WO2020144714A1

WO2020144714A1 - Robotic system

Info

Publication number: WO2020144714A1
Application number: PCT/IN2020/050031
Authority: WO
Inventors: Gandhi PRASANNA S.; Nakhwa CHINMAY PRAKASH; Syed SANA NASSAR; Shimpi SURAJ SANJAY
Original assignee: Indian Council Of Medical Research; Indian Institute Of Technology, Bombay
Priority date: 2019-01-11
Filing date: 2020-01-10
Publication date: 2020-07-16

Abstract

The present disclosure relates to a robotic system (100) used for performing minimally invasive surgery. The robotic system (100) comprises a first actuator (104-1), a second actuator (106-1), a third actuator (110-1) and a tool (116). The second actuator (106-1) is connected with the first actuator (104-1) configured to move the second actuator (106-1) about a first axis (X). The third actuator (110-1) is connected with the second actuator (106-1) configured to move the third actuator (110-1) about a second axis (Y) orthogonal to the first axis (X). The third actuator (110-1) is configured to move a tool (116) along a third axis (Z) orthogonal to the second axis (Y) and first axis (X). The robotic system (100) further comprises at least one compliant RCM mechanism (104-2, 106-2) configured to connect the first actuator (104-1) to the second actuator (106-1) and, the second actuator (106-1) to the third actuator (110-1).

Description

ROBOTIC SYSTEM

FIELD OF PRESENT DISCLOSURE

[0001] The present disclosure relates to the field of surgical devices. Particularly, the present disclosure relates to a robotic system used for performing minimally invasive surgery.

BACKGROUND OF PRESENT DISCLOSURE

[0002] Manual/ Invasive/open surgeries are generally associated with long recovery periods for patients due to damage of extraneous tissues during such procedures. During manual surgeries, the surgeons have to operate in the uncomfortable and tiring postures, and a limited freedom of motion and poor tactile perception. In fact, the surgeons have to carry out several consecutive interventions per day, each intervention takes 30 minutes to several hours. This causes excessive fatigue in the surgeon’s hands and may lower their accuracy.

[0003] In spite of these difficulties, the trend toward minimal invasive surgeries is going to increase from last few years to get effective surgical solutions. The use of laparotomy and minimally invasive surgeries have the benefit of reducing the amount of extraneous tissue that is damaged during diagnostic or surgical procedures. This results in shorter patient recovery time, less discomfort and deleterious side effects, and lower costs of the hospital stay. Therefore, minimally invasive surgical techniques have been widely used in number of surgical operations. Many minimal invasive surgeries are assisted by the robots. The robotically assisted minimal invasive surgeries have known significant development since the early nineties. Some commercial robotic surgery systems such as“ DA VINCI” and“ PRECEYES” are already used in hospitals to perform robotically assisted minimal invasive surgeries.

[0004] In existing robotic surgery systems, the surgeon operates a master console by holding a pair of joysticks, which mediates the interaction between the surgeon’s hand motions and the slave console operating on the patient. In these cases, the surgical feel is compromised or maybe lost as the surgeon is no longer holding the actual surgical tool. Further, the joystick operated systems require additional training for the surgeons than in cases where the surgeon holds the actual surgical tool. Moreover, the existing robotic surgery systems contain analog strain sensors that cause unwanted noise. After a prolonged use, the moving parts of joystick may induce unwanted play and reduce the accuracy of the robotic surgery system, which require regular maintenance checks for consistent accuracy. Therefore, such existing robotic surgery systems have a high purchase and maintenance cost.

[0005] Accordingly, there is an immense need to develop a robotic system that addresses one or more problems as discussed above and other problems associated with the existing robotic systems with alternative methods.

SUMMARY OF PRESENT DISCLOSURE

[0006] The present disclosure relates to a robotic system used for performing minimally invasive surgery. The robotic system comprising a first actuator, a second actuator, third actuator and a tool. The second actuator is connected with the first actuator configured to move the second actuator about a first axis. The third actuator is connected with the second actuator configured to move the third actuator about a second axis orthogonal to the first axis. The tool is connected to the third actuator configured to move the tool along a third axis orthogonal to the second axis and the first axis. Further, robotic system comprises at least one compliant RCM mechanism configured to connect the first actuator to the second actuator and, the second actuator to the third actuator. At least one compliant RCM mechanism comprises a fixed flange, a moveable flange and at least one flexible link. The fixed flange is attached with at least one actuator. The moveable flange connected to the fixed flange and at least one first flexible link disposed between the fixed flange and the moveable flange.

[0007] In an aspect, at least one compliant RCM mechanism is attached with the first and second actuator using mechanical arrangements. [0008] In an aspect, a first connector is configured to connect at least one compliant RCM mechanism with the second actuator.

[0009] In an aspect, the first connector comprises a first end configured to connect with the at least one compliant RCM mechanism and, a second end configured to connect with said second actuator.

[0010] In an aspect, comprises a second connector is configured to connect the at least one compliant RCM mechanism with the third actuator.

[0011] In an aspect, the second connector comprises a first end configured to connect with the at least one compliant RCM mechanism and, a second end configured to connect with said third actuator.

[0012] In an aspect, at least one compliant RCM mechanism comprises a rotary encoder disposed between the fixed flange and the moveable flange.

[0013] In an aspect, a tool holder is configured to hold the tool.

[0014] In an aspect, at least one complaint single parallelogram mechanism is configured to connect the third actuator to the tool holder.

[0015] In an aspect, the tool holder (114) comprises a top tool adapter (406) and a bottom tool adapter (404) for rotating the tool (116) about the third axis (Z).

[0016] In an aspect, at least one complaint single parallelogram mechanism comprises a moveable block configured to support the tool holder and, move the tool holder along the third axis. [0017] In an aspect, at least one complaint single parallelogram mechanism comprises a linear encoder disposed adjacent to the moveable block.

[0018] In an aspect, the first, second and third actuators are configured to facilitate the gross motion of the tool and, at least one complaint single parallelogram mechanism and at least one compliant RCM mechanism are configured to facilitate the fine motion of the tool.

[0019] Further, a compliant RCM mechanism for a robotic system comprises at least one actuator, comprising a fixed flange, moveable flange and at least one first flexible link. The fixed flange is attached with at least one actuator. The moveable flange is connected to the fixed flange and, at least one first flexible link disposed between the fixed flange and the moveable flange. At least one first flexible link is configured to transfer the motion of at least one actuator to the moveable flange. [0020] In an aspect, a rotary encoder is disposed between the fixed flange and the moveable flange.

BRIEF DESCRIPTION OF THE DRAWINGS [0021] The figure(s) are incorporated with the specification, and serve to further illustrate the embodiments and illustrate various principles and advantages, in accordance with the present disclosure wherein:

[0022] Figure 1 illustrates a perspective view of a robotic system in accordance with an embodiment of the present disclosure.

[0023] Figure 2 illustrates a perspective view of compliant RCM mechanism of the robotic system in accordance with an embodiment of the present disclosure. [0024] Figure 3 illustrates a perspective view of complaint single parallelogram mechanism of the robotic system in accordance with an embodiment of the present disclosure.

[0025] Figure 4 illustrates a perspective view of a tool holder in accordance with an embodiment of the present disclosure.

[0026] Figure 5 illustrates the different axes of the robotic system in accordance with an embodiment of the present disclosure.

[0027] The figure(s) depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the assembly as illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF PRESENT DISCLOSURE

[0028] The present disclosures provide a robotic system for surgical applications. The robotic system comprising a first actuator, a second actuator, third actuator and a tool. The second actuator is connected with the first actuator configured to move the second actuator about a first axis. The third actuator is connected with the second actuator configured to move the third actuator about a second axis orthogonal to the first axis. The tool is connected to the third actuator configured to move the tool along a third axis orthogonal to the second axis. Further, robotic system comprises at least one compliant RCM mechanism configured to connect the first actuator to the second actuator and, the second actuator to the third actuator. At least one compliant RCM mechanism comprises a fixed flange, a moveable flange and at least one first flexible link. The fixed flange is attached with at least one actuator. The moveable flange connected to the fixed flange and at least one first flexible link disposed between the fixed flange and the moveable flange. [0029] The robotic system of the present disclosure can be used for performing Minimally Invasive Surgery (MIS) such as retinal surgeries. Regardless of their specific construction, the robotic system may achieve four degrees of freedom about a Remote Center of Motion (RCM) while performing minimally invasive surgery. The robotic system described herein can provide the controlled gross and fine motion simultaneously, to move the tool in three of the four degrees of freedom. In an embodiment, the robotic system can be used in multiple configurations such as a surgical assist for cooperative surgery and, fully automated high precision joystick-controlled surgical robot. In a cooperative surgery, the tool is shared between the surgeon and the robot, thereby preserving the surgical feel of the operation procedure. In the joystick-controlled surgery, the surgical feel is not preserved as the surgeon does not directly hold the tool.

[0030] The robotic system of the present disclosure is described with reference to the figures and alternative embodiments; this description is not meant to be constructed in a limiting sense.

[0031] Referring to figure 5, the first axis (X) is defined as an axis along the line X-X. The second axis (Y) is an axis along the line Y-Y and orthogonal to the first axis (X). The third axis (Z) is an axis along the line Z-Z and orthogonal to the first axis (X) and second axis (Y). In an embodiment, the first, second and third axis are not limited to the above explanation, the first, second and third axis may be changed corresponding to the rotation the robotic system (100).

[0032] Referring to Figure 1, the robotic system (100) having a base (102), a first actuator (104-1), a second actuator (106-1), a third actuator (110-1) and a tool (116). Further, the robotic system (100) has at least one compliant RCM mechanism (104-2, 106-2) configured to connect the first actuator (104-1) to the second actuator (106-1) and, the second actuator (106-1) to the third actuator (110-1). The robotic system (100) have provision to move in four degrees of freedom about the RCM (118) or the incision point, i.e., to facilitate high precision MIS applications. In an embodiment as shown, RCM is centre point from where the surgical operation is originated. The first (104-1) and second actuators (106-1) may be connected with one or more motors that facilitates the motion to the at one actuator (104-1; 106-1).

[0033] The first actuator (104-1) is mounted on the base (102) using mechanical arrangements. The first actuator (104-1) is connected with the compliant RCM mechanism (104-2). The compliant RCM mechanism (104-2) is further connected with the second actuator (106-1) using a first connector (108). The first connector (108) has a first end configured to connect with the compliant RCM mechanism (104-2) and a second end configured to connect with the second actuator (106-1). The first actuator (104-1) is configured to move the second actuator (106-1) about a first axis (X). In an embodiment, mechanical arrangements may be nut-bolt joint, welding or clamping joint etc. In another embodiment as shown, more than one connector may be deployed to connect the first actuator (104-1) to the second actuator (106-1). In another embodiment, the first actuator (104-1) may be a direct current (DC) direct drive motor.

[0034] Referring to Figure 2, the compliant RCM mechanism (104-2; 106-2) is configured to configured to connect the first actuator (104-1) to the second actuator (106-1) and, the second actuator (106-1) to the third actuator (110-1). The compliant RCM mechanism (104-2, 106-2) has a fixed flange (204), a moveable flange (202) and a first motor mount (214). The fixed flange (204) is attached with at least one actuator (104-1, 106-1) and, the moveable flange (202) connected to the fixed flange. Further, at least one compliant RCM mechanism (104-2; 106-2) includes at least one first flexible link (206) disposed between the fixed flange (204) and the moveable flange (202). A rotary encoder (208) is disposed between the fixed flange (204) and the moveable flange (202) for monitoring the movements of the robotic system. The rotary encoder (208) may a digital encoder. In an embodiment, the rotary encoder (208) is placed near the moveable flange (202). The rotary encoder (208) may include a reader (2084) and a scale (2082) is attached to the movable flange (202). In an embodiment, the one or more motor may be placed on the first motor mount (214) to provide the motion to at least one actuator (104-1; 106-1). In one more embodiment, at least one compliant RCM mechanism (104-2; 106-2) may be more than one flexible links (206). The first flexible links (206) transfers the motion of the first motor to the moveable flange (202). In another embodiment, the compliant RCM mechanism (104-2; 106-2) may be an ultra-precision torque sensor that facilitates the fine motion of the tool (116). In another embodiment as shown, four equal sized flexible links (206) are angularly placed at angle of 90°. The flexible links (206) may have cuboidal or cylinder shape. The accuracy of compliant RCM mechanisms (104-2; 106-2) depends on the beam stiffnesses and force-displacement relationships. In another embodiment, at least one compliant RCM mechanism (104-2; 106-2) may have high resolution noise-free linear and rotary digital encoders to accurately sense the displacement caused by compliance and hence the corresponding torque or force. In one more embodiment as shown, the robotic system has two compliant RCM mechanisms.

[0035] The second actuator (106-1) is configured to move the third actuator (110-1) about a second axis (Y) orthogonal to the first axis (X). The second actuator (106-1) is connected with the compliant RCM mechanism (106-2). The compliant RCM mechanism (106-2) is further connected with the third actuator (110-1) using a second connector (112). The second connector (112) has a first end (1122) configured to connect with the at least one compliant RCM mechanism (106-2) and, a second end (1124) configured to connect with said third actuator (110-1). In an embodiment, the second actuator (106-1) may be a direct current (DC) direct drive motor.

[0036] The third actuator (110-1) is configured to move the tool (116) along a third axis (Z) orthogonal to the second axis (Y). The third actuator (110-1) is connected to at least one complaint single parallelogram mechanism (110-2). In an embodiment, the third actuator (106- 1) may be a drive device that provides translational motion. The third actuator (110-1) has a carriage (312), a lead screw (314), fixed block (304), coupling (322) and second motor mount (318). The lead screw (314) is configured to deliver the translational motion along a third axis (Z). The coupling (322) is provided to mount the motor. The fixed block (304) is mounted on the carriage (312) of the third actuator (110-1). The carriage (312) is configured to support a lead screw (314). In an embodiment as shown, a brushed DC direct drive motor (320) is configured to facilitate the motion to the lead screw (314). [0037] The complaint single parallelogram mechanism (110-2) is configured to connect the third actuator (110-1) to the tool holder (114). The complaint single parallelogram mechanism (110-2) comprises a movable block (302) configured to support a tool holder (114). The movable block (302) is moveably connected with the fixed block (304) using at least second flexible link (306). The lead screw (314) permits the translational motion of the movable block (302) along a third axis (Z). Further, the complaint single parallelogram mechanism (110-2) has a linear encoder (308) mounted on an encoder mount (310). The linear encoder (308) is configured to monitor the translational movements of the robotic system (100). In an embodiment as shown, the linear encoder (308) is positioned adjacent to the movable block (302). In an embodiment as shown, the flexible links (306) are two in number. In another embodiment, the flexible links have equal size and cuboidal shape. The flexible links may have cuboidal or cylindrical shape. In one more embodiment, the linear encoder (308) is a digital encoder.

[0038] Referring to Figures 1 and 4, a tool holder (114) is provided to hold the tool (116). The tool holder (114) has a top tool adapter (406) configured to rotate the tool (116) about the third axis (Z). A plurality of holes (402) is provided on the tool holder (114) to mount the tool holder (114) with the moveable block (302). The tool holder (114) is mounted on the movable block (302) using fasteners. The tool holder (114) includes a bottom tool adapter (404) fitted on the bottom of the tool 116 and the top tool adapter (406) fitted on the top of the tool (116). In an embodiment as shown, the surgical tool (116) includes a portion (116-2) from where it can be held and includes a tip (116-4) extending downwards from the bottom tool adapter (404). Further, the top tool adapter (406) is mounted on a bearing (408) using a bearing adapter (410).

[0039] The first (104-1), second (106-1) and third actuators (110-1) are configured to facilitate the gross motion of the tool (116) and, at least one complaint single parallelogram mechanism (110-2) and at least one compliant RCM mechanism (104-2, 106-2) are configured to facilitate the fine motion of the tool (116). Accordingly, the robotic system (100) is enabled to provide the gross and fine motion to the tool (116) simultaneously. The robotic system (100) can enhance the quality of surgery by provision of several features such as tremor cancellation, improved precision and accuracy in surgical motion and in sensing of tool forces and moments, allowing freezing of surgical tool at any position, compatibility with existing surgical tools, and preserving the surgical feel of the operation procedure in the case of cooperatively controlled system.

[0040] The robotic system (100) is disclosed in the present disclosure can be effectively used for a cooperatively controlled and joystick-controlled surgeries to move the tool (116) in four degree of freedoms. The robotic system (100) is compatible with all surgical tools without modifications to any parts of the tool. Moreover, at least one compliant RCM mechanism (104- 2, 106-2) also allows the surgeon to make small and precise friction— free motions due to the presence of compliance and damp out physiological tremors passively. Accordingly, the robotic system (100) allows accurate and tremor free surgeries in MIS applications. [0041] A list of reference numerals:

Claims

The Claims:

1. A robotic system (100) for performing minimally invasive surgery, the robotic system (100) comprising:

a first actuator (104-1);

a second actuator (106-1) connected with the first actuator (104-1), the first actuator (104-1) is configured to move the second actuator (106-1) about a first axis

(X); and

a third actuator (110-1) connected with the second actuator (106-1), the second actuator (106-1) is configured to move the third actuator (110-1) about a second axis

(Y) orthogonal to the first axis (X);

a tool (116) connected to the third actuator (110-1), the third actuator (110-1) is configured to move the tool (116) along a third axis (Z) orthogonal to the second axis (Y) and the first axis (X); and

wherein at least one compliant RCM mechanism (104-2, 106-2) is configured to connect the first actuator (104-1) to the second actuator (106-1) and, the second actuator (106-1) to the third actuator (110-1), at least one compliant RCM mechanism (104-2, 106-2) comprises:

a fixed flange (204) attached with at least one actuator (104-1, 106-1);

a moveable flange (202) connected to the fixed flange;

at least one first flexible link (206) disposed between the fixed flange (204) and the moveable flange (202).

2. The robotic system (100) as claimed in claim 1, wherein at least one compliant RCM mechanism (104-2, 106-2) is attached with the first (104-1) and second actuator (106-1) using mechanical arrangements.

3. The robotic system (100) as claimed in claim 1, comprises a first connector (108) is configured to connect at least one compliant RCM mechanism (104-2, 106-2) with the second actuator (106-1).

4. The robotic system (100) as claimed in claim 3, wherein the first connector (108) comprises a first end (1082) configured to connect with the at least one compliant RCM mechanism (104- 2, 106-2) and, a second end (1084) configured to connect with said second actuator (106-1).

5. The robotic system (100) as claimed in claim 1, comprises a second connector (112) is configured to connect at least one compliant RCM mechanism (104-2, 106-2) with the third actuator (110-1).

6. The robotic system (100) as claimed in claim 5, wherein the second connector (112) comprises a first end (1122) configured to connect with the at least one compliant RCM mechanism (104-2, 106-2) and, a second end (1124) configured to connect with said third actuator (110-1).

7. The robotic system (100) as claimed in claim 1, wherein at least one compliant RCM mechanism (104-2, 106-2) comprises a rotary encoder (208) disposed between the fixed flange (204) and the moveable flange (202).

8. The robotic system (100) as claimed in claim 1, wherein a tool holder (114) is configured to hold the tool (116).

9. The robotic system (100) as claimed in claim 8, comprises at least one compliant single parallelogram mechanism (110-2) configured to connect the third actuator (110-1) to the tool holder (114).

10. The robotic system (100) as claimed in claim 8, wherein the tool holder (114) comprises a top tool adapter (406) and a bottom tool adapter (404) for rotating the tool (116) about the third axis (Z).

11. The robotic system (100) as claimed in claim 9, wherein at least one complaint single parallelogram mechanism (110-2) comprises a moveable block (302) configured to support the tool holder (114) and, move the tool holder (114) along the third axis (Z).

12. The robotic system (100) as claimed in claim 11, wherein at least one complaint single parallelogram mechanism (110-2) comprises a linear encoder (308) disposed adjacent to the moveable block (302).

13. The robotic system (100) as claimed in claims 1 and 9, wherein the first (104-1), second (106-1) and third actuators (110-1) are configured to facilitate the gross motion of the tool (116) and, at least one complaint single parallelogram mechanism (110-2) and at least one compliant RCM mechanism (104-2, 106-2) are configured to facilitate the fine motion of the tool (116).

14. A compliant RCM mechanism (104-2, 106-2) for a robotic system (100) comprises at least one actuator and at least one motor, the compliant RCM mechanism (104-2, 106-2) comprising:

a fixed flange (204) attached with at least one actuator;

a moveable flange (202) connected to the fixed flange (204);

at least one first flexible link (206) disposed between the fixed flange (204) and the moveable flange (202), at least one first flexible link (206) is configured to transfer the motion of at least one actuator to the moveable flange (202).

15. The compliant RCM mechanism (104-2, 106-2) as claimed in claim 13, comprises a rotary encoder (208) disposed between the fixed flange (204) and the moveable flange (202).