display may include crosshairs to indicate the image center). Once centered, processing software within the device may be manually initiated to search for the segmentation starting from the center of the image. After the initial segmentation, the target may then be tracked automatically.

[0035] The catheterization device 200 further includes a number of sensors for providing inputs to the main processor 210 and the microcontroller 220. The sensors may include an imaging probe 262, such as an ultrasound probe, a force sensor 264 for sensing the force applied to the guide needle or to the motor when the positioning unit is in operation, a respective position encoder 266a, 266b for each motor controller 240a, 240b for monitoring the manipulation of the needle by the device's motor, a position sensor 268 for tracking changes in translation and orientation of the handheld catheterization device 200, a carriage latch 272 for disengaging the guide needle carriage from the support of the catheter sheath, and a blood flush sensor 274 for detecting successful puncture or cannulation of the target vessel. In the case of a handheld catheterization device, the position sensor 268 is essential to track whether the catheterization device is moved, either intentionally or inadvertently, from its initial position.

[0036] The main processor 210 and the microprocessor 220 may be programmed with software instructions to execute the operations and protocols outlined in this disclosure. For example, the microprocessor may be programmed to receive analog or digital inputs from each of the force sensors, position encoders, position sensors, and blood flush sensors, process the received inputs into a format acceptable to the main processor, and then transmit the reformatted input data to the main processor for further processing. The microcontroller may further be responsible for controlling the operation of various components of the device, such as motors and carriage latches to control the movement in the positioning unit. The main processor may be programmed to receive and process the imaging data, such as identifying a target location within the patient and determining a trajectory for guiding the catheter treatment instrument to the target location. The determined trajectory may include velocities, accelerations, or both along the various degrees of freedom controlled by the motors, such that operating the motors at the indicated velocities and / or accelerations may result in the catheter treatment instrument following a desired path to its target location. The main processor may further determine and continuously track the relative position of the catheter treatment instrument with respect to the target location based on the received input, and may update the determined trajectory based on changes in the relative position.

[0037] Figures 3(a)-3(c) illustrate the time course of a mechanical device 300 for controlling the movement of the guide needle 315 and the catheter sheath 325, either independently or in conjunction. Figure 3(a) illustrates an initial configuration of the mechanical device 300, such as when successful puncture of the target blood vessel is detected. Figure 3(b) illustrates a next configuration after the initial configuration, where the carriage supporting the guide needle has disengaged from the pusher or support supporting the catheter sheath. Finally, Figure 3(c) illustrates a final configuration in which the mechanical device 300 may rest after disengagement shown in Figure 3(b).

[0038] In the initial configuration, the guide needle 315 and the catheter sheath 325 are connected to each other such that the guide needle 315 provides structural support for the catheter sheath 325 as the sheath is inserted into the target vessel. A distal portion of the guide needle 315 is attached to the carriage 310. In the example of FIG. 3(a), the carriage 310 is configured to receive the guide needle 315 through an opening so that the guide needle can be removed after use. The catheter sheath 325 is supported by a catheter sheath support 320, such as a pusher. In the example of FIG. 3(a), the catheter sheath support 320 includes a base 322 and a sidewall 324. The base 322 and the sidewall 324 may define a space to receive the carriage 310 of the guide needle 315. The carriage 310 may be configured to move along a longitudinal axis of the catheter sheath support 320. In the initial position, the carriage may be positioned in front of the carriage, such that the carriage can move rearwardly but not forwardly relative to the catheter sheath support 320.

[0039] The mechanical device 300 may further include a connector 340. The connector 340 may be positioned between the carriage 310 and the catheter sheath support 320 and configured to maintain an engagement, e.g., a lock or latch connection, between the carriage 310 and the catheter sheath support 320. In the example of FIG. 3(a), the connector is positioned between the base of the carriage 310 and the top surface of the base 322 of the catheter sheath support 320, and therefore is not visible in the illustration. The connector 340 may be any one or combination of connection devices, including but not limited to latches, locks, magnets, bolts, and the like. In the example of FIG. 3(c), the connector 340 is shown as a solenoid, a latch, or more specifically, a plunger controlled between a latched position and a released position by a solenoid coil.

[0040] The mechanical device may also include one or more sensors 330 for detecting puncture of the vessel wall by the guide needle 315 and catheter sheath 325. In the example of FIG. 3(a), a force sensor 330 is included in the carriage 310 to detect the force applied to the guide needle. The force sensor 330 may be coupled to the distal end of the guide needle such that puncture of the vessel wall may be detected by the force applied to the force sensor. For example, an increase in force followed by a sudden decrease may indicate successful puncture. The force sensor may be capable of detecting a force of about 0-5 N. Other sensors may be included in addition to or in place of the force sensor. For example, a blood flush sensor may be provided to indicate a successful catheterization procedure. The blood flush sensor may include an infrared light emitter and a sensor such that infrared light emitted by the emitter and reflected off blood entering the catheter may bounce back toward the infrared sensor to indicate the presence of blood in the catheter. Other sensors and techniques may include detecting the puncture using a pressure sensor, determining the puncture based on imaging, such as ultrasound or other types of images received from an imaging unit, position tracking, such as using a position encoder included with the motor of the positioning unit, temperature sensing, such as using a thermocouple to detect blood contacting the needle tip, and combinations thereof.

[0041] In response to detecting successful puncture of the vessel wall of the target vessel, the sensor 330 may automatically transmit a signal to the connector 340 to disengage the carriage 310 from the catheter sheath support 320. The carriage 310 may be biased by a constant force actuator 350, such as one or more springs configured to apply a constant force. The actuator may be attached to the catheter sheath support 320 such that no force can move the carriage 310 while the carriage 310 remains engaged with the catheter sheath support 320. However, once the carriage 310 is disengaged from the catheter sheath support 320, the biasing force of the actuator 350 causes the carriage 310 to retract from a front position toward a rear position in the space within the catheter sheath support 320, which is represented by the arrow 355 in Figures 3(a) and 3(b).

[0042] The constant force applied by the actuator 350 may move the carriage at a uniform velocity relative to the catheter sheath support 320. At the same time, one or more motors of the positioning unit may continue to advance the guide needle and catheter sheath toward the target vessel to complete the catheter procedure process, as represented by the arrow 365 in FIG. 3(b). The advancement of the guide needle 310 and catheter sheath 320 may also be performed at a uniform velocity, in particular at the same uniform velocity as the retraction of the carriage. The uniform velocity may be 2-15 mm / s. In some embodiments, a velocity greater than 15 mm / s may be used. In effect, from the reference frame of the catheter sheath support 320, the carriage 310 and guide needle 315 may appear to translate backwards at a uniform velocity. However, from the reference frame of the target vessel, the carriage 310 and guide needle 315 may appear to remain stationary while the catheter sheath support and catheter sheath advance further into the target vessel.

[0043] In some examples, a force of about 0.4 lb to 1 lb may be applied by the actuator 350. More specifically, a force of about 0.6 to 0.7 lb may be applied. The applied force may be further controlled by providing a force limiting or rate limiting element 360 to limit the applied force. In the example of FIG. 3(a) and FIG. 3(b), a rotational speed limiter, which may be a rotational damper 360, is shown attached to the inner surface of the sidewall 324 of the catheter sheath support 320. The rotational damper 360 may interact with the base of the carriage 310 to maintain a limited speed at which the carriage 310 may retract. This prevents buckling in the catheter sheath from occurring during the guide needle removal process. In other examples, a rate limiting element may be used, including but not limited to a friction tape, a constant force rotational spring, or another motor.

[0044] Finally, in Figure 3(c) the guide needle 315 is shown as completely separated from the catheter sheath 325. In the example of Figure 3(c) this involves the guide needle reaching the rear wall of the catheter sheath support 320 where the actuator 350 is located. At this stage the guide needle 315 can be easily removed and disposed of without disturbing the catheter.

[0045] Further features of the machine can be observed from the top perspective and side views shown in Figure 4. For example, it can be seen that the blood flush sensor 410 is positioned on the surface of the catheter sheath support 320 just beneath the catheter sheath 325. As also shown in Figure 4, the guide needle can include a blood flush chamber 412 for collecting blood from the catheter sheath 325.

[0046] In the example devices of Figures 3 and 4, the guide needle and catheter sheath may be supported by a carriage. However, in other devices, the guide needle and catheter sheath may be held in place and manipulated using other retention mechanisms. For example, in the example catheter treatment device 501 of Figures 5A-5C, the catheter sheath 502 and guide needle 504 are held in place by a first gripper 512 and a second gripper 514, respectively. Each of the grippers 512, 514 may include two or more arms or prongs extending from a bottom surface of the body of the catheter treatment device 501. The angle formed by the arms of the first gripper 512 may be controllable between a closed position, in which the arms are held at a relatively narrow angle with each other and the catheter sheath 502 is held in place by the arms, and an open position, in which the arms are held at a relatively wide angle with each other and the catheter sheath 502 is free to move. Similarly, the arms of the second grasper 514 may be controllable between a closed position in which the guide needle 504 is held in place and an open position in which the guide needle 504 is free to be released from the second grasper 514. To facilitate grasping of the guide needle 502 and the catheter sheath 504, the catheter sheath 502 and the guide needle 504 may each include a respective casing 522, 524 having a width wider than the catheter sheath 502 and the guide needle 504, respectively. The first and second graspers 512, 514 may be adapted to grasp an object having a width approximately equal to the diameter of the respective casing 522, 524.

[0047] The first gripper 512 may be fixed in place relative to a bottom surface of the body of the catheter treatment device 501. The second gripper 514 may be mounted on a track 530 that may translate forward and backward relative to the body of the catheter treatment device 501, where forward is the direction toward the target vessel 505 and backward is the opposite direction away from the target vessel 505. As such, when the catheter sheath 502 and the guide needle 504 are connected to one another and held together by the second gripper 514, the catheter sheath 502 and the guide needle 504 may be advanced toward the target vessel 505 by actuating the track in a forward direction. Conversely, when the catheter sheath 502 is gripped by the first gripper 512, the catheter sheath 502 may be prevented from moving forward or backward relative to the body of the catheter treatment device 501.

[0048] In operation, and as shown in FIG. 5A, the catheter sheath 502 and guide needle 504 may begin as grasped by the second grasper 514 and aligned with the target vessel 505. In the initial position, the rail may include approximately a half inch track for advancing the guide needle 504. Then, as shown in FIG. 5B, the motor may move the track 530, such as by rotating a gear 540 coupled to the track 530, to shift an object positioned on the track 530 relative to the body of the catheter treatment device 501, thereby advancing the catheter sheath 502 and guide needle 504 toward the target vessel 505. The advancement may be a distance of approximately a half inch. In response to reaching the target vessel (which may be sensed using any of the example sensing mechanisms described in other examples of this disclosure), the first gripper 512 may transition from an open state to a closed state, thereby gripping the casing 522 of the catheter sheath 502. During this time, the second gripper 514 may maintain its grip on the guide needle 504. Then, as shown in FIG. 5C , the motor may rotate the gear 540 in the opposite direction to shift the track 530 in the opposite direction relative to the body of the catheter treatment device 501, thereby moving the guide needle 504, still gripped by the second gripper 514, away from the target vessel 505. However, because the catheter sheath 502 is engaged with the first gripper 512, the catheter sheath 502 remains in place and does not move back with the guide needle 504, thereby separating the guide needle 504 from the catheter sheath 502. In the example of FIG. 5C, the rearward translation of guide needle 504 is shown to be approximately 1.5 inches.

[0049] In the example of Figures 5A-5C, individually controllable mechanisms are required to control the respective gripping on the catheter sheath and the guide needle. Alternatively, a control mechanism may not be required for the second gripper 514 since it may remain engaged with the guide needle at all times. For example, the second gripper 514 may be any attachment mechanism for releasably connecting the catheter sheath to the device, including but not limited to clips, fasteners, and the like. In yet further devices, it may be possible to control the movement of the catheter sheath without transitioning the arms between open and closed positions. For example, in the example of Figures 6A and 6B, the catheter sheath is shown held by a support having one or more arms 610 extending from a bottom surface of the body of the catheter treatment device. The one or more arms may have a single configuration for holding the catheter sheath and may not be configured to open or close. The one or more arms 610 may extend from a slider 620 configured to slide along a second rail 630. In operation, in FIG. 6A, the slider 620 may start at the rear end of the second rail 630, and the catheter sheath and guide needle may be connected to one another. The slider 620 may then engage the magnet 640 as the catheter sheath and guide needle are advanced toward the target vessel. In some examples, the slider 620 may automatically attach to the magnet 640 as soon as it touches or approaches the magnet 640, depending on the strength of the magnet 640. In other examples, the slider 620 may not attach to the magnet 640 until the magnet 640 is actuated in response to detection of reaching the target vessel, which may be detected using any of the example detection mechanisms described in other examples of this disclosure. The magnetic force may exceed the pulling force exerted by the guide needle on the catheter sheath, such that once the slider 620 engages the magnet 640, moving the guide needle backwards may cause the guide needle to separate from the catheter sheath.

[0050] The operation of the mechanical apparatus 300 may be automated along with other aspects of the catheter treatment device. For example, the carriage may automatically disengage from the catheter sheath support in response to detection of a vessel wall puncture. In a further example, disengagement may automatically result in retraction of the carriage, either through a mechanical process, such as bias from one or more springs, or through a different automated process, such as the operation of a motor. Finally, the catheter may continue to be advanced by an automated program of the catheter treatment device during retraction of the guide needle and carriage. FIG. 7 illustrates a flow diagram of an example automated workflow 700 of a control device for controlling the operation of a catheter treatment device during a catheter treatment event. The workflow may begin with a scanning operation after manually loading the needle into the device 710, which allows the device's probe to be positioned over the target vessel. Positioning the device may include collecting image data, such as image frames from a camera or video recording device. The scanning operation may further include ultrasound imaging 720 of the target location using the device probe. Ultrasound imaging 720 may include any one or combination of in-plane imaging, out-of-plane imaging 722, or 3D imaging, and may provide imaging just below the patient's skin using ultrasound 724 (e.g., 0-30 mm depth for peripheral venous access, and greater than 30 mm for central venous access). Collected images may be stored locally or remotely at a remote storage location connected to the device via a network connection. Local and remote storage may be useful for overview or review of workflow during or after operation.

[0051] The workflow may continue with image analysis of the collected images. This may involve identifying a target vessel for catheterization. Target vessel identification may itself involve vessel segmentation 730, where the acquired images are analyzed to identify segments of candidate target vessels and ultimately select the target segments. Segmentation 720 may be performed using a convolutional neural network (CNN) 732 and may involve defining the boundaries of each segment by a best-fit ellipse 734, and the center of the target segment by vessel segment center coordinate determination 736. In some cases, multiple vessels may be identified and the best vessel may be selected. Further details regarding vessel selection are described herein in connection with FIG. 9. Finally, the selected vessel may be tracked frame by frame. In the case of a vein, the vein may be further analyzed to determine the blood flow through the vessel to ensure that it is a good candidate for cannulation.

[0052] Once the target vessel segment is selected, the needle alignment process 740 may begin automatically. Optionally, user input may further act as a decision as to whether the cannulation process should begin. If it is decided not to begin cannulation (NO), such as if the user is not satisfied with the identified target vessel, the operation may revert to image analysis and vessel segmentation so that another target vessel segment may be selected. If instead insertion is to begin (YES), the workflow may involve calculating the kinematics of the free-held device as it moves above the target position 742, aligning the cannulation instrument along the Y and Z axes to maintain a trajectory toward the target vessel 744, and advancing the cannulation instrument along the depth of the insertion axis toward the target vessel 746.

[0053] When the catheterization instrument reaches the target vessel, the workflow 700 may also perform a catheter placement process 750 to ensure proper insertion of the catheter into the target vessel. The catheter insertion process 750 may involve lowering the angle of insertion of the guide needle 752, retracting the guide needle 554, and inserting the catheter sheath into the target vessel 756. After completion of catheter placement, the device may be moved away from the patient and the guide needle may be removed from the device. Some or all steps of the catheter placement process 750 may be monitored using an imaging unit, such that one or more steps may be confirmed by visualization before proceeding to the next step of the process. A long axis (longitudinal) orientation of the ultrasound probe may be advantageous for imaging the catheter sheath during insertion.

[0054] Lowering the angle of insertion of the guide needle 752 may be performed as part of an automatic routine along with needle and catheter insertion. One example routine may involve gradually adjusting the angle of insertion of the instrument at different stages of the insertion process. For example, after aligning the catheter with the target vessel segment, the angle of insertion may be approximately 30 degrees. Then, after inserting the catheter into the target vessel center, the angle of insertion may be lowered to approximately 15 degrees. Finally, as the catheter is slowly inserted into the vessel lumen, the angle of the instrument may be changed to approximately 10 degrees. This may be performed during or before the guide needle is automatically retracted 754. Additionally, and as can be seen from FIG. 7, the degrees of freedom of the device include the ability to move the catheter in a vertical translation direction Z m , needle insertion direction Inj m , and the insertion angle θ m This allows the angle to be moved in an angular direction to vary, thus enabling the above routine.

[0055] 8 is a flow diagram of an example routine 800 for a catheter placement process according to the present disclosure. In block 810, the guide needle and catheter sheath are advanced toward the target vessel location in the direction of insertion. At this stage, the guide needle and catheter sheath may be locked together using a latch or other connecting element. In block 820, the device continuously or repeatedly checks whether the target vessel has been successfully punctured. Successful puncture may involve an indication of increased pressure, a blood flush, any one or more other indicators set forth herein.

[0056] Upon detection of successful puncture, operation may continue at block 830 where the guide needle and carriage are retracted in a direction opposite to the direction of insertion. The retraction may be controlled to have a constant velocity, which may be equal and opposite to the rate at which the guide needle and catheter sheath are advanced toward the target vascular location beginning at block 810.

[0057] FIG. 8 shows an example subroutine 800 for retracting the needle carriage and guide needle. In the subroutine, in block 832, the carriage is first released from the catheter sheath support. Then, in block 834, a constant force is applied to the carriage, which pushes or pulls the carriage away from the target vessel location. Additionally, in block 636, a speed or force limiting effect is applied to the constant force to ensure that the speed at which the carriage retracts away from the catheter heath does not exceed a predetermined amount. The routine 800 further includes, in block 840, that as the needle carriage and guide needle are retracted, the catheter sheath and catheter sheath support continue to be advanced toward the target vessel. Because the advancement occurs at the same speed as the retraction, the guide needle can be effectively held stationary relative to the target vessel while the catheter sheath continues to advance into the target vessel. This can prevent the catheter sheath from buckling as the guide needle is being removed.

[0058] FIG. 9 illustrates an example subroutine for selecting a target vessel for catheter insertion. The target vessel may be a segment of a vessel identified using a vessel segmentation routine. The vessel segmentation routine may use a machine learning model, such as a convolutional neural network (CNN), to identify candidate segments for catheterization. In one implementation, the machine learning model may be based on a U-Net architecture that provides pixel-level semantic labeling of each ultrasound image acquired by the imaging unit. The image labels identify which pixels belong or do not belong to a vessel segment. The model may be trained and validated using previously collected ultrasound images of the vessel.

[0059] In block 910, the device acquires one or more images of a target location. The target location may be a location under the patient's skin that includes one or more potential target blood vessels for insertion of a catheter. In block 920, the device identifies a number of candidate blood vessel segments.

[0060] In block 930, characteristics or features of each of the candidate vessel segments may be determined. The characteristics or features of the segments may include, but are not limited to, blood flow quality 932, distance of the candidate segment from a nearby artery 934, a confidence value 936 indicating a degree or level of certainty that the machine learning model will identify the candidate segment, and a cross-sectional area 938 of the candidate segment. The blood flow quality measurement 932 may be obtained by optical detection or a block tracking technique, including but not limited to measuring the Doppler signal strength of blood flow through the candidate segment. The distance from the artery 934 and the cross-sectional area 938 may be determined based on visual data collected by the imaging unit. The confidence value 936 may describe the certainty that the machine learning model will correctly identify the candidate segment. Additional factors such as the depth and angle of the candidate segment relative to the device may be included as characteristics or features of each of the candidate vessel segments. Respective values ​​may be calculated for and assigned to each of the determined characteristics or features.

[0061] In block 940, the device calculates a score for each candidate segment based on the determined features or characteristics of the segment in block 930. In one example, each value calculated in block 930 may be weighted by a respective weighting factor, and the weighted values ​​may be summed to arrive at a weighted sum. The weighted sum may then represent an overall score for the candidate segment. The candidate segment with the highest score may then be the best candidate for catheter insertion. The weighting of each factor may be pre-determined and stored in the memory of the device. In general, certain factors, such as cross-sectional area, typically have more influence on vessel segment selection and therefore may be assigned a larger weight than other factors.

[0062] In some instances, the score may be influenced by additional factors, such as vascular elasticity, vascular containment to indicate the likelihood of vascular collapse or deformation based on established clinical rules and conventions.

[0063] The highest scoring candidate vessel segment may be selected for catheterization in block 950, and the device may initiate a program to advance the catheter and guide needle toward the selected segment in block 960. In this regard, the selection may be fully automated, from acquiring image and sensor data to the positioning unit initiating advancement of the catheter toward the selected segment.

[0064] The above example subroutines may be implemented using a processor, microcontroller, and memory included in a catheter treatment device, such as the components shown and described in connection with Figure 2. Additionally, it should be recognized that the steps of the example subroutines may, in some cases, be performed in a different order or simultaneously, some steps may be omitted from some example routines, or other steps may be added.

[0065] The present disclosure generally describes techniques for catheterization using fully automated handheld devices. However, it should be understood that the same or similar techniques may be beneficial and applicable to other devices that are not handheld, such as bench-mounted devices, or other devices that are not fully automated, such as partially automated or manual catheterization devices. For example, the techniques described herein for vessel segmentation and selection are suitable for any device used for catheterization, regardless of how the needle and catheter sheath are advanced and operated under the patient's skin. In a further example, the techniques for automatically disengaging a catheter sheath from a needle may be applied to any catheterization device, regardless of whether the sheath is advanced toward its target location in a manual or automated fashion.

[0066] The present disclosure generally describes the guidance and release of a catheter into a target blood vessel of a patient. However, it should be appreciated that at least some of the devices and techniques described above may be used to guide or release other instruments into a target blood vessel of a patient, for example, a cannula into a vein of a patient. Additionally, the devices and techniques described above may be used for other venous or arterial access applications, including, but not limited to, guidewire penetration, intravenous infusion, short-term peripherally inserted catheters, long-term peripherally inserted catheters, central venous catheters, intravenous fluid bolus, introduction of intravenous devices, initiation of hemodialysis, arteriovenous fistulas, arterial blood gas sampling, intra-arterial blood pressure measurement, arterial blood transfusion, and introduction of intra-arterial devices. The devices and techniques may further be implemented in other needle insertion procedures, including, but not limited to, peripheral nerve blocks, targeted tissue biopsies, fluid aspiration and drainage, joint aspiration and infusion, needle-based ablation, spinal tap, trocar introduction, and percutaneous surgery.

[0067] The devices and methods described above are applicable to both human patients and other animal subjects, such as veterinary applications. More generally, those skilled in the art will readily understand and appreciate that the above-described devices and methods for correcting the trajectory of a handheld cannulated treatment instrument based on movement of a target location may be applicable to any cannulated treatment procedure in which unpredictable movement of the subject, unpredictable movement of the person holding the device, or both may be present.

[0068] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and other arrangements may be devised without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. 1. A method of automated cannulation, comprising: receiving, by one or more processors, imaging data of a target location including one or more target blood vessels for insertion of a cannula under the patient's skin; identifying, by the one or more processors, a number of candidate vessel segments from among the one or more vessels; determining, by the one or more processors, a plurality of characteristics of each of the candidate vessel segments based on the imaging data, at least one of the plurality of characteristics being a vessel cross-sectional area; assigning, by the one or more processors, a respective plurality of values ​​for each of the identified candidate vessel segments based on the determined plurality of features, each value corresponding to a respective feature; calculating, by the one or more processors, a total score for each of the identified candidate vessel segments based on the respective plurality of values; selecting, by the one or more processors, the highest scoring candidate vessel segments based on the calculated total scores; outputting, by the one or more processors, the selected highest scoring candidate vessel segments; and A method comprising:

2. further comprising assigning a respective predefined weight to each of the respective plurality of values ​​of the identified candidate vessel segments; The method of claim 1 , wherein for each identified candidate vessel segment, the total score of the identified candidate vessel segment is a weighted sum of its corresponding multiple values.

3. 2. The method of claim 1, wherein the plurality of features includes a distance of the identified candidate vessel segment from the patient's artery, the distance of the identified candidate vessel segment from the patient's artery being determined based on the imaging data.

4. The method of claim 1 , wherein the plurality of features includes a quality of blood flow through the identified candidate vessel segment, the quality of blood flow being determined based on a Doppler signal intensity derived from the imaging data.

5. 2. The method of claim 1, wherein identifying the plurality of candidate vessel segments from among the one or more vessels is performed using a machine learning model, and the plurality of features include a confidence level output by the machine learning model.

6. The method of claim 5 , wherein the machine learning model is a convolutional neural network.

7. 1. A method for automated catheterization, comprising: detecting, by a sensor, a puncture of a vessel wall of a target vessel by a needle supporting a catheter sheath; in response to detecting the vessel wall puncture, automatically releasing the needle carriage from a catheter sheath support to which the catheter sheath is attached; automatically retracting the carriage along an insertion axis of the needle at a uniform speed relative to the catheter sheath support; automatically advancing the catheter sheath into the target vessel along the insertion axis of the needle at the constant velocity while the carriage is automatically retracted such that a position of the needle relative to the target vessel is maintained; A method comprising:

8. 8. The method of claim 7, wherein automatically retracting the carriage includes applying a constant force to the carriage in a direction along the insertion axis of the needle away from the target vessel, the constant force being controlled to not exceed a predetermined threshold.

9. The method of claim 7 , wherein the sensor is a force sensor, and automatically releasing the carriage includes actuating a solenoid latch in response to detection of the vessel wall puncture by the force sensor.

10. 8. The method of claim 7, further comprising receiving an indication of success of the catheterization procedure separately from the indication of vessel wall puncture, and wherein automatically releasing the carriage is performed further in response to both the detection of vessel wall puncture and the indication of success of the catheterization procedure.

11. The indicators of success of the catheterization procedure include: an infrared emitter and collector sensor for detecting blood flushes; a force profile of force data collected at the force sensor during insertion of the needle into the target blood vessel; or Temperature readout indicating the presence of blood flush, The method of claim 10, wherein the at least one of

12. receiving, by one or more processors, imaging data of a target location under the patient's skin; identifying, by the one or more processors, a number of candidate vessel segments from among the one or more vessels; assigning, by the one or more processors, a respective likelihood of success value for each of the identified candidate vessel segments, the likelihood of success value indicating a likelihood of success of a cannulation procedure using the corresponding candidate vessel segment; determining, by the one or more processors, a cross-sectional area of ​​each of the candidate vessel segments based on the imaging data; assigning, by the one or more processors, a respective size value for each of the identified candidate vessel segments; calculating, by the one or more processors, a total score for each of the identified candidate vessel segments based on the respective likelihood of success values ​​and the respective size values; selecting, by the one or more processors, the highest scoring candidate vessel segments based on the calculated total scores; advancing, by the one or more processors, the guide needle and catheter toward the selected highest scoring candidate vessel segment of the target vessel; The method of claim 7 further comprising:

13. 1. A device for automated catheterization, comprising: a catheter sheath support configured to be mounted on a catheter treatment device, the catheter sheath support configured to hold a catheter sheath; a carriage configured to support a guide needle; a connector configured to removably engage the catheter sheath support to the carriage, the carriage configured to translate along an insertion axis of the guide needle independent of the catheter sheath support when the carriage is disengaged from the connector; a constant force actuator configured to control separation of the carriage from the catheter sheath support at a uniform velocity in response to disengagement of the connector; A device comprising:

14. The device of claim 13 , wherein the constant force actuator is a spring.

15. The device of claim 13 , wherein the constant speed is equal to a speed of insertion of the catheter sheath controlled by an injection motor of the handheld catheter treatment device.

16. The device of claim 13 , further comprising a rotational speed limiter configured to limit the magnitude of the constant speed to a predetermined threshold.

17. The force sensor may further include a force sensor positioned along the insertion axis of the guide needle, the force sensor comprising: Detecting a vessel wall puncture; transmitting a vessel wall puncture signal in response to detecting the vessel wall puncture; The device of claim 13 configured to:

18. The device of claim 17 , wherein the connector is configured to disengage in response to the vessel wall puncture signal.

19. 20. The device of claim 18, wherein the connector is a solenoid latch and the vessel wall puncture signal is a voltage to activate the solenoid latch.

20. 20. The device of claim 18, further comprising a blood flush sensor configured to detect successful insertion of the guide needle, the connector configured to disengage further in response to a signal indicating detection of successful insertion of the guide needle by the blood flush sensor.

21. 1. A device for automated catheterization, comprising: a first plurality of prongs extending from a bottom surface of a catheter treatment device, the first plurality of prongs having an open state and a closed state, the first plurality of prongs configured to hold the catheter sheath in place relative to the catheter treatment device when in the closed state; a track located on the bottom surface of the catheter treatment device; and a second plurality of prongs extending from the track and configured to hold a guide needle; a motor configured to control the track, where controlling the track moves the guide needle, where moving the guide needle moves the catheter sheath support when the first plurality of prongs are in an open state; and a controller configured to transition the first plurality of prongs from the open state to the closed state in response to detecting a successful catheterization procedure; A device comprising:

22. Successful catheterization is an infrared emitter and collector sensor for detecting blood flushes; a force profile of force data collected at the force sensor during insertion of the needle into the target blood vessel; or a temperature sensor for detecting an increase in temperature indicative of a blood flush; The device of claim 21 , wherein the detection is based on at least one of:

23. 1. A device for automated catheterization, comprising: A rail attached to the bottom surface of the catheter treatment device; a first support connected to the rail and configured to slide forward and backward along the rail, the first support configured to hold a catheter sheath; a magnet positioned at a front end of the rail, the first support being configured to magnetically attach to the magnet; and a track located on the bottom surface of the catheter treatment device; and a second support extending from the track and configured to hold a guide needle; a motor configured to control the track, where control of the track moves the guide needle to the second support, where movement of the guide needle moves the catheter sheath support and slides the first support along the rail when the first support is not magnetically attached to the magnet; and A device comprising:

24. 24. The device of claim 23, further comprising a controller configured to actuate the magnet in response to detecting a successful catheter procedure, the actuation of the magnet being configured to magnetically attach the first support to the magnet.

25. Successful catheterization is an infrared emitter and collector sensor for detecting blood flushes; a force profile of force data collected at the force sensor during insertion of the needle into the target blood vessel; or a temperature sensor for detecting an increase in temperature indicative of a blood flush; The device of claim 24, wherein the device is detected based on at least one of:

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