Patent Publication Number: US-2018036086-A1

Title: Novel robotic surgical device

Description:
BACKGROUND 
     The present invention relates to robotic devices, and more particularly, to a robotic surgical device. 
     Today, autonomous and semi-autonomous robotic devices are used in various fields. The robotic devices are used to perform repetitive jobs or tasks which are considered dangerous or tedious for humans. Such robotic devices have become a part of many industrial and scientific areas like medicine, space exploration, construction, food packaging and are even used to perform complex surgeries. 
     With technological developments, robotic devices are now used to aid in complex surgeries. Such robotic devices help in providing minimally invasive surgical approaches and minimize human errors, by enabling actions which may be impossible to perform by a human. In some surgeries, the robotic devices are controlled via a computer control system by a surgeon who guides the robotic devices. In other surgeries, the surgeon uses a three-dimensional coordinate system to locate small targets inside a body to perform the surgery, which needs precise planning and execution. Such a method of performing guided surgery within the body is known as stereotactic method of performing the surgery. Stereotactic approaches are commonly employed in neurosurgical procedures and craniofacial surgery. 
     Craniofacial surgery is a subspecialisation of plastic surgery and maxillofacial surgery, that deals with the deformities of the head, skull, face, neck, jaws and associated structures. Craniofacial treatment often involves cutting and manipulation of craniofacial bones, in order to reconstruct bony deformities. Currently, such craniofacial treatment is conducted using long bi-coronal scalp incisions. Conventional craniofacial surgical methods are highly invasive and involve detaching a portion of the skull resulting in significant blood loss, dural damage and significant morbidity, with possible mortality. 
     Hence, there is a need for an improved system and method to address the aforementioned issues. 
     BRIEF DESCRIPTION 
     In one embodiment, a robotic surgical device is provided. The robotic surgical device is configured to subcutaneously cut a bone of a vertebrate from a first location to a second location, wherein the robotic surgical device is introduced within the vertebrate through an incision made into the vertebrate. 
     In another embodiment, a method for cutting a bone in a vertebrate along a predetermined path from a first location to a second location is provided. The method includes controlling a robotic surgical device to subcutaneously reach a first bone cutting location in the predetermined path. The method also includes stabilising the robotic surgical device at the first bone cutting location. The method further includes using a bone cutting system located in the robotic surgical device to cut the bone subcutaneously at the first bone cutting location. The method also includes navigating the robotic surgical device to subcutaneously move a second bone cutting location along the predetermined path. 
     In yet another embodiment, a robotic surgical device configured to be introduced between a skin and a skull of a human being is provided. The robotic surgical device includes a bone cutting system configured to subcutaneously cut the skull of the human being from a first location to a second location along a predetermined path. The robotic surgical device also includes a movement system configured to subcutaneously move the robotic surgical device between the skin and the skull. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram representing a robotic surgical device placed in a vertebrate in accordance with an embodiment of the invention. 
         FIG. 2  is a schematic representation of a robotic surgical device used to cut a skull of a human being in accordance with an embodiment of the invention. 
         FIG. 3  is a schematic representation of a robotic surgical device configured to cut a bone in the vertebrate in accordance with an embodiment of the invention. 
         FIG. 4  is a schematic representation of a third robotic segment of  FIG. 3  in accordance with an embodiment of the invention. 
         FIG. 5  is a schematic representation of a first robotic segment of  FIG. 3  in accordance with an embodiment of the invention. 
         FIG. 6  is a schematic representation of a third robotic segment of  FIG. 3  comprising a bone cutting system in accordance with an embodiment of the invention. 
         FIG. 7  is a flow chart representing steps involved in a method for cutting a bone in a vertebrate along a predetermined path from a first location to a second location in accordance with an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention relate to a robotic surgical device configured to subcutaneously cut a bone of a vertebrate from a first location to a second location, wherein the robotic surgical device is introduced within the vertebrate through an incision made into the vertebrate. 
       FIG. 1  is a schematic diagram representing a robotic surgical device  10  placed in a vertebrate  20  in accordance with an embodiment of the invention. In an event of conducting a bone surgery in the vertebrate  20 , an incision  30  is made on a skin  40  of the vertebrate  20  at a first location  50 . The robotic surgical device  10  is introduced between the skin  40  and a bone  60  of the vertebrate  20  at the first location  50  through the incision  30  made in the vertebrate  20 . Furthermore, a cavity  70  is formed using a drilling mechanism in the bone  60  at the first location  50 . In one embodiment, the robotic surgical device  10  may include a retractor  80  that is introduced below the bone  60  through the cavity  70  made at the first location  50  such that the retractor  80  is positioned between the bone  60  and a soft tissue  85  such as marrow within the bone  60 . Subsequently, the robotic surgical device  10  is used to subcutaneously cut the bone  60  from the first location  50  to a second location  90  along a predetermined path  100 . In one embodiment, the predetermined path may include a plurality of intermediate locations  52 ,  54 ,  56  between the first location  50  and the second location  90  at which the bone  60  is cut to enable cutting of the bone  60  along the predetermined path  100 . 
       FIG. 2  is a schematic representation of a skull  110  of a human being comprising the robotic surgical device  10  for cutting the skull  110  in accordance with an embodiment of the invention. In embodiments, where the bone  60  is the skull  110  of the human being, the robotic surgical device  10  may be introduced in human being at a first location  120  in the skull  110  between a periosteum  130  and a loose sub-aponeurotic layer  140  at the first location  120  to cut the skull  110  from the first location  120  to a second location  150  on the skull  110  along a predetermined path  160 . In embodiments where the robotic surgical device  10  includes the retractor  80 , a cavity  170  may be drilled in the skull  110  at the first location  120  to insert the retractor  80  below the skull  110  to prevent damage to the duramater  180  during the cutting of the skull  110 . 
       FIG. 3  is a schematic representation of the robotic surgical device  10  configured to cut the bone  60  in the vertebrate ( FIG. 1 ) in accordance with an embodiment of the invention. The robotic surgical device  10  includes a movement system  190 . In one embodiment, the movement system  190  includes a plurality of segments mechanically coupled to each other. In a specific embodiment, the movement system  190  includes a first robotic segment  210 , a second robotic segment  220 , and a third robotic segment  230  mechanically coupled to each other via a plurality of links  240 . The movement system  190  is further explained in details with respect to  FIG. 4 - FIG. 5 . 
       FIG. 4  is a schematic representation of the third robotic segment  230  of  FIG. 3  in accordance with an embodiment of the invention. The movement system  190  includes a rotating joint  250  disposed in the third robotic segment  230 . In one embodiment, the rotating joint  250  is a cylindrical joint. The cylindrical joint is mechanically coupled to the first robotic segment  210  via the plurality of links  240  to control a direction  260  of the first robotic segment  210 . The rotating joint  250  is used to turn the first robotic segment  210  in the predetermined direction  260  that enables the robotic surgical device  10  to move the predetermined direction  260 . 
       FIG. 5  is a schematic representation of the first robotic segment  210  of  FIG. 3  in accordance with an embodiment of the invention. The first robotic segment  210  further includes a first slider crank system  270  mechanically coupled to the plurality of links  240  via a first connecting rod  280 . The first slider crank system  270  enables the first robotic segment  210  to move in a forward direction and a backward direction to enable movement of the first robotic segment  210 . Similarly, the second robotic segment  220  also includes a substantially similar second slider crank system (not shown) mechanically coupled to the plurality of links  240  via a second connecting rod (not shown). 
     Referring again to  FIG. 3 , the movement system  190  further includes a plurality of flaps  310 . Each of the first robotic segment  210  and the second robotic segment  220  include a flap  310  for stabilizing the robotic surgical device  10  on the bone  60 . Each of the flap  310  is mechanically coupled to the respective first robotic segment  210  and second robotic segment  220  via a pivot mechanism  320  at a first end  330  of the flap  310 . The pivot mechanism  320  enables an angular movement  340  of a second end  350  of the flap  310  using a screw joint  360 , where the angular movement  340  of the second end  350  may be defined as a vertical movement of the second end  350  of the flap  310  with respect to the first end  330  of the flap  310 . The screw joint  360  is used to control the angular movement  340  of the second end  350  of the flap  310  based on a shape of the bone  60 . For example, in situations, where the shape of the bone  60  is convex, the screw joint  360  may be actuated based on an interior angle of the bone  60  such that the angular movement  340  of the second end  350  of the flap  310  brings the flap  310  in contact with the bone  60 . Furthermore, a plurality of suction caps  370  is provided below the flaps  310 , which are actuated to affix the robotic surgical device  10  to the bone  60 . In another embodiment, a plurality of tongs may be provided instead of suction caps  370  which can latch on to the bone  60  to affix the robotic surgical device  10  to the bone  60 . Moreover, each of the flap  310  in the first robotic segment  210  and the second robotic segment  220  is configured to be controlled individually or in combination to affix the robotic surgical device  10  to the bone  60  based on the shape of the bone  60 . 
     In operation, the movement system  190  is used to move the robotic surgical device  10  from the first location ( FIG. 1 ) to an intermediate location along the predetermined path ( FIG. 1 ). To this end, initially the flap  310  of the first robotic segment  210  is detached from the bone  60  by actuating the screw joint  360  to lift the flap  310 . Subsequently, the first robotic segment  210  is moved forward using the first slider crank system  270  in the first robotic segment  210 , which is actuated through a first motor (not shown) in the first robotic segment  210 . Upon moving forward, the first robotic segment  210  is affixed to the intermediary location using the flap  310  of the first robotic segment  210 . Furthermore, the second robotic segment  220  includes a second motor (not shown) that actuates the second slider crank system  290  in the second robotic segment  220  to push the third robotic segment  230  forward via the plurality of links  240 . The first motor and the second motor operate simultaneously such that the first robotic segment  210  pulls the third robotic segment  230  via the plurality of links  240  and the second robotic segment  220  pushes the third robotic segment  230  forward via the plurality of links  240 . Thus, the third robotic segment  230  moves forward and is subsequently attached to the bone  60 . Later, the flap  310  of the second robotic segment  220  is lifted to detach from the bone  60  and the second robotic segment  220  moves forward using the second slider crank system  290  and attaches to the intermediate location using the flap  310  of the second robotic segment  220 . The aforementioned process is repeated to move to a new intermediate location along the predetermined path. Such a configuration enables an earthworm like movement of the robotic surgical device  10  that also provides stability and reduces risk of errors during bone cutting. 
     Additionally, the first robotic segment  210  and the second robotic segment  220  include a first shell  380  and a second shell  390  respectively. The first shell  380  forms a covering for the first robotic segment  210  and is configured to separate the skin  40  from the bone  60  to enable movement of the robotic surgical device  10 . To this end, a shape of the first shell  380  includes a sharp edge  400  at a front end  410  of the first robotic segment  210  and a flat surface  420  at a rear end  430  of the first robotic segment  210 . Furthermore, an inclined surface  440  is used to connect the sharp edge  400  and the flat surface  420 , which enables the first shell  380  to lift the skin  40  attached to the bone  60  and allowing the robotic surgical device  10  to move forward. Similarly, the second shell  390  forms a covering for the second robotic segment  220  and is of a shape substantially similar to the shape of the first shell  380 . However, due to the positioning of the second shell  390  at the second robotic segment  220 , the second shell  390  is configured to smoothly lay the skin  40  separated by the first shell  380  back on the bone  60  during the movement of the robotic surgical device  10 . In one embodiment, each of the first shell  380  and the second shell  390  may be operatively coupled to a first shell actuator  450  and a second shell actuator  460  respectively. The first shell actuator  450  is used to exert additional force to separate the skin  40  from the bone  60  and the second shell actuator  460  is used to move the second shell  390  in a vertical direction to smoothly lay the skin  40  over the bone  60  during movement of the robotic surgical device  10 . 
     Furthermore, the robotic surgical device  10  includes a bone cutting system  470  provided in the third robotic segment  230 . The bone cutting system  470  is used to cut the bone  60  at a location along the predetermined path ( FIG. 1 ) such as the first location ( FIG. 1 ), the intermediate location and the second location ( FIG. 1 ). The bone cutting system  470  further includes a cutting means  480 . In another embodiment, the bone cutting system  470  may include at least one of an irrigation system  490  and a suction system  500 . The irrigation system  490  is used to irrigate the bone  60  at the location during the cutting of the bone  60 . Furthermore, the suction system  500  is used to remove a bone residue after the bone  60  is cut at the location. Further details of the bone cutting system  470  are disclosed in  FIG. 6 . 
       FIG. 6  is a schematic representation of the third robotic segment  230  including the bone cutting system  470  located in the third robotic segment  230  in accordance with an embodiment of the invention. The bone cutting system  470  includes a cutting motor platform  510  on which a cutting motor  520  and the cutting means  480  are mounted. The cutting motor  520  is configured to drive the cutting means  480  using external power. In one embodiment, the cutting means  480  may include a saw blade. In a specific embodiment, the saw blade includes a T-joint that is used to attach the saw blade to a rotating disk of the cutting motor  520 . 
     In another embodiment, the cutting means may include a milling burr. The cutting motor  520  and the milling burr are mounted on the cutting motor platform  510  such that an axle of the cutting motor  520  is placed facing towards the bone ( FIG. 3 ) without the T-joint. In other embodiments, the cutting means  480  and the cutting motor  520  may be replaced with an ultrasonic bone cutting system, or a laser bone cutting system. 
     The bone cutting system  470  further includes the retractor  80 . As previously discussed, the retractor  80  is inserted below the bone  60  through the cavity ( FIG. 1 ) and is placed between the soft tissue ( FIG. 1 ) such as the marrow and the bone  60 . The retractor  80  prevents the cutting means  480  from damaging the soft tissue during the cutting of the bone  60 . In the embodiment discussed in  FIG. 2 , where the skull is cut from the first location to the second location, the retractor  80  is located between the bone and the duramater. In such embodiments, the retractor  80  prevents damage to the duramater during cutting of the skull. 
     Furthermore, the bone cutting system  470  includes a height adjustable platform  530  configured to adjust a depth of the cut created by the cutting means  480 . To this end, the height adjustable platform  530  includes a height adjustment motor  540  and a height adjustment screw joint  550 . The height adjustment motor  540  actuates the height adjustment screw joint  550  to rotate in a clockwise or an anticlockwise direction to vertical move the cutting means  480 . The vertical movement of the cutting means  480  increases or decreases the height of the cutting means  480  with respect to the bone  60  thereby altering the depth of the cut created by the cutting means  480 . 
     With returning reference to  FIG. 3 , the robotic surgical device  10  also includes a conduit (not shown) operatively coupled to one or more external devices. The conduit includes at least one cable for enabling operations of one or more systems in the robotic surgical device  10 . In one embodiment, the conduit may include an electrical cable for providing operating power to the robotic surgical device  10 . In another embodiment, the conduit may include a data communication cable for transmitting and receiving data. In a specific embodiment, the data communication cable may transmit images obtained using an image capturing device in the robotic surgical device  10  to an external display. In another embodiment, the data communication cable may be used to provide control signal to the robotic surgical device  10  from an external controller. Furthermore, the data communication cable may be used to track a current location of the robotic surgical device  10 . Based on the aforementioned uses of the data communication cable, a stereotactic navigation of the robotic surgical device  10  may be achieved for performing the bone cutting surgeries. In yet another embodiment, the conduit may also include an irrigation tube for providing a fluid to the irrigation system  490  from an external fluid source and a suction tube that enables the suction system  500  to remove the bone residue from the vertebrate ( FIG. 1 ). 
     Furthermore, the operation of the robotic surgical device  10  is discussed with respect to  FIG. 7  representing a flowchart depicting steps involved in a method  600  for cutting the bone  60  in the vertebrate  20  along the predetermined path  100  from the first location  50  to the second location  90  in accordance with an embodiment of the invention. It may be noted that the predetermined path  100  for cutting the bone  60  from the first location  50  to the second location  90  may include a plurality of bone cutting locations. The method  600  is discussed with respect to one instance, where the robotic surgical device  10  is used to cut the bone  60  at the first bone cutting location. The method  600  disclosed herein below may be repeated to cut the bone  60  at the plurality of bone cutting locations, thereby cutting the bone  60  from the first location  50  to the second location  90  along the predetermined path  100 . 
     The method  600  includes controlling the robotic surgical device  10  to subcutaneously reach the first bone cutting location in the predetermined path in step  602 . In one embodiment, the controlling the robotic surgical device  10  to subcutaneously reach the first bone cutting location in the predetermined path may include introducing the robotic surgical device  10  in the vertebrate  20  at the first location  50  through the incision  30  made in the vertebrate  20  at the first location  50 . For the purpose of explanation of  FIG. 7 , the first location  50  and the first bone cutting location are the same locations as the robotic surgical device  10  is initially introduced in the vertebrate  20  at the first location  50 . As previously discussed, the cavity  70  is drilled at the first bone cutting location  50  and the retractor  80  is inserted below the bone  60  such that the bone  60  is between the cutting means  480  and the retractor  80 . In the embodiment of  FIG. 2 , where the skull  110  is cut from the first location  120  to the second location  150  along the predetermined path  160 , the retractor  80  is inserted between the skull  110  and the duramater  180  to avoid damage to the duramater  180 . 
     Subsequently, the robotic surgical device  10  is stabilized at the first bone cutting location  50  using the flaps  310  in step  604 . In one embodiment, the flaps  310  of the first robotic segment  210  and the second robotic segment  220  of the robotic surgical device  10  are actuated using the screw joint  360  based on a curvature of the bone  60  to attach to the bone  60 . In a specific embodiment, the flaps  310  affix to the bone  60  using a plurality of suction cups  370  or a plurality of tongs provided below the flaps  310 . 
     The robotic surgical device  10  uses the bone cutting system  470  located in the robotic surgical device  10  to cut the bone  60  at the first bone cutting location  50  in step  606 . In one embodiment, a height of a cutting means  480  is adjusted based on a thickness of the bone  60  to modify a depth of the cut in the bone  60 . Furthermore, the cutting means  480  is actuated using a cutting motor  520 , which allows the cutting means  480  to cut the bone  60 . In another embodiment, the first bone cutting location  50  is irrigated using the irrigation system  490  during the bone cutting to clean the first bone cutting location  50 . In yet another embodiment, a bone residue generated after cutting of the bone  60  is removed using the suction system  500  in the robotic surgical device  10 . 
     Furthermore, the robotic surgical device  10  is navigated to subcutaneously move to a second bone cutting location  52  along the predetermined path  100  in step  608 . It may be noted that the predetermined path  100  may include the plurality of intermediate locations  52 ,  54 ,  56  between the first location  50  and the second location  90  as previously discussed in  FIG. 1  and one such intermediate location  52  is used as the second bone cutting location for the purposes of explanation of the method  600 . In a specific embodiment, the robotic surgical device  10  is employs a stereotactic navigation for moving from the first bone cutting location  50  to the second bone cutting location  52 . In one embodiment, the flap  310  of the first robotic segment  210  is detached from the bone  60  prior to moving to the second bone cutting location  52 . Furthermore, the first robotic segment  210  moves forward to the second bone cutting location  52  from the first bone cutting location  50  using the first slider crank system  270  and attaches to the second bone cutting location  52  using the flap  310  of the first robotic segment  210 . Subsequently, the flap  310  of the second robotic segment  220  detaches from the bone  60  and pushes the third robotic segment  230  forward to the second bone cutting location  52  using the second slider crank system  290  provided in the second robotic segment  220 . Simultaneously, the first robotic segment  210  pulls the third robotic segment  230  to the second bone cutting location  52 , which enables the movement of the second robotic segment  220  and the third robotic segment  230  to the second bone cutting location  52 . The aforementioned process of cutting the bone  60  is repeated again to cut the bone  60  at the second bone cutting location  52 . Similarly, the aforementioned method  600  may be repeated at the plurality of intermediate locations along the predetermined path  100  to cut the bone  60  from the first location  50  to the second location  90 . 
     The various embodiments of the robotic surgical device described above enable a subcutaneous cutting of the bone, which leads to minimally invasive bone surgery, minimal incisions, minimal blood loss and minimal damage to the soft tissues within the bone. Also, the robotic surgical device minimizes damage to a duramater of the brain in craniofacial surgeries as the robotic surgical device includes a retractor that is placed between a skull bone and the duramater to prevent a cutting means from coming in contact with the duramater during the cutting of the bone. 
     It is to be understood that a skilled artisan will recognize the interchangeability of various features from different embodiments and that the various features described, as well as other known equivalents for each feature, may be mixed and matched by one of ordinary skill in this art to construct additional systems and techniques in accordance with principles of this disclosure. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.