Patent Application
20250049305
The present invention relates to a steerable instrument for endoscopic and/or invasive type of applications, such as in surgery. The instrument according to the invention is in particular suited for colonoscopic and/or gastroscopic applications. 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 that respect the possibility to use a natural orifice of the body would even be better. 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 through which these instruments are guided towards the target area are well-known in the art. Both the invasive instruments and endoscopes can comprise a steerable instrument that enhances its navigation and steering capabilities. Such a steerable instrument preferably comprises a proximal end part including at least one flexible zone, a distal end part including at least one flexible zone, and a rigid intermediate part, wherein the steerable instrument 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 rigid intermediate part into a related deflection of at least a part of the distal end part.
Furthermore, the steerable instrument preferably comprises a number of co-axially arranged cylindrical elements including an outer element, an inner element and one or more intermediate elements depending on the number of flexible zones in the proximal and distal end parts of the instrument 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 member. 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 instrument. 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, it is preferred to avoid them and to implement the steering members by one or more sets of longitudinal elements that form integral parts of the one or more intermediate cylindrical elements. Each of the intermediate cylindrical elements including the longitudinal elements can be fabricated either by using a suitable material addition technique, such as injection molding or plating, or by starting from a cylindrical element 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. 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. Further details regarding the design and fabrication of the abovementioned steerable instrument 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.
Steerable invasive instruments typically comprise a handle that is arranged at the proximal end part of the steerable instrument for steering the instrument and/or for manipulating a tool that is arranged at the distal end part of the steerable instrument. 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.
Assembling a steerable instrument having an intermediate cylindrical element in a steerable instrument is quite difficult since the longitudinal elements provide the intermediate cylindrical element with a very much decreased bending stiffness. The intermediate cylindrical element with the longitudinal steering elements may deform in a very uncontrolled manner. It easily loses its geometrical coherence. Manipulating the intermediate cylindrical element during and after providing the longitudinal elements therein can become problematic, especially while assembling the steerable instrument. This is quite cumbersome when carrying out the assembly, and it may also cause damage to the intermediate cylindrical element. Such damage generally yields a steerable instrument with deteriorated performance, which is very much undesired.
These issues are addressed by WO 2016/089202 A1, disclosing a steerable instrument and a method of manufacturing such. The method provides an efficient and well-controlled method of manufacturing a steerable instrument. In order to avoid displacement, deformation and/or disordering of the longitudinal elements, elements are provided for keeping adjacent longitudinal elements and/or in a set relationship with respect to one another during assembly of the instrument. These elements may be flexible elements, which have a permanent attachment to the respective longitudinal element(s). Alternatively, the elements may be releasably or temporarily attached to the longitudinal elements, for example by fracture points or by elements referred to as fracture elements. These temporary or releasable attachments can be caused to fracture, break, or otherwise release after assembly of the instrument. An embodiment hereof is reproduced in
While the use of the fracture elements as described by WO 2016/089202 A1 offers many advantages during assembly of the instrument, after assembly they remain within the open space between neighboring longitudinal elements. Thereby, relative movement of the two neighboring longitudinal elements is limited. Furthermore, if not breaking properly at each fraction point, the relative movement of the longitudinal elements may be even more obstructed, e.g. limited to half of its intended extension. Still further, if the operator of the instrument applies a force to the instrument causing it to bend to such an extent that a relative movement of the neighboring longitudinal elements exceeds the range set by the length of the open space, the fracture element may be forced into an undesired position, such as into longitudinal slits separating adjacent longitudinal elements, or into a space below or above the longitudinal elements, where it might get stuck or otherwise causing severe damage to the instrument.
Another problem which might occur during use of the steerable instruments relates to inadvertent clamping of the longitudinal elements between the inner and outer layers. In these steerable instruments, the longitudinal elements need to be flexible in at least those portions of the instrument that should allow bending relative to the longitudinal axis of the instrument, both at the proximal and distal ends. These longitudinal elements are often located between an adjacent outer and adjacent inner cylindrical element. When bending these flexible zones of the instrument, in each such zone these longitudinal elements bend together with bendable portions of the outer and inner cylindrical element. However, sometimes the bending of such zone causes the bending outer and bending inner cylindrical element to clamp the longitudinal element between the outer and inner cylindrical elements such that it is difficult to move the longitudinal elements any further in the longitudinal direction. This effect may also be caused/increased by different longitudinal elements arranged on top of each other in the bendable portions.
WO 2019/009710 A1 describes a steerable instrument having a construction aimed at preventing clamping of the longitudinal element between the outer and inner cylindrical elements. Several different embodiments are presented for creating a distance between different cylindrical elements, such that clamping of longitudinal elements there between is prevented. In some embodiments, as reproduced in
However, the presence of such radial spacers formed by bent lip shaped portions may put restrictions on the degree to which the instrument can be bent. As shown in
Furthermore, if in WO 2019/009710 A1 the different cylindrical elements are not aligned with sufficient accuracy, and/or if the direction and/or point of application of the force applied for bending the lip shaped portion is not accurate, the lip shaped portion may not be bent as intended. The bending of the lip shaped portion may inadvertently result in the lip shaped portion not touching the inner cylinder, whereby the desired radial spacing may not be achieved, and/or in the lip shaped portion abutting one or both of the adjacent longitudinal elements, causing friction during use of the instrument.
Some locations to be examined and/or operated in a body need specifically designed instruments. In particular if these locations are located at a relatively large distance from a suitable point of entry into the body, the instrument needs sufficient length, and a high degree of flexibility may be required in the intermediate part of the instrument, while, obviously, maintaining functionality of the instrument.
It is an object of the invention to provide a steerable instrument for endoscopic and/or invasive type of applications where at least one of the above mentioned problems are solved or at least reduced.
In particular, it is an object of the invention to provide a steerable instrument having improved bending properties, e.g. a steerable instrument which can handle higher bending and/or torsional stress or forces.
This is achieved by a steerable instrument as claimed in claim 1.
In another embodiment, the object of the invention is to provide a steerable instrument which can be more easily assembled and/or manufactured, in particular wherein the instrument is less prone to be associated with faults, errors or imperfections caused by the manufacturing process.
This is achieved by a cylindrical element as claimed in claim 17.
Embodiments of the invention are claimed in dependent claims.
In a first aspect a steerable instrument for endoscopic and/or invasive type of applications, such as in surgery, is provided, the instrument comprising:
The first cylindrical element may also be referred to as an intermediate cylindrical element or layer. The instrument may comprise more than one such intermediate cylindrical layer, depending on, e.g., the number of flexible distal zones in, and/or construction requirements of, the steerable instrument.
In order to avoid confusion and to clearly distinguish between corresponding features of the various cylindrical elements, such as proximal and distal end parts, flexible distal portions, etc., these are referred to with reference to the cylindrical element in which they are provided. For example, the feature “first proximal end part” refers to the proximal end part of the first cylindrical element. This feature may alternatively be referred to as “proximal end part of the first cylindrical element”.
The at least one longitudinal element is separated from tangentially adjacent or near-by located parts of the first cylindrical element by the at least one tangential spacer. In some embodiments, more than one longitudinal element, e.g. a plurality of longitudinal elements are provided, as well as a plurality of tangential spacers. In such embodiments, adjacent longitudinal elements are separated from one another by at least one tangential spacer located therebetween.
That is, the expression “an other portion of the first cylindrical element”, used herein above, may encompass any parts of the cylindrical element extending in the longitudinal direction, i.e. adjacent the at least one longitudinal element, but not forming a longitudinal element arranged for transferring force, as well as any further longitudinal element(s) in an embodiment comprising a plurality of longitudinal elements.
The at least one longitudinal element provides a controlled bending of the at least one first flexible distal zone of the instrument. If a plurality of longitudinal elements are provided, these may be arranged to control bending of a plurality of distal zones. At the proximal end part of the steerable instrument, an operator, such as a surgeon, or a computer or a robot, controls bending of the one or more flexible distal zones, by applying a force to the at least one longitudinal element or at least some of the plurality of longitudinal elements. The at least one longitudinal element, extending between the proximal and distal end parts of the instrument, transfers this force to the distal end part, whereby one or more of the flexible distal zones are bent. When more than one flexible distal zones are provided, these are individually controlled, such that bending of the distal end part of the instrument can be achieved in accordance with the intention of the operator.
To this end, at the proximal end part, the longitudinal elements may be connected to linear actuators controlled by e.g. a computer or control unit like a robot. Alternatively, the proximal end part of the first cylindrical element may include at least one flexible proximal portion, arranged such that the bending of this flexible proximal portion results in a controlled bending of a corresponding flexible distal portion. Such a flexible portion may be implemented by corresponding hinges in the cylindrical element in the form of a suitable slit shaped pattern, or by a ball shaped steering unit or a tiltable plate, as a person skilled in the art will understand.
The second cylindrical element may also be referred to as an outer cylindrical element or layer. The second cylindrical element may also be an intermediate layer within the assembled instrument, whereby a further outer layer is provided.
The different cylindrical elements or layers are coaxially aligned, such that corresponding flexible portions are aligned along the cylindrical axis. As will be described below, a third cylindrical element may be provided as an inner cylindrical element or a further intermediate cylindrical element.
The intermediate part, extending between the proximal end part and the distal end part, is flexible throughout its extension, such as to be able to bend in different directions. This bending is in general not directly controllable by the operator, but takes place in correspondence with e.g. the geometry of the space into which the instrument is introduced, e.g. as the instrument, during insertion into and/or passage through a space, such as the colon or intestine, touches walls or other obstructions thereof. The flexibility of the intermediate region must be such that no damage is caused to the internal walls of the passage through which it passes through. A substantially fully bendable and/or flexible instrument is provided, suitable for various applications where the distal end portion of the steerable instrument has to reach a position which is difficult to reach and/or located at some distance from a point of entry into a body, such as a human body. Examples of such applications include colonoscopic and gastroscopic applications.
The tangential spacer is arranged to provide and/or maintain a distance between the at least one longitudinal element and other parts of the first cylindrical element, and/or between adjacent longitudinal elements in embodiments comprising a plurality of longitudinal elements, and to limit movement of the at least one longitudinal element in tangential, circumferential and/or transversal direction.
The tangential spacer is provided with at least one aperture, into which the radial spacer protrudes, thereby confined in its movement with respect to the at least one longitudinal element in the direction parallel and antiparallel to the extension of the longitudinal element and in a tangential direction of the first cylindrical element.
The tangential spacer may be formed by an element which prior to assembly of the instrument is attached to the at least one longitudinal element via one or more fracture locations or fracture elements, which are fractured after assembly of the instrument, e.g. in a manner as described in WO 2016/089202 A1.
In embodiments wherein a plurality of longitudinal elements are provided, these are arranged with a gap or distance between adjacent longitudinal element in the longitudinal direction, forming an open space. In each of these open spaces, one or more of said tangential spacers can be arranged. The longitudinal elements preferably have a shape and/or dimension such that movement of longitudinal elements relative to one another and relative to the tangential spacers is not limited by the longitudinal elements themselves or portions thereof.
By the at least one radial spacer, movement of the tangential spacer with respect to the second cylindrical element is limited and/or confined. The tangential spacer can be said to be maintained in place by the radial spacer. Hence, the distance between neighboring longitudinal elements is maintained by the tangential spacer, while relative movement of adjacent longitudinal elements along one another is enabled, and while unintended displacement of the spacer, e.g. in the form of the tangential spacer sliding on top of or underneath the first cylindrical element, is prevented.
The radial spacer protrudes into, and preferably extends through, the open space between the at least one longitudinal element and other parts of the cylindrical element adjacent thereto, or between adjacent longitudinal elements. It is attached to, and/or forms part of, e.g. by being formed by a part of, the second cylindrical element. Preferably, it is flexible and/or has at least some degree of elasticity or flexibility with respect to the second cylindrical element. The radial spacer may be a radial spacer of the second aspect of the invention.
Preferably, a plurality of tangential spacers and a plurality of radial spacers are provided between adjacent longitudinal elements.
The tangential spacer is provided with an aperture and the radial spacer protrudes at least partly into said aperture. Thereby, one radial spacer is sufficient for limiting a movement of the tangential spacer both in the longitudinal and tangential direction of the steerable instrument.
The first cylindrical element may be a first cylindrical tube, and both the at least one longitudinal element and the at least one tangential spacer may be portions of the first cylindrical tube.
The second cylindrical element may be a second cylindrical tube. The at least one radial spacer and the at least one further radial spacer may be formed by a lip shaped portion of the second cylindrical tube and protruding from the second cylindrical tube. The lip shaped portion may have a lip shaped portion width and the aperture an aperture width, wherein the lip shaped portion width is either smaller than the aperture width or is configured such that it clamps the tangential spacer when bent into the aperture.
The at least one longitudinal element has a length in the longitudinal direction and a width in a direction substantially perpendicular to said longitudinal direction in said first intermediate part, wherein preferably said width is substantially constant throughout said length. This further reduces the risk of the tangential spacer sliding on top of or underneath the longitudinal element. If the at least one longitudinal element has a uniform width throughout at least the extension of the intermediate part of the first cylindrical element, such that the distance between adjacent longitudinal elements is substantially constant in this part, the movement of adjacent longitudinal elements with respect to one another will not be limited by interactions between the longitudinal elements and the tangential or radial spacers.
The instrument may further comprise a third cylindrical element arranged coaxially with said first cylindrical element and said second cylindrical element, wherein said first cylindrical element is arranged between said second cylindrical element and said third cylindrical element, and wherein at least one of the following applies: said at least one radial spacer or said at least one further radial spacer is arranged to abut said third cylindrical element, is engaged with said third cylindrical element, and is attached to said third cylindrical element. This arrangement contributes to the mechanical stability of the instrument.
The at least one radial spacer provides a distance between the second and third cylindrical elements, which is preferably larger than the thickness of the longitudinal elements and the tangential spacer in the radial direction. Clamping of the at least one longitudinal element between the second and third cylindrical elements during bending of the flexible zone is thereby prevented.
The third cylindrical element may advantageously be a third cylindrical tube provided with a at least one recess or aperture, and wherein said at least one radial spacer or said at least one further radial spacer protrudes into said at least one recess or aperture. By this arrangement, the second and third cylindrical elements are fixed, or locked, with respect to one another in axial, radial and tangential direction. The radial spacer or said at least one further radial spacer may comprise a first part having a first width and a second part having a second width which is smaller than said first width, and wherein said second part protrudes into said recess or aperture. Thereby, the relative fixation of the second and third cylindrical elements may be improved.
In some embodiments, the third cylindrical tube may be provided with a plurality of recesses or apertures, wherein each of the at least one radial spacer and the at least one further radial spacer protrude into a respective one of the plurality of recesses or apertures. In such embodiment, both the at least one radial spacer and the at least one further radial spacer may comprise the first and the second parts.
The third cylindrical element comprises a third proximal end part, a second distal end part including at least one third flexible distal portion, and a third intermediate part between said third proximal end part and said third distal end part, corresponding to and substantially aligned with, respectively, said first proximal end part, said first distal end part and said first intermediate part of said first cylindrical element.
In general, the third cylindrical element forms an inner cylindrical element, said first cylindrical element forms an intermediate cylindrical element, and said second cylindrical element forms an outer cylindrical element. This provides for easy manufacturing when the radial spacer is provided by a lip shaped portion in the second cylindrical element, which lip shaped portion is bent in a radial direction. Alternatively, the second cylindrical element may form an inner cylindrical element and the third cylindrical element an outer cylindrical element.
The at least one radial spacer may advantageously be formed by a lip shaped portion protruding from said second cylindrical element. This lip shaped portion may be formed in the second cylindrical element e.g. by laser cutting, and, after assembly and alignment of the cylindrical elements, be bent in the radial direction such as to form the radial spacer. When the second cylindrical element forms an outer cylindrical element, this bending is performed from the outside, in a direction directed radially inwards.
The lip shaped portion may be formed in a second wall of said second cylindrical element such as to be attached thereto via a beam having a beam axis extending substantially perpendicular to said longitudinal direction;
wherein said lip shaped portion is defined by a first slot in said second wall, said first slot extending around said lip shaped portion except for where the lip shaped portion is attached to said beam;
The steerable instrument may be substantially flexible throughout its length. In that case, said cylindrical element, said second cylindrical element, and, where present, said third cylindrical element are provided with one or more flexible portions throughout their lengths.
The steerable instrument may comprise a plurality of tangential spacers and a plurality of radial spacers as well as a plurality of longitudinal elements, wherein between each pair of adjacent longitudinal elements at least one tangential spacer and at least one radial spacer are provided. That is, tangential spacers and associated radial spacers are provided in each open gap between adjacent longitudinal elements in the intermediate part of the first cylindrical element. This provides a steerable instrument having high flexibility.
Alternatively, the steerable instrument comprises a plurality of tangential spacers, a plurality of radial spacers, and a plurality of longitudinal elements,
According to a second aspect of the invention a cylindrical element for use in a steerable instrument is provided, said cylindrical element extending along a cylindrical axis and comprising a wall, wherein at least one lip shaped portion is formed in said wall,
Thereby, the bending direction of the lip shaped portion is defined with high accuracy, as the risk of the lip shaped portion having a direction deviating from the radial direction decreases. If the force for bending the lip shaped portion is applied perpendicular to the wall of the cylindrical element, the lip shaped portion will bend around the beam axis. Abutment and/or friction between the radial spacers and the adjacent longitudinal elements during use of the instrument can be avoided, as the radial spacer has a well-defined position and/or orientation.
The cylindrical element according to the second aspect may be used as the second cylindrical element in the steerable instrument of the first aspect, whereby the lip shaped portion forms the radial spacer.
The lip shaped portion may comprise a first part having a first width in a direction substantially parallel to said beam axis and a second part having a second width in a direction substantially parallel to said beam axis, wherein said first part is arranged between said beam and said second part, and wherein said second width is smaller than said first width. The second part is advantageously used to engage with and/or be inserted into an aperture or recess of a further, e.g. third, cylindrical element arranged coaxial with the cylindrical element provided with the lip shaped portion. Thereby, a stable fixation of the cylindrical elements may be provided.
In general, the lip shaped portion is symmetrical with respect to said beam axis and an axis substantially perpendicular to said beam axis.
The beam axis may extend in a direction substantially perpendicular to said cylindrical axis. This is preferred when the cylindrical element is used for providing radial spacers in a steerable instrument of the first aspect when the longitudinal elements extend in a direction parallel to the cylindrical axis of the first cylindrical element.
Alternatively, the beam axis may extend in a direction oriented at a different angle to the cylindrical axis of the cylindrical element. This is advantageous when the cylindrical element is used for providing radial spacers in a steerable instrument of the first aspect in an embodiment where the longitudinal elements extend in a spiraling or helical arrangement with respect to a cylinder axis of the first cylindrical element. In this case, the beam axis is preferably oriented substantially perpendicular to the longitudinal direction at the location of the radial spacer.
In general, a plurality of lip shaped portions are provided in the cylindrical element.
The lip shaped portion of the second aspect is advantageously used as the lip shaped portion, or radial spacer, of the first aspect.
In a third aspect, a method of manufacturing a cylindrical element for use in a steerable instrument, said cylindrical element extending in a direction of a cylinder axis, said method comprising:
This cylindrical element is preferably the cylindrical element of the second aspect.
The beam axis may extend in a direction at an angle to said cylinder axis. Said angle is larger than 0°, preferably larger than 45° and smaller or equal to 90°, and more preferably 90°.
The piece of material may be provided in the form of a cylindrical element, or may be rolled into a cylindrical element after forming said first and second slots.
The beam axis may extend in a direction substantially perpendicular to said cylindrical axis. Alternatively, the beam axis may extend in a different direction. Effects and applications hereof have been described above with respect to the cylindrical element of the second aspect.
In a fourth aspect a method of assembling a steerable instrument is provided, the method comprising:
The steerable instrument of the first aspect may be assembled by the method according to the fourth aspect. The various features of the method may be associated with technical effects and advantages analogous to the effects and advantages described above.
Said third cylindrical element may be provided with at least one aperture or recess in a third wall of said third cylindrical element, and wherein after said bending said lip shaped portion engages with said aperture or recess.
Said lip shaped portion may be attached to said second wall via a beam having a beam axis, said lip shaped portion comprising a first part having a first width in direction substantially parallel to said beam axis and a second part having a second width in a direction substantially parallel to said beam axis, wherein said first part is arranged between said beam and said second part, and wherein said second width is smaller than said first width, wherein said second part engages with said aperture or recess of said third cylindrical element.
The method may further comprise releasing said at least one releasable attachment of said at least one tangential spacer after sliding said cylindrical elements into one another.
The various embodiments described above may be combined with one another. Embodiments described with respect to one aspect may be applied analogously with respect to one or more of the other aspects.
The cylindrical elements described above are, preferably, manufactured from a single cylindrical tube of any suitable material like stainless steel, cobalt-chromium, shape memory alloy such as Nitinol®, plastic, polymer, composites or other cuttable material. Alternatively, the cylindrical elements can be made by a 3D printing process. The thickness of that tube depends on its application. For medical applications the thickness may be in a range of 0.1-2.0 mm, preferably 0.1-1.0 mm, more preferably 0.1-0.5 mm, and most preferably 0.2-0.4 mm. The diameter of the cylindrical elements depends on its 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. In many applications, the cylindrical element has a circular cross section. However, the term “cylindrical element” is not restricted to this interpretation. It may have an oval cross section or any other suitable cross section, including a rectangular cross section.
The slits and openings in all cylindrical elements to make, e.g., the at least one longitudinal element and the at least one tangential spacer can be made by laser cutting. The smaller slits which are made to just separate adjacent elements may have a width, preferably, in a range of 5-50 μm, more preferably 15-30 μm.
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.
It is observed that the term “substantially” as used in the present document refers to manufacturing tolerances which exclude that features like sizes and distances have exact values. Depending on used manufacturing processes such tolerances may be smaller than 10%, preferably smaller than 5%, and even more preferably smaller than 1%.
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:
body of the steerable instrument as shown in
cylindrical element for a steerable instrument according to an embodiment of the invention.
While in the embodiment shown in
In operation, usually, several invasive instruments are inserted through the colonoscope 42 to provide one or more tools for some function at its distal end 44. In colonoscopy, such a tool typically includes a camera lens and a lighting element. To assist the surgeon in steering the camera view to the desired location and view in colon 30, typically, the distal end is deflectable from a longitudinal axis in all angular directions. This also holds for the inserted instruments with tools 2. That can be implemented by providing such an instruments with one or more flexible zones, like the flexible zones 16, 17 of the instrument shown in
In operation, usually, several invasive instruments are inserted through the gastroscope 56 to provide one or more tools for some function at its distal end 60. In gastroscopy, such a tool typically includes a camera lens and a lighting element. To assist the surgeon in steering the camera view to the desired location and direction in stomach 50, typically, the distal end 60 of the instrument is deflectable from a longitudinal axis in all angular directions. This also holds for the inserted instruments with tools 2. That can be implemented by providing such an instrument with one or more flexible zones, like the flexible zones 16, 17 of the instrument shown in
The steerable instruments according to the invention can be used in such colonoscopes and gastroscopes. Therefore, general requirements to the presented instruments are that they show a high rotational stiffness, high longitudinal stiffness, flexibility along its entire length and deflectability at its flexible distal zones even in cases of long instruments, e.g., longer than 1 m, and with a relatively small diameter that fits to the working channels within or attached to colonoscopes and gastroscopes Also, such instruments should be designed such that they can be manufactured quite easily. In accordance with the invention this can be achieved with instruments having a tubular body with at least one tube element made from a metal and provided with suitable slotted structures to provide the instrument with enough flexibility along its entire length.
In
It will be clear to the skilled person that the elongated tubular body 18 as shown in
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 10.
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 element 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 elements 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 element 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 elements 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 together 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 18 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 preferably is smaller than a wall thickness of the longitudinal elements to prevent an overlapping configuration thereof. Restricting the clearance to about 30% to 40% of the wall thickness of the longitudinal elements is generally sufficient.
As can be seen in
For the sake of convenience, as shown in
Although the portions 115, 125, 135 and 143 making up the zone 155 are described herein above as being rigid, alternatively, when the instrument is an instrument for use in e.g. colonoscopy or gastroscopy as described above, these portions will be flexible or bendable. However, contrary to the flexible distal portions, flexing or bending of the intermediate portions are not controlled by the operator of the instrument. Embodiments of such flexible intermediate portions are provided by the present invention, and are described in detail e.g. with respect to
In order to deflect at least a part of the distal end part 13 of the steerable instrument 10, 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
The steering members comprise one or more sets of longitudinal elements that form integral parts of the one or more intermediate cylindrical elements 102, 103. Preferably, the longitudinal elements 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 elements.
Further details regarding the fabrication of the latter longitudinal steering elements are provided with reference to
The inner cylindrical element 2202 comprises a first rigid end part 2221, which is located at the distal end part 13 of the instrument 2201, a first flexible part 2222, an intermediate rigid part 2223, a second flexible part 2224 and a second rigid end part 2225, which is located at the proximal end part 11 of the instrument 2201.
The outer cylindrical element 2204 also comprises a first rigid end part 2241, a first flexible part 2242, an intermediate rigid part 2243, a second flexible part 2244 and a second rigid end part 2245. The lengths of the different parts of the cylindrical elements 2202 and 2204 are substantially the same so that when the inner cylindrical element 2202 is inserted into the outer cylindrical element 2204, the different parts are positioned against each other.
The intermediate cylindrical element 2203 also has a first rigid end part 2331 and a second rigid end part 2335 which in the assembled condition are located between the corresponding rigid parts 2221, 2241 and 2225, 2245 respectively of the two other cylindrical elements 2202, 2204. The intermediate part 2333 of the intermediate cylindrical element 2203 comprises three or more separate longitudinal elements which can have different forms and shapes as will be explained below. After assembly of the three cylindrical elements 2202, 2203 and 2204 whereby the element 2202 is inserted in the element 2203 and the two combined elements 2202, 2203 are inserted into the element 2204, at least the first rigid end part 2221 of the inner cylindrical element 2202, the first rigid end part 2331 of the intermediate cylindrical element 2203 and the first rigid end part 2241 of the outer cylindrical element 2204 at the distal end of the instrument are attached to each other. In the embodiment shown in
Although the intermediate parts 2223, 2333 and 2243 are described herein above as being rigid, alternatively, when the instrument is an instrument for use in e.g. colonoscopy or gastroscopy as described above, these portions will be flexible or bendable. However, contrary to the flexible distal portions, flexing or bending of the intermediate parts are not controlled by the operator of the instrument. Embodiments of such flexible intermediate portions are provided by the present invention, and are described in detail e.g. with respect to
In the embodiment shown in
The production of such an intermediate part is most conveniently done by injection molding 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 to end up with the desired shape of the intermediate cylindrical element 2203. 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 member 2203 can be made so to say in one process, without requiring additional steps for attaching 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 2202 and 2204 with their respective flexible parts 2222, 2224, 2242 and 2244.
The flexible portions 112, 132, 114, 142, 116, 144, 118, and 138 as shown in
Such flexible parts may have a structure as shown in
Furthermore, if the portions 122, 123, 124, 125, 126, 127, and 128 of the first intermediate cylindrical element 102 and the portions 134, 135, and 136 of the second intermediate cylindrical element 103 that respectively form the first and second set of longitudinal steering members, as shown in
Otherwise, the longitudinal elements 4, 2338 can also be obtained by any other technique known in the art such as for example described in EP 1 708 609 A. The only restriction with respect to the construction of the longitudinal elements used in these portions is that the total flexibility of the instrument in these locations where the flexible portions coincide must be maintained.
The different co-axially arranged layers or cylindrical elements 101, 102, 103, 104, 2202, 2203 and 2204 as described above in relation to the exemplary embodiments of the steerable instruments shown in
In the above embodiments, the proximal portions and distal portions are constructed in a similar way. However, that need not always be the case as has been indicated above and as will become apparent hereinafter.
In the embodiment shown in
The longitudinal elements of the second intermediate layer 103 are passing through the slits 67 and connected to the set 81 of linear actuators. The longitudinal elements of the first intermediate layer 102 are passing through the cylindrical member 83 and connected to the second set 82 of linear actuators. By means of an appropriate actuation of the linear actuators 81 and 82 the orientation of the flexible distal zones 152 and 154 can be changed so that the same effects are obtained as with the instrument according to
Other robotic embodiments may be applied as well.
The steering arrangement at the proximal end may alternatively be
implemented by a ball shaped steering unit or a tiltable disc to which the longitudinal elements are attached. Such implementations are known as such. They may be operated by a human operator or by a robotic device which itself may be controlled by a human operator.
According to some embodiments, the proximal portion may have a wider diameter as shown in
Such widening of the instrument with increasing diameter towards the proximal portions can also be applied in an instrument with more than two bendable portions, as shown in
After assembly of the instrument, the fracture elements will be caused to break (fracture), due to a combination of bending forces and tension forces created by rolling of the circular shaped fracture element 7 along sides of the longitudinal elements 4. In general a fracture element 7 can be designed to have a shape such that one or more of shear forces, bending forces and tension forces act upon the fracture locations 7.1 of the fracture elements when adjacent longitudinal elements 4 are moved relative to one another.
In the embodiment of
Since fracture or breakage of the fracture locations takes place after the different cylindrical elements have been slid into one another, the fracture elements will remain inside the instrument. As can be understood from inspection of
As shown in
As shown in
When the intermediate cylindrical element 206 is inserted into the cylindrical element 204, lip shaped portions 294e are located above a free space 320. Each lip shaped portion 294e is bent inwardly such that it remains in an inward bent position and extends through free space 320 and touches a portion of cylindrical element 208.
Assuming that intermediate cylindrical element 206 has a height h1, then, lip shaped portion 294e is bent inwardly over a distance of h3 where h3>h1. Thus, at the location of the bent lip shaped portion 294e a well-defined radial space between intermediate cylindrical elements 204 and 208 is created which is larger than the height h1 of the longitudinal element portions 282. This supports movement of them in the longitudinal direction even in situations where the instrument is bent in the flexible zone.
However, the embodiment of
Furthermore, the force applied for bending the lip shaped portion 294e has to be applied with a high degree of accuracy, i.e. as radial as possible, as otherwise the lip shaped portion may not be bent as intended. This might result in the lip shaped portion 294c not touching the cylindrical element 208, whereby the desired radial spacing may not be achieved, and/or in the lip shaped portion 294e abutting one or both of the adjacent longitudinal elements portions 282, causing friction during use of the instrument.
The intermediate cylindrical element 1002, 1003 represents embodiments of the first cylindrical element described in the Summary section above.
In the embodiment shown in
As described above, e.g. with reference to
The longitudinal elements 1038 extend in a longitudinal direction 1008. This may be parallel to the cylindrical axis 1010, as in the embodiment of
Alternatively, the longitudinal direction 1008 may be arranged in a helical manner with respect to the cylindrical axis 1010, e.g. as illustrated in
The longitudinal elements 1038 are arranged with a gap or open space 1006 between adjacent longitudinal elements 1038. In an embodiment, the longitudinal elements have uniform dimension throughout the intermediate portion and are uniformly distributed along the circumference of the cylindrical element, such that all open spaces 1006 have the same dimensions.
Tangential spacers 1007, 1017 are arranged in the open space 1006 between adjacent longitudinal elements 1038. The longitudinal elements 1038 and the tangential spacers 1007, 1017 are movable with respect to one another in the longitudinal direction.
Preferably, the longitudinal elements 1038 and the tangential spacers 1007, 1017 are not attached to one another, such as to not limit their respective movements in the longitudinal direction. The tangential spacers 1007, 1017 maintain a tangential distance between adjacent longitudinal elements 1038, while providing sufficient support of the longitudinal elements 1038 in the tangential direction, such as to provide mechanical strength and stability to the instrument.
Although
Although
In the embodiment of
The longitudinal elements 1038 preferably have the same width w throughout their extension within the intermediate part. Thereby, the relative movement between the tangential spacers 1007, 1017 and the adjacent longitudinal elements 1038 will not be limited by widened portions of the longitudinal elements 1038. Thereby, the risk of a tangential spacer sliding on top of or underneath the longitudinal elements 1038 is reduced.
During assembly of the instrument, the tangential spacers 1007, 1017 may be attached to the adjacent longitudinal elements 1038 at fracture elements 1007a, 1017a which are fractured or destroyed after assembly of the instrument, by moving adjacent longitudinal elements 1038 relative to one another in opposite longitudinal directions as described in WO 2016/089202 A1 and PCT/NL2022/050318 of the present applicant. This provides stability of the intermediate cylindrical element and geometrical coherence of the longitudinal elements 1038 during assembly of the instrument.
In the embodiment of
In accordance with the present invention, tangential spacer 1007 is provided with one or more apertures 1029. Also tangential spacer 1017 may be provided with one more of such apertures 1029. This is schematically indicated in
As can be seen, a plurality of radial spacers 1094 are provided, which are attached to, or formed from a part of, the outer cylindrical element 1004. The radial spacers 1094 extend in a radially inward direction, and protrude into, in fact extends through, the open space 1006 formed between adjacent longitudinal elements 1038 in the intermediate cylindrical element 1002, 1003. Preferably, the radial spacers 1094 are formed by lip shaped portions formed in the wall of the outer cylindrical element 1004, as will be described in more detail with respect to
As will be described with reference to
As can be understood from
The inner cylindrical element 1001 is provided with a plurality of apertures 1096, which after assembly of the instrument cooperate with the radial spacers 1094 such that the tips of the radial spacers 1094 extend in an aperture 1096, as illustrated in
In the embodiment shown in
In alternative embodiments, the inner cylindrical element 1001 may be provided without apertures 1096, wherein the radial spacers 1094 are arranged to abut the inner surface of the wall of the inner cylindrical element 1001, and to, at least to some degree, provide fixation of the outer cylindrical element 1004 with respect to the inner cylindrical element 1001 by means of friction between the radial spacer 1094 and the inner cylindrical element 1001.
The radial spacers 1094 provide a distance between the inner cylindrical element 1001 and the outer cylindrical element 1004. The radial spacers 1094 have a radial dimension such that this distance is larger than the thickness of the longitudinal elements 1038 and the tangential spacers 1007, 1017 in the radial direction. Thereby, clamping or obstruction of the longitudinal elements 1038 between the inner and outer cylindrical elements 1001, 1004 during bending or flexing of the intermediate part of the instrument can be prevented.
In the embodiment of
In an embodiment, tangential spacers 1017 may also be provided with one or more apertures 1029, through which radial spacers 1094 extend, in the same way as explained with reference to
Advantageously, the lip shaped portions 1097, 1098, 1099 are formed in the outer cylindrical element 1004, whereby the radial spacers can be formed by bending each of these lip shaped portions in a radially inward direction after assembly of the instrument. Alternatively, it can be formed in the inner cylindrical element 1001, and be bent in a radially outward direction in order to form radial spacers.
In addition to forming the radial spacers 1094 used in the intermediate part 12 of the instrument, the lip shaped portions 1098, 1099 shown in
The lip shaped portion 1097 shown in
As shown in
In the embodiment shown in
Alternatively, the beam axis 1101 may be oriented at a different angle with respect to the cylindrical axis 1010, for instance, depending on the direction of extension of the longitudinal elements 1038 throughout the intermediate region. As discussed above, in some embodiments the longitudinal elements may be arranged to form, at least partly, a helix, or be arranged to extend in an at least partly spiraling direction, with respect to the cylindrical axis. In such embodiments, the angle may be slightly less than 90 degrees. It is observed, however, that also in case the longitudinal elements 1038 extend along a helical path, the beam axes 1101 may extend perpendicular to the cylindrical axis 1010.
In short, the beam axis 1101 may extend in a direction substantially perpendicular to the direction of extension of the longitudinal elements 1038, at the location of the beam axis, in the intermediate cylindrical element together with which the outer cylindrical element 1004 is intended to be used.
The lip shaped portion 1098, 1099 is defined by a first slot 1102 formed in the wall of the cylindrical element 1004. This slot 1102 extends around the lip shaped portion 1098, 1099 on all sides, except for where the lip shaped portion is attached to the wall via the beam 1100. In addition, first slot portions 1102b extend in a direction substantially parallel to the beam axis 1101 on either side of the lip shaped portion 1098, 1099, at one side of the beam 1100. The beam 1100 is defined by a second slot 1103 provided in the wall of the second 1004, wherein the second slot 1103 extends in a direction substantially parallel to the beam axis 1101 at the other side of the beam 1100.
The slots 1102, 1103 may advantageously be formed by laser cutting through the wall of a cylindrical element.
By this construction of the lip shaped portion 1098, 1099 and the beam 1100 forming the attachment to the cylindrical element 1004, defined by the slots 1102, 1003, bending of the lip shaped portion in the radial direction of the cylindrical element is defined with high accuracy. If a force is applied in the radial direction onto the lip shaped portion, this will bend around the beam axis 1101.
In the embodiment shown in
As shown in
It should be noted that the number and distribution of the lip shaped portions and radial spacers illustrated in
Although with reference to the embodiments illustrated in
The steerable instrument may be formed by providing an inner cylindrical element 1001, an outer cylindrical element 1004, and one or more intermediate cylindrical elements 1002, 1003 as described herein above. Thereby, an inner cylindrical element 1001 as illustrated in
Subsequently, these cylindrical elements 1001-1004 are coaxially aligned by sliding them into one another, and aligning them along the direction of the cylinder axis such that corresponding flexible and bendable parts and regions of the various cylindrical elements are aligned. Subsequently, the lip shaped portions 1094 formed in the outer cylindrical element is bent radially inwards by the application of a force applied perpendicular to the lip shaped portion in the wall, such that the lip shaped portion bends radially inwards until it protrudes through the open space 1006 or opening 1029 (
After assembly of the instrument, the releasable attachments of the tangential spacers 1007, 1017 are released. The releasable attachments are preferably provided by fracture elements 1007a, 1017a, which are fractured by bending of the instrument in various directions after assembly thereof. Alternatively, such fracture elements may be destroyed by an energy, e.g. laser, beam or by applying fatigue.
By providing cylindrical elements having an intermediate portion in accordance with one or more of the embodiments described herein above with reference to
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 |
|---|---|---|---|
| 2030128 | Dec 2021 | NL | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/NL2022/050718 | 12/13/2022 | WO |
