Cannula assembly and ultrasound system

Abstract

The invention relates to a cannula assembly having a cannula tube, which extends longitudinally between a distal cannula end and a proximal cannula end and has a distal cannula tip, and having a cannula attachment, which is mounted on the proximal cannula end. The cannula assembly also has a locating lance, which extends longitudinally between a distal lance end and a proximal lance end and is mounted in the cannula tube so as to be axially movable along the longitudinal axis of the cannula tube, the locating lance having a locating element at the distal lance end, the locating element being designed to be located by means of an ultrasound imaging method. The cannula assembly also has an actuating device, which is designed for a manual actuation and is operatively connected to the locating lance and by means of which the locating lance can be moved from a starting position into a locating position, wherein, in the starting position, the locating element is positioned within the cannula tube and, in the locating position, the locating element protrudes distally from the cannula tip outside the cannula tube. The invention also relates to an ultrasound system for use in an ultrasound imaging method, the ultrasound system having the locating lance.

Description

[0001] P 62167 WO 26 February 2026

[0002] - 1 - SR / rb

[0003] Cannula arrangement and ultrasound system

[0004] The invention relates to a cannula arrangement comprising a cannula tube extending longitudinally between a distal cannula end and a proximal cannula end and having a distal cannula tip, and a cannula connector arranged at the proximal cannula end. The invention further relates to an ultrasound system for use in an ultrasound imaging procedure.

[0005] Cannulas, also known as hollow needles, are used for a wide variety of medical applications, primarily for puncturing body tissue and subsequently injecting or aspirating fluids. They can also be used to insert catheters or other invasive devices, with the cannula tube serving as a delivery channel for the device.

[0006] In many medical applications, precise positioning of the cannula within body tissue is of particular importance, for example, when performing a peripheral nerve block, where the anesthesiologist must identify the nerve to be anesthetized and then position the cannula tip as close as possible to the nerve. Cannulas are therefore often positioned using ultrasound imaging techniques, whereby the position of the cannula, especially its tip, is monitored with the aid of an ultrasound image. This requires sufficient visibility of the cannula in the ultrasound image. In other words, the cannula must be clearly visible on ultrasound.

[0007] For example, the patent application EP 3 787 520 B1 discloses a method for providing instructions for operating a biopsy needle using an ultrasound imaging technique.

[0008] Typical cannulas have a hollow cylindrical profile with an annular cross-section and are made of metal, which usually provides sufficient ultrasound visibility.

[0009] Cannulas are known in the art that are intended to achieve improved ultrasonic visibility by modifying the surface properties of the cannula tube. This is achieved by providing echogenic structures on the cannula tube or by permanently attaching sensors to the cannula tip. The object of the invention is to provide a cannula arrangement of the type mentioned above that offers advantages over the prior art. In particular, it aims to enable improved visual differentiation between the cannula tube and the cannula tip in the ultrasonic image and, in particular, to improve the ultrasonic visibility of the cannula tip.

[0010] This problem is solved by providing a cannula arrangement with the features of claim 1 and an ultrasound system with the features of claim 7. Advantageous embodiments are specified in the dependent claims. The wording of the claims is incorporated herein by reference.

[0011] The cannula arrangement according to the invention comprises a locating lance extending longitudinally between a distal and a proximal end. The locating lance is axially movable within the cannula tube along a longitudinal axis of the cannula tube. The locating lance has a locating element at its distal end, which is configured to be located using an ultrasound imaging method. The locating element is arranged at a known axial distance from the distal end of the lance. Preferably, the axial distance is zero or, at least, negligibly small with regard to position determination. In other words, the locating element is preferably arranged directly at the distal end of the lance, particularly at a distal end tip. The locating element has improved ultrasound visibility compared to the cannula tube.The cannula assembly further comprises an actuating device designed for manual operation, which is operatively connected to the locating lance and by means of which the locating lance can be moved from a starting position to a locating position. In the starting position, the locating element is arranged inside the cannula tube. In the locating position, however, the locating element is arranged at least partially, and advantageously completely, extending distally from the cannula tip outside the cannula tube. The locating lance is movably mounted between these two positions.

[0012] The cannula arrangement according to the invention allows the user to reliably locate or identify the cannula tip in a corresponding ultrasound image using a generally known ultrasound imaging system. The user performs the medical procedure, such as a peripheral nerve block, as usual. During the puncture, the locating lance, including the locating element, is located inside the cannula tube, so the puncture characteristics of the cannula remain unchanged. If the user wishes to orient themselves during the puncture, i.e., when the cannula tip is inside the body, they can move the locating lance from its starting position to the locating position by manually operating the actuating device, in particular by pushing or sliding it.In the locating position, the locating element protrudes distally beyond the cannula tip from the cannula tube, making it clearly visible in the ultrasound image. This allows for easy determination of the cannula tip's position. The cannula arrangement according to the invention also has the advantage of not requiring complex (software and / or hardware) integration into the ultrasound imaging system. Therefore, the cannula arrangement according to the invention is particularly versatile and can be easily used in place of conventional cannulas. The locating lance is designed as a separate component. Since the locating element is not located on the cannula tube but rather on or attached to the locating lance, the manufacturing of the cannula tube is also simplified. In other words, standard cannulas can be used.To assemble the cannula assembly, the locating lance is inserted distally through the cannula connector and from there through the proximal end of the cannula into the cannula tube. The cannula connector has a corresponding opening for this purpose.

[0013] In one embodiment of the invention, the locating element is a sensor. This sensor can, for example, be a piezoelectric sensor, specifically a PVDF film with a gold coating. Additionally or alternatively, the locating element can have a highly echogenic structure. The highly echogenic structure can, for example, be a porous surface structure which, compared to a smooth surface of the rest of the cannula tube, reflects the ultrasound waves better and thus provides improved visibility in an ultrasound image. In particular, the highly echogenic structure can be easily incorporated into the proximal end of the locating lance.

[0014] In a further embodiment of the invention, the distal end of the locating lance protrudes from the cannula tip by a maximum of 10 mm, preferably a maximum of 7 mm, and particularly preferably a maximum of 5 mm, when the lance is advanced into the locating position. The distal end of the lance is preferably a front face of the locating lance. The mobility of the locating lance is thus limited axially in the proximal direction. The mobility of the locating lance is preferably also limited in the distal direction or secured by a locking mechanism to prevent the lance from accidentally falling out of the cannula tube during use of the cannula assembly.

[0015] In a further embodiment of the invention, the actuating device comprises a pressure element for its actuation. The pressure element can, for example, be a push button or be designed in the manner of a thumb rest on a syringe. The pressure element is arranged at the proximal end of the locating lance. In an advantageous embodiment, the pressure element is directly connected to the locating lance. The pressure element is preferably formed integrally with the locating lance. The actuating device or the pressure element has an actuation direction that extends along the longitudinal axis of the cannula tube or the locating lance toward the distal end of the locating lance. When the actuating device is actuated, the actuation path is axially limited. During actuation, the pressure element is pressed in until it preferably abuts a stop element.When the pressure element rests against this stop element, the locating lance is in the locating position in this advantageous design. The axial limitation of the actuation path also allows for error-free and repeatable use of the cannula arrangement, in particular error-free and repeatable positioning of the cannula tip.

[0016] In a further embodiment of the invention, the cannula assembly comprises a retraction unit, which is advantageously arranged at the cannula base. The retraction unit is designed to move the locating lance axially within the cannula tube along the longitudinal axis of the cannula tube from the locating position to the initial position. In other words, the retraction unit causes the locating lance to retract or be pre-tensioned towards the initial position. It can therefore also be referred to as a pre-tensioning unit. This automatically retracts the locating lance back into the cannula tube to its initial position after the actuating device has been activated and, if applicable, after the cannula tip has been located. This simplifies the handling of the cannula assembly during the puncture.

[0017] In a further embodiment of the invention, the cannula assembly comprises an intermediate piece that is detachably connected to the cannula tip. The locating lance is axially guided within the intermediate piece. In one embodiment, the locating lance has a connecting unit by means of which it is connected to a complementary connecting unit of the intermediate piece. The locating lance can be withdrawn from the cannula tube in a proximal direction, optionally after prior release of a retention device for the locating lance. This allows, among other things, reuse of the locating lance. Preferably, a connecting tube, in particular an injection tube, can be fluidly connected to the cannula tube via the intermediate piece. For this purpose, the intermediate piece has at least one corresponding connection, such as a Luer-lock connector.

[0018] The ultrasound system according to the invention is designed for use in an ultrasound imaging procedure. The ultrasound system is further designed to determine the position of a cannula tip in an ultrasound image. The ultrasound system according to the invention comprises a locating lance that extends longitudinally between a distal and a proximal end and has a locating element at the distal end, which is configured to be located by means of an ultrasound imaging procedure. The locating lance is designed to be arranged in the cannula tube of a cannula, in which the locating lance is axially movable along a longitudinal axis of the cannula tube. An actuating device, as already described above for the cannula arrangement, can be associated with the locating lance, with which the locating lance can be moved from the initial position to the locating position.

[0019] Further advantages and features of the invention will become apparent from the claims and from the following description of preferred embodiments of the invention, which are illustrated with reference to the drawings.

[0020] Fig. 1 shows a schematically simplified side view of an embodiment of a cannula arrangement according to the invention with a locating lance which is in a starting position,

[0021] Fig. 2 shows the cannula arrangement according to Fig. 1, wherein the locating lance is in a locating position, and

[0022] Fig. 3 shows a schematic block representation of an embodiment of an ultrasound system according to the invention.

[0023] According to Figures 1 and 2, a cannula arrangement 1 according to the invention comprises a cannula tube 2 and a cannula tip 4. The cannula arrangement 1 is used in particular for the puncture of body tissue for subsequent injection and / or aspiration of fluid.

[0024] The cannula tube 2 extends longitudinally between a distal cannula end 2A and a proximal cannula end 2B and has a distal cannula tip 3. In the illustrated embodiment, the distal cannula end 2A forms the cannula tip 3.

[0025] The cannula attachment 4 is attached to the proximal cannula end 2B in a known manner.

[0026] The cannula assembly 1 further comprises a locating lance 5, which extends longitudinally between a distal lance end 5A and a proximal lance end 5B. The locating lance 5 is axially movable within the cannula tube 2 along a longitudinal axis L of the cannula tube 2, as shown in Figures 1 and 2. The locating lance 5 has a locating element 6 at its distal lance end 5A.

[0027] The locating element 6 is designed to be located using an ultrasound imaging method. The locating element 6 is arranged at a known axial distance from the distal end of the lance 5A, in particular from a distal end of the lance. In this case, this axial distance is zero, so that the locating element 6 is located directly at the distal end of the lance 5A. In the embodiment shown, the locating element 6 is a sensor 6'.

[0028] In alternative versions not shown, the locating element 6 has an echogenic structure, such as a porous surface structure.

[0029] The cannula assembly 1 further comprises an actuating device 7. The actuating device 7 is designed for manual operation. Furthermore, the actuating device 7 is operatively connected to the locating lance 5, whereby the locating lance 5 can be moved from a starting position to a locating position by actuating the actuating device 7. The actuation direction BR of the actuating device 7, or the pressure element 8, runs along the longitudinal axis L of the cannula tube 2, or of the locating lance 5, in the direction of the distal end 2A of the lance, as shown in Fig. 1.

[0030] In the initial position, the locating element 6 is arranged inside the cannula tube 2, as shown in Fig. 1.

[0031] In the locating position, the locating element 6 projects distally from the cannula tip 3 and is positioned outside the cannula tube 2 (Fig. 2). In the illustrated embodiment, the locating element 6 projects completely out of the cannula tip 3 in the locating position. In this position, the locating element 6 is clearly and distinctly displayed in an ultrasound image.

[0032] In the illustrated embodiment, the distal end 5A of the locating lance 5 protrudes from the cannula tip 3 by a projection d of 5 mm in the locating position. The locating position corresponds here to the endpoint of the maximum possible range of motion in the proximal direction.

[0033] The actuating device 7 has a pressure element 8 for its actuation. The pressure element 8 is arranged at the distal end 5B of the locating lance 5. In the embodiment shown, the pressure element 8 is formed integrally with the locating lance 5 and can be actuated by the user with a finger.

[0034] The cannula assembly 1 further comprises a reset unit 9. The reset unit 9 is designed to hold the pressure element 8, and thus also the locating lance 5, in the initial position as long as the actuating device 7 is in a non-actuated state, and to hold the locating lance 5 in the locating position as long as the actuating device 7 is in an actuated state.

[0035] In the embodiment shown, the reset unit 9 is arranged proximally to the cannula connection 4 and is configured to, on the one hand, move the locating lance 5 axially within the cannula tube 2 along the longitudinal axis L of the cannula tube 2 from the locating position to the initial position, and on the other hand, to return the pressure element 8 of the actuating device 7 to the non-actuated state. If the pressure element 8 is pressed from the position shown in Fig. 1 towards the cannula tip 3, the locating lance 5 is also pressed or moved against the action of the reset unit 9 towards the cannula tip 3 until the sensor 6' protrudes from the cannula tube 2. If the pressure element 8 is then released, the reset unit 9 pushes the pressure element 8, and thus also the locating lance 5, into the position shown in Fig. 1.

[0036] In the embodiment shown, the return unit 9 is a compression spring 10. The compression spring 10 is arranged between the cannula attachment 4 and the pressure element 8. In this configuration, when the locating lance 5 is in the locating position, the compression spring 10 is in a maximally compressed state, thus limiting the axial movement of the locating lance 5 in the proximal direction.

[0037] In an embodiment not shown, the cannula arrangement 1 has a stop element which limits the axial movement of the locating lance 5 in the proximal direction.

[0038] In the present case, the cannula assembly 1 further comprises an intermediate piece 12. The intermediate piece 12 is arranged between the cannula attachment 4 and the pressure element 8. In the example shown, the intermediate piece 12 is detachably connected to the cannula attachment 4. The locating lance 5 is guided axially within the intermediate piece 12.

[0039] The locating lance 5 has a fastening unit (not shown in the figures) by means of which the locating lance 5 is detachably connected to a complementary connecting unit of the intermediate piece 12 (also not shown in the figures). In the example shown, the intermediate piece 12 has a connection 13, in this case in the form of a Luer-lock connection. A connecting hose 11 is fluidly connected to the cannula tube 2 via this connection 13.

[0040] Before administering an injection, the locating lance 5 can be withdrawn proximally from the cannula tube 2 and removed. However, configurations are also conceivable and possible in which the locating lance 5 can remain in the cannula tube 2 for this purpose.

[0041] According to Fig. 3, an ultrasound system 100 according to the invention is provided for use in an ultrasound imaging procedure. The ultrasound system 100 is further configured to determine the position of a cannula tip in an ultrasound image.

[0042] The ultrasound system 100 includes an ultrasound device 20. The ultrasound device 20 has a function that is generally known to specialists, so that its features do not need to be discussed in detail.

[0043] The ultrasound device 20 comprises an optional ultrasound head 21, an evaluation unit 22, and an optional display unit 23. The optional ultrasound head 21 and the optional display unit 23 are not present in all embodiments.

[0044] The ultrasound system 100 according to the invention has a locating lance 5 as shown in Figs. 1 and 2.

[0045] To determine the position of a cannula tip 3 in an ultrasound image, the user first performs the medical procedure as usual. During the puncture of body tissue using the cannula assembly 1, the locating lance 5, including the locating element 6, is located inside the cannula tube 2. To determine the position of the cannula tip 3, the user manually activates the actuating device 7 as described above, causing the locating lance 5 to move from its initial position to the locating position. The locating element 6, which protrudes distally from the cannula tip 3, is clearly displayed on the display unit 23 in the ultrasound image, thus allowing the position of the cannula tip 3 to be determined.

Claims

Patent claims 1. Cannula arrangement (1), comprising: a cannula tube (2) which extends longitudinally between a distal cannula end (2A) and a proximal cannula end (2B) and has a distal cannula tip (3), a cannula attachment (4) arranged at the proximal cannula end (2B), a locating lance (5) extending longitudinally between a distal lance end (5A) and a proximal lance end (5B) and arranged axially movable in the cannula tube (2) along a longitudinal axis (L) of the cannula tube (2), wherein the locating lance (5) has a locating element (6) at the distal lance end (5A) which is configured to be located by means of an imaging ultrasound procedure, and an actuating device (7) which is designed for manual actuation, is operatively connected to the locating lance (5) and by means of which the locating lance (5) can be moved from a starting position to a locating position, wherein in the starting position the locating element (6) is arranged inside the cannula tube (2) and in the locating position the locating element (6) is arranged distally outside the cannula tube (2) protruding from the cannula tip (3).

2. Cannula arrangement (1) according to claim 1, wherein the locating element (6) is a sensor (6') and / or has an echogenic structure.

3. Cannula arrangement (1) according to claim 1 or 2, wherein the distal end of the lance (5A), in particular a front end face, of the locating lance (5) projects distally from the cannula tip (3) by a maximum of 10 mm, preferably by a maximum of 7 mm, particularly preferably by a maximum of 5 mm, in the locating position.

4. Cannula arrangement (1) according to one of claims 1 to 3, wherein the actuating device (7) has a pressure element (8) for its manual actuating, which is arranged at the distal lance end (5B) of the locating lance (5) and is preferably directly connected to the locating lance (5).

5. Cannula arrangement (1) according to any one of claims 1 to 4, wherein a return unit (9) is provided which is arranged on the cannula attachment (4) and is configured to move the locating lance (5) axially in the cannula tube (2) along the longitudinal axis (L) of the cannula tube (2) from the locating position to the starting position.

6. Cannula arrangement (1) according to any one of claims 1 to 5, wherein an intermediate piece (12) is provided which is detachably connected to the cannula attachment (4) and in which the locating lance (5) is guided, wherein the locating lance (5) can be withdrawn from the cannula tube (2) in a proximal direction.

7. Ultrasound system (100) for use in an ultrasound imaging procedure, comprising a locating lance (5) which extends longitudinally between a distal lance end (5A) and a proximal lance end (5B) and has a locating element (6) at a distal end (5A) which is configured to be located by means of an ultrasound imaging procedure.

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