Patent Application
20250049307
The present invention relates to a steerable instrument for endoscopic and/or invasive type of applications, such as in surgery. The steerable instrument according to the invention can be used in both medical and non-medical applications. Examples of the latter include inspection and/or repair of mechanical and/or electronic hardware at locations that are difficult to reach. Hence, terms used in the following description such as endoscopic application or invasive instrument, must be interpreted in a broad manner.
Transformation of surgical interventions that require large incisions for exposing a target area into minimal invasive surgical interventions, i.e. requiring only natural orifices or small incisions for establishing access to the target area, is a well-known and ongoing process. In performing minimal invasive surgical interventions, an operator such as a physician, requires an access device that is arranged for introducing and guiding invasive instruments into the human or animal body via an access port of that body. In order to reduce scar tissue formation and pain to a human or animal patient, the access port is preferably provided by a single small incision in the skin and underlying tissue. In some applications, a natural orifice of the body can be used as an entrance. Furthermore, the access device preferably enables the operator to control one or more degrees of freedom that the invasive instruments offer. In this way, the operator can perform required actions at the target area in the human or animal body in an ergonomic and accurate manner with a reduced risk of clashing of the instruments used.
Surgical invasive instruments and endoscopes are well-known in the art. Both the invasive instruments and endoscopes can comprise a steerable tube that enhances its navigation and steering capabilities. Such a steerable tube may comprise a proximal end part including at least one flexible zone, a distal end part including at least one flexible zone, and an intermediate part, wherein the steerable tube further comprises a steering arrangement that is adapted for translating a deflection of at least a part of the proximal end part relative to the intermediate part into a related deflection of at least a part of the distal end part. Alternatively, the distal flexible zone may be steered by a robotic instrument arranged at the proximal end of the steerable instrument.
Steerable invasive instruments may comprise a handle that is arranged at the proximal end part of the steerable tube for steering the tube and/or for manipulating a tool that is arranged at the distal end part of the steerable tube. Such a tool can for example be a camera, a manual manipulator, e.g. a pair of scissors, forceps, or manipulators using an energy source, e.g. an electrical, ultrasonic or optical energy source.
Furthermore, such a steerable tube may comprise a number of co-axially arranged cylindrical elements including an outer cylindrical element, an inner cylindrical element and one or more intermediate cylindrical elements depending on the number of flexible zones in the proximal and distal end parts of the tube and the desired implementation of the steering members of the steering arrangement, i.e. all steering members can be arranged in a single intermediate cylindrical element or the steering members are divided in different sets and each set of steering members is arranged, at least in part, in a different or the same intermediate cylindrical element. In most prior art devices, the steering arrangement comprises conventional steering cables with, for instance, sub 1 mm diameters as steering members, wherein the steering cables are arranged between related flexible zones at the proximal and distal end parts of the tube. Other steering units at the proximal end, like ball shaped steering units or robot driven steering units, may be applied instead.
However, as steering cables have many well-known disadvantages, for some applications one may want to avoid them and to implement the steering members by one or more sets of longitudinal steering elements that form integral parts of the one or more intermediate cylindrical elements. Each of the intermediate cylindrical elements including the longitudinal steering elements, i.e., the steering wires, can be fabricated either by using a suitable material addition technique, such as injection molding or plating, or by starting from a tube and then using a suitable material removal technique, such as laser cutting, photochemical etching, deep pressing, conventional chipping techniques such as drilling or milling or high-pressure water jet cutting systems. Longitudinal steering elements manufactured in that way are, then, implemented as longitudinal strips resulting from the tube material, and can be used as pulling/pushing wires. Of the aforementioned material removal techniques, laser cutting is very advantageous as it allows a very accurate and clean removal of material under reasonable economic conditions.
The inner and outer cylindrical elements may be manufactured from tubes too. These tubes should be flexible at locations where the distal end, and possibly the proximal end too, of the instrument is bendable. Also at other locations where the instrument should be flexible, the inner and outer cylindrical elements should be flexible. This can be implemented by providing the inner and outer cylindrical elements with hinges at these flexible locations. Such hinges may result from (laser) cutting predetermined patterns in the tube. Many different patterns are known from the prior art. Which pattern to use depends on design requirements at the location concerned including but not limited to the required bending angle, bending flexibility, longitudinal stiffness, and radial stiffness.
Further details regarding the design and fabrication of the abovementioned steerable tube and the steering arrangement thereof have been described for example in WO 2009/112060 A1, WO 2009/127236 A1, U.S. Ser. No. 13/160,949, and U.S. Ser. No. 13/548,935 of the applicant, all of which are hereby incorporated by reference in their entirety.
Many steerable instruments have in common that manipulation of the user interface, for example a handle or a joystick, is transformed into longitudinal displacement of longitudinal steering elements, that run from the user interface end of the instrument to the tip of the instrument. At the tip, this displacement is transformed into steering of that tip. In most cases, steering of the tip is accomplished by bending of the tip. A common problem is that the tip of the instrument has a certain resistance against that bending. This bending stiffness is caused by for example the bending stiffness of the used construction of the flexible zone in the tip, the actuation cable of the tool attached to the tip, the guiding tube of this cable, the electrical isolation around the flexible part of the tip, etc., but also by the bending stiffness of the steering elements itself. This is cause of many disadvantages.
When the tip has almost no bending stiffness, only small forces in the longitudinal steering elements are required to bend the tip and the biggest part of the applied forces to the steering elements by the user, can be used for tissue manipulation forces. When the tip has an increased bending stiffness, bigger forces are needed to bend the tip and less of the forces can be used for tissue manipulation at a certain mechanical strength of the tip and steering elements construction. When this residual tissue manipulation force is not sufficient for adequate use of the instrument, one can only increase this force by using a stronger construction with stronger steering elements. This on itself usually also increases the stiffness of the construction and one ends up with the same problem. The right solution for this problem is often a trade-off between many performance aspects like the achievable bending angle, tissue manipulation forces (often referred to as ‘payload’ of the instrument), haptic feedback (the bending force can be that high that the user mainly ‘feels’ bending force and the tissue manipulation force is fully camouflaged by the required steering force), the achievable fatigue life (how many times can the tip bend before failure of the construction or the steering elements), etc.
It is clear that optimizing an instrument's performance often is achieved by minimizing the bending stiffness of the flexible part of the tip. Many solutions have been found. One can use for example a less stiff construction of coils or hinges instead of a flexible tube for the body of the flexible section or for the guiding tube of the tip tool actuation cable. One can also use an actuation cable for the tip tool that is as flexible as possible, for example, a cable of stranded metal wires is more flexible than a solid metal wire. Also for the steering elements one can use these stranded cables or for example Dyneema, Aramide or other high strength fibers.
Also in steerable instruments that are made from solid material tubes, like as in WO 2009/112060 A1, WO 2009/127236 A1 stiffness of the steering elements may be improved. Because the steering elements are of a solid metal they are already more stiff than stranded cables.
EP2259710A discloses steerable instruments in which steering wires are made by cutting strips from a tube. In an embodiment, portions of the steering wire at the proximal end and at the distal end are made from another material than the rest of the steering wire. The rest of the steering wire is connected to the proximal and distal portions by interconnecting joints. Such interconnection joints are only applied in portions of the steering wire which do not coincide with longitudinal locations of the instruments that have to bend or deflect. They are not designed to be flexible themselves.
WO 2010/151698 A2 describes a steerable medical delivery device, including a steerable portion comprising a first tubular member and a second tubular member, wherein one of the first and second tubular members is disposed within the other, wherein the first and second tubular elements are axially fixed relative to one another at a fixation location distal to the steerable portion, and wherein the first and second tubular members are axially movable relative to one another along the steerable portion to steer the steerable portion in a first direction, and wherein the first tubular member is adapted to preferentially bend in a first direction. In this known device each tube has a spine in a bendable region of the device. In some embodiments the spine is implemented by means of adjacent portions of the tube wherein the portions are provided with extensions located inside a hole of an adjacent portion such that adjacent portions cannot move relative to one another in the axial direction of the device. However, these adjacent portions are attached to one another by a spiral strip, and adjacent portions are shaped such that they cannot rotate relative to one another in the tangential direction of the tube.
It is an object of the invention to provide a steerable instrument for endoscopic and/or invasive type of applications having steering wires with an improved balance between strength and bending stiffness.
In particular, it is an object of the invention to provide a steerable instrument having steering wires in the form of strips resulting from cutting predetermined patterns in a tube which strips having an optimized strength and a bending stiffness along their length.
More specifically, by implementing at least those parts of steering wires which need to be flexible in the form of shackled chain links which are resulting from cutting patterns in such tubes too, these flexible steering wire parts can have a minimum bending stiffness. This is especially advantageous in those parts of the instrument that need to be deflected in use as controlled from the proximal end.
To that end, independent aspects of the invention are defined in independent claims whereas dependent claims relate to advantageous embodiments.
According to a first aspect, defined in independent claim 1, a steerable instrument is provided comprising at least one tube extending in a longitudinal direction, the steerable instrument having a proximal end and a deflectable distal end, the at least one tube comprising at least one steering wire which is made from the at least one tube, separated by a slotted structure from the remainder of the at least one tube, attached to the deflectable distal end and configured to be movable in a longitudinal direction of the at least one tube such as to deflect the deflectable distal end, the at least one steering wire having at least one flexible portion located in a flexible zone of the steerable instrument and implemented by a series of adjacent chain links.
The at least one steering wire can be formed by cutting predetermined patterns in the tube, e.g. through a materials removing technique, thereby forming the slotted structure. Each steering wire of the at least one steering wire may be implemented as a chain link in the flexible portion, extending in the longitudinal direction and separated laterally from other steering wires and/or from the remainder of the tube. The at least one steering wire is separated, in a circumferential direction of the tube, from adjacent steering wires and from eventual remaining portions of the tube not forming part of a steering wire. Each of the at least one steering wire may hence be seen as forming a free-standing structure, attached to the deflectable distal end and extending in the longitudinal direction of the tube.
The slotted structure may comprise slots extending parallel to and along lateral sides of the at least one steering wire.
Hence, by the slotted structure separating the steering wire from the remainder of the tube, the steering wire is not connected nor attached laterally to other parts or portions of the tube. In particular, in the flexible zone, where the steering wire is implemented as a series of adjacent chain links, these chain links are linked, connected or attached, to adjacent chain links to form a chain forming at least a portion of the steering wire. Due to the slotted structure, the chain links are not connected nor attached to other elements or portions of the tube, in particular not to other tube portions in a direction different from the longitudinal direction, thus making the bendable region more flexible than in e.g. the prior art device of WO 2010/151698.
The expression of the steering wire and/or chain link as “extending in the longitudinal direction” encompasses both an extension parallel to an axial direction of the tube, as well as an extension in a helical manner along the tube, wherein the center of the helix substantially coincides with the axis of the tube.
In this application, the terms “proximal” and “distal” are defined with respect to an operator, e.g. a robot or physician that operates the instrument or endoscope. For example, a proximal end part is to be construed as a part that is located near the robot or physician and a distal end part as a part located at a distance from the robot or physician, i.e., in the area of operation.
Further features and advantages of the invention will become apparent from the description of the invention by way of non-limiting and non-exclusive embodiments. These embodiments are not to be construed as limiting the scope of protection. The person skilled in the art will realize that other alternatives and equivalent embodiments of the invention can be conceived and reduced to practice without departing from the scope of the present invention. Embodiments of the invention will be described with reference to the figures of the accompanying drawings, in which like or same reference symbols denote like, same or corresponding parts, and in which:
For the purpose of the present document, the terms cylindrical element and tube may be used interchangeably, i.e., like the term tube a cylindrical element also refers to a physical entity. The invention will be explained with reference to longitudinal steering elements which are cut from such cylindrical elements and are operative as push and/or pull wires to transfer movement of the steering elements at the proximal end of the instrument to the distal end to thereby control bending of one or more flexible distal end portions.
Instruments in which the Invention can be Applied
a, and 3b are known from WO2009/112060. They are explained in detail because the present invention can be applied in this type of instruments.
The inner cylindrical element 2 comprises a first rigid end part 5, which is located at a distal end part 13 of the instrument, a first flexible part 6, an intermediate rigid part 7 located at an intermediate part 12 of the instrument, a second flexible part 8 and a second rigid end part 9, which is located at a proximal end part 11 of the instrument. Distal end part 13 is a distal deflectable zone 13. Proximal end part 11 is a proximal bendable zone 11.
The outer cylindrical element 4 also comprises a first rigid end part 17, a first flexible part 18, an intermediate rigid part 19, a second flexible part 20 and a second rigid end part 21. The lengths of the parts 5, 6, 7, 8, and 9, respectively, of the cylindrical element 2 and the parts 17, 18, 19, 20, and 21, respectively, of the cylindrical element 4 are, preferably, substantially the same so that when the inner cylindrical element 2 is inserted into the outer cylindrical element 4, these different respective parts are longitudinally aligned with each other.
The intermediate cylindrical element 3 also has a first rigid end part 10 and a second rigid end part 15 which in the assembled condition are located between the corresponding rigid parts 5, 17 and 9, 21 respectively of the two other cylindrical elements 2, 4. The intermediate part 14 of the intermediate cylindrical element 3 comprises one or more separate longitudinal steering wires 16 which can have different forms and shapes as will be explained below. In
In the embodiment shown in
It is observed that the longitudinal steering wires 16 need not have a uniform cross section across their entire length. They may have a varying width along their length, possibly such that at one or more locations adjacent longitudinal steering wires 16 are only separated by a small slot resulting from the laser cutting in the cylindrical element 3. These wider portions of the longitudinal steering wires, then, operate as spacers to prevent adjacent longitudinal steering wires 16 from buckling in a tangential direction in a pushed state. Spacers may, alternatively, be implemented in other ways.
An embodiment with spacers is shown in
In the other two portions 61 and 63 each longitudinal steering wire consists of a relatively small and flexible part 64, 65 as seen in circumferential direction, so that there is a substantial gap between each pair of adjacent flexible parts, and each flexible part 64, 65 is provided with a number of spacers 66, extending in the tangential direction and almost bridging completely the gap to the adjacent flexible part 64, 65. Because of these spacers 66 the tendency of the longitudinal steering wires 16 in the flexible portions of the instrument to shift in tangential direction is suppressed and tangential direction control is improved. The exact shape of these spacers 66 is not very critical, provided they do not compromise flexibility of flexible parts 64 and 65. The spacers 66 may or may not form an integral part with the flexible parts 64, 65 and may result from a suitable laser cutting process too.
In the embodiment shown in
In the embodiment of
The production of such an intermediate part is most conveniently done by injection moulding or plating techniques or starting from a cylindrical tube with the desired inner and outer diameters and removing parts of the wall of the cylindrical tube required e.g. by laser or water cutting to end up with the desired shape of the intermediate cylindrical element 3. However, alternatively, any 3D printing method can be used.
The removal of material can be done by means of different techniques such as laser cutting, photochemical etching, deep pressing, conventional chipping techniques such as drilling or milling, high pressure water jet cutting systems or any suitable material removing process available. Preferably, laser cutting is used as this allows for a very accurate and clean removal of material under reasonable economic conditions. The above mentioned processes are convenient ways as the cylindrical element 3 can be made so to say in one process, without requiring additional steps for connecting the different parts of the intermediate cylindrical element as required in the conventional instruments, where conventional steering cables must be connected in some way to the end parts. The same type of technology can be used for producing the inner and outer cylindrical elements 2 and 4 with their respective flexible parts 6, 8, 18 and 20. These flexible parts 6, 8, 18 and 20 can be manufactured as hinges resulting from cutting out any desired pattern from the cylindrical elements, e.g., by using any of the methods described in European patent application 08 004 373.0 filed on 10 Mar. 2008, page 5, lines 15-26, but any other suitable process can be used to make flexible portions.
It is observed that the instruments shown in
Whereas our cylindrical element 4 and inner cylindrical element 2, respectively, as shown in
It will be clear to the skilled person that the elongated tubular body 76 as shown in
The steering arrangement in the exemplary embodiment of the elongated tubular body 76 as shown in
Flexible zones 72, 73, 74, and 75 are, in this embodiment, implemented by providing the respective cylindrical elements with slits 72a, 73a, 74a, and 75a, respectively. Such slits 72a, 73a, 74a, and 75a may be arranged in any suitable pattern such that the flexible zones 72, 73, 74, and 75 have a desired flexibility in the longitudinal and tangential direction in accordance with a desired design.
The inner cylindrical element 101, as seen along its length from the distal end to the proximal end of the instrument, comprises a rigid ring 111, which is arranged at the distal end part 13 of the steerable instrument 10, a first flexible portion 112, a first intermediate rigid portion 113, a second flexible portion 114, a second intermediate rigid portion 115, a third flexible portion 116, a third intermediate rigid portion 117, a fourth flexible portion 118, and a rigid end portion 119, which is arranged at the proximal end portion 11 of the steerable instrument.
The first intermediate cylindrical element 102, as seen along its length from the distal end to the proximal end of the instrument, comprises a rigid ring 121, a first flexible portion 122, a first intermediate rigid portion 123, a second flexible portion 124, a second intermediate rigid portion 125, a third flexible portion 126, a third intermediate rigid portion 127, a fourth flexible portion 128, and a rigid end portion 129. The portions 122, 123, 124, 125, 126, 127 and 128 together form a longitudinal steering wire 120 that can be moved in the longitudinal direction like a wire. The longitudinal dimensions of the rigid ring 121, the first flexible portion 122, the first intermediate rigid portion 123, the second flexible portion 124, the second intermediate rigid portion 125, the third flexible portion 126, the third intermediate rigid portion 127, the fourth flexible portion 128, and the rigid end portion 129 of the first intermediate element 102, respectively, are aligned with, and preferably approximately equal to the longitudinal dimensions of the rigid ring 111, the first flexible portion 112, the first intermediate rigid portion 113, the second flexible portion 114, the second intermediate rigid portion 115, the third flexible portion 116, the third intermediate rigid portion 117, the fourth flexible portion 118, and the rigid end portion 119 of the inner cylindrical element 101, respectively, and are coinciding with these portions as well. In this description “approximately equal” means that respective same dimensions are equal within a margin of less than 10%, preferably less than 5%.
Similarly, the first intermediate cylindrical element 102 comprises one or more other longitudinal steering wires of which one is shown with reference number 120a.
The second intermediate cylindrical element 103, as seen along its length from the distal end to the proximal end of the instrument, comprises a first rigid ring 131, a first flexible portion 132, a second rigid ring 133, a second flexible portion 134, a first intermediate rigid portion 135, a first intermediate flexible portion 136, a second intermediate rigid portion 137, a second intermediate flexible portion 138, and a rigid end portion 139. The portions 133, 134, 135 and 136 together form a longitudinal steering wire 130 that can be moved in the longitudinal direction like a wire. The longitudinal dimensions of the first rigid ring 131, the first flexible portion 132 together with the second rigid ring 133 and the second flexible portion 134, the first intermediate rigid portion 135, the first intermediate flexible portion 136, the second intermediate rigid portion 137, the second intermediate flexible portion 138, and the rigid end portion 139 of the second intermediate cylinder 103, respectively, are aligned with, and preferably approximately equal to the longitudinal dimensions of the rigid ring 111, the first flexible portion 112, the first intermediate rigid portion 113, the second flexible portion 114, the second intermediate rigid portion 115, the third flexible portion 116, the third intermediate rigid portion 117, the fourth flexible portion 118, and the rigid end portion 119 of the first intermediate element 102, respectively, and are coinciding with these portions as well.
Similarly, the second intermediate cylindrical element 103 comprises one or more other longitudinal steering wires of which one is shown with reference number 130a.
The outer cylindrical element 104, as seen along its length from the distal end to the proximal end of the instrument, comprises a first rigid ring 141, a first flexible portion 142, a first intermediate rigid portion 143, a second flexible portion 144, and a second rigid ring 145. The longitudinal dimensions of the first flexible portion 142, the first intermediate rigid portion 143 and the second flexible portion 144 of the outer cylindrical element 104, respectively, are aligned with, and preferably approximately equal to the longitudinal dimension of the second flexible portion 134, the first intermediate rigid portion 135 and the first intermediate flexible portion 136 of the second intermediate element 103, respectively, and are coinciding with these portions as well. The rigid ring 141 has approximately the same length as the rigid ring 133 and is fixedly attached thereto, e.g. by spot welding or gluing. Preferably, the rigid ring 145 overlaps with the second intermediate rigid portion 137 only over a length that is required to make an adequate fixed attachment between the rigid ring 145 and the second intermediate rigid portion 137, respectively, e.g. by spot welding or gluing. The rigid rings 111, 121 and 131 are attached to each other, e.g., by spot welding or gluing. This may be done at the end edges thereof but also at a distance of these end edges.
In an embodiment, the same may apply to the rigid end portions 119, 129 and 139, which can be attached to one another as well in a comparable manner. However, the construction may be such that the diameter of the cylindrical elements at the proximal portion is larger, or smaller, with respect to the diameter at the distal portion. In such embodiment the construction at the proximal portion differs from the one shown in
The inner and outer diameters of the cylindrical elements 101, 102, 103, and 104 are chosen in such a way at a same location along the elongated tubular body 76 that the outer diameter of inner cylindrical element 101 is slightly less than the inner diameter of the first intermediate cylindrical element 102, the outer diameter of the first intermediate cylindrical element 102 is slightly less than the inner diameter of the second intermediate cylindrical element 103 and the outer diameter of the second intermediate cylindrical element 103 is slightly less than the inner diameter of the outer cylindrical element 104, in such a way that a sliding movement of the adjacent cylindrical elements with respect to each other is possible. The dimensioning should be such that a sliding fit is provided between adjacent elements. A clearance between adjacent elements may generally be in the order of 0.02 to 0.1 mm, but depends on the specific application and material used. The clearance may be smaller than a wall thickness of the longitudinal steering wires to prevent an overlapping configuration thereof. Restricting the clearance to about 30% to 40% of the wall thickness of the longitudinal steering wires is generally sufficient.
As can be seen in
For the sake of convenience, as shown in
In order to deflect at least a part of the distal end part 13 of the steerable instrument, it is possible to apply a bending force, in any radial direction, to zone 158. According to the examples shown in
It is to be noted that the exemplary downward bending of zone 156, only results in the upward bending of zone 154 at the distal end of the instrument as shown in
Obviously, it is possible to vary the lengths of the flexible portions shown in
In the shown embodiment, the longitudinal steering wires comprise one or more sets of longitudinal steering wires that form integral parts of the one or more intermediate cylindrical elements 102, 103. Preferably, the longitudinal steering wires comprise remaining parts of the wall of an intermediate cylindrical element 102, 103 after the wall of the intermediate cylindrical element 102, 103 has been provided with longitudinal slits that define the remaining longitudinal steering wires.
As shown, here, instrument 76 comprises a flexible zone 77 in its intermediate part between flexible zone 72 and flexible zone 74. I.e., intermediate cylindrical element 204 (which is located at the outer side in the area of flexible zone 77) is provided with a slotted structure to provide intermediate cylindrical element with a desired flexibility. The longitudinal length of the slotted structure in flexible zone 77 depends on the desired application. It may be as long as the entire part between flexible zones 72 and 74. All other cylindrical elements 206, 208, 210 inside intermediate cylindrical element 204 are also flexible in flexible zone 77. Those cylindrical elements that have steering wires in the flexible zone 77 should be made as flexible as possible in that zone 77. Others are provided with suitable hinges, preferably made by suitable slotted structures.
In
The instrument 1 comprises an outer tube 1103 covering the steering wires 16(j). The outer tube 1103 comprises a plurality of openings 1105((j), i.e., one per steering wire 16(j). Each steering wire 16(j) of instrument 1 also comprise one or more openings 1101(j) overlapping with respective openings 1105(j) of outer tube 1103.
The openings 1105(j) of outer tube 1103 and the openings 1101(j) of the steering wires 16(j) may result from laser cutting in respective cylindrical tubes inserted into one another. As an alternative to laser cutting other techniques may be used, e.g., cutting by means of water jets. Also, other methods such as 3D laser printing may be used. These openings 1101(j) and 1105(j) extend through the whole thickness of the material.
Such steering is accomplished by rotating steering unit 1309 in three dimensions about ball shaped supporting unit 1111. Control of such rotation may be implemented by a handle which can be manually controlled or controlled by a robotic device. A robotic device may also steer each steering wire individually, without the use of steering unit 1109.
The chains of
The variant of
One known disadvantage of known steerable instruments is that they are often built from many separate parts and are difficult to assemble. Because of the usually complex structure, they also often require a high degree of maintenance and are prone to mechanical failure. These instruments and the use of these instruments generally are expensive and they have to be used many times to get costs per use down to commercially acceptable levels. Making steering elements from many separate parts of course would add to this complexity but still is a viable solution in some cases.
The prior art instrument as discussed with reference to
In one of its simplest forms a flexible steering wire part 1300 implemented by shackled chain links of a strip like steering wire 16(j) could look like the one shown in
The structure of
The embodiment of
Some implementation examples of chain structures, which may be used to form a steering wire part in a flexible portion of an instrument, are explained with reference to
Circular end portion 1511(k) extends into a first opening 1503(k+1) of an adjacent chain link 1501(k+1). Circular end portion 1511(k) has a size which matches the size of first circular opening 1505(k+1) such that circular end portion 1511(k) can freely rotate inside first circular opening 1505(k+1). Moreover, first circular opening 1505(k+1) extends along a circular arc of more than 180 degrees such that circular end portion 1511(k) cannot be retracted from first circular opening 1505(k+1). Circular end portion 1511(k+1) and first circular opening 1505(k+1) are separated by a slot of which the width is determined by the used material removal technique. When a laser beam is used to produce the slot the slot width may be between 0.01 to 2.00 mm, more typically for this application, between 0.015 and 0.04 mm.
The flexible steering wire part 1300 of
The same principle as shown in
Chain links 1701(k) have a horseshoe shape with end portions 1703(k), 1705(k) and an opening 1707(k). Horseshoe openings 1707(k), 1707(k+2), 1707(k+4), . . . face in one direction whereas horseshoe openings 1707(k+1), 1707(k+3), 1707(k+5), . . . face in an opposite direction such that horseshoe openings 1707(k), 1707(k+2), 1707(k+4), respectively, are interlocking with horseshoe openings 1707(k−1)/1707(k+1), 1707(k+1)/1707(k+3), and 1707(k+3)/1707(k+5), respectively. In the embodiment shown in
As illustrated in
Inner tube 2 and outer tube 4 are not shown in
As one can see, flexible steering part 1300 is in a bent state in
It is observed that all shown embodiments of chain links in
A steering wire cut from a tube wall or a sheet, only has the ‘chain of shackles’ geometry in its cutting plane. However, in a steerable instrument a steering wire 16(j) has to be able to bend in all directions. That can be explained with reference to
One could accept that the bending stiffness in that perpendicular bending direction is minimized by the chain geometry allowing adjacent chain links 1301(k) to rotate relative to one another and that the bending stiffness in the direction perpendicular to that bending direction is the same as for a standard, straight cut element that bends by elastic deformation. This is shown in
In practise, when consecutive chain links 1301(k) are made from a tube with a material removal technique, as explained above, there is, however, a certain play between them because of the slots between them. Then, as shown in
The two pins 1309(k) and 1311(k) are located inside respective notches 1304(k) and 1306(k) in opening 1303(k) such that they can rotate inside respective notches 1304(k) and 1306(k) allowing adjacent chain links 1301(k−1) and 1301(k) to also rotate in the plane perpendicular to the surface of chain links 1301(k−1) and 1301(k).
In the embodiment of
Rotation in a plane perpendicular to the surface of the chain links 1301(k) may be improved by the embodiment shown in
Now the series of chain links 1301(k) can bend in all directions without bending stiffness. Many more geometries are possible with bending axes in two planes. Also asymmetric geometries in which the bending stiffness in one direction has a higher magnitude than in the other direction can be envisioned. In practice, the bending capacity preferably is symmetric and the bending capacity in the cutting plane of the tube is the same as the bending capacity perpendicular to that plane. One can also limit the bending capacity to a certain amount. In this way one can make sure that per chain link length only a certain maximum bending angle can be achieved. In this way one can assure that if one, for example, wants to bend the instrument tip with 30 degrees and one designs for example 6 hinge structures and 6 chain links 1301(k) in the curve length, one hinge structure and one chain link 1301(k) can have a limited bending capacity of 5 degrees maximum. In this way one can assure that the bent tip has a nice round bending behaviour without local bends bigger than 5 degrees. This can positively affect fatigue life of the hinges, chain links 1301(k) and steering wires 16(j) and can prevent high friction forces in steering wires 16(j) that one would have when an instrument tip bends sharply in one location.
As one can see, tubes are used to manufacture instrument 1. Its operative portions, like hinges and steering wires, are made by providing the tubes with suitable, predetermined slotted patterns. Especially if these slotted structures are large or if they enclose a portion which is entirely separate from the rest of the tube structure through the slotted structure, manufacturing of the instrument may be complex because these operative portions may no longer be positioned in the original cylindrical shape of the tube directly after the slot forming process. This could make inserting tubes into one another complex. As known from WO2016/089202 from the present applicant, this can be solved by applying fracture elements bridging the slots at predetermined locations and fracturing these fracture elements after tubes have been inserted into one another. Such fracture elements can also be applied in the instrument of the present document, as will be explained with reference to
First an embodiment of reduction of play between adjacent chain links will be described.
The serrated outside edge 2403 of circular extension 2477 has extending portions 2403a and an indented portion 2403b between each two adjacent extending portions 2403a. Both the extending portions 2403a and the indented portions 2403b may have a circular form extending along a circle about center point 2483. However, they may have any other suitable form. In the shown embodiment, the indented portions 2403b extend along a first circle having a first radius r1. The extending portions 2403a extend along a second circle having a second radius r2 which is larger than the first radius r1.
The serrated outside edge 2401 of circular opening 2475 has extending portions 2401a and an indented portion 2401b between each two adjacent extending portions 2401a. Both the extending portions 2401a and the indented portions 2401b may have a circular form extending along a circle about center point 2483. However, they may have any other suitable form. In the shown embodiment, the extending portions 2401a extend along a third circle having a third radius r3. The indented portions 2401b extend along a fourth circle having a fourth radius r4 which is larger than the third radius r3.
In an embodiment, the second radius r2 is about equal to the third radius r3. I.e., they may be equal within manufacturing tolerances which may be less than 10%, preferably less than 5% of r2 or r3. In the shown embodiment, the second radius r2 is not larger than the third radius r3 because otherwise circular extension 2477 cannot rotate inside circular opening 2475. An alternative definition is that the extending portions 2403a have a height which is at maximum about equal to the width of slot 2405 (or distance) between an adjacent indented portion 2403b and an opposing extending portion 2401a, where “about equal” again refers to equal within manufacturing tolerances, i.e., that height and distance differ by 10% or less, alternatively 5% or less, or further alternatively 1% or less.
At locations where one or more extending portions 2403a of circular extension 2477 abut one or more extending portions 2401a of circular opening 2475 they cannot move any more towards one another in the radial direction as seen from center point 2483. So, in the rotated status, play between abutting extending portions 2403a and extending portions 2401a is removed. Depending on the design, play may have been removed in at least one of the longitudinal direction or tangential direction of the tube in which the chain links 1301(k)/1501(k), 1301(k+1)/1501(k+1) are made.
Outer edge 2403 of circular extension 2477 has a transition edge portion between each extending portion 2403a and each adjacent indented portion 2403b. Outer edge 2401 of circular opening 2475 has a transition edge portion between each extending portion 2401a and each adjacent indented portion 2401b. Transition edge portions of outer edge 2403 and transition edge portions of outer edge 2401 are separated from one another by a distance which, after manufacturing, is as wide as the width of slot 2405 resulting from the cutting process. The width of slot 2405 at locations between opposing transition edge portions of outer edge 2403 and transition edge portions of outer edge 2401 may be as wide as the width of slot 2405 at locations between other opposing portions of outer edges 2403 and outer edge 2401 but that is not necessary.
If the width of slot 2405 at locations between opposing transition edge portions of outer edge 2403 and transition edge portions of outer edge 2401 is very small relative to the radius of circular extension 2477, only a very small rotation between circular extension 2477 and circular opening 2475 will result in extending portions 2403a of circular extension 2477 abutting extending portions 2401a of circular opening 2475. Consequently, only when two adjacent chain links 1301(k)/1501(k), 1301(k+1)/1501(k+1) are not rotated relative to one another, i.e. the status equal to the resting status, they show some play relative to one another which is as large as the width of slot 2405. In a relative rotated (or deflected) status about a certain deflection angle β, however, all play may be removed. In a typical example, such deflection angle β may <5 degrees or even <3 degrees or <1 degrees. In use, many adjacent chain links 1301(k)/1501(k), 1301(k+1)/1501(k+1) of invasive instrument 1 may be bent relative to one another about an angle >β, e.g. due to curvatures in a canal, for instance a human intestinal canal, in which the instrument is inserted. So, in use, a high percentage of play between adjacent chain links 1301(k)/1501(k), 1301(k+1)/1501(k+1) may be reduced by the embodiment of
It is observed that the slots resulting from the manufacturing process to make the different operative parts of instrument 1 cause some play between such operative parts. Such play can be minimized with similar techniques as explained with reference to
Now a possible use of fracture elements between adjacent chain links 1301(k)/1501(k), 1301(k+1)/1501(k+1) is described.
As shown in
Here, fracture element 2411(m) is shown to be a bridge between circular extension 2477 and opposing chain link portion 2408. However, fracture element 2411(m) can have any suitable design, as explained in above mentioned patent application WO2016/089202 of the present applicant.
In general, as e.g. explained herein below with reference to fracture elements 2411(m), such fracture elements can be designed in the following way. Fracture elements are made in the same process step as other elements are cut from a tube. Before being fractured, each fracture element is attached to opposite portions of two tube portions. In this way they keep these two opposite portions together and prevent the two portions from falling apart after the cutting process. These opposite portions have a geometrical shape such that the stresses in the fracture element will increase more than the stresses in the surrounding material and/or structure during manipulation. Therefore, if a deflection or a high enough force is applied on the two opposite portions such as to try to move them relative to one another, the stress in the fracture element rises above the yield stress of the tube material, causing permanent deflection of the fracture element. Applying even more deflection or a higher force results in the stress reaching the ultimate tensile stress of the fracture element causing a fracture of fracture element without causing a permanent deformation of the two portions because the stress as developed in the two portions remains below their yield stress.
In this way elements of the tubes that should be independently movable relative to one another in the final steerable instrument can be separated by operating the instrument after the different tubes are inserted into one another and the elements cannot fall apart anymore. I.e., the process of fracturing is preferably done when the steerable instrument is finished and all tubes are inserted into one another, and the elements that should be attached to one another have been attached.
Fracture elements 2411(m) should be designed in the following way. Before being fractured, each fracture element 2411(m) is attached to opposite portions of the tube from which the chain links are made. These opposite portions of the tube have a geometrical shape such that the stresses in the fracture element 2411(m) are higher than in the surrounding material and/or structure. Therefore, if a deflection or a high enough force is applied on a structure with a fracture element 2411(m)—here caused by rotating adjacent chain links relative to one another—the stress in the fracture element rises above the yield stress of the tube material, causing permanent deflection of fracture element 2411(m). Applying even more deflection or a higher force results in the stress reaching the ultimate tensile stress causing a fracture of fracture element 2411(m). An other mechanism to break the fracture element may be achieved by applying low or high cycle fatigue to fracture element 2411(m). The stress in fracture element 2411(m) is raised above the fatigue limit, causing a fatigue fracture when a sufficient number of deflections is used. In all cases the stresses in the surrounding structure/material stays at least below the yield stress of the tube material.
Fracture elements as described herein above may be applied to any adjacent elements of the embodiments of the present application in analogous manner.
Concepts of using fracture elements are schematically shown in
Although
An other mechanism to break the fracture element 4306 may be achieved by applying low or high cycle fatigue to a fracture element. The stress in fracture element is raised above the fatigue limit, causing a fatigue fracture. Note that this fatigue limit is lower than the above mentioned ultimate tensile stress. In all cases the stresses in the surrounding structure/material of the two opposite tube elements to which fracture element 4306 is attached stays at least below the yield stress of the tube material. The process of fracturing by applying several fatigue cycles is preferably done when the steerable instrument is finished and all tubes are inserted into one another, and the elements that should be attached to one another have been attached.
As a further alternative, a fracture element may be melted by an energy, e.g. laser, beam after tubes are inserted into one another. Such an energy beam may be directed to the fracture element through a suitable hole in a tube outside the tube in which the fracture element is located. Of course, any combination of fracturing, applying fatigue and melting may be used if desired.
When elastic bridges 1308(k), 1310(k), 1312(k) are used, the shackled chain links 1301(k) of steering wire 16(j) will gain a certain amount of bending stiffness, but when the elastic bridges 1308(k), 1310(k), 1312(k) have small dimensions as compared to what the width and thickness of a solid steering wire 16(j) would have, this increase of bending stiffness is minimal or even negligible.
Even though
The invention can also be applied in multi-tube instruments in which portions of adjacent chain links manufactured from one tube are attached to portions of an adjacent tube, as will be explained with reference to
As shown in the enlarged view of
Now, flexible bridges are made in an underlying tube layer.
Instead of (laser) welding any other suitable attachment technique, like gluing, may be used.
Reference numbers 1317(k) and 1319(k), respectively, refer to fracture elements used to keep extension 1305(k) and other portions of chain link 1301(k) attached to adjacent parts of the tube during the process of cutting the slot pattern in the tube, which fracture elements are removed once the tube is inserted into another tube, as explained above.
It is observed that the arrangement shown in
As mentioned above, the clearance between adjacent tubes may generally be in the order of 0.02 to 0.1 mm, but depends on the specific application and material used. In order for adjacent chain links or force equalizing structure elements to fall apart in use of the instrument, the clearance is, preferably, smaller than a wall thickness of the tubes. Restricting the clearance to a value between 5-50%, preferably, between 30-40% of the wall thickness of the tubes is generally sufficient.
In the above specification, adjacent portions of a steering wire connected to one another by means of a rotatable connection have been shown and explained in detail. A series of such adjacent portions of a steering wire may form chain links of a chain which provide the steering wire with a very large flexibility which can be advantageously used in flexible zones of the instrument where the steering wire should be highly flexible but still have a large strength in the longitudinal direction.
An alternative implementation of a portion of a steering wire 16(j) with a large flexibility and still large longitudinal strength will be explained with reference to
To that end, first the principle of a force equalizer will be briefly explained with reference to
Third steering wire portion 16(j,3) is shown to have an end portion which is connected at a third point of connection 2802 to a transverse structure 2804 which, in rest, extends in a direction T perpendicular to the longitudinal direction of steering wire 16(j), as well as perpendicular to the radius of the tube. First steering wire portion 16(j,1) is connected to transverse structure 2804 at a first point of connection 2806. Second steering wire portion 16(j,2) is connected to transverse structure 2804 at a second point of connection 2808. In the preferred embodiment, third point of connection 2802 is located exactly between the first and second points of connection 2806 and 2808. It is to be understood that “exactly” means as close as possible to a location exactly in the middle between the other two points of connection in dependence on the used method of manufacturing. To guarantee that first and second steering wire portions 16(j,1), 16(j,2) are more flexible in the transverse direction than third steering wire portion 16(j,3) of steering wire 16(j) they are smaller in the transverse direction than the width of third steering wire portion 16(j,3).
The longitudinal movement of third steering wire portion 16(j,3), first steering wire portion 16(j,1) and second steering wire portion 16(j,2), respectively, is indicated with |(16(j,3)), |(16(j,1)) and |(16(j,2)), respectively. The direction in which the transverse structure 2804 extends when |(16(j,1))=|(16(j,2)) is indicated with a solid line in
If |(16(j,1)) and |(16(j,2)) are unequal, then transverse structure 2804 rotates relative to the third steering wire portion 16(j,3) about third point of connection 2802, rotates relative to first steering wire portion 16(j,1) about first point of connection 2806, and rotates relative to second steering wire portion 16(j,2) about second point of connection 2808. In this way, path length differences between first steering wire portion 16(j,1) and second steering wire portion 16(j,2) translate into rotations at three points 2802, 2806, 2808 of steering wire 16(j). As is evident to persons skilled in the art, even if first steering wire portion 16(j,1) and second steering wire portion 16(j,2) show a different path length movement, a longitudinal movement of third steering wire portion 16(j,3) translates into a longitudinal movement of both first steering wire portion 16(j,1) and second steering wire portion 16(j,2) (which movements may be slightly different).
In FIGS. 12, 13 and 14 of WO2018/067004 these three connection points 2802, 2806, 2808 are implemented with solid portions of steering wire 16(j) that are allowed to bend in order to allow the above mentioned rotations. However, such bending causes stresses in the material that might be a cause for early failure of this mechanisms due to fatigue issues. Furthermore, the required bending force to bend these elements adds stiffness to the steerable tip section of the instrument. The present document describes some improved examples with points of connection with free rotation allowing for larger path offsets.
It is observed that in
At its opposite outer ends, transverse strip 2804 is provided with a first circular opening 2812 and a second circular opening 2814, respectively. First steering wire portion 16(j,1) is provided with a first end portion 2818 extending at a first angle of, e.g., between 5 and 40 degrees, preferably between 10 and 30 degrees, more preferably between 15 and 25 degrees relative to an axis of symmetry 2822 of steering wire 16(j) to first circular opening 2812. First end portion 2818 is provided with a first circular portion 2806 accommodated inside first circular opening 2812. Second steering wire portion 16(j,2) is provided with a second end portion 2820 extending at a second angle of, e.g., between 5 and 40 degrees, preferably between 10 and 30 degrees, more preferably between 15 and 25 degrees relative to axis of symmetry 2822 of steering wire 16(j) to second circular opening 2812. First and second angles may have the same value being it in opposite directions. Second end portion 2820 is provided with a second circular portion 2808 accommodated inside second circular opening 2814. All elements shown in
First circular portion 2806, second circular portion 2808 and third circular portion 2802, respectively, have a play inside first circular opening 2812, second circular opening 2814 and third circular opening 2810, respectively, that may be between 0.01 to 2.00 mm, more typically for medical applications, between 0.015 and 0.04 mm.
At their opposing longitudinal ends, first and second steering wire portions 16(j,1), 16(j,2) may be attached to a still further steering wire portion (or to a fixed tube portion) by a further, similar force equalizer structure as the one shown in
In order for the circular portions 2802, 2806 and 2808 to remain inside their respective openings 2810, 2812 and 2814 and not to fall out of them, the tube in which steering wire 16(j) is made should be inserted between an outer tube and inner tube. Moreover, the play between this tube and such inner tube and outer tube is less than the thickness of these tubes, e.g., the play may be in a range between 1-50% of this thickness
It is observed that
Moreover, it is observed that the circular portions 2802, 2806 and 2808 can be substituted by portions having another shape. Equally, the circular openings 2810, 2812, 2814 need not be fully circular. The only requirement is that these portions 2802, 2806, 2808 and openings 2810, 2812, 2814 are shaped such that these portions 2802, 2806, 2808 can rotate inside openings 2810, 2812, 2814, respectively, to a certain predetermined angle.
Fracture elements as explained with reference to
Second steering wire portion 16(j,2) is provided with a second end portion 3017 facing third steering wire portion 16(j,3) and extending under a second angle away from an axis of symmetry 3018 in a direction opposite to the direction of first end portion 3016. The second angle is preferably the same as the first angle and may be, e.g., between 5 and 40 degrees, preferably between 10 and 30 degrees, more preferably between 15 and 25 degrees. At its end, second end portion 3017 is provided with a second circular opening 3014 accommodating a second circular disk 3008.
Preferably, a gap is provided between first end portion 3016 and second end portion 3017 which may be widening towards their ends (here, the distal ends of them), as shown in
Third steering wire portion 16(j,3) is, at a third end portion facing first and second steering wire portions 16(j,1), 16(j,2), provided with a circular opening 3010 accommodating a circular disk 3002.
First circular disk 3006, second circular disk 3008 and third circular disk 3002, respectively, are, in the shown embodiment, provided with a first attachment structure 3013, a second attachment structure 3015 and a third attachment structure 3003, respectively, They may result from providing first circular disk 306, second circular disk 3008 and third circular disk 3002, respectively, with a suitable slotted pattern, e.g. a zig-zag pattern. The first attachment structure 3013, second attachment structure 3015 and third attachment structure 3003 may be used in a (laser) welding process to attach them to a rotatable structure 3004 located inside or outside the tube in which steering wire 16(j) is made.
Once third circular disk 3002 is attached to rotatable structure 3004 rotatable structure 3004 can rotate together with third circular disk 3002. Rotatable structure 3004 may have the form of a circular disk rotatably arranged inside a circular opening 3005 in the tube inside or outside the tube in which steering wire 16(j) is made. However, rotatable structure 3004 may have any other suitable form configured to rotate together with third circular disk 3002.
First circular disk 3006 is also attached to rotatable structure 3004 at a distance from circular disk 3002, preferably located at a line intersecting the center of rotatable disk 3002 and extending perpendicular to axis of symmetry 3018. Second circular disk 3008 is also attached to rotatable structure 3004 at a distance from circular disk 3002, also preferably located at that line but at a location opposite to the location of first circular disk 3006.
First circular disk 3006, second circular disk 3008 and third circular disk 3002, respectively, have a play inside first circular opening 3012, second circular opening 3014 and third circular opening 3010, respectively, that may be between 0.01 to 2.00 mm, more typically for medical applications, between 0.015 and 0.04 mm.
Third steering wire portion 16(j,3) is shown to have a larger width than first and second steering wire portions 16(j,1), 16(j,2), which may have the same width. In some applications, however, third steering wire portion 16(j,3) may have a width smaller than the width of first and second steering wire portions 16(j,1), 16(j,2).
In use, first and second steering wire portions, may be located in a zone of the instrument which is bendable. Like the embodiment of
Thus, the embodiment of
As is evident to persons skilled in the art, even if first steering wire portion 16(j,1) and second steering wire portion 16(j,2) show a different path length movement, a longitudinal movement of third steering wire portion 16(j,3) translates into a longitudinal movement of both first steering wire portion 16(j,1) and second steering wire portion 16(j,2) (which movements may be slightly different). Next to that, a steering force that is applied to 16(j,3) is divided over 16(j,1) and 16(j,2) in a ratio equal to the perpendicular distance between the central axis through 16(j,3) and the centre of rotation of 3002 and 3006 respectively. If this distance is equal, the steering force F is divided in ½ F in wire 16(j,1) and ½ F in wire 16(j,2)
At their opposing longitudinal ends, first and second steering wire portions 16(j,1), 16(j,2) may be attached to a still further steering wire portion (or to a fixed tube portion) by a further, similar force equalizer structure as the one shown in
In the embodiment shown in
It is observed that
Moreover, it is observed that the circular portions 3002, 3006 and 3008 can be substituted by portions having another shape. Equally, the circular openings 3010, 3012, 3014 need not be fully circular. The only requirement is that these portions 3002, 3006, 3008 and openings 3010, 3012, 3014 are shaped such that these portions 3002, 3006, 3008 can rotate inside openings 3010, 3012, 3014, respectively, to a certain predetermined angle.
Fracture elements as explained with reference to
In order for the circular portions 3002, 3006 and 3008 to remain inside their respective openings 3010, 3012 and 3014 and not to fall out of them, the clearance between the tube in which steering wire 16(j) is made and the tube in which rotatable structure 3004 is made is, in an embodiment, less than the thickness of these tubes, e.g., the clearance may be in a range between 1-50%. Alternatively, the method used to attach the circular portions 3002, 3006 and 3008 to the adjacent tube may result in some extra material (e.g. glue or some welding material) being present in the space between them and the adjacent tube.
The thickness of cylindrical elements according to the described embodiments depend on their application. For medical applications the thickness may be in a range of 0.03-2.0 mm, preferably 0.03-1.0 mm, more preferably 0.05-0.5 mm, and most preferably 0.08-0.4 mm. The diameter of cylindrical elements depend on their application. For medical applications the diameter may be in a range of 0.5-20 mm, preferably 0.5-10 mm, more preferably 0.5-6 mm.
Longitudinal elements in one cylindrical element can be attached to longitudinal elements in adjacent cylindrical elements such that they are together operable to transfer a longitudinal motion from a longitudinal element at the proximal end of the instrument to a bendable portion of the instrument at the distal end of the instrument such that the bendable portion bends. This is explained in detail in WO 2017/213491 (cf. e.g.
It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims. While the invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The present invention is not limited to the disclosed embodiments but comprises any combination of the disclosed embodiments that can come to an advantage.
Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the description and claims, the word “comprising” does not exclude other elements, and the indefinite article “a” or “an” does not exclude a plurality. In fact it is to be construed as meaning “at least one”. The mere fact that certain features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope of the invention. Features of the above described embodiments and aspects can be combined unless their combining results in evident technical conflicts.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2030159 | Dec 2021 | NL | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/NL2022/050721 | 12/15/2022 | WO |
