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EP-4520390-B1 - SET FOR NERVE STIMULATION

EP4520390B1EP 4520390 B1EP4520390 B1EP 4520390B1EP-4520390-B1

Inventors

  • PAJUNG-SCHELLING, Simone
  • Hauger, Martin

Dates

Publication Date
20260513
Application Date
20240828

Claims (18)

  1. Set (10) for nerve stimulation comprising a device (100) for nerve stimulation with a distal end (100a), wherein the device (100) comprises an electrically conductive stimulation element and a channel for supplying a fluid, and comprising an indwelling cannula (200) with an indwelling cannula tube (240) having a distal end (240a) and a proximal end (240b), wherein the device (100) has a first connector part (180) and the indwelling cannula (200) has a second connector part (280) complementary to the first connector part (180), wherein, by connecting the first connector part (180) and the second connector part (280), the device (100) can be fixed in an axial position in which the distal end (100a) of the device (100) projects beyond the distal end (240a) of the indwelling cannula (200), wherein, in the connected state of the first connector part (180) and the second connector part (280), the first connector part (180) and the second connector part (280) are connected to one another in such a way that a circumferential first seal (500) is formed, characterized in that the second connector part (280) sealingly surrounds the indwelling cannula tube (240) at a distal end (280a) and widens in the direction toward a proximal end (280b), so that, adjacent to the proximal end (280b) of the second connector part (280), an annular gap (410) is formed between the second connector part (280) and the inserted device (100), and in that the first connector part has an annular groove (187) open in the direction toward a distal end (180a), into which, in the connected state of the first connector part (180) and the second connector part (280), the proximal end (280b) of the second connector part (280) dips.
  2. Set according to claim 1, characterized in that the first seal (500) is formed by abutment of a first contact surface (181) of the first connector part (180) against a second contact surface (281) of the second connector part (280).
  3. Set according to claim 2, characterized in that the first connector part (180) has a distal surface (182) on which a circumferential first projection (185) projecting in the axial direction is arranged, and the second connector part (280) has a proximal surface (182) on which a circumferential second projection (285) projecting in the axial direction is arranged, and the first contact surface (181) is arranged on the outside of the first projection (185) and the second contact surface (281) is arranged on the inside of the second projection (285), or alternatively the first contact surface (181) is arranged on the inside of the first projection (185) and the second contact surface (182) is arranged on the outside of the second projection (285).
  4. Set according to one of claims 2 to 3, characterized in that the first contact surface (181) has a circumferential bead projecting in the direction toward the second contact surface (281) and/or the second contact surface (281) has a circumferential bead (283) projecting in the direction toward the first contact surface (181).
  5. Set according to one of the preceding claims, characterized in that the first projection (185) is arranged on a bottom surface (187a) of the annular groove (187).
  6. Set according to one of the preceding claims, characterized in that the channel of the device (100), in particular the tube (140) of the device (100), has a lateral opening (149), which opens in particular into the annular gap (410) in the connected state of the first connector part (180) and the second connector part (280).
  7. Set according to one of the preceding claims, characterized in that the connecting of the first connector part (180) and the second connector part (280) is effected in the manner of a bayonet lock, wherein preferably the engagement of the bayonet lock is perceptible haptically and/or acoustically.
  8. Set according to one of the preceding claims, characterized in that the stimulation element is designed as an electrically conductive stimulation wire (120) having a diameter (AD), a distal end (120a), and a proximal end (120b), and the channel is designed as an electrically insulating tube (140) having an inner diameter (IS), an outer diameter (AS), a distal end (140a), and a proximal end (140b), wherein the stimulation wire (120) is arranged in the tube (140), wherein the inner diameter (IS) of the tube (140) is greater than the diameter (AD) of the stimulation wire (120), so that a gap (146) for supplying fluid is formed in the tube (410), wherein a stimulation electrode (130) is electrically conductively arranged at the distal end (120a) of the stimulation wire (120), said stimulation electrode projecting beyond the distal end (140a) of the tube (140).
  9. Set according to claim 8, characterized in that the proximal end (140b) of the tube (140), together with the connection point to the stimulation cable (150) and the connection point to the injection tube (160), is arranged in a housing (170), wherein the stimulation cable (150) and the injection tube (160) are led proximally out of the housing (170), in particular parallel to the longitudinal axis of the tube (140), and the first connector part (180) is arranged on the housing (170), in particular integrally connected thereto.
  10. Set according to one of the preceding claims, characterized in that the set (10) further comprises a rigid cannula (300) with a cannula tube (340) having a distal end (340a) and a proximal end (340b) for insertion into a body, onto which the indwelling cannula (200) can be pushed before insertion and which has, at its proximal end (340b), a third connector part (380) complementary to the second connector part (280), wherein, by connecting the third connector part (380) and the second connector part (280), the cannula (300) can be fixed in an axial position in which the distal end (340a) of the cannula tube (340) projects beyond the distal end (240a) of the indwelling cannula (200), wherein the third connector part (380) and the second connector part (280) are connected to one another in such a way that a circumferential second seal (500) is formed.
  11. Set according to claim 10, characterized in that the second seal (500) is formed by abutment of a third contact surface (381) of the third connector part (380) against the second contact surface (281) of the second connector part (280).
  12. Set according to claim 3 and claim 11, characterized in that the third connector part (380) has a distal surface (382) on which a circumferential third projection (385) projecting in the axial direction is arranged, and the third contact surface (381) is arranged on the outside of the third projection (385) and the second contact surface (281) is arranged on the inside of the second projection (285), or alternatively the third contact surface (381) is arranged on the inside of the third projection (385) and the second contact surface (281) is arranged on the outside of the second projection (285).
  13. Set according to one of claims 11 or 12, characterized in that the third contact surface (381) has a circumferential bead projecting in the direction toward the second contact surface (281) and/or the second contact surface (281) has a circumferential bead (283) projecting in the direction toward the third contact surface (381).
  14. Set according to one of claims 10 to 13 and according to claim 5, characterized in that the third connector part (380) has an annular groove (387) open in the direction toward a distal end (380a), into which, in the connected state of the third connector part (380) and the second connector part (280), the proximal end (280b) of the second connector part (280) dips, wherein preferably the third projection (385) is arranged on a bottom surface (387a) of the annular groove (387).
  15. Set according to claim 14, characterized in that the cannula tube (340) has a lateral opening (349), which opens in particular into the annular gap (510) in the connected state of the third connector part (380) and the second connector part (280).
  16. Set according to one of claims 10 to 15, characterized in that the connecting of the third connector part (380) and the second connector part (280) is effected in the manner of a bayonet lock, wherein preferably the engagement of the bayonet lock is perceptible haptically and/or acoustically.
  17. Set according to one of claims 10 to 16, characterized in that the cannula tube (340) is made of an electrically conductive material and an electrically conductive stimulation cable (350) is electrically conductively connected to the outside of the cannula tube (340), and wherein an injection tube (360) is slipped sealingly in sections over the proximal end (340b) of the cannula tube (340).
  18. Set according to claim 17, characterized in that the proximal end (340b) of the cannula tube (340), together with the connection point to the stimulation cable (350) and the connection point to the injection tube (360), is arranged in a housing (370), wherein the stimulation cable (350) and the injection tube (360) are led proximally out of the housing (370), in particular parallel to the longitudinal axis of the cannula tube (340), and the third connector part (380) is arranged on the housing (370), in particular integrally connected thereto.

Description

The invention relates to a set for nerve stimulation. It is known that electrical current pulses, such as low-frequency alternating current, are used to deliver low-voltage pulses to the skin via electrodes placed on the skin to stimulate the nerves transcutaneously. However, the skin presents a comparatively high contact resistance. Furthermore, the stimulation is usually applied over a large area. It is also known to design rigid cannulas, which are inserted through the skin, especially those guided through an indwelling cannula, to be stimulated with an electrical connection in order to obtain conclusions about the positioning of the tip of the cannula, in particular whether the tip of the cannula is in contact with a nerve. The state of the art includes the following: WO 97/15347 A1 , US 2009/287140 A1 , DE 298 20 525 U1 and US 2004/073159 A1 named. The object of the invention is to provide an improved method for nerve stimulation, which is particularly versatile and preferably allows for more direct stimulation. The object of the invention is solved by a set for nerve stimulation with the features of claim 1. Advantageous embodiments and further developments of the invention are specified in the dependent claims. The nerve stimulation set according to the invention comprises a nerve stimulation device with a distal end, wherein the device includes an electrically conductive stimulation element and a channel for supplying a fluid, and further comprises an indwelling cannula with an indwelling cannula tube having a distal end and a proximal end, wherein the device has a first connector part and the indwelling cannula has a second connector part complementary to the first connector part, wherein by connecting the first connector part and the second connector part the device can be fixed in an axial position in which the distal end of the device projects beyond the distal end of the indwelling cannula, wherein in the connected state of the first connector part and the second connector part the first connector part and the second connector part are connected to each other in such a way that a circumferential first seal is formed. The set according to the invention is suitable for both nerve stimulation and the administration of a fluid, for example, a liquid such as an anesthetic. The device can be positioned in the body for extended periods via the indwelling cannula, enabling a wide range of applications. The indwelling cannula tube can be made of a plastic, preferably a polyamide, and is preferably electrically insulating. In particular, the indwelling cannula tube has a higher flexural rigidity than the part of the nerve stimulation device inserted into the indwelling cannula, thus simplifying the advancement of the device through the indwelling cannula tube. On the other hand, a flexible design is also possible. of the indwelling cannula tube, in order to have as little disturbance as possible to the patient, even when the indwelling cannula is placed in the body for a long time. The circumferential first seal seals the space between the nerve stimulation device and the indwelling cannula, allowing fluid to be introduced into this space. This offers the advantage that the nerve stimulation device, located within the indwelling cannula, can be observed more effectively along its entire length using ultrasound. Preferably, the first seal is formed by placing a first contact surface of the first connector part on a second contact surface of the second connector part, thereby avoiding the need for additional components such as a sealing ring. According to an advantageous embodiment, the first connector part has a distal surface on which an axially projecting circumferential first projection is arranged, and furthermore, the second connector part has a proximal surface on which an axially projecting circumferential second projection is arranged, wherein the first contact surface is located on the outside of the first projection and the second contact surface on the inside of the second projection, or alternatively, the first contact surface is located on the inside of the first projection and the second contact surface on the outside of the second projection. In this way, a circumferential contact surface can be formed between the first contact surface and the second contact surface over an axially extending section. which enables reliable formation of the first seal. Preferably, the first contact surface has a circumferential bead projecting towards the second contact surface and/or the second contact surface has a circumferential bead projecting towards the first contact surface, which in particular causes the first projection and the second projection to bear against each other under preload, thereby improving the sealing effect. According to the invention, the second connector part seals around the indwelling cannula tube at a distal end and widens towards a proximal end, so that an annular gap is for