DE102024116129A1 - Shaft arrangement for a medical instrument - Google Patents

Abstract

The invention relates to a shaft assembly (12) for a medical instrument (10), comprising a proximal shaft section (18) having a proximal shaft section longitudinal axis (26), and a distal shaft section (20) having a distal shaft section longitudinal axis (32), wherein the two shaft sections are connected to each other in the region of a connecting joint (22) and are rotatable relative to each other, wherein at least one of the end faces of the two shaft sections facing the connecting joint is oriented at an angle deviating from 90° relative to the respective shaft section longitudinal axis, wherein the connecting joint has at least one locking element displaceable along a displacement path, which in a locking state of the shaft assembly assumes a locking position and secures the distal shaft section to the proximal shaft section, and which in a release state of the shaft assembly assumes a release position and prevents the distal shaft section from being released from the proximal shaft section enabled.

Description

The invention relates to a shaft arrangement for a medical instrument, comprising a proximal shaft section having a proximal shaft section longitudinal axis, and a distal shaft section having a distal shaft section longitudinal axis, wherein the two shaft sections are connected to each other in the region of a connecting joint and are rotatable relative to each other, wherein at least one of the end faces of the two shaft sections facing the connecting joint is oriented at a 90° angle relative to the respective shaft section longitudinal axis.

Such a shaft arrangement is derived from the WO 2023/006541 A1 known.

The invention is based on the objective of providing an easily cleanable shaft arrangement, which is preferably modularly expandable.

This task is solved in a shaft arrangement mentioned above by the fact that the connecting joint has at least one locking element that can be displaced along a displacement path, which in a locking state of the shaft arrangement assumes a locking position and secures the distal shaft section to the proximal shaft section, and which in a release state of the shaft arrangement assumes a release position and allows the distal shaft section to be released from the proximal shaft section.

The shaft arrangement is a component of a medical instrument, which may be, for example, a hand-held or robot-held instrument, or a hybrid instrument that is hand-held and has robotic and/or motor support for individual functions.

The medical instrument can be a fully handheld instrument where all movements are performed manually. Alternatively, it can be a robotic instrument, in which an actuator unit replaces the handle to control the instrument's movements. This actuator unit is mounted, for example, on a robotic arm or can be mounted on one. Another alternative is a hybrid instrument, which may have a handle, but where certain movements are controlled or assisted robotically or by motors/electrics. In all variants, it is possible to incorporate additional electrical components, such as sensors or electrical elements like ultrasound or RF electrodes (RF: radio frequency), which are typically located in or on an applicator (e.g., the mouthpiece of the instrument).

The shaft arrangement according to the invention makes it possible to selectively secure the distal shaft section to the proximal shaft section or to remove the distal shaft section from the proximal shaft section. The locking state of the shaft arrangement corresponds to a locking position of the locking element in which the locking element prevents the distal shaft section from detaching from the proximal shaft section. This locking state corresponds to a usage state of the medical instrument, particularly during a surgical procedure.

In the released state and in a state where the distal shaft section is detached from the proximal shaft section, both shaft sections are easily accessible in the area of their end faces and can be cleaned in a simple manner.

The ability to detach the distal shaft section from the proximal shaft section also means that the proximal shaft section can be optionally connected to different distal shaft sections. This is particularly advantageous with regard to the rapid availability of identical or different applicators, each located at the distal ends of the distal shaft sections.

A particularly preferred embodiment provides that the at least one locking element is secured or can be secured against displacement from the locking position to the release position by means of a locking element that is at least indirectly actuated and has a contact section for contacting the locking element. This enables simple and reliable securing of the locking element in its locking position.

It is particularly preferred if the system section can be moved out of contact with the locking element by movement along at least one of the shaft section's longitudinal axes. This allows for easy operation of the locking element.

The locking element is preferably arranged in a cavity formed by the two shaft sections. In this way, the locking element is protected from external influences. In particular, even an unobstructed Intentional activation of the safety element is prevented.

According to a particularly preferred embodiment, the locking element is formed by a shaft or an axle which is arranged in the cavity formed by the two shaft sections. In this way, the shaft or axle can also be handled in an area spaced apart from the connecting joint, in particular moved along at least one of the longitudinal axes of the shaft sections.

It is further preferred that the shaft or axle is bendable at least at the level of the connecting joint, so that the shaft or axle can extend with different shaft sections in both the proximal shaft section and the distal shaft section, at least as required.

It is further preferred if the locking position is located further outwards than the release position with respect to the proximal longitudinal axis of the shaft section. This allows the use of a locking element located further inwards.

It is further preferred if the displacement path is limited at the ends so that the locking element is held securely against loss on the proximal or distal shaft section. For example, the shaft arrangement for limiting the displacement path includes an additional element that is provided separately by the proximal and distal shaft sections and joined to one of the two shaft sections. This allows for the provision of a displacement path with end undercuts that limit the displacement path.

The aforementioned additional element advantageously also forms a support for the at least one locking element. Such a support can also be referred to as a "cage".

It is possible that the at least one locking element is mounted on an end face of the proximal shaft section and that, in the locked position, the at least one locking element is positively engaged in a locking element receptacle of the distal shaft section, with the positive engagement acting in a direction parallel to the longitudinal axis of the distal shaft section. Alternatively, it is possible that the at least one locking element is mounted on an end face of the distal shaft section and that, in the locked position, the at least one locking element is positively engaged in a locking element receptacle of the proximal shaft section, with the positive engagement acting in a direction parallel to the longitudinal axis of the proximal shaft section. In both alternatives, the positive engagement prevents the distal shaft section from being pulled away from the proximal shaft section.

A particularly preferred embodiment provides that the locking element receptacle extends along a circumference around the longitudinal axis of the proximal shaft section or around the longitudinal axis of the distal shaft section. This allows the locking element to be used as part of a rotary bearing by means of which the distal and proximal shaft sections are mounted against each other and rotatable relative to one another.

It is possible that the aforementioned rotary bearing comprises a sliding bearing with, for example, cylindrical, conical, and/or stepped sliding surfaces. However, particularly for providing a rolling bearing, it is preferred if the shaft assembly has at least two, preferably at least three, locking elements, wherein the locking elements are distributed around the circumference of the locking element receptacle, preferably in a regularly distributed manner. In this way, the shaft section containing the locking element receptacle is positively locked to the other shaft section at several points along the circumference of the locking element receptacle.

The at least one locking element is preferably a ball or a roller. This allows for the provision of a locking element that can be easily displaced along the displacement path.

A locking element designed as a ball or roller has the further advantage that, in addition to its locking function, it can simultaneously act as a rolling element of a rolling bearing, with which the two shaft sections can be rotated relative to each other.

The at least one locking element can also comprise a group of balls, a group of rollers, or a group with at least one ball and at least one roller. The elements of such a group are preferably displaceable simultaneously along the same displacement path. In this way, it is possible to achieve locking with relatively small movements of the balls and/or rollers involved along the displacement path. The roles define both a locking position and a release position.

Instead of balls or rollers, the locking elements can also be formed by pins, studs or similar elements.

The medical instrument can be a fully handheld instrument where all movements are performed manually. Alternatively, it can be a robotic instrument, in which an actuator unit replaces the handle to control the instrument's movements. This actuator unit is mounted, for example, on a robotic arm or can be mounted on one. Another alternative is a hybrid instrument, which may have a handle, but where certain movements are controlled or assisted robotically or by motors/electrics. In all variants, it is possible to incorporate additional electrical components, such as sensors or electrical elements like ultrasound or RF electrodes (RF: radio frequency), which are typically located in or on an applicator (e.g., the mouthpiece of the instrument).

Further features and advantages of the invention are the subject of the following description of a preferred embodiment.

• 1 eine perspektivische Ansicht einer Ausführungsform einer Schaftanordnung als Bestandteil eines medizinischen Instruments;
• 2 eine Seitenansicht des Instruments;
• 3 einen in 2 mit III bezeichneten Bereich in vergrößerter und teilweise geschnittener Darstellung;
• 4 einen in der 3 mit IV bezeichneten Bereich in vergrößerter Darstellung eines Verbindungsgelenks mit einem Verriegelungselement in dessen Verriegelungszustand;
• 5 eine der 4 entsprechende Darstellung des Verriegelungselements in dessen Freigabezustand; und
• 6 eine perspektivische Darstellung eines Zusatzelements, das einen Träger für das Verriegelungselement bildet.

The drawing shows:

• 1 a perspective view of an embodiment of a shaft arrangement as part of a medical instrument;
• 2 a side view of the instrument;
• 3 one in 2 Area marked III in enlarged and partially cutaway view;
• 4 one in the 3 Area designated IV in an enlarged view of a connecting joint with a locking element in its locked state;
• 5 one of the 4 corresponding representation of the locking element in its released state; and
• 6 a perspective view of an additional element that forms a support for the locking element.

A medical instrument is in the 1 All are designated with the reference number 10. Instrument 10, for example, is designed as a hand instrument.

The instrument has a shaft arrangement 12, which is connected at a proximal end to a handle 14 and at a distal end to an applicator 16.

The shaft arrangement 12 comprises a proximal shaft section 18 and a distal shaft section 20, which are connected to each other via a connecting joint 22 and can be rotated relative to each other.

The shaft section 18 has an end face 24 facing the connecting joint 22, which, with respect to a proximal longitudinal axis 26 of the proximal shaft section 18, forms an angle 28 that deviates from 90°. The angle 28 is, in particular, less than 90°.

Similarly, the distal shaft section 20 has an end face 30 facing the connecting joint 22, which, with respect to a distal shaft section longitudinal axis 32 of the distal shaft section 20, encloses an angle 34 which also deviates from 90°, in particular is less than 90°.

Angles 34 and 28 are identical, for example. In this case, it is possible to rotate the distal shaft section 20 relative to the proximal shaft section 18 such that the two shaft section longitudinal axes 26 and 32 are aligned. This configuration is in 2 shown, where an angle of 180° lies between the two shaft section longitudinal axes 26 and 32. A corresponding angle is shown in 1 Designated with the reference symbol 36. Angle 36 is at least 180° minus angle 28 and minus angle 34.

The shaft sections 18 and 20 each have interior spaces 38 and 40, which combine to form a cavity 42, cf. 3 . In the cavity 42 a particularly hollow shaft 44 is arranged, which extends with a proximal shaft section 46 into the interior 38 of the proximal shaft section 18 and with a distal shaft section 48 into the interior 40 of the distal shaft section 20, cf. 4 .

The shaft 44 has slots 50 at the level of the connecting joint 22, which provide flexibility and deformability, i.e., bendability of the shaft 44, so that the shaft 44 can be adapted to different angles 36 between the two shaft section longitudinal axes 26 and 32.

The shaft 44 forms a locking element 52, which has a system section 54, which for example, it is arranged on the distal shaft section 48. The contact section 54 preferably points outwards with respect to the proximal longitudinal axis 26 of the shaft section.

At a 4 By actuating the shaft 44 indicated by reference numeral 56 (displacement of the shaft 44 along the longitudinal axis 26 of the shaft section away from the distal shaft section 20 in the direction of the handle 14), the contact section 54 can be removed from the connecting joint 22, cf. 5 .

The proximal shaft section 18 has a peg-shaped area 58 facing the distal shaft section 20, with a recess 60 which serves to accommodate at least one locking element 62. The at least one locking element 62 comprises, for example, at least one ball 64 or at least two balls 64, 66. The at least one locking element 62 is displaceable along a displacement path 68, specifically between a locking position (see Figure 1). 4 ) and a release position (see below). 5 ).

The displacement path 68 is preferably straight. Preferably, an imaginary extension of the displacement path 68 intersects the proximal longitudinal axis 26 of the shaft section.

The recess 60 has an end-side limit 70 that prevents the at least one locking element 62 from protruding outwards from the recess 60 in its release position. On the other side of the recess 60, facing the proximal longitudinal axis 26 of the shaft section, an additional element 72 is arranged that limits the inward displacement path 68 and prevents the at least one locking element 62 from falling outwards from the recess 60.

The distal shaft section 20 has a pin-shaped area 74 facing the proximal shaft section 18, in which a locking element receptacle 76 extending over its circumference is arranged. The locking element receptacle 76 extends in a ring-like fashion around the distal longitudinal axis 32 of the shaft section. Adjacent to the locking element receptacle 76 and on a side of the pin-shaped area 74 facing the proximal shaft section 18, the distal shaft section 20 has an actuating section 78 for actuating the at least one locking element 62.

In the locked state of the shaft assembly 12, the contact section 54 of the locking element 52 rests against the at least one locking element 62, for example, against the ball 66 located further inwards. Simultaneously, the at least one locking element 62, for example, the ball 64 located further outwards, is arranged within the locking element receptacle 76. In this state, the distal shaft section 20 is positively locked to the proximal shaft section 18. At the same time, the distal shaft section 20 is rotatable relative to the proximal shaft section 18, with the at least one locking element 62 (in the exemplary embodiment: the ball 64 located further outwards) acting as a rolling element.

If the system section 54 of the safety element 52 is brought out of the system with the at least one locking element 62 (corresponds to a change of state according to 4 in the state according to 5 ), causes a pulling movement of the distal shaft section 20 from the proximal shaft section 18, such that the actuating section 78 of the distal shaft section 20 pushes the at least one locking element 62 inwards in the direction of the proximal shaft section longitudinal axis 26, cf. 5 This releases the positive locking connection between the locking element receptacle 76 and the at least one locking element 62, so that the distal shaft section 20 can be detached from the proximal shaft section 18.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• WO 2023/006541 A1 [0002]

Claims (15)

A shaft assembly (12) for a medical instrument (10), comprising a proximal shaft section (18) having a proximal shaft section longitudinal axis (26), and a distal shaft section (20) having a distal shaft section longitudinal axis (32), wherein the two shaft sections (18, 20) are connected to each other in the region of a connecting joint (22) and are rotatable relative to each other, wherein at least one of the end faces (24, 30) of the two shaft sections (18, 20) facing the connecting joint (22) is oriented at an angle deviating from 90° relative to the respective shaft section longitudinal axis (26, 32), characterized in that the connecting joint (22) has at least one locking element (62) that is displaceable along a displacement path (68) and which, in a locked state of the shaft assembly (12), assumes a locking position and secures the distal shaft section (20) to the proximal shaft section (18) and, in a release state of the shaft assembly (12), assumes a release position and allows the distal shaft section (20) to be released from the proximal shaft section (18). shaft arrangement (12) according Claim 1 , characterized in that the at least one locking element (62) is secured or can be secured against displacement from the locking position to the release position by means of a locking element (52) that can be actuated at least indirectly and which has a component section (54) for contact with the at least one locking element (62). shaft arrangement (12) according Claim 2 , characterized in that the installation section (54) can be brought out of alignment with the locking element (62) by movement along at least one of the shaft section longitudinal axes (26, 32). shaft arrangement (12) according Claim 2 or 3 , characterized in that the locking element (52) is arranged in a cavity (42) formed by the two shaft sections (18, 20). shaft arrangement (12) according to one of the Claims 2 until 4 , characterized in that the locking element (52) is formed by a shaft (44) or by an axis which is arranged in the cavity (42). shaft arrangement (12) according Claim 5 , characterized in that the shaft (44) or the axle is bendable at least at the level of the connecting joint (22). Shaft arrangement (12) according to one of the preceding claims, characterized in that the locking position is arranged further outwards with respect to the proximal longitudinal axis (26) of the shaft section than the release position. Shaft arrangement (12) according to one of the preceding claims, characterized in that the displacement path (68) is limited at the end. shaft arrangement (12) according Claim 8 , characterized in that the shaft arrangement (12) for limiting the displacement path (68) has an additional element (72) which is provided separately by the proximal shaft section (18) and by the distal shaft section (20) and is joined to one of the two shaft sections (18, 20). shaft arrangement (12) according Claim 9 , characterized in that the additional element (72) forms a support for the at least one locking element (62). Shaft arrangement (12) according to a preceding claim, characterized in that the at least one locking element (62) is mounted on an end face (58) of the proximal shaft section (18) or on an end face (74) of the distal shaft section (20) and that the at least one locking element (62) is positively engaged in the locking position in a locking element receptacle (74) of the distal shaft section (20) or the proximal shaft section (18), wherein the positive engagement is effective in a direction parallel to the distal shaft section longitudinal axis (32) or the proximal shaft section longitudinal axis (26). shaft arrangement (12) according Claim 11 , characterized in that the locking element receptacle (74) extends along a circumference around the shaft section longitudinal axis (32) of the distal shaft section (20) or around the shaft section longitudinal axis (26) of the proximal shaft section (18). shaft arrangement (12) according Claim 12 , characterized in that the shaft arrangement (12) has at least two, preferably at least three locking elements (62), wherein the locking elements (62) are arranged distributed around the circumference of the locking element receptacle (74), preferably in a regularly distributed manner. Shaft arrangement (12) according to one of the preceding claims, characterized in that the at least one locking element (62) is a ball (64, 66) or a roller. Shaft arrangement (12) according to one of the preceding claims, characterized in that the at least one locking element (62) comprises a group of balls (64, 66) or a group of rollers or a group with at least one ball (64, 66) and at least one roller.