Multiband ligation device

Abstract

The present invention relates to a multiband ligation device (100) for use in conjunction with a medical endoscope (200) for endoscopic band ligation for treatment of varices comprising a controller unit (110) and a ligation unit (300). The controller unit (110) comprises a body component (130), a rotating component (140) rotatably supported on the body component (130), a spool (155) assembled to the rotating component (140) and having a clicker (160) assembled thereon, and a biasing means (170) engaged to the spool (155) and the rotating component (140). The biasing means (170) and the spool (155) along with the clicker (160) are configured to transition from a relaxed configuration to a compressed configuration and actuate a sequential deployment of a plurality of ligation bands (305) arranged on the ligation unit (300) to a targeted treatment site and simultaneously generates a notification signaling a deployment of the ligation band (305).

Description

[0001] MULTIBAND LIGATION DEVICE

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention relates to the field of medical engineering, and more particularly, it relates to a multiband ligation device for use in conjunction with a medical endoscope for administering an endoscopic band ligation for the treatment of varices

[0004] BACKGROUND OF THE INVENTION

[0005] Esophageal varices are commonly found in cirrhosis patients. The symptoms are most often a consequence of portal hypertension and involve swelling of veins in the lining of an esophagus. If left untreated, they pose the risk of rupture and internal bleeding, the so called “variceal hemorrhage” which can be fatal.

[0006] Band ligation is often a first-line recommended treatment therapy for esophageal varices. Typically, band ligation involves use of an esophageal varices ligator in conjunction with an endoscope. During operation, by manipulating the band ligation device mounted to a non-invasive part of the endoscope, a band is deployed from a barrel mounted to the tip of an invasive part of the endoscope onto the varices. The compression force from the deployed band constricts the blood flow into the varices resulting in necrosis of the tissue, and the varices will naturally fall off into the patient’s gastrointestinal tract, completing the treatment.

[0007] While band ligation is recognized as an effective treatment therapy, it requires great skills of the operator to maneuver the band ligation device and determine if the band has been effectively deployed to a targeted site. One of the aspects of the inventions surrounding band ligation devices focuses on generating a notification as a mechanical, an acoustical, a visual notification, or a combination thereof to facilitate effective and accurate band deployment. For example: US6066145 A disclosed a multi-ligator device that provides a signal to an operator indicating the release of a ligation ring from the ligator head. The device simplifies the use of mechanically decoupled ligator-devices and relieving an operator from having to sense via transmitted vibrations when a ligation ring is detached from a ligator head. The multi-ligator device is constructed using a control unit to operate a ligator head that is connected to the control unit via a flexible shaft. The ligator head supports a plurality of ligation rings that are released by operating the control unit. When a ligation ring is released a signal which can be any one, or a combination, of a mechanical, an acoustical, and a visual signal is generated.

[0008] US8585715 B2 disclosed a variceal banding endoscope that includes an elongated shaft having a distal end and a proximal end that is removably connected to a control unit. The endoscope includes a variceal banding apparatus fixedly attached to the distal end of the endoscope and capable of receiving a plurality of ligation bands. A trigger cable extends from the proximal end to the distal end of the shaft and is digitally actuated by an actuator in the control unit or handle of the scope in response to a user input device. However, both US6066145 A and US8585715 B2 employ various electronic or digital components and related software which significantly increase the complexity of the device.

[0009] A widely commercial ligation device, Speedband Super 7™ by Boston Scientific, and an invention disclosed in EP 1621147 Al, attempted to avoid the complexity of the electronics or digital components by proposing a feed-forward mechanism which generates clicking sounds at a predetermined rotational distance which is pre-calculated to be in synchronized with each band deployment. The mechanism involves multiple grooves located on a component that rotates along with a rotation of a handle and a stationary flexible component that is configured to abut against the groove and thereby generating a clicking sound. However, with this configuration, changes to the wire length during the maneuvering of the device for each deployment would likely cause the pre-calculated wire length to be out of sync with each subsequent band deployment and thus requiring readjustment of the device during the operation which can be an inconvenience. Therefore, an alternative multiband ligation device that is simpler in construction, easy to operate, and provides accurate and effective band deployment and generates a notification of a band deployment to the device operator is desirable.

[0010] SUMMARY OF THE INVENTION

[0011] It is an object of the present invention to provide a multiband ligation device configured to issue a notification to the device operator signaling a successful ligation band deployment. The multiband ligation device is to be used in conjunction with a medical endoscope for administering an endoscopic band ligation for the treatment of varices, in particular, esophageal varices.

[0012] According to an embodiment of the present invention, the multiband ligation device comprising a controller unit configured to engage to a non-invasive part of the endoscope, and a ligation unit having an actuation wire that connects the ligation unit to the controller unit coupled to a distal end of a flexible invasive part of the endoscope.

[0013] According to an embodiment of the invention, the controller unit of the multiband ligation device of the present invention comprises a body component, a rotating component rotatably supported on the body component, a spool assembled to the rotating component and having a clicker assemble thereon, and a biasing means engaged to the spool and the rotating component. The body component is configured to hold the rotating component in position such that the rotating component is operable to rotate and actuate the biasing means along with the spool, and the clicker to transition between a relaxed configuration and a compressed configuration and concurrently causes a tension in the actuation wire engaged to the spool to actuate a sequential deployment of a plurality of ligation bands arranged on the ligation unit to a targeted treatment site. The rotating component is configured to move between locked and unlocked positions relative to the body component. In a locked position, the rotating component is configured to move in a clockwise direction only. Rotation of the rotating component having the actuation wire assembled to the spool causes tension in the actuation wire and at the same time causes a biasing means engaged to the rotating component and the spool together with a clicker assembled to the spool to transition from a relaxed configuration to a compressed configuration. As the rotation of the rotating component continues and the tension in the actuation wire continues to build up reaching a point where it overcomes the friction force of the ligation band of the ligation unit, the ligation band will then deploy from the ligation unit. The deployment of the ligation band causes a sudden cessation in the tension of the actuation wire and consequently a sudden decompression of the biasing means. That is, the biasing means transitions from a compressed configuration to a relaxed configuration and causes the spool and the clicker to bounce back and the interaction between the clicker and the rotating component simultaneously generates a notification signaling the device operator that a ligation band has been deployed. Thereafter, the biasing means, the spool, and the clicker resume its default relaxed configuration and ready for the next ligation band deployment.

[0014] BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Advantages and characteristics of the invention will be appreciated from the following description, in which, as non-limiting examples, some preferable embodiments of the invention are described, in reference to the accompanying drawings, in which:

[0016] FIG. 1 shows an embodiment of a multiband ligation device according to the present invention assembled to an endoscope for endoscopic band ligation;

[0017] FIG. 2 shows a relationship of a controller unit and a ligation unit of the multiband ligation device according to the present invention (with the exclusion of an invasive part of the endoscope);

[0018] FIG. 3 shows an embodiment of a controller unit of the multiband ligation device according to the present invention;

[0019] FIG. 4 shows an exploded view of an embodiment of a controller unit of the multiband ligation device according to the present invention;

[0020] FIG. 5.1 shows a body component of the multiband ligation device according to the present invention;

[0021] FIG. 5.2 shows a partially assembled rotating component of the multiband ligation device according to the present invention;

[0022] FIG. 5.3 shows a partial assembly of a spool, a clicker, and a basing means of the multiband ligation device according to the present invention; FIG. 6 shows a partially assembled view of a controller unit of the multiband ligation device according to the present invention in which the spool and the biasing means assembled on the rotating component are in a relaxed configuration;

[0023] FIG. 7 shows a sectional view of a partially assembled controller unit in FIG. 6 to illustrate the relationship between keys on the shaft and grooves inside the spool;

[0024] FIG. 8 shows a partially assembled view of a controller unit of the multiband ligation device according to the present invention in which the spool and the biasing means assembled on the rotating component are in a compressed configuration;

[0025] FIG. 9 shows a sectional view of a partially assembled controller unit in FIG. 8 to illustrate the relationship between keys on the shaft and grooves inside the spool;

[0026] FIG. 10 shows a side by side illustration of a comparison of a change in the relationship between keys on the shaft and grooves inside the spool between a relaxed configuration (left) and a compressed configuration (right) of a partially assembled controller unit of FIGs. 7 and 9;

[0027] FIG. 11 shows a side by side illustration of a comparison in a posture of a clicker as the spool and the biasing means assembled on the rotating component are transitioned from a relaxed to a compressed configuration;

[0028] FIG. 12 shows an enlarged view of a clicker ramp integrated to a handle of a rotating component of a controller unit; and

[0029] FIG. 13 shows a simplified illustration of a clicker ramp and travelling paths of a tip of a clicker arm.

[0030] DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention provides a multiband ligation device for use in conjunction with a medical endoscope for administering an endoscopic band ligation for the treatment of varices, in particular, esophageal varices. The multiband ligation device is configured to issue a notification to the device operator signaling the operator of a successful ligation band deployment. The advantages and characteristics of the invention will be more apparent from the following description, in which, as non-limiting examples, Figs 1-13 show some preferable embodiments of the invention in which the same reference numerals are used throughout the different figures to designate the same components.

[0032] The terms being used herein in reference to a direction, such as “front,” “rear,” and the like throughout the description, are provided for the purposes of explaining a specific embodiment or configuration of a particular component or part of an embodiment as specifically oriented and illustrated in the drawings. While in use, the article of the invention may be arranged in different orientations. Hence, such terms are not intended as limitations to the invention or components of the invention.

[0033] FIGs 1-13, show exemplary embodiments of a multiband ligation device 100 according to the present invention for use in conjunction with a medical endoscope 200 for endoscopic band ligation for treatment of varices, in particular, esophageal varices. As shown in FIG. 1, the multiband ligation device 100 comprises a controller unit 110 configured to engage to a non- invasive 210 part of the endoscope, and a ligation unit 300 configured to couple to a distal end of an invasive part 220 of the endoscope 200.

[0034] According to an embodiment of the invention, the multiband ligation device 100 comprises a controller unit 110 which comprises a body component 130, a rotating component 140 rotatably supported on the body component 130, a spool 155 assembled to the rotating component 140, and a biasing means engaged to the spool 155 and the rotating component 140. The body component 130 is configured to hold and secure the rotating component 140 in position such that the rotating component 140 is operable to rotate and actuate the biasing means 170 along with the spool 155, and the clicker 160 to transition between a relaxed configuration and a compressed configuration and concurrently causes a tension in the actuation wire 400 engaged to the spool 155 to actuate a sequential deployment of a plurality of ligation bands 305 arranged on the ligation unit 300 to targeted treatment sites. The rotating component 140 is configured to move between locked and unlocked positions relative to the body component 130. Rotation of the rotating component 140 having the actuation wire 400 assembled to the spool 155 causes a tension in the actuation wire 400. At the same time, rotation of the rotating component 140 also causes the biasing means 170 engaged to the rotating component 140 and the spool 155 together with a clicker 160 assembled to the spool 155 to transition from a relaxed configuration to a compressed configuration. As the rotation continues and the tension in the actuation wire 400 continues to build up to a point where it overcomes the friction force of a ligation band 305 of the ligation unit 300, the ligation band 305 will then deploy from the ligation unit 300 onto a targeted tissue where the treatment is required. The deployment of the ligation band 300 causes a sudden cessation in the tension of the actuation wire 400 and consequently causes a sudden transition from a compressed configuration to a relaxed configuration of the biasing means 170. At the same time, the transition in the configuration of the biasing means 170 causes the spool 155 and the clicker 160 to bounce back and the interaction of the clicker 160 with the rotating component 140 simultaneously generates a notification signaling the device operator that a ligation band 305 has been deployed. The rotating component 140 including the biasing means 170, the spool 155, and the clicker 160 resumes its default relaxed configuration and is ready for the subsequent ligation band deployment.

[0035] According to the present invention, the biasing means 170 maybe realized as a device that provides a biasing force that acts the components or parts engaged to the biasing means to transition from a first configuration to a second configuration. For example, the biasing means 170 according to the present invention may be realized as a spring, for example, a torsion spring, a compression spring, and the like. For the purpose of the explanation and illustration of the present invention, a torsion spring will now be used as an example of the biasing means 170 and the same numeral reference i.e. 170 will be retained throughout the description of the invention. Hence, the terms “biasing means”, “spring”, and “torsion spring” are used interchangeably throughout the description of the specification of the present invention. Furthermore, the term “clicker” and “clicker arm” are also used interchangeably throughout the specification.

[0036] According to an embodiment of the present invention, the ligation unit 300, as shown in FIGs. 1 and 2, comprises an actuation wire 400 and a plurality of ligation bands 305 arranged on a barrel 310. The barrel 310 has a substantially cylindrical body and defines a first end 312 configured to facilitate a secured coupling to a distal end of the invasive part of the endoscope 200. According to an embodiment, the first end 312 is made of a soft- flexible material structured to form a tight fit to the distal end of the endoscope 200. The barrel 310 also defines a second end 313 opposing the first end 312. According to an embodiment of the invention, the cylindrical body of the barrel 310 further comprising a plurality of recess 311 which receives a plurality of ligation band 305 disposed therein. Each of the plurality of the ligation band 305 is weaved to the actuation wire 400 such that by manipulating the actuation wire 400 via the operation of the controller unit 110, each ligation band 305 is sequentially deployed via the second end 313 of the barrel 310 to a targeted treatment site.

[0037] According to an embodiment of the invention, as illustrated in FIGs 2 and 3, the controller unit 110 of the multiband ligation device 100 of the present invention comprises the body component 130, the rotating component 140 rotatably supported on the body component 130, the spool 155 assembled to the rotating component 140, the clicker 160 arranged on the spool 155, and a torsion spring 170 engaged to the spool 155 and a shaft 120 of the rotating component 140. The rotation of the rotating component 140 exerts tension to the actuation wire 400 and causes the spool 155 along with the torsion spring 170 engaged to the spool 155 to transition from a relaxed configuration to a compressed configuration.

[0038] As shown in FIGs 2, 3, 4, and 5.1, the body component 130 comprises a main body 135, a front frame 145 fastened to the front of the main body 135, a rear frame 150 fastened to the rear of the main body 135. The front frame 145 projects upward from the main body 135 and defines a front frame housing 146 configured to accommodate a front end 158 of the spool 155 and spring holders 171, 171’ , to be further described below.

[0039] Similarly, opposite the front frame 145, the rear frame 150 projects upward from the main body 135, and defines a rear frame housing 151 configured to accommodate a rear end 159 of the spool 155. The rear frame 150 is configured to allow fitting of a pawl 141 to the rear frame 150, for example, by way of a corresponding mating element between the rear frame 150 and the pawl 141 to enable fitting between them. The configuration and function of the pawl 141 will be further discussed in later paragraphs below. The main body 135 defines a through hole 136 and a socket 137 configured to enable coupling of a stem 138 and placement of a seal 139 therein. The stem 138 is adapted to allow assembling of the multiband ligation device 100 to the endoscope 200. Furthermore, the stem 138 provides a passage of the actuation wire 400 through a hollow cavity of the stem 138 and through the seal 139 towards the spool 155 to allow securing of the actuation wire 400 to the spool 155. The seal 139 and the hollowed stem 138 also facilitate irrigation of the treatment site there through. The main body 135, the front frame 145, and the rear frame 150 are fastened together to form a stationary and rigid structure using an appropriate fastening means, for example, a body nut 131 and a body bolt 132.

[0040] According to an embodiment of the invention, as shown in FIGs. 2, 3, and 5.2, the rotating component 140 of the controller unit 110 comprises a handle 115, a shaft 120 mounted to the handle 115, a spring housing 171 coupled to the shaft 120, and a shaft end cap 153 and the shaft nut 154 disposed on the distal end of the shaft 120. According to an embodiment of the invention, the handle 115 defines a cavity where a shaft socket 117, an outer ring 118, and an inner ring 119 are arranged therein. The shaft socket 117 is configured to receive an end of the shaft 120 which is mounted to the shaft socket 117 and secure the shaft 120 therein using appropriate mounting, fastening, or mating elements between the shaft socket 117 and the shaft 120, for example, a bolt 121. According to an alternative embodiment, the shaft 120 may be integrally formed to the handle

[0041] 115 and thereby eliminating any corresponding fastening or mounting mechanisms needed to fasten or mount the shaft 120 to the handle 115. Further, it is also within the knowledge of a skilled person that other forms of mounting mechanisms, mating elements, fastening means for securing the shaft 120 to the handle 115 are possible. The outer ring 118 inside the handle 115 defines teeth

[0042] 116 along its circumference. The teeth 116 are structured to engage with the pawl 141 coupled to the stationary rear frame housing 151 of the body component 130. The inner ring 119 includes one or more, preferably, two opposing spaced-apart clicker ramps 111 on the inner circumference of the inner ring 119. Each clicker ramp 111 defines a slope 162, a peak 113, a descending path 114, and a clicking step 112 which form a travelling path of a tip of the deformable arms 161 of the clicker 160. As clicker ramps 111 are positioned to engage to deformable arms 161 of the clicker 160, the circumference of the inner ring 119, therefore, should correspond to the span of the arms 161 of the clicker 160 in their non-deformed state. The handle 115 together with the shaft 120 mounted thereto is configured to operable between locked or unlocked position relative to the body component 130 via engagement or disengagement of the pawl 141 to / from the teeth 116 inside the handle 115. In a locked position, the rotating component 140, including the handle 115 and the shaft 120 as well as the spool 155 assembled to the shaft 120 are configured to move in a clockwise direction only. The one-way, clockwise rotation of the rotating component 140 is achievable by the interaction between the pawl 141 assembled to the rear frame housing 151 and corresponding teeth 116 formed on the outer ring 118 inside the handle 115. In an unlocked position, the handle 115 is pulled backward to disengage the pawl 141 from the teeth 116 allowing a clockwise or counterclockwise (forward or backward) rotation of the rotating component 140 as needed. In an unlocked position, the shaft end cap 153 and the shaft nut 154 on the distal end of the shaft 120 restricts the shaft 120 from dislodging beyond the front frame housing 146. Forward rotation of the handle 115 increases the tension in the actuation wire 400. Rotation of the handle 115 backward in an unlocked position will ease the tension on the actuation wire 400.

[0043] According to an embodiment of the invention, the shaft 120 is mounted to the handle 115 using a suitable fastening means, for example, a bolt 121. The spool 155 is coupled to the shaft 120 using a corresponding key and groove structure. In an embodiment, one or more keys 122 are formed on the external of the shaft 120 and one or more grooves 123 having a configuration corresponding to the configuration of the keys 122 are formed inside a hollow body of the spool 155. In an exemplary configuration of the key and groove structure, the keyl22 is an elongated protruded rib structure integrally formed to the shaft 120 and the groove 123 is formed as an elongated indentation inside the spool 155. The groove 123 defines a shape corresponding to the shape of the key 122 to enable insertion of the key 122 (lengthwise) into the groove 123. In an exemplary configuration of the key and groove, where there are more than one corresponding keys 122 and grooves 123, each key 122 and groove 123 are uniformly spaced-apart at corresponding positions on the shaft 120 and the spool 155. In an exemplary embodiment, four corresponding keys 122 and grooves 123 are formed lengthwise on the shaft 120 and inside the spool 155, respectively. Rotation of the handle 115 having the shaft 120 mounted thereto actuates the spool 155 to turn in the same direction. It is worth noting that, according to the present invention, it is essential that width of the groove 123 is greater than the width of the key 122 to allow a relative rotation of the spool 155 on the shaft 120 in correlation with the rotational force of the rotating component 140, the biasing force of the spring 170 and the tension force from the actuation wire 400.

[0044] As shown in FIG. 3, the spool 155, being part of the controller unit 110, has a substantially cylindrical shape and comprises one or more grooves 123 formed inside its hollowed cavity. According to an embodiment of the invention, the spool 155 defines a front end 158, an enlarged body 156, and a rear end 159. The front end 158 is rotatably arranged within the front frame housing 146 of the body component 130 and defines a spring housing 171 ’ configured to engage to a leg of the torsion spring 170. The enlarged body 156 is formed along the circumference of the spool 155 adjacent to the rear end 159. The enlarged body 156 is dimensioned to fit the rear frame housing 151 of the rear frame 150 such that the enlarged body 156 is configured to rotatably arranged within the rear frame housing 151. The rear end 159 of the spool 155 protrudes through the rear frame housing 151 towards the handle 115. The rear end 159 of the spool 155 is configured to receive coupling of the clicker 160. Further, as the enlarged body 156 is housed within the rear frame housing 151 of the rear frame 150, a rear edge 163 of the enlarged body 156 rests on a step 152 arranged on the inner surface of the rear frame housing 151. The step 152 is arranged to restrict the spool 155 from moving beyond the step 152 as the device operator manipulates the rotating component 140 between a locked or unlocked position

[0045] As mentioned above, the spool 155, more specifically, its rear end 159 is configured to receive coupling of the clicker 160. Accordingly, the rear end 159 of the spool 155 and the clicker 160 are provided with corresponding mating elements, coupling means, and the like which permit tight coupling of the clicker 160 to the rear end 159 of the spool 155. In fact, any forms of mating element or coupling mechanism and the like, including an adhesive means that are capable of providing a tight fit between the rear end 159 of the spool 155 and the clicker 160 are acceptable as long as such means serves the function of restricting the clicker 160 from rotating freely along a rotation axis of the spool 155 as the spool 155 is rotated by the operation of the handle 115. According to an embodiment of the invention, the clicker 160 comprises one, preferably, two opposing deformable clicker arms 161 wherein the tip of the clicker arm 161 is deformable and adapted to transition its posture in response to a transitioning between a relaxed configuration and a compressed configuration of the torsion spring 170. To elaborate, a rotation of the shaft 120 via the rotation of the handle 115, which results in a rotational force and a reactive wire tension in the actuation wire 400, causes the spring 170 as well as the spool 155 to transition from a relaxed configuration to a compressed configuration, because the spring 170 is engaged to both the shaft 120 and the spool 155 assembled to the shaft 120. Concurrently, as the clicker 160 is attached to the spool 155, the configuration change of the spool 155 also causes the arm 161 of the clicker 160 to transition to a deformed posture (see Fig. 11). The interaction of the deformable arm 161 of the clicker 160 with the rotating component 140, in particular, the handle 115 following a deployment of the ligation band 305 as the arm 161 is recovering from a deformed posture to a non-deformed posture 155 generates a notification. The mechanism for generating the notification will be further discussed below.

[0046] Furthermore, the spool 155 also comprises at least one, preferably, two spaced-apart actuation wire locking slits 157 formed on the external surface of the spool 155. Each slit 157 extends along the circumference of the cylindrical spool 155 and a small indentation is arranged at each end of the slit 157. The slit 157 receives and secures a knot on an end of the actuation wire 400 to the spool 155 facilitating tensioning of the actuation wire 400 as the spool 155 is rotated forward. Therefore, it is preferable that the slits 157 are arranged at a position which aligns with the location of the through hole 136 of the main body 135 for ease of engagement of the actuation wire 400 to the spool 155 and a smaller friction between the actuation wire 400 and the seal 139.

[0047] According to the present invention, the multiband ligation device 100 is configured to generate a notification of a deployment of the ligation band 305 to the device operator. The ability to generate the notification lies in the configuration, arrangement, and interaction among the torsion spring 170, the spool 155, the clicker 160 and the rotating component 140. As mentioned, the spool 155 and the rotating component 140 are coupled together via the key 122 and groove 123 and the clicker 160 is coupled to the rear end 159 of the spool 155. Thus, the position of the key 122 and groove 123 would determine the position of the spool 155 on the rotating component 140. Consequently, as the spool 155 having the clicker 160 assembled thereto is already in a specific position, it is possible to determine the position of the clicker ramp 111 on the handle 115 based on the span of the clicker arm 161. As for the torsion spring 170, the stiffness thereof must be carefully chosen to correspond the force needed to deploy the ligation band 305, the detail of which is further discussed below.

[0048] According to an embodiment of the invention, the torsion spring 170 is coupled to the shaft 120 and held in place with a pair of spring holders 171, 171’, wherein the spring holders 171’ is integrally formed with the front end of the spool 155, whereas the spring holder 171 is a separate piece assembled to the shaft 120. The torsion spring 170 is housed within the torsion spring holder 171, 171 ’ wherein one leg of the torsion spring 170 is engaged to the spring holder 171’ on the spool 155 and another leg is engaged to the spring holder 171 on the shaft 120. The spring holders 171 , 171’ are housed within the front frame housing 146 of the body component 130. Upon rotation of the handle 115 and consequently, the shaft 120 secured to the handle 115 and the spool 155 assembled to the shaft 120, along the rotational axis X (see FIG. 3), the rotational force and the tension in the actuation wire 400 bias the spring 170, spool 155, and the clicker 160 towards the compressed configuration. As the spool 155 and the clicker 160 bias towards the compressed configuration, each arm 161 of the clicker concurrently transitions to a deformed configuration as it is actuated to travel up a slope 162 of the clicker ramp 111. As the torsion spring 170 progresses to a maximum compression state, the tip of the clicker arm 161 would also progress towards the peak 113 of the slope 162 of the clicker ramp 111. As the rotation of the handle 115 and the shaft 120 continues, the tension in the actuation wire 400 continues to build up to a point where it overcomes the friction force of the ligation band 305, the ligation band 305 will then deploy from the ligation unit 300. The deployment of the ligation band 305 causes a sudden cessation in the tension of the actuation wire 400 and consequently causes a sudden transition of the spring 170 from a compressed configuration to a relaxed configuration (i.e. a decompression of the spring 170). The transition from a compressed configuration to a relaxed configuration of the spring 170 causes the spool 155 along with the clicker 160 to bounce back, resulting in a simultaneous interaction between the clicker 160 and the handle 115 of the rotating component 140, and thereby simultaneously generates a notification signaling the device operator that the ligation band 305 has been deployed.

[0049] As described above and as illustrated in FIG. 5.3, the clicker 160 is assembled to the rear end 159 of the spool 155 and configured to interact with the handle 115 of the rotating component 140 in order to generate the notification. According to an embodiment, the clicker 160 comprises one, preferably, two opposing deformable clicker arms 161 configured to engage to the clicker ramp 111. The tip of the clicker arm 161 changes its posture in response to contributing factors, including the rotational force from the rotating component 140, the tension force from the actuation wire (400), and the relative movement of the clicker 160, all of which actuate the tip of the clicker 160 to travel up the clicker ramp 111 and at the same time transition to a deformed posture. FIG. 11 illustrate a side-by-side comparison of a transition in a posture of the clicker arm 161 relative to the clicker ramp 111 disposed on the inside of the handle 115, as the spring 170 is transitioning from a relaxed configuration to a compressed configuration. In a relaxed configuration, the clicker arm 161 is in its non-deformed posture and the tip of the clicker arm 161 positions proximate to the base of the clicker ramp 111. In a compressed configuration, the clicker arm 161 is in its compressing posture (deformed posture) and its tip has travelled up the slope 162 and positioned at the peak 113 of the clicker ramp 111. As clearly illustrated, in a relaxed configuration, the clicker arm 161 of the clicker 160 in a non-deformed posture locates away from the body of the clicker 160 whereas in a compressed configuration, the clicker arm 161 of the clicker 160 is in a deformed posture and locates closer towards the body of the clicker 160.

[0050] Again, referring to FIGs 11-13, as the spring 170 is transitioning from a relaxed configuration to a compressed configuration, the tip of the clicker arm 161 travels up a slope 162 of the clicker ramp 111. As the torsion spring 170 reaches its maximum compressed configuration and the tension in the actuation wire 400 is about to overcome the friction force of the ligation band 305, i.e. where the ligation band 305 is about to deploy, the tip of the clicker arm 161 reaches the peak 113 of the slope 162 of the clicker ramp 111. Then, as the tension in the actuation wire 400 finally overcomes the friction force of the ligation band 305 follows by a deployment of the ligation band 305, the tension is ceased. Simultaneously with the cessation in the tension of the actuation wire 400, the spring 170 also transitions from a compressed configuration to a relaxed configuration and hence, the spool 155 along with the clicker 160 bounces back to a starting state (i.e. a default posture). Consequently, as the spring 170 is decompressed, the tip ofclicker arm 161 of the clicker 160 moves away from the body of the clicker 160 (i.e. transition from its deformed states to its normal, non-deformed state) as it is travelling down, with a potential force, from the peak 113 of the slope 162 of clicker ramp 111 via a descending path 114. Simultaneously, as the tip of the of the clicker arm 161 reaches the base of the clicker ramp 111, and recovers to its original nondeformed posture at the base of the clicker ramp 111, the tip of the arm 161 is deflected against a clicking step 112 and hit the inner ring 119 resulting in a generation of the notification. The notification may be in the form of an acoustic notification, for example, a clicking sound or a tactile feel or both. The clicking sound, the tactile feel or both serves as a notification means signaling the multiband ligation device operator of a deployment of the ligation band 305.

[0051] Due to the interaction between the biasing force of the torsion spring 170, the rotation force, and the friction force of the ligation band 305, it is essential that the stiffness of the spring 170 must be pre-calculated. If the spring 170 is too stiff, the spring force would prematurely deploy the ligation band 305 before the spring 170 and the spool 155 on the rotating component 140 reach the compressed configuration. Hence, there will be no generation of the notification. Therefore, the force of the spring 170 must be less than the friction force of the ligation band 305. In other words, the required force to transition the spring 170 to a compressed configuration must be less than the force required to deploy the ligation band 305 as it would bring the spring 170 to the compressed configuration prior to the ligation band 305 deployment. Once the ligation band 305 is deployed, the spring 170 is recovered and the notification is generated in sync with the deployment of the ligation band 305

[0052] Furthermore, as described above, the spool 155 is coupled to the shaft 120 using the key 122 and groove 123 arrangement, wherein one or more keys 122 is formed on the external of the shaft 120 and one or more groove 123 is formed inside the spool 155. FIGs 7 and 9-10 illustrate an exemplary configuration and interaction between the key 122 and the groove 123 on the shaft 120 and the spool 155. According to this embodiment, four corresponding keys 122 are formed on the shaft 120 and four corresponding grooves 123, uniformly spaced-apart at corresponding positions, are formed inside the spool 155.

[0053] It is essential that the width of the groove 123 is greater than the width of the key 122 to allow relative rotation of the spool 155 in correlation with the transition between the relaxed configuration and the compressed configuration of the spring 170. As the rotation of the handle 115 begins, it results in the tension in the actuation wire 400, which at the same time compresses the spring 170 and pulls the spool 155 along with the clicker 160 towards the compressed configuration, see FIGs. 10 and 11. At this point, there is no change in length of the actuation wire 400 or movement of the ligation band 305 because the spring force alone is not sufficient to deploy the ligation band 305. As the rotation of the handle 115 continues, the key 122 abuts against the groove 124. This further increases the tension in the actuation wire 400. When the tension in the actuation wire 400 reaches an adequate amount to overcome the friction force of the ligation band 305, the ligation band 305 starts to move and the actuation wire 400 is rolled up by the rotation. As adequate length of the actuation wire 400 is rolled up, the ligation band 305 would have reached the second end 313 of the barrel 310 and results in the ligation band 305 deployment. The deployment of the ligation band 305 simultaneously generates the notification as set out in the objective of the invention.

[0054] While the invention has been described as an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted for elements thereof without departing from the scope of the invention. Throughout the description of the invention, the features of certain elements, for example two deformable arms 161 of the clicker 160, two clicker ramps 111 on the handle, one or more keys 122, one or more grooves 123, are described as an example only. It is worth noting that the device will work just as well with just one clicker arm 161, one clicker ramp, one key 122, and one groove 123. The example embodiments as described and illustrated are based on preferred embodiments from the perspective of an ease of production only. Hence, many modifications may be made to the invention without departing from the essential scope thereof. Therefore, it is intended that the invention is not limited to the embodiment disclosed as the best mode contemplated for carrying out this invention but that it will include all embodiments falling within the scope of the appended claims.

Claims

CLAIMS1. A multiband ligation device (100) for use in conjunction with a medical endoscope (200) for endoscopic band ligation for treating varices, comprising:-a controller unit (110) configured to engage to a non-invasive part (210) of the endoscope (200); and-a ligation unit (300) having a plurality of ligation bands (305) is configured to couple to a distal end of an invasive part (220) of the endoscope (200), and engaged to the controller unit (110) via an actuation wire (400); wherein the controller unit (110) comprises-a body component (130);-a rotating component (140) rotatably supported on the body component (130);-a spool (155) assembled to the rotating component (140), and having a clicker (160) assembled thereon; and-a biasing means (170) engaged to the spool (155) and the rotating component (140); wherein the rotating component (140) is configured to actuate the biasing means (170) and the spool (155) along with the clicker (160) to transition between a relaxed configuration and a compressed configuration and concurrently causes a tension in the actuation wire (400) to actuate a sequential deployment of a plurality of ligation bands (305) arranged on the ligation unit (300) to a targeted treatment site; and wherein a cessation in the tension of the actuation wire (400) and a decompression of the biasing means (170) following the ligation band (305) deployment consequently causes the biasing means (170) and the spool (155) along with the clicker (160) to transition from a compressed configuration to a relaxed configuration resulting in an interaction between the clicker (160) and the rotating component (140) which simultaneously generates a notification signaling a device operator of the ligation band (305) deployment.

2. The multiband ligation device (100) according to Claim 1; wherein the body component (13) is configured to support the rotating component (140), and comprising:- a main body (135) which defines a through hole (136) and a socket (137) configured to enable coupling of a stem (138) and placement of a seal (139) therein; the stem (138) is configured to allow assembling of the multiband ligation device (100) to the endoscope 200 and provide a passage of the actuation wire (400) through the seal (139) towards the spool (155);-a front frame (145) projects upward from the main body (135) and defines a front frame housing (146) configured to accommodate a front end (158) of the spool (155) and biasing means holders (171, 171 ’); and-a rear frame (150) projects upward from the main body (135) and defines a rear frame housing (151) configured to accommodate a rear end (159) of the spool (155); and the rear frame housing (151) allows fitting of a pawl (141) thereto.

3. The multiband ligation device (100) according to Claim 1 , wherein the rotating component (140) comprising a handle (115), a shaft (120) mounted to the handle (115), a biasing means housing (171) assembled to the shaft (120) and a shaft end cap (153) and a shaft nut (154) disposed on a distal end of the shaft (120); and wherein the handle (115) comprising:- an outer ring (118) comprises teeth (116) formed along a circumference of the outer ring (118); the teeth (116) are configured to engage or disengage with the pawl (141) coupled to the rear frame housing (151) of the body component (130) enabling movement of the rotating component ( 140) between a locked and unlocked position relative to the body component (130); and-an innerring (119) comprising one or more, preferably, two opposing spaced-apart clicker ramps (111) formed along an inner circumference of the inner ring (119), and configured to engage with the clicker (160) coupled to the spool (155).

4. The multiband ligation device (100) according to Claim 1, wherein the spool (155) comprising:-one or more grooves (123) formed inside of the spool (155);-a front end (158) rotatably arranged within the front frame housing (146) of the body component (130), and comprising a biasing means housing (171’);-an enlarged body (156) rotatably arranged within the rear frame housing (156) of the body component (130);-one or more actuation wire locking slits (157) formed on the external surface of the spool (155); said one or more actuation wire locking slits (157) receive and secure a free end of the actuation wire (400) to the spool (155); and-a rear end (159) configured to receive coupling of the clicker (160).

5. The multiband ligation device (100) according to Claim 3, wherein the shaft (120) comprises one or more keys (122) configured to engage to one or more grooves (123) of the spool (155); and wherein each groove (123) of the spool (155) has a width greater than a width of each corresponding key (122) of the shaft (120) enabling a rotation of the spool (155) relative to the shaft (120) in correlation with the rotational force of the rotating component (140), the biasing force of the biasing means (170), and the tension force of the actuation wire (400).

6. The multiband ligation device (100) according to Claim 1, wherein the clicker (160) is configured to form a tight-fit coupling to the rear end (159) of the spool (155); and comprising one, preferably, two opposing deformable arms (161) configured to engage to the one, preferably, two clicker ramps (111) disposed on the inner circumference of the inner ring (119);wherein each arm (161) is deformable and adapted to transition its posture in response to a transition between a relaxed configuration and a compressed configuration of the biasing means (170) and the spool (155).

7. The multiband ligation device ( 100) according to Claim 6, wherein each of the clicker ramp (111) defines a slope (162), a peak (113), a descending path (114), and a clicking step (112) which form a travelling path of a tip of the arm (161).

8. The multiband ligation device (100) according to Claim 1, wherein the biasing means (170) at a maximum compression exerts a force less than a friction force of the ligation band (305).

9. The multiband ligation device (100) according to Claim 1, wherein the ligation unit (300) comprising:-a barrel (310) which defines a first end (312) structured to form a tight fit to a distal end of the endoscope (200), a second end (313) opposing the first end (312),; and -a plurality of ligation bands (305), arranged on the barrel (310); wherein each ligation band (305) is sequentially weaved to the actuation wire (400), and the actuation wire (400) is operable to actuate each ligation band (305) to sequentially deploy via the second end (313) of the barrel (310).

10. The multiband ligation device (100) according to Claim 9, wherein barrel (310) further comprising a plurality of recesses (311), and each of said plurality of ligation bands (305) are arranged in each of said recesses (311) of the barrel (310)11. The multiband ligation device (100) according to Claim 1, wherein the notification generates via the interaction between the clicker (160) and the handle (115) of the rotating component (140) is in the form of an acoustic notification or a tactile feel, or both.

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