US20080245173A1 - System for controlling the movement of a multi-linked device - Google Patents

Abstract

A system for controlling the movement of a steerable multi-linked device may include a steerable multi-linked device a feeder mechanism releaseably connected to the steerable multi-linked device and a controller device. The steerable multi-linked device may include a first link, a plurality of intermediate links, and a second link movably coupled to a second one of the intermediate links. A first one of the intermediate links may be movably coupled to the first link. The controller device may be configured to control movement of the multi-linked device via the feeder mechanism.

Description

B. CROSS REFERENCE TO RELATED APPLICATIONS
• This application claims priority to U.S.Patent Application 60/891,881 filed Feb. 27, 2007, the entirety of which is incorporated by reference herein, This application is related to co-pending U.S. patent application Ser. No. 12/038,560 (attorney docket no. 132041.00401) and Ser. No. 12/038,691 (attorney docket no. 132041.00411).
C.-E.
• Not Applicable
F. BACKGROUND
• This application discloses an invention that is related, generally and in various embodiments, to a system for controlling the movement of a multi-linked device.
G. SUMMARY
• A system for controlling the movement of a steerable multi-linked device may include a steerable multi-linked device, a feeder mechanism releaseably connected to the steerable multi-linked device and a controller device. The steerable multi-linked device may include a first link, a plurality of intermediate links, and a second link movably coupled to a second one of the intermediate links. A first one of the intermediate links may be movably coupled to the first link. The controller device may be configured to control movement of the multi-linked device via the feeder mechanism.
H. BRIEF DESCRIPTION OF DRAWINGS
• Various embodiments of the invention are described herein by way of example in conjunction with the following figures.
• FIGS. 1A and 1B illustrate various embodiments of a steerable multi-linked device;
• FIG. 2 illustrates various embodiments of a core mechanism of the device ofFIG. 1;
• FIGS. 3A-3C illustrate various embodiments of a proximal link of the core mechanism;
• FIGS. 4A-4C illustrate various embodiments of an intermediate link of the core mechanism;
• FIGS. 5A-5C illustrate various embodiments of a distal link of the core mechanism;
• FIG. 6 illustrates various embodiments of a sleeve mechanism of the device ofFIG. 1;
• FIGS. 7A-7C illustrate various embodiments of a proximal link of the sleeve mechanism;
• FIGS. 8A-8C illustrate various embodiments of an intermediate link of the sleeve mechanism;
• FIGS. 9A-9D illustrate various embodiments of a distal link of the sleeve mechanism;
• FIG. 10 illustrates various embodiments of a motion sequence of the device ofFIG. 1;
• FIG. 11 illustrates various embodiments of a steerable multi-linked device traversing a path having tight curvatures;
• FIG. 12A illustrates various embodiments of a joystick for controlling the movement of a multi-linked device;
• FIG. 12B illustrates various embodiments of a haptic controller for controlling the movement of a multi-linked device; and
• FIG. 13 illustrates various embodiments of a method for controlling movement of a multi-linked device.
I. DETAILED DESCRIPTION
• It is to be understood that at least some of the figures and descriptions of the invention have been simplified to focus on elements that are relevant for a clear understanding of the invention, while eliminating, for purposes of clarity, other elements that those of ordinary skill in the art will appreciate may also comprise a portion of the invention. However, because such elements are well known in the art, and because they do not necessarily facilitate a better understanding of the invention, a description of such elements is not provided herein.
• According to various embodiments, the invention described herein may be utilized to control movement of a multi-linked device such as the steerable multi-linked device described herein. For ease of explanation purposes, the invention will be described in the context of its use with various embodiments of the steerable multi-linked device described herein. However, one skilled in the art will appreciate that the invention may be utilized with other types of multi-linked devices.
• FIGS. 1A and 1B illustrate various embodiments of a steerablemulti-linked device10. According to various embodiments, the steerable multi-linked device may be a snake robot, a continuum robot or the like. Various embodiments of thedevice10 may be utilized for medical procedures (e.g., as a robotic bore, positioning device, ablation tool, camera or instrument support, or guidance system for minimally invasive procedures), for surveillance applications, for inspection applications, for search and rescue applications, etc. For purposes of clarity only, the utility of thedevice10 will be described hereinbelow in the context of its applicability to medical procedures. However, a person skilled in the art will appreciate that thedevice10 can be utilized in a variety of different applications.
• Thedevice10 comprises afirst mechanism12 and asecond mechanism14. According to various embodiments, a mechanism may be a snake robot, a continuum robot or the like. According to various embodiments, thesecond mechanism14 is structured and arranged to receive and surround thefirst mechanism12 as shown inFIG. 1B. Thus, the first mechanism and second mechanism may be concentric. For such embodiments, thefirst mechanism12 may be considered the inner mechanism or the core mechanism, and thesecond mechanism14 may be considered the outer mechanism or the sleeve mechanism. According to other embodiments, the first andsecond mechanisms12,14 may be structured and arranged to have a relationship other than a concentric relationship. For example, one skilled in the art will appreciate that, according to various embodiments, the first andsecond mechanisms12,14 may be structured and arranged to operate in a side-by-side arrangement, where thefirst mechanism12 operates adjacent to thesecond mechanism14. According to various embodiments, additional and/or alternate configurations may be used within the scope of this disclosure. According to various embodiments, a three-dimensional space240 may be provided between the first and second mechanisms. This space will be described in more detail below.
• As described in more detail hereinbelow, thefirst mechanism12 may operate in either a rigid mode or a limp mode, thesecond mechanism14 may operate in either a rigid mode or a limp mode, and the first andsecond mechanisms12,14 may operate independent of one another. Both thefirst mechanism12 and thesecond mechanism14 may be steerable mechanisms. Accordingly, it will be appreciated that thedevice10 may be utilized to navigate a luminal space as well as any three-dimensional path within an intracavity space. According to various embodiments, thedevice10 may advance by alternating the operation of thefirst mechanism12 and thesecond mechanism14 between a limp mode and a rigid mode.
• According to various embodiments, thedevice10 may also comprise one or more cables. According to various embodiments, one or more of the cables may be steering cables and/or tensioning cables. For example, the device may include three steering cables and one tensioning cables.
• FIG. 2 illustrates various embodiments of thefirst mechanism12 of thedevice10. Thefirst mechanism12 is a multi-linked mechanism and includes afirst end24 and asecond end26. Thefirst end24 may be considered the proximal end and thesecond end26 may be considered the distal end. Thefirst mechanism12 may comprise afirst link28, asecond link30, and one or moreintermediate links32 between the first andsecond links28,30. Thefirst link28 may be considered the proximal link, and thesecond link30 may be considered the distal link.
• FIGS. 3A-3C illustrate various embodiments of the first link28 (inner proximal link) of thefirst mechanism12. Thefirst link28 includes afirst end34 and asecond end36, and defines alongitudinal axis38 that passes through the center of thefirst end34 and the center of thesecond end36 as shown inFIG. 3B. Thefirst link28 may be fabricated from any suitable material. According to various embodiments, thefirst link28 is fabricated from a fiber reinforced material such as, for example, G10/FR4 Garolite®. Thefirst link28 has a generally cylindrical shaped exterior and is described in more detail hereinbelow.
• Thefirst link28 comprises afirst portion40 and asecond portion42. Thefirst portion40 may be considered the proximal portion and thesecond portion42 may be considered the distal portion. Thefirst portion40 may be fabricated integral with thesecond portion42. Thefirst portion40 has a cylindrical shaped exterior, and extends from thefirst end34 of thefirst link28 toward thesecond end36 of thefirst link28. According to various embodiments, the diameter of thefirst portion40 may be on the order of approximately 6.35 millimeters. Other sizes are possible.
• Thesecond portion42 has a generally cylindrically shaped exterior, with other features described below. Thesecond portion42 has a cylindrically shaped exterior where it contacts thefirst portion40, and tapers toward thesecond end36 of thefirst link28. Thesecond portion42 may be shaped in the form of a generally segmented hemisphere at thesecond end36 of thefirst link28. According to various embodiments, the diameter of thesecond portion42 may be on the order of approximately 4.75 millimeters where it contacts thefirst portion40. Other sizes are possible.
• Thesecond portion42 comprises afirst surface44. Thefirst surface44 may be considered the outer surface of thesecond portion42. Thesecond portion42 defines afirst groove46 parallel to thelongitudinal axis38 along thefirst surface44, asecond groove48 parallel to thelongitudinal axis38 along thefirst surface44, and athird groove50 parallel to thelongitudinal axis38 along thefirst surface44. Each of the first, second andthird grooves46,48,50 extend along thefirst surface44 toward thesecond end36 of thefirst link28. The first, second andthird grooves46,48,50 may be semi-tubular shaped and may be evenly spaced about thefirst surface44 of thesecond portion42 of thefirst link28 as shown inFIG. 3C. According to various embodiments, the first, second, andthird grooves46,48,50 may be configured in the shape of a segmented cylinder. The size of each of thegrooves46,48,50 may be identical to one another or may be different from one another. For example, according to various embodiments, the first andsecond grooves46,48 may be configured as segments of a cylinder having a diameter on the order of approximately 1.25 millimeters, and thethird groove50 may be configured as a segment of a cylinder having a diameter on the order of approximately 2.50 millimeters. The length of thefirst link28 may be on the order of approximately 65 millimeters. However, one skilled in the art will appreciate that the length or diameter of thefirst link28 can vary based on the application.
• Thefirst link28 also defines apassage52 extending from thefirst end34 to thesecond end36 along thelongitudinal axis38 as shown inFIG. 3B. Thepassage52 is of a size sufficient to allow at least one cable to pass therethrough. According to various embodiments, thepassage52 may be of a sufficient size to allow a tensioning cable to pass therethrough. According to various embodiments, thepassage52 is generally configured as a complex shape that comprises a combination of afirst cylinder54 that extends from thefirst end34 toward thesecond end36, and asecond cylinder56 that extends from thefirst cylinder54 toward thesecond end36. The diameter of thefirst cylinder54 is larger than the diameter of thesecond cylinder56. For example, according to various embodiments, thefirst cylinder54 may have a diameter on the order of approximately 3.20 millimeters and thesecond cylinder56 may have a diameter on the order of approximately 1.50 millimeters. Other sizes are possible.
• FIGS. 4A-4C illustrate various embodiments of one of the intermediate links32 (inner intermediate link) of thefirst mechanism12. Theintermediate link32 is representative of the otherintermediate links32. Theintermediate link32 includes afirst end58 and asecond end60, and defines alongitudinal axis62 that passes through the center of thefirst end58 and the center of thesecond end60 as shown inFIG. 4B. Theintermediate link32 may be fabricated from any suitable material. According to various embodiments, theintermediate link32 is fabricated from a fiber reinforced material such as, for example, G10/FR4 Garolite®. Theintermediate link32 has a generally bullet-shaped exterior and is described in more detail hereinbelow.
• Theintermediate link32 comprises afirst portion64 and asecond portion66. Thefirst portion64 may be considered the proximal portion and thesecond portion66 may be considered the distal portion. Thefirst portion64 may be fabricated integral with thesecond portion66. Thefirst portion64 has a generally cylindrical shaped exterior, and extends from thefirst end58 of theintermediate link32 toward thesecond end60 of theintermediate link32. According to various embodiments, thesecond portion66 has a generally cylindrically shaped exterior where it contacts thefirst portion64, and tapers toward thesecond end60 of theintermediate link32. The exterior of thesecond portion66 is configured in the form of a generally segmented hemisphere. According to various embodiments, the diameter of theintermediate link32 may be on the order of approximately 4.75 millimeters at thefirst end58 thereof. The length of theintermediate link32 may be on the order of approximately 5.85 millimeters. However, one skilled in the art will appreciate that the length or diameter of theintermediate link32 can vary based on the application.
• Theintermediate link32 also comprises afirst surface68 that extends from thefirst end58 of theintermediate link32 to thesecond end60 of theintermediate link32. Thefirst surface68 may be considered the outer surface of theintermediate link32. Theintermediate link32 also defines afirst groove70 parallel to thelongitudinal axis62 along thefirst surface68, asecond groove72 parallel to thelongitudinal axis62 along thefirst surface68, and athird groove74 parallel to thelongitudinal axis62 along thefirst surface68. Each of the first, second andthird grooves70,72,74 extend along thefirst surface68 from thefirst end58 of theintermediate link32 toward thesecond end60 of theintermediate link32. The first, second andthird grooves70,72,74 may be semi-tubular shaped and may be evenly spaced about thefirst surface68 of theintermediate link32 as shown inFIG. 4C. According to various embodiments, the first, second, andthird grooves70,72,74 may be configured in the shape of a segmented cylinder. The size of each of thegrooves70,72,74 may be identical to one another or may be different from one another. For example, according to various embodiments, the first andsecond grooves70,72 are configured as segments of a cylinder having a diameter on the order of approximately 1.75 millimeters at thefirst end58 of theintermediate link32, and thethird groove74 is configured as a segment of a cylinder having a diameter on the order of approximately 2.50 millimeters at thefirst end58 of theintermediate link32. The first, second andthird grooves70,72,74 are each configured to receive and partially surround any of a variety of tools or instruments (e.g., ablation tools) which may pass from thefirst end24 of themulti-linked device10 to thesecond end26 of themulti-linked device10.
• Theintermediate link32 also defines apassage76 extending from thefirst end58 to thesecond end60 along thelongitudinal axis62 as shown inFIG. 4B. Thepassage76 may be of a size sufficient to allow one or more cables to pass therethrough. According to various embodiments, thepassage76 may be of a size sufficient to allow a tensioning cable to pass therethrough. According to various embodiments, thepassage76 is generally configured as a complex shape that comprises a combination of a firstsegmented hemisphere78 that extends from thefirst end58 toward thesecond end60, a secondsegmented hemisphere80 that extends from the firstsegmented hemisphere78 toward thesecond end60, acylinder82 that extends from the secondsegmented hemisphere80 toward thesecond end60, and a thirdsegmented hemisphere84 that extends from thecylinder82 to thesecond end60 of theintermediate link32. According to various embodiments, the firstsegmented hemisphere78 represents a portion of a sphere having a diameter on the order of approximately 4.75 millimeters, the secondsegmented hemisphere80 represents a portion of a sphere having a diameter on the order of approximately 2.25 millimeters, thecylinder82 may have a diameter on the order of approximately 1.0 millimeter, and the thirdsegmented hemisphere84 represents a portion of a sphere having a diameter on the order of approximately 2.25 millimeters. Other sizes are possible.
• The firstsegmented hemisphere78 of thepassage76 is configured to receive thesecond end36 of thefirst link28 when thefirst link28 is coupled to theintermediate link32. Similarly, for a givenintermediate link32, the firstsegmented hemisphere78 of thepassage76 is configured to receive thesecond end60 of anotherintermediate link32 when the otherintermediate link32 is coupled to the givenintermediate link32. The thirdsegmented hemisphere84 may serve to reduce the pinching or binding a cable when oneintermediate link32 moves relative to an adjacentintermediate link32 coupled thereto. Similarly, when thesecond link30 is coupled to a givenintermediate link32, the thirdsegmented hemisphere84 may serve to reduce the pinching or binding of a cable when thesecond link30 moves relative to the givenintermediate link32.
• With the above described structure, thefirst link28 may be coupled to theintermediate link32 by seating thesecond end36 of thefirst link28 in the firstsegmented hemisphere78 of thepassage76 of theintermediate link32. As the convex configuration of thesecond end36 of thefirst link28 generally corresponds with the concave configuration of the firstsegmented hemisphere78 of thepassage76 of theintermediate link32, thefirst link28 may be coupled to theintermediate link32 such that thelongitudinal axis38 and the first, second andthird grooves46,48,50 of thefirst link28 are respectively aligned with thelongitudinal axis62 and the first, second andthird grooves70,72,74 of theintermediate link32. Theintermediate link32 may be moved relative to thefirst link28 such that thelongitudinal axis62 of theintermediate link32 is not aligned with thelongitudinal axis38 of thefirst link28. According to various embodiments, the configuration of thefirst link28 and theintermediate link32 allows for theintermediate link32 to be moved relative to thefirst link28 coupled thereto such that thelongitudinal axis38 of thefirst link28 and thelongitudinal axis62 of theintermediate link32 are up to approximately 25° out of alignment with one another. Similarly, oneintermediate link32 may be coupled to anotherintermediate link32, and so on, by seating thesecond end60 of oneintermediate link32 in the firstsegmented hemisphere78 of thepassage76 of anotherintermediate link32. As the convex configuration of thesecond end60 of theintermediate link32 generally corresponds with the concave configuration of the firstsegmented hemisphere78 of thepassage76 of theintermediate link32, theintermediate links32 may be coupled such that the respectivelongitudinal axes62 and the respective first, second andthird grooves46,48,50 of theintermediate links32 are aligned. The coupledintermediate links32 may be moved relative to one another such that the respectivelongitudinal axes62 of the coupledintermediate links32 are not aligned. According to various embodiments, the configuration of the coupledintermediate links32 allows for oneintermediate link32 to be moved relative to an adjacentintermediate link32 coupled thereto such that the respectivelongitudinal axes62 are up to approximately 25° out of alignment with one another.
• FIGS. 5A-5C illustrate various embodiments of the second link30 (inner distal link) of thefirst mechanism12. Thesecond link30 includes afirst end86 and asecond end88, and defines alongitudinal axis90 that passes through the center of thefirst end86 and the center of thesecond end88 as shown inFIG. 5B. Thesecond link30 may be fabricated from any suitable material. According to various embodiments, thesecond link30 is fabricated from a thermoplastic material such as, for example, Delrin®.
• Thesecond link30 comprises afirst portion92 and asecond portion94. Thefirst portion92 may be considered the proximal portion and thesecond portion94 may be considered the distal portion. Thefirst portion92 may be fabricated integral with thesecond portion94. Thefirst portion92 has a generally cylindrical shaped exterior, and extends from thefirst end86 of thesecond link30 toward thesecond end88 of thesecond link30. According to various embodiments, thesecond portion94 has a generally cylindrically shaped exterior where it contacts thefirst portion92, and tapers toward thesecond end88 of thesecond link30. The exterior of thesecond portion64 is configured in the form of a generally segmented cone. According to various embodiments, the diameter of thesecond link30 may be on the order of approximately 4.75 millimeters at thefirst end86 thereof, and the taper of thesecond portion94 may be at an angle of approximately 30° relative to the exterior of thefirst portion92. The length of thesecond link30 may be on the order of approximately 5.90 millimeters. However, one skilled in the art will appreciate that the length or diameter of thesecond link30 can vary based on the application.
• Thesecond link30 also comprises afirst surface96 that extends from thefirst end86 of thesecond link30 to thesecond end88 of thesecond link30. Thefirst surface96 may be considered the outer surface of thesecond link30. Thesecond link30 also defines afirst groove98 parallel to thelongitudinal axis90 along thefirst surface96, asecond groove100 parallel to thelongitudinal axis90 along thefirst surface96, and athird groove102 parallel to thelongitudinal axis90 along thefirst surface96. Each of the first, second andthird grooves98,100,102 extend along thefirst surface96 from thefirst end86 of thesecond link30 toward thesecond end88 of thesecond link30. The first, second andthird grooves98,100,102 may be semi-tubular shaped and may be evenly spaced about thefirst surface96 of thesecond link30 as shown inFIG. 5C. According to various embodiments, the first, second, andthird grooves98,100,102 may be configured in the shape of a segmented cylinder. The size of each of thegrooves98,100,102 may be identical to one another or may be different from one another. For example, according to various embodiments, the first andsecond grooves98,100 are configured as segments of a cylinder having a diameter on the order of approximately 1.25 millimeters at thefirst end86 of thesecond link30, and thethird groove102 is configured as a segment of a cylinder having a diameter on the order of approximately 2.50 millimeters at thefirst end86 of thesecond link30. The first, second andthird grooves98,100,102 are each configured to receive and partially surround any of a variety of tools or instruments (e.g., ablation tools) which may pass from thefirst end24 of themulti-linked device10 to thesecond end26 of themulti-linked device10.
• Thesecond link30 also defines apassage104 extending from thefirst end86 to thesecond end88 along thelongitudinal axis90 as shown inFIG. 5B. Thepassage104 may be of a size sufficient to allow at least one cable to pass therethrough. According to various embodiments, thepassage104 may be of a size sufficient to allow a tensioning cable to pass therethrough. According to various embodiments, thepassage104 is generally configured as a complex shape that comprises a combination of a firstsegmented hemisphere106 that extends from thefirst end86 toward thesecond end88, a secondsegmented hemisphere108 that extends from the firstsegmented hemisphere106 toward thesecond end88, and acylinder110 that extends from the secondsegmented hemisphere108 to thesecond end88 of thesecond link30. According to various embodiments, the firstsegmented hemisphere106 represents a portion of a sphere having a diameter on the order of approximately 4.75 millimeters, the secondsegmented hemisphere108 represents a portion of a sphere having a diameter on the order of approximately 2.50 millimeters, and thecylinder110 may have a diameter on the order of approximately 1.0 millimeter. The firstsegmented hemisphere106 of thepassage104 may be configured to receive thesecond end60 of anintermediate link32 when theintermediate link32 is coupled to thesecond link30.
• With the above described structure, anintermediate link32 may be coupled to thesecond link30 by seating thesecond end60 of theintermediate link32 in the firstsegmented hemisphere106 of thepassage104 of thesecond link30. As the convex configuration of thesecond end60 of theintermediate link32 generally corresponds with the concave configuration of the firstsegmented hemisphere106 of thepassage104 of thesecond link30, theintermediate link32 may be coupled to thesecond link30 such that thelongitudinal axis62 and the first, second andthird grooves70,72,74 of theintermediate link32 are respectively aligned with thelongitudinal axis90 and the first, second andthird grooves98,100,102 of thesecond link30. Thesecond link30 may be moved relative to theintermediate link32 coupled thereto such that the respectivelongitudinal axes62,90 are not aligned. According to various embodiments, the configuration of thesecond link30 allows for anintermediate link32 coupled thereto to be moved relative to thesecond link30 such that the respectivelongitudinal axes62,90 are up to approximately 25° out of alignment with one another.
• FIG. 6 illustrates various embodiments of thesecond mechanism14 of thedevice10. Thesecond mechanism14 is a multi-linked mechanism and includes afirst end120 and asecond end122. Thefirst end120 may be considered the proximal end and thesecond end122 may be considered the distal end. Thesecond mechanism14 comprises afirst link124, asecond link126, and any number ofintermediate links128 between the first andsecond links124,126. Thefirst link124 may be considered the proximal link, and thesecond link126 may be considered the distal link.
• FIGS. 7A-7C illustrate various embodiments of the first link124 (outer proximal link) of thesecond mechanism14. Thefirst link124 includes afirst end130 and asecond end132, and defines alongitudinal axis134 that passes through the center of thefirst end130 and the center of thesecond end132 as shown inFIG. 7B. Thefirst link124 may be fabricated from any suitable material. According to various embodiments, thefirst link124 is fabricated from a stainless steel material such as, for example, 316 stainless steel. Thefirst link124 has a generally bullet-shaped exterior and is described in more detail hereinbelow.
• Thefirst link124 comprises afirst portion136 and asecond portion138. Thefirst portion136 may be considered the proximal portion and thesecond portion138 may be considered the distal portion. Thefirst portion136 may be fabricated integral with thesecond portion138. Thefirst portion136 has a cylindrical shaped exterior, and extends from thefirst end130 of thefirst link124 toward thesecond end132 of thefirst link124. According to various embodiments, the diameter of thefirst portion136 may be on the order of approximately 12.70 millimeters. Other sizes are possible.
• Thesecond portion138 has a generally cylindrically shaped exterior. Thesecond portion138 has a cylindrically shaped exterior where it contacts thefirst portion136, and tapers toward thesecond end132 of thefirst link124. Thesecond portion138 may be shaped in the form of a generally segmented hemisphere at thesecond end132 of thefirst link124. According to various embodiments, the diameter of thesecond portion138 may be on the order of approximately 9.50 millimeters where it contacts thefirst portion136. Other sizes and shapes are possible.
• Thesecond portion138 comprises afirst surface140. Thefirst surface140 may be considered the outer surface of thesecond portion138. Thesecond portion138 defines afirst groove142 along thefirst surface140, a second groove144 along thefirst surface140, and athird groove146 along thefirst surface140. Each of the first, second andthird grooves142,144,146 are oblique relative to thelongitudinal axis134 and extend along thefirst surface140 toward thesecond end132 of thefirst link124. According to various embodiments, each of thegrooves142,144,146 are oriented at an angle on the order of approximately 15° relative to thelongitudinal axis134. As shown inFIG. 7C, the first, second andthird grooves142,144,146 may be evenly spaced about thefirst surface140 of thefirst link124. According to various embodiments, the first, second, andthird grooves142,144,146 may be configured in the shape of a segmented cylinder. The size of each of thegrooves142,144,146 may identical to one another or may be different from one another. For example, according to various embodiments, each of thegrooves142,144,146 are configured as segments of respective cylinders having diameters on the order of approximately 3.0 millimeters. The first, second andthird grooves142,144,146 are each configured to facilitate the introduction of various tools or instruments (e.g., ablation tools) into themulti-linked device10. The length of thefirst link124 may be on the order of approximately 18.5 millimeters. However, one skilled in the art will appreciate that the length or diameter of thefirst link124 can vary based on the application.
• Thefirst link124 also defines apassage148 extending from thefirst end130 to thesecond end132 along thelongitudinal axis134 as shown inFIG. 7B. Thepassage148 is of a size sufficient to allow thefirst mechanism12 to pass therethrough. According to various embodiments, thepassage148 is generally configured as a complex shape that comprises a combination of asegmented cone150 that extends from thefirst end130 toward thesecond end132, and acylinder152 that extends from thesegmented Cone150 to thesecond end132 of thefirst link124. According to various embodiments, thesegmented cone150 has a diameter on the order of approximately 7.0 millimeters at thefirst end130 of thefirst link124, and may be tapered at an angle on the order of approximately 45° relative to thelongitudinal axis134. Thecylinder152 may have a diameter on the order of approximately 5.50 millimeters. Other dimensions are possible.
• Thefirst link124 also defines a first through-hole154, a second through-hole156, and a third through-hole158. (SeeFIG. 7C). The first through-hole154 is substantially parallel to thelongitudinal axis134, extends from thefirst portion136 toward thesecond end132, and is positioned between thepassage148 and thefirst surface140. The second through-hole156 is substantially parallel to thelongitudinal axis134, extends from thefirst portion136 to thesecond end132, and is positioned between thepassage148 and thefirst surface140. The third through-hole158 is substantially parallel to thelongitudinal axis134, extends from thefirst portion136 to thesecond end132, and is positioned between thepassage148 and thefirst surface140. The first, second and third through-holes154,156,158 are generally cylindrically shaped. According to various embodiments, the through-holes154,156,158 are evenly spaced from one another as shown inFIG. 7C. The size of each of the through-holes154,156,158 may be identical to one another or may be different from one another. For example, according to various embodiments, the respective diameters associated with the through-holes154,156,158 may each be on the order of approximately 1.20 millimeters. The first through-hole154 is configured to receive and surround a cable. The second through-hole156 is configured to receive and surround a cable. The third through-hole158 is configured to receive and surround a cable. The first, second and third through-holes154,156,158 may serve as guidepaths for movement of the cables.
• FIGS. 8A-8C illustrate various embodiments of one of the intermediate links128 (outer intermediate link) of thesecond mechanism14. Theintermediate link128 is representative of the otherintermediate links128. Theintermediate link128 includes afirst end160 and asecond end162, and defines alongitudinal axis164 that passes through the center of thefirst end160 and the center of thesecond end162 as shown inFIG. 8C. Theintermediate link128 may be fabricated from any suitable material. According to various embodiments, theintermediate link128 is fabricated from a polymer thermosplastic material such as, for example, polysulfone. Theintermediate link128 has a generally bullet-shaped exterior and is described in more detail hereinbelow.
• Theintermediate link128 comprises afirst portion166 and asecond portion168. Thefirst portion166 may be considered the proximal portion and thesecond portion168 may be considered the distal portion. Thefirst portion166 may he fabricated integral with thesecond portion168. Thefirst portion166 has a generally cylindrical shaped exterior, and extends from thefirst end160 of theintermediate link128 toward thesecond end162 of theintermediate link128. According to various embodiments, thesecond portion168 has a generally cylindrically shaped exterior where it contacts thefirst portion166, and tapers toward thesecond end162 of theintermediate link128. The exterior of thesecond portion168 is configured in the form of a generally segmented hemisphere. According to various embodiments, the diameter of theintermediate link128 is on the order of approximately 9.65 millimeters at thefirst end160 thereof The length of theintermediate link128 may be on the order of approximately 8.40 millimeters. However, one skilled in the art will appreciate that the dimensions of theintermediate link128 can vary based on the application.
• Theintermediate link128 also comprises afirst surface170 that extends from thefirst end160 of theintermediate link128 to thesecond end162 of theintermediate link128, and asecond surface170 that extends from thefirst end160 of theintermediate link128 to thesecond end162 of theintermediate link128. Thefirst surface170 may be considered the outer surface of theintermediate link128, and thesecond surface172 may be considered the inner surface of theintermediate link128. Theintermediate link32 also defines afirst groove174 substantially parallel to thelongitudinal axis164 along thesecond surface172, asecond groove176 substantially parallel to thelongitudinal axis164 along thesecond surface172, and athird groove178 substantially parallel to thelongitudinal axis164 along thesecond surface172. Each of the first, second andthird grooves174,176,178 extend along thesecond surface172 toward thesecond end162 of theintermediate link128. The first, second andthird grooves174,176,178 may be semi-tubular shaped and may be evenly spaced about thesecond surface172 of theintermediate link128 as shown inFIG. 8C. According to various embodiments, the first, second, andthird grooves174,176,178 may be configured in the shape of a segmented cylinder. The size of each of thegrooves174,176,178 may be identical to one another or may be different from one another. For example, according to various embodiments, the first andsecond grooves174,176 are configured as segments of cylinders having diameters on the order of approximately 1.75 millimeters at thefirst end160 of theintermediate link128, and thethird groove178 is configured as a segment of a cylinder having a diameter on the order of approximately 2.50 millimeters at thefirst end160 of theintermediate link128. The first, second andthird grooves174,176,178 are each configured to receive and partially surround any of a variety of tools or instruments (e.g., ablation tools) which may pass from thefirst end24 of themulti-linked device10 to thesecond end26 of themulti-linked device10.
• Theintermediate link128 also defines apassage180 extending from thefirst end160 to thesecond end162 along thelongitudinal axis164 as shown inFIG. 8B. Thepassage180 is of a size sufficient to allow thefirst mechanism12 to pass therethrough. According to various embodiments, thepassage180 is generally configured as a complex shape that comprises a combination of asegmented hemisphere182 that extends from thefirst end160 toward thesecond end162, a firstsegmented cone184 that extends from the segmentedhemisphere182 toward thesecond end162, acylinder186 that extends from the firstsegmented cone184 toward thesecond end162, and a secondsegmented cone188 that extends from thecylinder186 to thesecond end162 of theintermediate link128. According to various embodiments, thesegmented hemisphere182 represents a portion of a sphere having a diameter on the order of approximately 9.65 millimeters, the firstsegmented cone184 is tapered at an angle on the order of approximately 15° relative to thelongitudinal axis164, thecylinder186 has a diameter on the order of approximately 5.50 millimeters and the secondsegmented cone188 is tapered at an angle on the order of approximately 15° relative to thelongitudinal axis164. Thesegmented hemisphere182 of thepassage180 is configured to receive thesecond end132 of thefirst link124 when thefirst link124 is coupled to theintermediate link128. Similarly, for a givenintermediate link128, thesegmented hemisphere182 of thepassage180 is configured to receive thesecond end162 of anotherintermediate link128 when the otherintermediate link128 is coupled to the givenintermediate link128.
• Theintermediate link128 also defines a first through-hole190, a second through-hole192, and a third through-hole194. (SeeFIG. 8C). The first through-hole190 is substantially parallel to thelongitudinal axis164, extends from thefirst portion166 toward thesecond end162, and is positioned between thepassage180 and thefirst surface170. The second through-hole192 is substantially parallel to thelongitudinal axis164, extends from thefirst portion166 to thesecond end162, and is positioned between thepassage180 and thefirst surface170. The third through-hole194 is substantially parallel to thelongitudinal axis164, extends from thefirst portion166 to thesecond end162, and is positioned between thepassage180 and thefirst surface170. The first, second and third through-holes190,192,194 are generally cylindrically shaped. According to various embodiments, the through-holes190,192,194 are evenly spaced from one another. The size of each of the through-holes190,192,194 may be identical to one another or may be different from one another. For example, according to various embodiments, the respective diameters associated with the through-holes190,192,194 may each be on the order of approximately 1.25 millimeters. The first through-hole190 is configured to receive and surround a cable. The second through-hole192 is configured to receive and surround a cable. The third through-hole194 is configured to receive and surround a cable. The first, second and third through-holes190,192,194 may serve as guidepaths for movement of the cables.
• As shown inFIG. 8C, theintermediate link128 also defines first, second andthird indents196,198,200 at thesecond end162 thereof resulting, in part, from the combination of the taper associated with thesecond portion168 and the configuration and orientation of the first, second, andthird grooves174176,178. The first, second andthird indents196,198,200 may be evenly spaced about thesecond end162 of theintermediate link128 as shown inFIG. 8C. The first, second andthird indents196,198,200 may serve to reduce the pinching or binding of various tools or instruments (e.g., ablation tools) when oneintermediate link128 of thesecond mechanism14 is moved relative to anotherintermediate link128 coupled thereto.
• Theintermediate link128 also defines fourth, fifth andsixth indents202,204,206 at thesecond end162 thereof resulting from the combination of the taper associated with thesecond portion168 and the configuration and orientation of the first, second, and third through-holes190,192,194. The fourth, fifth andsixth indents202,204,206 may be evenly spaced about thesecond end162 of theintermediate link128, and may be evenly spaced from the first, second andthird indents196,198,200 as shown inFIG. 8C. The fourth, fifth andsixth indents202,204,206 may serve to reduce the pinching or binding of the cables when oneintermediate link128 of thesecond mechanism14 is moved relative to anotherintermediate link128 coupled thereto.
• According to various embodiments, anintermediate link128 may also define an opening (not shown) that extends from thesecond surface172 or from one of thegrooves174,176,178 to thefirst surface170 of theintermediate link128. Theintermediate link128 may have any number of such openings, and any number of theintermediate links128 may have such openings. Referring toFIGS. 2 and 4, the opening may be utilized as an exit point for a tool or instrument which may pass from thefirst end24 of themulti-linked device10 toward thesecond end26 of themulti-linked device10. For such embodiments, the respectiveintermediate link128 may be positioned proximate to thesecond link126 of thesecond mechanism14. The opening may be oriented at any angle relative to thelongitudinal axis134 of theintermediate link128. When thefirst mechanism12 is removed from thesecond mechanism14, and a relatively large tool or instrument is advanced from thefirst end120 of thesecond mechanism14 to thesecond end122 of thesecond mechanism14, sufficient room may not exist for a second tool or instrument (e.g., fiber optic cable) to pass through thesecond end122 of thesecond mechanism14. For such instances, the second tool or instrument may exit through an opening of one of theintermediate links128.
• With the above described structure, thefirst link124 may be coupled to theintermediate link128 by seating thesecond end132 of thefirst link124 in the segmentedhemisphere182 of thepassage180 of theintermediate link128. As the convex configuration of thesecond end132 of thefirst link124 generally corresponds with the concave configuration of the segmentedhemisphere182 of thepassage180 of theintermediate link128, thefirst link124 may be coupled to theintermediate link128 such that thelongitudinal axis134, the first, second andthird grooves142,144,146, and the first, second and third through-holes154,156,158 of thefirst link124 are respectively aligned with thelongitudinal axis164, the first, second andthird grooves174,176,178, and the first, second and third through-holes190,192,194 of theintermediate link128. Theintermediate link128 may he moved relative to thefirst link124 such that thelongitudinal axis164 of theintermediate link128 is not aligned with thelongitudinal axis134 of thefirst link124. According to various embodiments, the configuration of thefirst link124 and theintermediate link128 allows for theintermediate link128 to be moved relative to thefirst link124 coupled thereto such that thelongitudinal axis134 of thefirst link124 and thelongitudinal axis164 of theintermediate link128 are up to approximately 10° out of alignment with one another. Similarly, oneintermediate link128 may be coupled to anotherintermediate link128, and so on, by seating thesecond end162 of oneintermediate link128 in the segmentedhemisphere182 of thepassage180 of anotherintermediate link128. As the convex configuration of thesecond end162 of theintermediate link128 generally corresponds with the concave configuration of the segmentedhemisphere182 of thepassage180 of theintermediate link128, theintermediate links128 may be coupled such that the respectivelongitudinal axes164, the respective first, second andthird grooves174,176,178, and the respective first, second and third through-holes190,192,194 of theintermediate links128 are aligned. The coupledintermediate links128 may be moved relative to one another such that the respectivelongitudinal axes164 of the coupledintermediate links128 are not aligned. According to various embodiments, the configuration of the coupledintermediate links128 allows for oneintermediate link128 to be moved relative to anotherintermediate link128 coupled thereto such that the respectivelongitudinal axes164 are up to approximately 10° out of alignment with one another.
• FIGS. 9A-9D illustrate various embodiments of the second link126 (outer distal link) of thesecond mechanism14. Thesecond link126 includes afirst end208 and asecond end210, and defines alongitudinal axis212 that passes through the center of thefirst end208 and the center of thesecond end210 as shown inFIG. 9C. Thesecond link126 may be fabricated from any suitable material. According to various embodiments, thesecond link126 is fabricated from a thermoplastic material such as, for example, Delrin®.
• Thesecond link126 comprises afirst portion214 and asecond portion216. Thefirst portion214 may be considered the proximal portion and thesecond portion216 may be considered the distal portion. Thefirst portion214 may be fabricated integral with thesecond portion216. Thefirst portion214 has a generally cylindrical shaped exterior, and extends from thefirst end208 of thesecond link126 toward thesecond end210 of thesecond link126. According to various embodiments, the diameter of thefirst portion214 is on the order of approximately 4.80 millimeters. Other dimensions are possible.
• According to various embodiments, thesecond portion216 has a generally cylindrically shaped exterior where it contacts thefirst portion214, and tapers toward thesecond end210 of thesecond link126. The exterior of thesecond portion216 is configured in the form of a generally segmented cone. According to various embodiments, the exterior of thesecond portion216 tapers from thefirst portion214 to thesecond end210 of thesecond link126 at an angle on the order of approximately 20° relative to the exterior of thefirst portion214. The length of thesecond link126 may be on the order of approximately 15 millimeters. However, one skilled in the art will appreciate that the length of thesecond link126 can vary based on the application.
• Thesecond link126 also comprises afirst surface218 that extends from thefirst end208 of thesecond link126 to thesecond end210 of thesecond link126, and asecond surface220 that extends from thefirst end208 of thesecond link126 toward thesecond end210 of thesecond link126. Thefirst surface218 may be considered the outer surface of thesecond link126, and thesecond surface220 may be considered the inner surface of thesecond link126.
• Thesecond link126 also defines afirst port222, asecond port224, and athird port226. (SeeFIG. 9B). Thefirst port222 extends from thesecond surface220 to thefirst surface218 and is substantially parallel to thelongitudinal axis212. Thesecond port224 extends from thesecond surface220 to thefirst surface218 and is substantially parallel to thelongitudinal axis212. Thethird port226 extends from thesecond surface220 to thefirst surface218 and is substantially parallel to thelongitudinal axis212. The first, second andthird ports222,224,226 may be cylindrical shaped and may be evenly spaced about thelongitudinal axis212 of thesecond link126 as shown inFIG. 9D. The size of each of theports222,224,226 may be identical to one another or may be different from one another. For example, according to various embodiments, the first andsecond ports222,224 are configured as cylinders having diameters on the order of approximately 1.50 millimeters, and thethird port226 is configured as a cylinder having a diameter on the order of approximately 2.50 millimeters. Other dimensions are possible. The first, second andthird ports222,224,226 are each configured to receive and surround any of a variety of tools or instruments (e.g., ablation tools) which may pass from thefirst end24 of themulti-linked device10 to thesecond end26 of themulti-linked device10.
• Thesecond link126 also defines a first through-hole228, a second through-hole230, and a third through-hole232. (SeeFIG. 9B). The first through-hole228 extends from thesecond surface220 to thefirst surface218 and is substantially parallel to thelongitudinal axis212. The second through-hole230 extends from thesecond surface220 to thefirst surface218 and is substantially parallel to thelongitudinal axis212. The third through-hole232 extends from thesecond surface220 to thefirst surface218 and is substantially parallel to thelongitudinal axis212. The first, second and third through-holes228,230,232 are generally cylindrically shaped. According to various embodiments, the through-holes228,230,232 are evenly spaced from one another as shown inFIG. 9D. The size of each of the through-holes228,230,232 may be identical to one another or may be different from one another. For example, according to various embodiments, the respective diameters associated with the through-holes228,230,232 may each be on the order of approximately 1.25 millimeters. The first through-hole228 is configured to receive and surround a cable. The second through-hole230 is configured to receive and surround a cable. The third through-hole232 is configured to receive and surround a cable.
• Thesecond link126 also defines arecess234 that extends from thefirst end208 toward thesecond end210 along thelongitudinal axis212 as shown inFIG. 9C. According to various embodiments, therecess234 is generally configured as a complex shape that comprises a combination of a firstsegmented hemisphere236 that extends from thefirst end208 toward thesecond end210, and a secondsegmented hemisphere238 that extends from the firstsegmented hemisphere236 toward thesecond end210 of thesecond link126. According to various embodiments, the firstsegmented hemisphere236 represents a portion of a sphere having a diameter on the order of approximately 9.50 millimeters, and the secondsegmented hemisphere238 represents a portion of a sphere having a diameter on the order of approximately 7.0 millimeters. The firstsegmented hemisphere236 of therecess234 is configured to receive thesecond end162 of anintermediate link128 when theintermediate link128 is coupled to thesecond link126.
• With the above described structure, anintermediate link128 may be coupled to thesecond link126 by seating thesecond end162 of theintermediate link128 in the firstsegmented hemisphere236 of therecess234 of thesecond link126. As the convex configuration of thesecond end162 of theintermediate link128 generally corresponds with the concave configuration of the firstsegmented hemisphere236 of therecess234 of thesecond link126, theintermediate link128 may be coupled to thesecond link126 such that thelongitudinal axis164, the first, second andthird grooves174,176,178, and the first, second and third through-holes190,192,194 of theintermediate link128 are respectively aligned with thelongitudinal axis212, the first, second andthird ports222,224,226, and the first, second and third through-holes228,230,232 of thesecond link126. Thesecond link126 may be moved relative to theintermediate link128 coupled thereto such that the respectivelongitudinal axes164,212 are not aligned. According to various embodiments, the configuration of thesecond link126 allows for anintermediate link128 coupled thereto to be moved relative to thesecond link126 such that the respectivelongitudinal axes164,212 are up to approximately 10° out of alignment with one another.
• When thefirst mechanism12 is inserted into thesecond mechanism14, the first second andthird grooves70,72,74 of theintermediate links32 of thefirst mechanism12 may be substantially aligned with the first, second andthird grooves174,176,178 of theintermediate links128 of thesecond mechanism14, and the first, second andthird grooves98,100,102 of thesecond link30 of thefirst mechanism12 may be substantially aligned with the first, second andthird ports222,224,226 of thesecond link126 of thesecond mechanism14. The combination of thefirst grooves70 of theintermediate links32 of thefirst mechanism12 aligned with thefirst grooves174 of theintermediate links128 of thesecond mechanism14 allows the respectivefirst grooves70,174 to collectively serve as a first working port that is substantially aligned with thefirst port222 of thesecond link126 of thesecond mechanism14. Thefirst groove70 may be considered the inner portion of the first working port and thefirst groove174 may be considered the outer portion of the first working port.
• Similarly, the combination of thesecond grooves72 of theintermediate links32 of thefirst mechanism12 aligned with thesecond grooves176 of theintermediate links128 of thesecond mechanism14 allows the respectivesecond grooves72,176 to collectively serve as a second working port that is substantially aligned with thesecond port224 of thesecond link126 of thesecond mechanism14 and the combination of thethird grooves74 of theintermediate links32 of thefirst mechanism12 aligned with thethird grooves178 of theintermediate links128 of thesecond mechanism14 allows the respectivethird grooves74,178 to collectively serve as a third working port that is substantially aligned with thethird port226 of thesecond link126 of thesecond mechanism14. Thesecond groove72 may be considered the inner portion of the second working port and thesecond groove176 may be considered the outer portion of the second working port. Thethird groove74 may be considered the inner portion of the third working port and thethird groove178 may be considered the outer portion of the third working port. The first, second and third working ports may be utilized to pass various tools or instruments (e.g., ablation tools) from thefirst end24 of themulti-linked device10 to thesecond end26 of themulti-linked device10. For the exemplary sizes described hereinabove, the third working port is larger than the first and second working ports. Accordingly, the third working port may be utilized to carry a particular tool or instrument that is too large to be carried by the first or second working ports.
• When therespective grooves70,72,74,174,176,178 of the respectiveintermediate links32,128 are aligned and collectively surround the various tools and instruments, the combination of thegrooves70,72,74,174,176,178 and the tools and instruments may serve to limit or prevent the rotation of thefirst mechanism12 relative to thesecond mechanism14.
• As the diameter of thepassage180 of theintermediate link128 of thesecond mechanism14 is larger than the diameter of any portion of thefirst mechanism12, a three-dimensional space240 exists between thefirst mechanism12 and thesecond mechanism14 when thefirst mechanism12 is received by the second mechanism14 (SeeFIG. 1B). According to various embodiments, thespace240 may be utilized to carry wiring, tools, instruments, etc. from thefirst end24 of themulti-linked device10 toward thesecond end26 of themulti-linked device10.
• According to various embodiments, one or more steering cables may he fabricated from any suitable material. For example, according to various embodiments, the steering cables may be fabricated from a polyethylene fiber cable such as, for example, Spectra®. The steering cables may be utilized to control the movement of themulti-linked device10. For example, by applying a substantially equal tension to each of the steering cables, thefirst mechanism12 and/orsecond mechanism14 may be steered in a direction such that the respectivelongitudinal axes38,62,90,134,164,212 of each of thelinks28,30,32,124,126,128 are all aligned. By applying a different tension to one or more of the steering cables, thefirst mechanism12 and/or thesecond mechanism14 may be steered in a direction such that the respectivelongitudinal axes38,62,90,134,164,212 of each of thelinks28,30,32,124,126,128 are not all aligned. The cables16,18,20 may also be utilized to control the relative state of thesecond mechanism14. For example, when a uniform tension is applied to the steering cables, thesecond mechanism14 may be placed in a “rigid” state, and when a tension is removed from the steering cables, thesecond mechanism14 may be placed in a “limp” state. According to various embodiments, one or more of the steering cables may be attached at thefirst end130 of thefirst link124 of thesecond mechanism14 to respective pullies (not shown) by, for example, respective stopper knots. The steering cables may be attached to thesecond end132 of thesecond link126 of thesecond mechanism14 by, for example, respective stopper knots. One skilled in the art will appreciate that, according to other embodiments, the “rigid” and “limp” states may be achieved by subjecting the first and/orsecond mechanisms12,14 to a twisting force, or by any other manner known in the art.
• According to various embodiments, one or more tensioning cables may be fabricated from any suitable material. For example, according to various embodiments, the tensioning cables may be fabricated from a polyethylene fiber cable such as, for example, Spectra®. The tensioning cables may be utilized to control the relative state of thefirst mechanism12. For example, when the tensioning cable is drawn tight, thefirst mechanism12 may be placed in a “rigid” state, whereas when the tensioning cable is let loose, thefirst mechanism12 may be placed in a “limp” state. According to various embodiments, the tensioning cable may be attached at thefirst end34 of thefirst link28 of thefirst mechanism12 to a pully (not shown) by, for example, a stopper knot. The tensioning cable may be attached to thesecond end88 of thesecond link30 of thefirst mechanism12 by, for example, a stopper knot.
• FIG. 10 illustrates various embodiments of a motion sequence of the steerablemulti-linked device10. At the start of the sequence, thesecond mechanism14 surrounds thefirst mechanism12 as shown in step “a” ofFIG. 10, thelongitudinal axes38,62,90 of thelinks28,30,32 of thefirst mechanism12 are substantially aligned with the respectivelongitudinal axes134,164,212 of thelinks124,126,128 of the second mechanism, and thesecond end26 of thefirst mechanism12 is at substantially the same position as thesecond end122 of thesecond mechanism14. A tensioning cable is pulled tight, thereby placing thefirst mechanism12 in the rigid mode. The steering cables are not pulled tight, thereby placing thesecond mechanism14 in the limp mode.
• Thesecond mechanism14 is then advanced so that itssecond link126 is positioned approximately one link ahead of thesecond end24 of thefirst mechanism12 as shown in step “b” ofFIG. 10. The cables16,18,20 may be utilized to orient thesecond link126 to a particular orientation, where thelongitudinal axis134 of thefirst link124 is no longer aligned with thelongitudinal axes164 of theintermediate links128 of thesecond mechanism14 or thelongitudinal axis90 of thesecond link30 of thefirst mechanism12. After thesecond link126 is in the desired position and orientation, the steering cables are pulled with identical force in order to place thesecond mechanism14 in the rigid mode, thereby preserving the position and orientation of thesecond mechanism14.
• The pulling force of the tensioning cable is then released to place thefirst mechanism12 in the limp mode. After thefirst mechanism12 is placed in the limp mode, thefirst mechanism12 is advanced so that itssecond link30 is at substantially the same position as thesecond end122 of thesecond mechanism14 as shown in step “c” ofFIG. 10. After thesecond link30 of thefirst mechanism12 is in the desired position and orientation, the tensioning cable is pulled tight to place thefirst mechanism12 back in the rigid mode, thereby preserving the position and orientation of thefirst mechanism12.
• The pulling forces of the steering cables are then released to place thesecond mechanism14 back in the limp mode, After thesecond mechanism14 is placed back in the limp mode, thesecond mechanism14 is advanced so that itssecond link126 is once again positioned approximately one link ahead of thesecond end26 of thefirst mechanism12 as shown in step “d” ofFIG. 10. After thesecond link126 is in the desired position and orientation, the steering cables are pulled with identical force in order to place thesecond mechanism14 in the rigid mode, thereby preserving the position and orientation of thesecond mechanism14.
• The pulling force of the tensioning cable is then released to place thefirst mechanism12 back in the limp mode. After thefirst mechanism12 is placed back in the limp mode, thefirst mechanism12 is advanced so that itssecond link30 is once again at substantially the same position as thesecond end122 of thesecond mechanism14 as shown in step “e” ofFIG. 10. After thesecond link30 of thefirst mechanism12 is in the desired position and orientation, the tensioning cable is pulled tight to place thefirst mechanism12 back in the rigid mode, thereby preserving the position and orientation of thefirst mechanism12. The general motion sequence described hereinabove, may be repeated any number of times, and thesecond link126 of thesecond mechanism14 may be advancing in any direction and orientation. One skilled in the art will appreciate that any number of motion sequences may be utilized with themulti-linked device10. For example, according to various embodiments, thesecond mechanism14 may advance any number of links ahead of thefirst mechanism12.
• The exemplary sizes described hereinabove are generally relative to each other, and one skilled in the art will appreciate that themulti-linked device10 can be scaled up or scaled down. For example, although the diameter at the largest portion of theintermediate link128 of themulti-linked device10 is on the order of approximately 9.65 millimeters for the embodiments described hereinabove, one skilled in the art will appreciate that, for other embodiments, theintermediate link128 can be scaled down such that the diameter at the largest portion of theintermediate link128 of themulti-linked device10 is on the order of approximately 1.0 millimeter. For such embodiments, each of the other components of themulti-linked device10 would also be proportionally scaled down.
• The combination of the unique configuration of therespective links28,30,32 which comprise thefirst mechanism12 and the unique configuration of therespective links124,126,128 which comprise thesecond mechanism14 provides themulti-linked device10 with the ability to traverse a path defined by the circumference of a circle having a relatively small radius. For example, for the exemplary sizes described hereinabove, themulti-linked device10 can traverse a path defined by the circumference of a circle having a radius on the order of approximately 45 millimeters. An example of themulti-linked device10 navigating such tight curvatures is shown inFIG. 11. For embodiments, where the largest portion of theintermediate link128 of themulti-linked device10 is on the order of approximately 1.0 millimeter, themulti-linked device10 can traverse a path defined by the circumference of a circle having a radius significantly smaller than 45 millimeters. One skilled in the art will appreciate that the ability to navigate such tight curvatures makes themulti-linked device10 suitable for use in a number of different minimally invasive procedures, both in luminal spaces and in intracavity spaces.
• A controller device may control the movement of a multi-linked device such as, for example, themulti-linked device10. According to various embodiments, the controller device may comprise one or more electromechanical devices that may receive input from a user. Exemplary electromechanical devices may include buttons, sliders, knobs, toggles, dials, handles or the like.
• According to various embodiments, the controller device may be embodied as a joystick, and the joystick may be similar to joysticks known in the art.FIG. 12A illustrates an exemplary joystick according to an embodiment. For such embodiments, thecontroller device500 comprises ahandle502 and abase504. In operation, movement of thehandle502 relative to the base504 signals the feeder mechanism400 to move themulti-linked device10 in a desired direction.
• According to various embodiments, a controller device may be associated with two or more independent degrees of freedom (DOF). For example, ajoystick500 may have two DOF, where one DOF is associated with a pitch of the multi-linked device and one DOF is associated with a yaw of the multi-linked device. According to various embodiments, a three DOF controller may use a modified Stewart platform to accept input representative of motion from a user. The third degree of freedom may be controlled simultaneously with steering of the device. This may allow the device to operate with continuous motion.
• The controller device may be in electrical and/or mechanical communication with the feeder mechanism400 and/or themulti-linked device10. According to various embodiments, the controller device may be utilized to control the movement of themulti-linked device10.
• A common problem associated with remotely controlling target devices, such as themulti-linked device10, is the dissociation that may occur between the controller device's motion and the device's motion. For example, a large target device may move very slowly, whereas a controller device controlling the motion of the target device may move very quickly, or vice versa. As such, the motion capabilities between a controller device and a target device may be mismatched. The use of a haptic controller may mitigate this problem.
• According to various embodiments, a controller device may be a haptic controller, such as that illustrated byFIG. 12B. A haptic controller may be a device that tactilely interacts with a user. A haptic controller may receive input having a plurality of degrees of freedom. According to various embodiments, the haptic controller may exert a force output that may be associated with one or more of the degrees of freedom. For example, if a user moves the haptic controller faster than the device that is being controlled, the haptic controller may output a force against the user's motion. According to various embodiments, the magnitude of the force output may be related to a difference between a command signal from the haptic controller and feedback received from the target device and/or the feeder.
• According to various embodiments, a relationship may exist between the location of the controller device and the target device, between the velocity and/or acceleration of the controller device and the target device, and the like.
• According to various embodiments, the haptic controller may convey information to a user by exerting one or more force outputs. For example, the haptic controller may cause an electromechanical device, such as a handle of the haptic controller, to pull toward a predetermined position, such as a home position. This may help orient the user as to the direction of the home position from a current position. According to various embodiments, the magnitude of the force associated with the force output may be proportional to a relationship between the handle and the home position. For example, a haptic controller may exert a greater force on the handle in the direction of the home position the further the handle is from the home position. According to various embodiments, the home position may be dynamically changed and its new location may be communicated to the user by one or more force outputs.
• According to various embodiments, one or more force outputs may be used to alert the user as to undesirable configurations and/or positions. As a result, the haptic controller may resist user motion into areas of the haptic controller's workspace that may result in undesirable configurations. For example, if the user is controlling the target device in such a way that may damage the area through which the target device is maneuvering or the target device itself the haptic controller may exert one or more force outputs that may resist the user's motion. According to various embodiments, the magnitude of the force output may be proportional to a relationship between the target device and the undesirable area. For example, if, during a medical procedure, there is an area that the target device should avoid, such as the aorta, the haptic controller may resist the user's motion when the target device approaches the vicinity of the transverse sinuses As the target device moves closer to the transverse sinuses, the magnitude of the force output exerted by the haptic controller may increase.
• According to various embodiments, the target device may comprise one or more force sensors. The force sensors may measure the force associated with contact between the target device and a surrounding structure, area or the like. According to various embodiments, the feeder device400 may receive information associated with the deformation of a surrounding external structure, area or the like caused by the target device. The deformation information, in conjunction with the measured force, may be used to estimate the compliance of the surrounding structure, area or the like. For example, if the target device is maneuvering through a portion of the body, a force sensor may measure the force with which the target device contacts an organ. This information may be used with deformation information to estimate the compliance of the organ.
• According to various embodiments, the type of force output exerted by the haptic controller may vary. For example, the haptic controller may exert a constant force, pulsating force, a vibrating force or the like. The type of force output may vary depending on the information being conveyed to a user. For example, the haptic controller may exert a constant force output to indicate the device is near an area that may be damaged by the device, but the haptic controller may exert a vibrating force output to indicate that the device is near an area that may cause damage to the device. According to various embodiments, the haptic controller may discontinue force output to inform the user that communication between the haptic controller and the target device has been lost.
• According to various embodiments, the controller device may provide for pause functionality. When pause functionality is invoked, the position of themulti-linked device10 may not change, regardless of whether or not the position of the handle changes relative to the base. The pause functionality may be invoked at any time. For example, the pause functionality may be invoked while controlling the movement of the first orsecond mechanisms12,14 of themulti-linked device10. When a user is controlling the position of themulti-linked device10 via the controller device, the user may invoke the pause functionality by keeping the handle in the same position relative to the base. The user may also accomplish this by simply removing his/her hand from the controller device. According to various embodiments, the controller device further comprises a pause button, which when pressed, invokes the pause functionality. The pause functionality may be toggled on/off via the pause button. The pause functionality allows the user to reorient and continue in a manner generally not available with typical medical devices. The pause functionality may also be utilized to allow a switch from one user to another user.
• FIG. 13 illustrates various embodiments of amethod600 for controlling movement of a multi-linked device such as, for example, themulti-linked device10. According to various embodiments, themethod600 may correspond to the use of a two DOF controller, such as the joystick illustrated inFIG. 12A. Themethod600 begins atblock602, where thehandle502 of thedevice500 is moved relative to thebase504 of thedevice500 to advance thesecond end122 of thesecond mechanism14 of themulti-linked device10 away from the feeder mechanism400. Fromblock602, the process advances to block604, where thehandle502 of thedevice500 is moved relative to thebase504 of thedevice500 to advance thesecond end26 of thefirst mechanism12 of themulti-linked device10 away from the feeder mechanism400. The process described at blocks602-604 may be repeated any number of times, and the movement of the second ends26,122 away from the feeder mechanism400 may be in a variety of directions.
• Fromblock604, the process advances to block606, where thedevice500 is placed in the pause mode. Fromblock606, the process advances to block608, where thedevice500 is removed from the pause mode. Fromblock608, the process may return to either block602 or block604, or the process may advance to block610, depending on how thehandle502 is moved relative to thebase504. Atblock610, thehandle502 is moved relative to the base504 to retract thefirst mechanism12 toward the feeder mechanism400. According to various embodiments, thehandle502 may be moved relative to the base504 in a manner which results in the full retraction of thefirst mechanism12. Fromblock610, the process may return to block604, or advance to block612 depending on how thehandle502 is moved relative to thebase504. Atblock612, thehandle502 is moved relative to the base504 to retract thesecond mechanism14 toward the feeder mechanism400. Fromblock610, the process may return to block602. According to various embodiments, thehandle502 may be moved relative to the base504 in a manner which results in the full retraction of thesecond mechanism14.
• According to various embodiments, a three DOF controller may be used to advance a target device, such as, for example, themulti-linked device10, in a continuous manner. For example, a handle of a three DOF controller may operate in a three-dimensional coordinate system. The x-direction may correspond to the horizontal direction, the y-direction may correspond to the vertical direction and the z-direction may correspond to forward (positive)/backward (negative). The home position may be zero for one or more directions. For a motion of the three DOF controller's handle, the x-component of position may be related to the yaw angle of the distal link relative to an adjacent link, the y-component of position may be related to the pitch angle of the distal link relative to an adjacent link, and the z-component of position may be related to the advancement and/or retraction of the target device. According to various embodiments, the relationship between motion of the target device may be related to the position of the handle of the target device relative to the base of the target devices the velocity of the handle relative to the base, the acceleration of the handle relative to the base and/or the like.
• In various embodiments, the controller device may be used to activate one or more modes of movement associated with thedevice10. Exemplary modes may include a homing mode, an advancing mode, a steering mode, a retract mode, a retract inner mode, and/or the like.
• In various embodiments, the homing mode may reset one or more settings associated with thedevice10. While operating in the advancing mode, thedevice10 may advance forward from one location to a next location. In various embodiments, this advancement may be repeated a plurality of times. While operating in the steering mode, thesecond mechanism14 may alternate between operating in a rigid mode and a limp mode. In various embodiments, the direction of thesecond link126 of thesecond mechanism14 may change direction while thedevice10 operates in the steering mode.
• While operating in a retract mode, thedevice10 may move backward from one location to a next location. In various embodiments, this retraction may be repeated a plurality of times. In various embodiment, while operating in retract mode, thedevice10 may automatically retract along the same path it had advanced. For example, if thedevice10 advanced along a path represented by the sequence of points {x₁, x₂, x₃, x₄, x₅}, the device may automatically retract along a path represented by the sequence of points {x₅, x₄, x₃, x₂, x₁} if the mode is switched to retract mode. While operating in a retract inner mode, the first mechanism16 may retract.
• In various embodiments, a movement of the controller device may correspond to a mode of movement associated with thedevice10. For example, moving the controller device forward may signal the feeder mechanism400 to operate thedevice10 in an advancing mode. In various alternate embodiments, the controller device may include one or more controls such as a button, a switch, a toggle a dial or the like. Each control may correspond to one or more modes. For example, a controller device may include a button corresponding to one or modes. To operate the device in a given mode, a user may enable a control, such as pressing a button corresponding to the desired mode. According to various embodiments, a user may cycle through the modes by repeatedly pressing a button. For example, pressing the button while in homing mode may trigger a change to advancing mode.
• While several embodiments of the invention have been described herein by way of example, those skilled in the art will appreciate that various modifications, alterations, and adaptations to the described embodiments may be realized without departing from the spirit and scope of the invention defined by the appended claims.

Claims (17)

1. A system for controlling the movement of a steerable multi-linked device, the system comprising:

a feeder mechanism;

a steerable multi-linked device releaseably connected to the feeder mechanism, wherein the steerable multi-linked device comprises:

a first link,

a plurality of intermediate links, wherein a first one of the intermediate links is movably coupled to the first link, and

a second link movably coupled to a second one of the intermediate links; and

a controller device configured to select a mode of movement associated with the multi-linked device.

2. The system ofclaim 1, wherein the controller device is a joystick.

3. The system ofclaim 1, wherein the controller device is a haptic controller.

4. The system ofclaim 1, wherein the controller device is configured to provide one or more output forces when the steerable multi-linked device is a certain distance from a predetermined area.

5. The system ofclaim 4, wherein a magnitude of the one or more output forces is related to a difference in motion between the controller device and the steerable multi-linked device.

6. The system ofclaim 1, wherein the controller device is configured to provide one or more output forces when the steerable multi-linked device is a certain distance from an area that may be damaged by the steerable multi-linked device.

7. The system ofclaim 1, wherein the controller device is configured to provide one or more output forces when the steerable multi-linked device is a certain distance from an area that may damage the steerable multi-linked device.

8. The system ofclaim 1, wherein:

the steerable multi-linked device comprises one or more force sensors configured to measure a force associated with a contact between the steerable multi-linked device and a surrounding area;

the feeder mechanism is configured to receive information associated with a deformation of the surrounding area; and

the controller device is configured to:

estimate a compliance associated with the surrounding area, and

provide one or more output forces based on the estimation.

9. The system ofclaim 1, wherein the controller device comprises one or more buttons, wherein each button is associated with a mode of movement of the multi-linked device.

10. The system ofclaim 1, wherein the controller device is configured to pause movement of the multi-linked device.

11. The system ofclaim 1, wherein the controller device is configured to select one or more of the following modes:

a homing mode;

an advancing mode;

a steering mode;

a retract mode; and

a retract inner mode.

12. The system ofclaim 1, wherein the steerable multi-linked device comprises:

a first multi-linked mechanism, wherein the first mechanism defines a first plurality of grooves;

a second multi-linked mechanism, wherein the second mechanism defines a second plurality of grooves, and wherein:

the first and second pluralities of grooves cooperate to define at least two working ports along a length of the device steerable multi-linked device; and

at least one of the first and second mechanisms are steerable.

13. The system ofclaim 12, wherein the second mechanism surrounds the first mechanism.

14. The system ofclaim 1, wherein the first link defines a passage extending from a first end of the first link to a second end of the first link along a longitudinal axis which passes through a center of the first end and a center of the second end.

15. The system ofclaim 1, wherein at least one of the intermediate links defines a passage extending from a first end of the at least one of the intermediate links to a second end of the at least one of the intermediate links along a longitudinal axis which passes through a center of the first end and a center of the second end.

16. The system ofclaim 1, wherein the controller device is in communication with one or more of the feeder mechanism and the steerable multi-linked device.

17. The system ofclaim 1, wherein the controller device comprises a base and a handle, wherein the controller device is configured to control movement of the steerable multi-linked device based on a relationship between one or more of the following:

position of a handle of the controller device relative to a base of the controller device,

a velocity associated with the handle of the controller device relative to the base of the controller device, and

an acceleration associated with the handle of the controller device relative to the based of the controller device.

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