Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
CALIBRATION ASSEMBLY FOR A ROBOTIC SURGERY
2. APPLICANT:
Name : Merai Newage Private Limited
Nationality : Indian
Address : Survey No. 1574, Bilakhia House, Chala Muktanand Marg, Vapi, Valsad-396191 Gujarat, India.

3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed:
 
FIELD OF INVENTION
[1] The present invention relates to a medical device. More specifically, the present invention relates to a calibration assembly associated with robotic surgery.
BACKGROUND OF INVENTION
[2] Robot-assisted surgery has emerged as a transformative advancement across multiple surgical specialties such as orthopedic surgical procedures. Incorporation of robotics into surgical processes improves accuracy, consistency, and control, which lowers outcome variability and minimizes problems. The robotic-assisted surgeries integrate robotic arms, surgical navigation, and advanced imaging to enable highly accurate interventions, particularly in joint replacement surgeries and spinal surgeries. To ensure the safety and efficacy of these procedures, it is critical that each component of the robotic system is precisely calibrated and verified before interacting with the patient.
[3] A critical requirement in robotic-assisted surgery involves calibration of the robotic arm and verification of a registration tool used for anatomical referencing prior to the surgical procedure. These two steps, although related in the broader surgical ecosystem, serve distinct purposes and are typically performed separately.
[4] The robotic arm calibration process ensures that the robot’s internal coordinate system is accurately aligned with the physical surgical environment. In other words, the robot system has an accurate understanding of its own kinematics and spatial positioning. This step typically involves using a calibration tool or fixture with known geometric properties. Through this process, the robotic arm aligns its internal coordinate system with an external tracking system, ensuring that any tool or implant it manipulates will be placed with sub-millimetric accuracy. This process compensates for mechanical tolerances, sensor drift, and variations in tool attachment. Failure to perform precise calibration may result in misalignment, leading to inaccuracies that may compromise patient safety and surgical success.
[5] Separately, the registration tool (or probe), which is used to digitize anatomical landmarks on the patient, is calibrated to ensure that its physical length - particularly the distance from the tracked markers to a probe tip - is accurately known by the navigation system. This step ensures that the tracking system knows the exact tip offset (distance from the tracking markers to the actual tip). Inaccurate tip offset input may result in errors in mapping the patient’s anatomy to preoperative imaging data, which may compromise the overall surgical plan and the patient’s safety.
[6] Conventionally, these steps are performed using separate setups - robotic arm calibration is carried out using a dedicated calibration fixture or reference frame, while probe length verification is conducted using a separate calibration block. The use of separate set-ups for both the steps leads to increased set-up complexity, requiring dedicated time and attention for each calibration sequence. Each setup must be correctly positioned, verified, and maintained throughout the procedure preparation phase, thereby extending an overall preoperative workflow. Both set-ups require precise alignment and testing, often needing technicians or engineers. The two set-ups often require coordination between different teams - for instance, one handling the robotic arm calibration, and another handling the registration tool calibration. Such compartmentalization not only makes the process resource-intensive but also increases the potential for workflow inefficiencies and miscommunication.
[7] For example, for calibrating the registration probe, a technician holds the probe and a tool in front of the tracking system. This step relies heavily on human accuracy and consistency, making it prone to errors. These errors in calibration often lead to compromising the overall accuracy of the robotic system and negatively affect surgical outcomes.
[8] Further, there is a need of separate sterilization and handling protocols for each set-up, as there are two different set-ups for calibration of the robotic arm and the probe. This adds to the logistical burden and increases the chance of cross-contamination or procedural delay.
[9] Therefore, there is a need for a tracking assembly that overcomes disadvantages of the conventional devices.
SUMMARY OF INVENTION
[10] Particular embodiments of the present disclosure are described herein below with reference to the accompanying drawings, however, it is to be understood that the disclosed embodiments are mere examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
[11] The present invention relates to a tracking assembly for a robotic surgery. In an embodiment, the tracking assembly includes a coupling element, a tracking element and a registration probe. In an embodiment, the coupling element includes a holder and a block. The holder is removably coupled to a tool guider of a surgical robot. The block is coupled to the holder. In an embodiment, the block includes a slot extending between a top end and a bottom end of the coupling element. In an embodiment, the tracking element includes a frame and a plurality of first markers. The frame is coupled to the block of the coupling element. The plurality of first markers is coupled to the frame and is arranged in a predefined geometry. In an embodiment, the registration probe includes a shaft at least partially disposed within the slot of the block and a plurality of second markers. The plurality of second markers is coupled to the shaft and is arranged in a predefined geometry. Each second marker is at a predefined distance from a tip of the shaft. Further, each second marker is at a respective predetermined distance from each of the first markers when the registration probe is disposed within the slot of the coupling element.
[12] Further, the present disclosure discloses a calibration method for the robotic surgery. In an embodiment, the method includes coupling the coupling element of the tracking assembly to the tool guider of a surgical robot; coupling the tracking element of the tracking assembly to the block of the coupling element; and inserting the registration probe into the slot of the block. The method further includes determining a distance between at least one of the plurality of second markers provided on the registration probe and at least one of the plurality of first markers provided on the tracking element; verifying a length of the registration probe based upon the determined distance between the at least one second marker and the at least one first marker and a corresponding predefined reference value; and providing an indication indicative of whether the length of the registration is correctly verified or not.
BRIEF DESCRIPTION OF DRAWINGS
[13] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the apportioned drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[14] Fig. 1a depicts a perspective view of a tracking assembly 100, according to an embodiment of the present disclosure
[15] Fig. 1b depicts an exploded view of the tracking assembly 100, according to an embodiment of the present disclosure.
[16] Fig. 1c depicts a cross-sectional view of the tracking assembly 100, according to an embodiment of the present disclosure.
[17] Fig. 2a depicts an exploded view of a tool guider 200, according to an embodiment of the present disclosure.
[18] Fig. 2b depicts coupling between the tool guider 200 and an end effector 50 of a robotic arm, according to an embodiment of the present disclosure.
[19] Fig. 3a depicts an exploded view of a coupling element 300, according to an embodiment of the present disclosure.
[20] Fig. 3b depicts a bottom perspective view of the coupling element 300, according to an embodiment of the present disclosure.
[21] Fig. 4a depicts a perspective view of a locking element of a locking assembly, according to an embodiment of the present disclosure.
[22] Fig. 4b depicts a perspective view of a locking key of the locking assembly, according to an embodiment of the present disclosure.
[23] Fig. 4c depicts a locked state of the holder 310 with the tool guider 200, according to an embodiment of the present disclosure.
[24] Fig. 4d depicts an unlocked state of the holder 310, according to an embodiment of the present disclosure.
[25] Fig. 5a depicts an exploded view of a tracking element 600, according to an embodiment of the present disclosure.
[26] Fig. 5b depicts a rear perspective view of the tracking element 600, according to an embodiment of the present disclosure.
[27] Fig. 6 depicts coupling between the tracking element 600 and the coupling element 300, according to an embodiment of the present disclosure.
[28] Fig. 7 depicts an exploded view of a registration probe 700, according to an embodiment of the present disclosure.
[29] Fig. 8 depicts a perspective view of a tracking system and the tracking assembly 100, according to an embodiment of the present disclosure.
[30] Fig. 9 depicts a flowchart of a method 900 of using the tracking assembly 100, according to an embodiment of the present disclosure.
[31] Fig. 10a depicts a visual representation of a plurality of first markers, a plurality of second markers and the registration probe 700 with an intact tip, according to an embodiment of the present disclosure.
[32] Fig. 10b depicts a visual representation of the registration probe 700 with a damaged tip, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[33] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like. Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[34] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[35] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[36] Furthermore, the described includes, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific includes or advantages of a particular embodiment. In other instances, additional includes and advantages may be recognized in certain embodiments that may not be present in all embodiments. These includes and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[37] The present disclosure pertains to a tracking assembly for robotic surgical device. The tracking assembly of the present invention may be used in the orthopedic surgeries such as, hip, spine, shoulder, knee, etc. In an embodiment, the tracking assembly includes a tool guider, a coupling element and a tracking element.
[38] The coupling element is coupled to the tool guider. The tracking element is coupled to the coupling element. In an embodiment, a registration probe (interchangeably referred to as a probe) is removably coupled to the tracking assembly. Specifically, the probe is removably coupled to the coupling element. The coupling element is designed for easy coupling and decoupling with the tool guide.
[39] The coupling element serves as a common structural interface, ensuring that the spatial arrangement between the tracking element and the probe (specifically, the spatial arrangement between a plurality of first markers provided on the tracking element and the plurality of second markers provided on the probe) remains fixed and stable throughout the procedure. As a result, the proposed calibration assembly eliminates the need for independent calibration fixtures and reduces reliance on manual positioning, which is often a source of setup error in conventional workflows.
[40] By coupling both the tracking element and the probe to the end effector of the robotic arm using the coupling element, the need for separate calibration setups is eliminated. The integrated configuration of the tracking element and the probe provides a common reference frame. In an embodiment, the tracking element helps in calibrating the robotic arm and verifying the probe. Specifically, the tracking element helps a tracking system to determine positions/orientation of the robotic arm and determine the position of a tip of the probe and verify the length of the probe.
[41] The plurality of first markers is provided in a predefined geometry. The predefined geometry of the plurality of first markers is also preset in the tracking system software. The plurality of first markers is detectable by the tracking system, thus helping the tracking system in determining the positions/orientation of the robotic arm. The calibration of the robotic arm ensures that the coordinate system of the robot is accurately aligned with the surgical environment.
[42] The plurality of second markers is provided in a predefined geometry. Each second marker of the probe is provided at a predefined distance from a tip of the probe. The predefined geometry of the plurality of second markers is preset in the tracking system software. Further, the distance between each second marker and each first marker is known and pre-set in the tracking system software. The plurality of second markers is detectable by the tracking system.
[43] Through careful design of the tracking element and the probe, a distance between each second marker and each first marker is predetermined and preset in the tracking system software. The predetermined distances help in determining position/orientation of the robotic arm as well as determine the position of a tip of the probe and verify length of the probe.
[44] Thus, the same tracking assembly is used for both the robot calibration as well as probe verification. The probe verification involves determining the position of a tip of the probe and verify length of the probe. This integration of the tracking element and the probe in the tracking assembly via the coupling element helps in reducing risk of misalignment and minimizing handling-induced variability.
[45] Further, the coupling element reduces the number of separate components, which simplifies sterilization procedures, saves time during setup, reduces operational cost and lowers manpower requirement. Overall, the integrated tracking assembly streamlines the surgical procedure and helps the robotic arm work more accurately and reliably.
[46] Now referring to figures, Fig. 1a depicts a perspective view and Fig. 1b depicts an exploded view of a tracking assembly 100, according to an embodiment. Fig. 1c depicts a cross-sectional view of the tracking assembly 100. The tracking assembly 100 has a first end 100a and a second end 100b. The tracking assembly 100 is coupled to an end effector of a robotic arm (explained later). In an embodiment, the tracking assembly 100 includes a tool guider 200, a coupling element 300 and a tracking element 600. In an embodiment, a registration probe 700 (interchangeably referred to as the probe 700) is removably coupled to the tracking assembly 100. The probe 700 is used to register anatomical points of a patient and/or landmarks, i.e., determining the position of the points or landmarks of a patient’s bone. The tracking assembly 100 helps in calibrating the probe 700 and the robotic arm during a surgical procedure. In an embodiment, the tracking element 600 is provided at the first end 100a. The tracking element 600 helps a tracking and navigation system (hereinafter referred to as a tracking system) to determine positions/orientation of the robotic arm and determine the position of a tip of the probe 700 and verify length of the probe 700 (explained later). Thus, the tracking assembly 100 provides an integrated assembly for performing both of these steps and eliminates the need for separate assemblies as seen in conventional systems.
[47] The coupling element 300 is configured to couple the tracking element 600 with the tool guider 200. The probe 700 is removably coupled to the tracking assembly 100 via the coupling element 300. The coupling element 300 enables integrated assembly of the coupling element 300 and the probe 700 for calibrating both the robotic arm and the probe 700. The tracking assembly 100 is used in surgeries like joint replacement surgeries and spinal surgeries. The coupling element 300 provides an easy coupling and decoupling of the tracking element 600 and the probe 700 with the tool guider 200.
[48] Fig. 2a depicts an exploded view of the tool guider 200, according to an embodiment of the present disclosure. The tool guider 200 is coupled to the end effector of the robotic arm (explained later). According to an embodiment, a surgical tool (e.g., a reamer, a cutter, etc.) is coupled to the tool guider 200 during a surgical procedure. The coupling element 300 is removably coupled to the tool guider 200. The tool guider 200 has a first end 200a and a second end 200b. In an embodiment, the tool guider 200 includes a sleeve 210, a stem 220 and a connector 230. The sleeve 210 and the connector 230 are provided at the first end 200a and at the second end 200b of the tool guider 200, respectively. The stem 220 extends between, and couples, the sleeve 210 and the connector 230 of the tool guider 200.
[49] The connector 230 helps in coupling the tool guider 200 to the end effector of the robotic arm. In an embodiment, the connector 230 has a predefined structure, such as, without limitation, a disc, an annular ring, etc. In an embodiment, the connector 230 has a disc-like structure. The connector 230 is coupled to the end effector of the robotic arm using techniques, such as, without limitation, threaded coupling, snap-fit, press-fit, welding, etc. In an embodiment, the connector 230 is coupled to the end effector of the robotic arm using threaded coupling mechanism.
[50] The connector 230 has a predefined outer diameter and a predefined thickness ranging between 35 mm and 80 mm, and 5 mm and 20 mm, respectively. In an embodiment, the predefined outer diameter and the predefined thickness of the connector 230 are 63 mm and 10 mm, respectively. The connector 230 may be made of material, such as, without limitation, medical grade stainless steel (SS 304, SS 316, SS 174-PH), etc. In an embodiment, the connector 230 is made of medical grade stainless steel 174-PH.
[51] In one embodiment, a periphery of the connector 230 is threaded, though it may be semi-threaded. The threads on the periphery of the connector 230 are configured to mate with one or more internal threads (not shown) provided on the end effector 50 of the robotic arm, as shown in Fig. 2b.
[52] The connector 230 has a first face 230a and a second face 230b. The connector 230 includes a central cavity 233 provided on the first face 230a. The central cavity 233 is configured to receive the stem 220 of the tool guider 200. The stem 220 may be fixedly or removably coupled to the connector 230, using techniques, such as, without limitation, threaded coupling, snap-fit, press-fit, welding, etc. In an embodiment, the central cavity 233 includes at least one hole 235 configured to receive a pin 240, thereby removably coupling the stem 220 to the connector 230.
[53] The stem 220 has a first end 220a and a second end 220b. The second end 220b of the stem 220 is received by the central cavity 233 and is coupled to the connector 230. In an embodiment, the connector 230 is coupled to the second end 220b of the stem 220 and the end effector 50 of the surgical robot. The stem 220 provides support to the sleeve 210 and the coupling element 300 during calibration. The stem 220 may be straight or may be bent. In an embodiment, a first portion 220c disposed towards the first end 200a is bent at an angle with respect to a second portion 220d disposed towards the second end 200b.
[54] The stem 220 may have a predefined length and diameter ranging between 60 mm and 150 mm, and 15 mm and 50 mm, respectively. In an embodiment, the predefined length and diameter of the stem 220 are 117 mm and 33 mm, respectively. The stem 220 may be made of a material, such as, without limitation, medical grade stainless steel (SS 304, SS 316, SS 174-PH), etc. In an embodiment, the stem 220 is made of medical grade stainless steel 174-PH.
[55] The stem 220 may be solid or may include at least one hole 225. In an embodiment, the stem 220 includes two holes 225 extending longitudinally. In an example implementation, one hole 225 is provided in each of the first portion 220c and the second portion 220d. The holes 225 reduce an overall weight of the tool guider 200.
[56] The sleeve 210 is coupled to the first end 220a of the stem 220.In an embodiment, the sleeve 210 is integrally coupled to the tool guider 200 (i.e., the sleeve 210 and the tool guider 200 form an integrated structure),), though they may be separate components coupled to each other using any suitable technique. This provides structural stability and prevents any bending. The sleeve 210 is configured to receive and couple with the coupling element 300, explained later.
[57] In an embodiment, the sleeve 210 includes a peripheral wall having a cavity 211 extending from a top end 210a to a bottom end 210b of the sleeve 210, thus defining an inner surface 219a and an outer surface 219b of the peripheral wall. The cavity 211 of the sleeve 210 is configured to receive the coupling element 300 and the inner surface 219a mates with the coupling element 300. The stem 220 is coupled to the outer surface 219b of the peripheral wall.
[58] In an embodiment, the peripheral wall of the sleeve 210 includes a gap 215 towards the first end 200a of the tool guider 200, defining a first edge 213a and a second edge 213b. The gap 215 extends from the top end 210a to the bottom end 210b of the sleeve 210. In an embodiment, the peripheral wall is cylindrical resulting in a C-shaped structure for the sleeve 210, though the peripheral wall may have any other shape.
[59] The diameter of the cavity 211 of the sleeve 210 may range between 15 mm and 40 mm. In an embodiment, the diameter of the cavity 211 of the sleeve 210 is25 mm. The length of the sleeve 210 is defined between the top end 210a and the bottom end 210b. An outer diameter of the sleeve 210 may range between 35 mm and 55 mm. The length of the sleeve 210 may range between 40 mm and 60 mm. In an embodiment, the outer diameter and the length of the sleeve 210 are 40 mm and 50 mm, respectively. The width of the gap 215 may range between 10 mm and 20 mm. In an embodiment, the width of the gap 215 is 13.5 mm. The sleeve 210 may be made of one or more materials including, without limitation medical grade stainless steel (SS 304, SS 316, SS 174-PH), polyetheretherketone (PEEK), polyphenylsulphone (PPSU), etc. In an embodiment, the sleeve 210 is made of medical grade stainless steel 174-PH.
[60] Fig. 3a depicts an exploded view and Fig. 3b depicts the bottom perspective view of the coupling element 300, according to an embodiment of the present disclosure. In an embodiment, the coupling element 300 includes a holder 310 and a block 320. The coupling element 300 has a top end 300a and a bottom end 300b, thereby defining a length. The length of the coupling element 300 may range between 45 mm and 60 mm. In an embodiment, the length of the coupling element 300 is 53 mm. The coupling element 300 has a first end 300c and a second end 300d.
[61] The holder 310 is removably coupled to the sleeve 210 of the tool guider 200. In an embodiment, the holder 310 is removably disposed in the cavity 211 of the sleeve 210 of the tool guider 200. In an embodiment, the holder 310 has a generally cylindrical body, though it may have any other structure, such as, without limitation, rectangle, triangle, pentagon, hexagon, etc. The holder 310 is configured to seat within the cavity 211 of the sleeve 210. An outer surface 311 of the holder 310 engages with the inner surface 219a of the sleeve 210. An outer diameter of the holder 310 corresponds to the inner diameter of the sleeve 210.
[62] In an embodiment, the holder 310 includes a rim 335 provided at the top end 300a of the coupling element 300. The rim 335 is configured to abut a top surface of the sleeve 210 when the coupling element 300 is assembled with the sleeve 210.
[63] A diameter of the rim 335 is greater than the inner diameter of the sleeve 210. Consequently, the rim 335 acts as a stopper and prevents the coupling member 300 from falling or slipping out of the sleeve 210. In an embodiment, the diameter of the rim 335 is greater than the outer diameter of the holder 310. The diameter of the rim 335 may range between 10 mm and 40 mm. In an embodiment, the diameter of the rim 335 is 14.5 mm.
[64] In an embodiment, the holder 310 includes a channel 331. The channel 331 extends along an entire length of the holder 310 from the top end 300a to the bottom end 300b of the coupling element 300. The channel 331 helps in locking the holder 310 of the coupling element 300 to the tool guider 200 (explained later).
[65] Additionally, or optionally, the holder 310 may be hollow and includes a cut-out 337. The cut-out 337 extends for at least partial length of the holder 310. In an embodiment, the cut-out 337 extends from the top end 300a to the bottom end 300b of the holder 310. The cut-out 337 reduces an overall weight of the coupling element 300. In one embodiment, an outer periphery 345 of the channel 331 protrudes into the cut-out 337, as depicted in Fig. 3a.
[66] The block 320 extends away from the outer surface 311 of the holder 310 towards the second end 300d. The block 320 extends from the top end 300a towards the bottom end 300b for at least a partial length of the holder 310. In an embodiment, the block 320 extends along the entire length of the holder 310. In an embodiment, the block 320 is integrally coupled to the holder 310. In another embodiment, the block 320 and the holder 310 may be separate components coupled together using a suitable coupling technique, such as, without limitation spring locking, snap locking, press fit and threaded lock, etc. The block 320 may have a pre-defined shape such as cylindrical, cuboidal, tapered, conical, etc. In an embodiment, the block 320 is cubical in shape. The block 320 is disposed (or is seated) within the gap 215 of the sleeve 210 such that the first edge 213a and the second edge 213b of the sleeve 210 abut the block 320. The length and width of the block 320 may range from 15 mm and 70 mm, and 10 mm and 30 mm, respectively. In an embodiment, the length and the width of the block 320 are 53 mm and 13.5 mm, respectively. The block 320 is coupled to the tracking element 600 and the probe 700.
[67] In an embodiment, the block 320 includes a slot 321 extending between the top end 300a and the bottom end 300b of the holder 310 of the coupling element 300. The slot 321 is configured to receive a portion of the registration probe 700, as shown in Fig. 1c. In an embodiment, the slot 321 has a circular cross-section. The diameter of the slot 321 is designed according to the portion of the registration probe 700 that resides within the slot 321 so that the registration probe 700 fits snugly and there are no unwanted movements. The diameter of the slot 321 may range between 4 mm and 8 mm. In an embodiment, the diameter of the slot 321 is 6 mm.
[68] At least one hole 360 is provided on a face A of the block 320 towards the second end 300d of the coupling element 300. The at least one hole 360 is used couple the block 320320 with the tracking element 600. Additionally, or optionally, the face A includes a protrusion 333 and the at least one hole 360 is provided on the protrusion 333. The protrusion 333 is coupled to the tracking element 600 (explained later). In an embodiment, the protrusion 333 is provided with two holes 360.
[69] In an embodiment, the coupling element 300 includes a plug 325. In an embodiment, the plug 325 has a first portion 327 towards a first end 325a of the plug 325 and a second portion 329 towards a second end 325b of the plug 325. The first portion 327 is disposed within and coupled to the slot 321 at the bottom end 300b. A diameter of the first portion 327 is equal to the diameter of the slot 321. In an embodiment, the diameter of the first portion 327 is less than a diameter of the second portion 329. In other words, the diameter of the second portion 329 is more than the diameter of the slot 321. The second portion 329 is configured to abut to a bottom surface of the block 320. The first portion 327 is fixedly or removably coupled to the slot 321. The first portion 327 is coupled to the slot 321 using techniques, such as, without limitation, snap-fit, thread coupling, adhesive coupling, press-fit, etc. In an embodiment, the first portion 327 of the plug 325 includes outer threads 327a configured to mate with corresponding inner threads 323 provided in the slot 321 at the bottom end 300b of the coupling element 300, as shown in Fig. 1c, thereby coupling the first portion 327 and the slot 321 via threaded coupling.
[70] A top surface 330 of the first portion 327 of the plug 325 acts as a resting surface for a tip 733 of the registration probe 700 during the calibration of the registration probe 700. In other words, the tip 733 of the registration probe 700 is configured to rest on a top surface 330 of the first portion 327. The plug 325 may be made of material, such as, without limitation, medical grade stainless steel (SS 304, SS 316, SS 174-PH), etc. In an embodiment, the plug 325 is made of medical grade stainless steel 174-PH.
[71] Figs. 4a and 4b depicts a locking assembly, according to an embodiment of the present disclosure. The locking assembly is coupled to the coupling element 300 and the sleeve 210. The locking assembly ensures secure locking between the coupling element 300 and the sleeve 210 of the tool guider 200 and prevents unintended movement of the holder 310. In an embodiment, the locking assembly includes a resilient member 350, a locking element 400 and a locking key 500. The resilient member 350 and the locking element 400 are disposed within the channel 331.
[72] Fig. 4a illustrates an exemplary locking element 400 according to an embodiment. The locking element 400 partially resides in the channel 331 of the holder 310. The locking element 400 has a first end 400a and a second end 400b. In an embodiment, the locking element 400 includes a shank 420, and a cap 410.
[73] The shank 420 extends between the first end 400a and the second end 400b of the locking element 400, thereby defining a length. The shank 420 resides in the channel 331. The length of the shank 420 corresponds to the length of the channel 331. The length of the shank 420 may range between 40 mm and 70 mm. In an embodiment, the length of the shank 420 is 62.5 mm. The shank 420 is rotatable in the first direction and the second direction to lock or unlock the locking element 400, respectively. The shank 420 may be made of material, such as, without limitation, medical grade stainless steel (SS 304, SS 316, SS 174-PH), polyetheretherketone (PEEK), polyphenylsulphone (PPSU, etc. In an embodiment, the shank 420 is made of medical grade stainless steel 174-PH.
[74] The shank 420 is coupled to the cap 410 at the first end 400a of the locking element 400. In an embodiment, the cap 410 includes a body 411 and one or more wings 413 (hereinafter, wings 413). The body 411 generally has a cylindrical structure, though it may have any other suitable structure. In an embodiment, the cap 410 has two wings 413 provided diametrically opposite to each other on a periphery of the body 411 of the cap 410. The wings 413 and the body 411 are integrally coupled (i.e., the wings 413 and the body 411 form an integrated structure). Alternatively, the wings 413 and the body 411 may be separate components coupled together using any suitable techniques.
[75] In an embodiment, the body 411 includes a cavity (not shown in the figure) for receiving a first end of the shank 420 towards the first end 400a of the locking element 400. The cap 410 is integrally coupled to the shank 420 at a first end 400a of the locking element 400. Alternatively, the cap 410 may be coupled together using any suitable techniques. The cap 410 is disposed on the rim 335 of the holder 310 at the top end 300a of the coupling element 300, while the shank 420 is disposed in the channel 331 of the holder 310. In an embodiment, the cap 410 is disposed on a top surface of the rim 335 of the holder 310. The rotation of the cap 410 causes the shank 420 to rotate in the same direction. The wings 413 enable the user to hold and rotate the cap 410 in an appropriate direction to lock and unlock the locking element 400 from the holder 310 as explained later. The cap 410 may be made of material, such as, without limitation, medical grade stainless steel (SS 304, SS 316, SS 174-PH), Polyetheretherketone (PEEK), polyphenylsulphone (PPSU), etc. In an embodiment, the cap 410 is made of medical grade stainless steel 174-PH.
[76] The second end 400b of the locking element 400 is coupled to the locking key 500. In an embodiment, the shank 420 includes a projection 430 provided at the second end 400b of the locking element 400. In an embodiment, the projection 430 has a hemispherical shape. The projection 430 is configured to engage with the locking key 500.
[77] Fig. 4b depicts an exemplary locking key 500. The locking key 500 is coupled to a second end 400b of the locking element 400. In an embodiment, the locking key 500 includes an aperture 500a. In an embodiment, the aperture 500a is configured to receive the projection 430 of the shank 420. In other words, the projection 430 configured to engage with an aperture 500a of the locking key 500. The projection 430 of the locking element 400 is coupled to the aperture 500a of the locking key 500 using techniques, such as, without limitation, press-fit, snap-fit, welding and threaded, etc. In an embodiment, the projection 430 of the locking element 400 is coupled to the aperture 500a of the locking key 500 using welding.
[78] In an embodiment, the locking key 500 generally has an elliptical shape, though it may have any other suitable shape, such as, without limitation, rectangle, square, circle and hexagon. The locking key 500 is disposed out of the channel 331. In an embodiment, the locking key 500 includes a first portion 500b disposed towards the second end 300d of the coupling element 300 and a second portion 500c disposed towards the first end 300c of the coupling element 300. In an embodiment, the aperture 500a is provided on the first portion 500b of the locking key 500. The second portion 500c is configured to lock the holder 310, preventing it from being removed from the sleeve 210. In an embodiment, the bottom surface 310a of the holder 310 includes a depressed portion 310b and an edge 310c. The depressed portion 310b is provided towards bottom end 300b of the holder 310. The depressed portion 310b is configured to receive the second portion 500c of the locking key 500. The edge 310c acts as a stopper for the locking key 500 and allows the locking key 500 to pivot within a defined range of motion. The depressed portion 310b may be formed using techniques, such as, without limitation, laser cut, computer numerical control (CNC), Electrical Discharge Machining (EDM), vertical machining center VMC machining, etc. In an embodiment, the depressed portion 310b is milled using VMC. The locking key 500 has a length, width and thickness ranging between 5 mm and 25 mm, 5 mm and 20 mm, and 1 mm and 10 mm, respectively. In an embodiment, the length, width and the thickness of the locking key 500 are 11 mm, 7 mm, and 2 mm, respectively. The locking key 500 may be made of material, such as without limitation, medical grade stainless steel (SS 304, SS 316, SS 174-PH), polyetheretherketone (PEEK), polyphenylsulphone (PPSU), etc. In an embodiment, the locking key 500 is made of medical grade stainless steel 174-PH.
[79] The resilient member 350 is disposed around the shank 420 towards the first end 400a of the locking element 400 and beneath the cap 410. The resilient member 350 is disposed in the channel 331 towards the top end 300a of the coupling element 300. In an embodiment, the channel 331 includes a ledge 340 towards the top end 300a of the coupling member 300. The ledge 340 extends radially inward from an inner surface of the channel 331. The resilient member 350 is seated or rested on the ledge 340. Thus, the resilient member 350 is positioned (or disposed) between the ledge 340 and a bottom surface of the cap 410. One end of the resilient member 350 (towards the top end 300a) is coupled to the bottom surface of the cap 410. And, another end of the resilient member 350 (towards the bottom end 300b) is coupled to the ledge 340 provided in the channel 331. In an embodiment, the resilient member 350 is in compressed or semi-compressed state and applies an opposite force on the locking element 400 to keep it in tension in the locked and unlocked state. In an embodiment, the resilient member 350 is a compression spring. The resilient member 350 may be made of material, such as, without limitation, music wire (High Carbon Steel, ASTM A228), ASTM A240 304 stainless steel plate, Stainless Steel (SS302, SS304, SS316), spring steel, etc. In an embodiment, the resilient member 350 is made of ASTM A240 304 stainless steel plate.
[80] The locking assembly is configurable between a locked state and an unlocked state. In the unlocked state, the coupling member 300 and the sleeve 210 are decoupled, and the coupling member 300 can be easily removed (e.g., lifted up) from the sleeve 210. In the locked state, the coupling member 300 is securely coupled to the sleeve 210 of the tool guider 200. The locking assembly is rotatable in one of a first directions or a second direction. In an embodiment, the first direction and the second direction correspond to the clockwise direction and the anticlockwise direction, respectively. The locking assembly is rotated in the first direction to lock the coupling member 300 and the sleeve 210 of the tool guider 200. In an embodiment, in this locked state, the second portion 500c of the locking key 500 abuts a bottom surface of the sleeve 210, which prevents the holder 310 from being taken out of the cavity 211 of the sleeve 210, thereby locking the coupling member 300 with the sleeve 210, as shown in Fig. 4c. Conversely, the locking assembly is rotated in the second direction to unlock the coupling element 300 and the sleeve 210 of the tool guider 200. In an embodiment, in this unlocked state, the second portion 500c of the locking key 500 sits within the depressed portion 310b of the holder 310, as shown in Fig. 4d. This allows the holder 310 to be taken out of the cavity 211.
[81] Additionally, or optionally, a top surface 335a of the rim 335 may include at least one indicator. The at least one indicator is configured to indicate the direction of rotation of the locking element 400 in the first direction and the second direction. The at least one indicator may be any marker that visually indicates the first direction and the second direction to the user. In an embodiment, two indicators (namely, a first indicator 370a and a second indicator 370b) are provided diametrically opposite to each other on the top surface 335a of the rim 335, as shown in Fig. 3a. The first indicator 370a and the second indicator 370b indicate the first direction and the second direction, respectively. In the depicted embodiment, the first indicator 370a and the second indicator 370b are in the form of arrows indicating the respective directions of rotation, though it may have any other suitable shape, size, pattern. In an embodiment, the top surface 335a of the rim 335 includes a third indicator 370c and a fourth indicator 370d indicating the locked state and the unlocked state, respectively of the locking assembly.
[82] The user locks and unlocks the locking element 400 with the help of the cap 410. The cap 410 helps in rotating the shank 420 in one of the first direction or the second direction to lock or unlock. The wings 413 provide firm grip for the user to hold the cap 410.
[83] In response to the rotation of the locking element 400 in the first direction (e.g., clockwise direction), the locking key 500 is configured to rotate in the same direction (i.e., in the first direction) and the second portion 500c of the locking key 500 is configured to abut the bottom surface of the sleeve 210 of the tool guider 200,, thus the coupling element 300 is locked with the sleeve 210 of the tool guider 200. The edge 310c prevents further motion of the locking key 500 in the first direction and thus, acts as a stopper.
[84] In response to the rotation of the locking element 400 in the second direction (e.g., anticlockwise direction), the locking key 500 is configured to rotate in the same direction (i.e., in the second direction).), causing the locking key 500 and the locking element 400 to return to the unlocked state. The second portion 500c of the locking key 500 is configured to sit in the depressed portion 310b of the holder 310. The edge 310c is configured to prevent further motion of the locking key 500 in the second direction. Consequently, the coupling member 300 is unlocked from the sleeve 210 of the tool guider 200. The locking assembly provides an easy means to lock and unlock the coupling member 300 and the sleeve 210, facilitating efficient and simply assembly of the tracking assembly 100 with the tool guider 200. The locking assembly also enables easy unlock.
[85] Figs. 5a-5b depict the tracking element 600, according to an embodiment of present disclosure. In an embodiment, the tracking element 600 includes a plurality of first markers 610, a frame 620, a plurality of first marker cavities 630 and a plurality of first marker caps 640.
[86] In an embodiment, the tracking element 600 includes a plurality of first markers 610 (hereinafter, first markers 610), a frame 620, a plurality of first marker cavities 630 (hereinafter, first marker cavities 630) and a plurality of first marker caps 640 (hereinafter, first marker caps 640).
[87] The frame 620 is configured to provide housing for the first markers 610. The first markers 610 are coupled to the frame 620. The first markers 610 are arranged in a predefined geometry. In an embodiment, the first markers 610 is provided on the frame 620 at a predefined and known distance from each other. In an embodiment, the first markers 610 are arranged in a quadrilateral geometry. A skilled person would appreciate that the predefined distances between the first markers 610 depend upon the dimensions of the frame 620, specific geometry of the first markers 610 and their positions, and are designed based upon requirements. The geometry of the first markers 610 defines a center point representing a center of a frame of reference of the first markers 610. In an embodiment, the center point corresponds to an intersection of lines connecting diagonally opposite first markers 610. In an embodiment, the pointer 650 represent a center of a frame 620 of reference of the plurality of first markers 610, for example, in the form of a hole. The first markers 610 is used to determine positions/orientation of configured to calibrate the robotic arm and verify the probe 700 determine the position of a tip of the probe 700 and verify length of the registration probe 700.
[88] In an embodiment, the tracking element 600 includes three or more first markers 610. In an exemplary embodiment, the tracking element 600 includes four first markers 610. The first markers 610 may be reflectors, radiopaque, ball marker, active marker, etc. In an embodiment, each first marker 610 is a hydro marker that acts as a reflector. In an embodiment, the first markers 610 are spherical in shape, though it may have any other suitable shape. Each first marker 610 has a predefined shape including, but not limited to, spherical, cylindrica, cuboidal, ellipsoid, etc. In an exemplary embodiment, the first marker 610 is spherical in shape. In an embodiment, the diameter of each first marker 610 is 14.5 mm, though the first markers 610 may have any other diameter. In an embodiment, each first marker 610 includes an annular ring 610a. Each first marker 610 is integrally coupled to an annular ring 610a. Alternatively, the first marker 610 and the annular ring 610a are two separate components coupled together using suitable techniques. The annular ring 610a helps in coupling the first marker 610 with the respective first marker cap 640. A diameter of each annular ring 610a is slightly larger than the diameter of the first marker 610. In an embodiment, the diameter of each annular ring 610a is 14.6 mm. In an embodiment, the annular ring 610a is made of polycarbonate resin, though it may be made of any other suitable material.
[89] Each of the first markers 610 is disposed within and is coupled to a respective first marker cap 640. In an embodiment, each first marker cap 640 includes a cavity 640a configured to receive the respective first marker 610. An outer periphery of the annular ring 610a of each first marker 610 is coupled to an inner surface of a corresponding first marker cap 640 using techniques, such as, without limitation, threaded technique press-fit. snap-fit, adhesive-fit, etc. In an embodiment, the outer periphery of the annular ring 610a is coupled to the inner surface of the first marker cap 640 using threaded technique.
[90] The plurality of first marker caps 640 (hereinafter, first marker caps 640) are coupled to the frame 620. Each first marker cap 640 is coupled to a corresponding first marker cavity 630 on the frame 620. An outer periphery of each first marker cap 640 may be threaded, semi-threaded or unthreaded. In an embodiment, as depicted in Fig. 5a, the periphery of each first marker cap 640 is threaded. For example, each first marker cap 640 is provided with external threads 633 configured to mate with internal threads 623 of the corresponding first marker cavity 630 of the frame 620.
[91] Fig. 5B illustrates the frame 620 according to one embodiment. The frame 620 has a predefined shape, such as, without limitation, square, rectangle, circle, oval, etc. In an embodiment, the frame 620 is quadrilateral in shape. In an embodiment, each side 620a of the frame 620 is curved. The curvature of each side may be either concave or convex relative to the center of the frame 620. According to one embodiment, the sides of the frame 620 are concave. In another embodiment, each side of the frame 620 is straight. In an embodiment, corners of the frame 620 are smoothly contoured, each forming a continuous arc that transitions seamlessly from one side to an adjacent side. The frame 620 includes the first marker cavities 630. Positions of the first marker cavities 630 correspond to the position of the respective first marker 610. According to one embodiment, the first markers 610 and the corresponding first marker cavities 630 are disposed at the corners of the frame 620. The first marker cavities 630 may be formed on the frame 620 using technique, such as, without limitation, laser cutting, Computer Numerical Control (CNC), Vertical Machining Center (VMC), etc. In an embodiment, the first marker cavities 630 is engraved on the frame 620 using VMC technique.
[92] Additionally, or optionally, the frame 620 includes a plurality of cut-outs 670. The plurality of cut-outs 670 is configured to reduce an overall weight of the frame 620.
[93] The tracking element 600 is coupled to the coupling element 300 using techniques, such as, without limitation, fastening, snap-fit, press-fit, adhesive bonding, etc. In an embodiment, the tracking element 600 is coupled to the coupling element 300 using fastening (explained later). The frame 620 is fixedly or removably coupled to the coupling element 300, for example, to the block 320. In an embodiment, the frame 620 is removably coupled to the block 320 of the coupling element 300 using, for example, at least one fastener 550 as depicted in Fig. 6. In an embodiment, the frame 620 includes at least one hole 660 for receiving a fastener 550 to couple the frame with the block 320 of the coupling element 300 as shown in Fig. 6. The fastener 550 may include a screw, a pin or the like. In an embodiment, the fastener 550 is a screw. In the depicted embodiment, two holes 660 are provided on either side of a central axis of the frame 620. Each hole 660 is aligned with a corresponding hole 360 provided on the block 320. The at least one hole 660 may be threaded, semi-threaded or unthreaded. In an embodiment, the at least one hole 660 is threaded. Each of the aligned holes 660 and 360 is configured to receive a respective fastener 550, thereby coupling the frame 620 with the coupling element 300.
[94] Additionally, or optionally, in an embodiment, the frame 620 includes a groove 665 provided on a back surface 620b of the frame 620, as shown in Fig. 5B. The at least one hole 660 is provided within the groove 665 of the frame 620. The groove 665 provided on a back surface of the frame 620is configured to mate with the protrusion 333, as shown in Fig. 6. The dimensions of the groove 665 and the protrusion 333 match with each other for a snug-fit. The mating between the groove 665 of the frame 620 and the protrusion 333 of the coupling element 300 prevents rotation/trembling of the frame 620 during the calibration process.
[95] Fig. 7 depicts an exploded view of the probe 700, according to an embodiment of the present disclosure. The probe 700 has a first end 700a and a second end 700b. In an embodiment, the probe 700 is used for registering anatomical points, i.e., determining positions of the points or landmarks. These points are then used to align the pre-operative plan or pre-operative images with the actual patient anatomy. The probe 700 has a predefined length ranging between 100 mm and 450 mm. In an embodiment, the predefined length of the probe 700 is 359.8 mm. The length of the probe 700 directly impacts the accuracy of anatomical localization during the robotic-assisted procedure. In an embodiment, the probe 700 includes a head 710 and a shaft 720 coupled to the head 710.
[96] The shaft 720 generally has an elongated, tubular structure and includes a first end 720a, a second end 720b and a tip 733 at the second end 720b. In an embodiment, the shaft 720 is at least partially disposed within the slot 321 of the block 320. The first end 720a of the shaft 720 is coupled to the probe head 710 using techniques, such as, without limitation, fastening, press-fit, snap-fit, threaded-fit, welding, etc. In an embodiment, the shaft 720 is coupled to the probe head 710 using a fastener 740, such as, a pin. The shaft 720 has a predefined length ranging between 50 mm and 200 mm. In an embodiment, the predefined length of the shaft 720 is 159 mm. In an embodiment, the shaft 720 has a tapered section 722 at the second end 720b. The diameter of the tapered section 722 gradually decreases towards the second end 720b. The tapered section 722 defines the tip 733. The shaft 720 has a tip 733 towards the second end 720b. In an embodiment, the tip 733 is pointed in profile as shown in Fig. 7. In another embodiment, the tip 733 is blunt. During a registration process, a user touches the tip 733 onto a patient’s bone at a plurality of points to register these points. The shaft 720 may be made of a material, including, without limitation, medical grade stainless steel (SS 304, SS 316, SS 174-PH). In an embodiment, the shaft 720 is made of medical grade stainless steel 174-PH.
[97] The probe head 710 is provided towards the first end 700a of the probe 700. In an embodiment, the probe head 710 includes a plurality of second markers 713 (hereinafter, second markers 713), a plurality of second marker caps 715 (hereinafter, second marker caps 715) and a plurality of second marker cavities 711 (hereinafter, second marker cavities 711). The probe head 710 is configured to provide housing for the second markers 713. The second markers 713 help in determining the position of a tip 733 of the probe 700 and verify the length of the probe 700 from the tip 733. The plurality of second markers 713 are coupled to the shaft 720 in a predefined geometry. In an embodiment, the second markers 713 are coupled to the probe head 710. The second markers 713 are placed at predefined and known distances from each other. Similar to the first markers 610, a skilled person would appreciate that the predefined distances between the second markers 713 depend upon the dimensions of the probe head 710, specific geometry of the second markers 713 and their positions, and are designed based upon requirements.
[98] In an embodiment, the probe 700 includes three or more second markers 713. In an exemplary embodiment, the probe 700 includes four second markers 713 arranged in a known geometry. In one embodiment depicted in Fig. 7, two second markers 713 of the second markers 713 are aligned to a longitudinal axis of the registration probe 700. The remaining two second markers 713 of the second markers 713 are positioned in such a way, that the second markers 713 form Y-structure. It should be understood that the arrangement of the second markers 713 depicted herein is merely exemplary and the second markers 713 may be arranged in any other geometry without deviating from the scope of the present disclosure. The second markers 713 may be reflectors, radiopaque, ball marker, active marker, etc. In an embodiment, the second marker 713 is a hydro marker that acts as a reflector, though any other suitable reflector may be employed for the same purpose. The plurality of second markers 713 may have a pre-defined shape such as spherical, cylindrical, cuboid, ellipsoid, etc. In an embodiment, the plurality of second marker 713 is spherical in shape having a diameter of 14.5 mm, though any other diameter may be suitably used.
[99] Each of the second markers 713 is disposed within a respective second marker cap 715. The second marker caps 715 are configured to enclose a respective second marker 713. In an embodiment, the second marker caps 715 are similar to the first marker caps 640 and their structure and function can be referred from that of the first marker caps 640. The same is not repeated for the sake of brevity. The plurality of second marker caps 715 (hereinafter, second marker caps 715) are coupled to the probe head 710. In an embodiment, the second markers 713 are coupled to the second marker caps 715 in a manner similar to the coupling between the first markers 610 and the first marker caps 640.
[100] Each second marker cap 715 comprises a cavity 715a configured to receive a respective second marker 713. In an embodiment, each second marker cap 715 is coupled to a corresponding second marker cavity 711 provided on the probe head 710 using the same techniques that is used for coupling each of the first marker caps 640 to the frame 620. The plurality of second marker cavities 711 may be formed on the probe head 710 using technique, such as, without limitation, laser cut, computer numerical control (CNC), vertical machining center (VMC), etc. In an embodiment, the plurality of second marker cavities 711 is engraved on the probe head 710 using VMC technique.
[101] In an embodiment, the distance between each second marker 713 with other second markers 713 as well as distance between each second marker 713 and the tip 733 of the shaft 720 are known and preset in the tracking system software. Thus, in an embodiment, each second marker 713 is provided at a predefined distance from the tip 733. Each second marker 713 is provided at a respective predetermined distance from each of the first markers 610 when the registration probe 700 is disposed within the slot 321 of the coupling element 300. A person skilled in the art will understand that actual values of the aforesaid predefined distances depend upon specific design parameters of the frame 610 and the probe 700 such as the length of the probe 700, dimensions of the probe head 710 and the frame 620, specific geometries of the first markers 610 and the second markers 713 and so on. The aforesaid distances are used by the tracking system software to determine the position of the tip 733 and the length of the shaft 720. Further, the distance between each first marker 610 and each second marker 713 is predetermined and preset in the tracking system software. The aforesaid predetermined distances are used by the tracking system to determine position and/or orientation of the robotic arm (or the end effector) as well as verify the probe 700. For example, during the calibration process, a tracking system 10 is placed such that the tracking assembly 100 is positioned within a field of view of the tracking system 10 as depicted in Fig. 8. The probe 700 is coupled to the coupling element 300 as explained herein. The tracking system 10 detects the first markers 610 and the second markers 713, and determines respective distances using any technique known in the art. The tracking system 10 determines, using any technique known in the art, the position and/or orientation of the robotic arm based upon the determined distances between the first markers 610 and the corresponding predefined distances. Similarly, the tracking system 10 compares the distance between the second markers 713 and the first markers 610 with the corresponding predefined distances and based upon the comparison, determines whether the length of the probe 700 matches with the predefined length of the probe 700 and the position of the tip 733 corresponds to the predefined position.
[102] Fig. 9 depicts a flowchart of a calibration method 900 for a robotic surgery using the tracking assembly 100, according to an embodiment of the present disclosure. Before or during the surgery, the calibration method 900 is performed for the calibration of the robotic arm and verification of the registration probe 700 with the help of the tracking assembly 100. It should be understood that the robotic arm illustrated herein is merely exemplary. The teachings of the present disclosure are applicable to any other structure of the robotic arm.
[103] At step 901, the tracking assembly 100 is assembled with the robotic arm. In an embodiment, steps 902 – 908 are performed to assemble the tracking assembly 100 with the robotic arm.
[104] For assembling the tracking assembly 100, at step 902, the connector 230 of the tool guider 200 is coupled with the end effector 50 of the robotic arm, as explained earlier. In an embodiment, the tool guider 200 may be pre-assembled with the end effector 50. In this case, the step 902 is not performed.
[105] At step 904, the coupling element 300 is coupled to the tool guider 200. For example, the holder 310 is inserted into the cavity 211 of the sleeve 210. The locking element 400 is rotated in the first direction to lock the coupling element 300 and the sleeve 210 of the tool guider 200. In one embodiment, the tracking element 600 is pre-assembled with the coupling element 300. This helps in reducing the procedure time. In another embodiment, the tracking element 600 and the coupling element 300 are not pre-assembled, in which case, the step 906 is performed.
[106] At step 906, the tracking element 600 is coupled to the block 320 of the coupling element 300, as explained earlier. For example, the protrusion 333 of the block 320 is inserted into the groove 665. The fasteners 550 are then inserted through the respective holes 660 and 360.
[107] At step 908, the probe 700 is inserted into the slot 321 in the block 320 of the coupling element 300 such that the tip 733 of the probe 700 abuts the top surface of the plug 325. The tip 733 of the probe 700 rests on the top surface of the plug 325.
[108] At step 910, the end effector 50 of the robot is calibrated with the help of the tracking element 600. The first markers 610 are detected by tracking system 10 having tracking sensors 30 (e.g., infrared cameras or electromagnetic field generator). The tracking system 10 is placed at a distance from the robot such that the tracking assembly 100, specifically, the first and second markers 610, 713 are in the field of view of the tracking sensors 30 as shown in Fig. 8. A distance between at least one of a plurality of second markers 713 provided on the registration probe 700 and at least one of a plurality of first markers 610 provided on the tracking element 600 are determined.
[109] The tracking system 10 is configured to detect the three-dimensional position and orientation of the first markers 610. For example, the tracking system 10 determines the 3D position and orientation of the first markers 610 based upon the detected distance between the first markers 610 and the corresponding predefined distances. The tracking system 10 uses the first markers 610 to track the real-time motion of the robotic arm. Once the position and orientation of the first markers 610 are known, the tracking system 10 computes a transformation matrix. The transformation matrix transforms an internal coordinate system of the robot to a coordinate system of the tracking system 10. The transformation matrix allows the robot to move the effector end 50 accurately in physical space in alignment with image data. The tracking system 10 employs any technique known in the art to perform aforesaid functions.
[110] At step 912, the registration probe 700 is verified. More specifically, the tip 733 of the probe 700 and the length of the probe 700 is verified before it is employed in verifying the anatomical structure of the patient. The verification of the length of the probe 700 helps to identify the intactness of the probe 700. In other words, the verification of the length of the probe 700 helps in identifying whether the length of the probe 700 is intact or is worn/damaged (for example, damaged tip 733, or the shaft 720 of the probe is bent), or whether a correct or a wrong probe 700 is being used.
[111] The length of the probe 700 is verified using a measured/determined distance between at least one second marker 713 and at least one first marker 610, and a corresponding predefined (also, referred to as reference) value for that distance. In an embodiment, more than one such pair of first marker 610 and the second marker 713 are used to improve robustness and accuracy of the verification.
[112] In an embodiment, the tracking system 10 determines the position of the second markers 713 and the first markers 610 in the coordinate system of the tracking system 10 using any technique known in the art. The tracking system 10 computes or determines the distance between at least one pair including one first marker 610 and one second marker 713.
[113] The tracking system software maintains reference or predefined values of the distance between each of the second markers 713 on the registration probe 700 and each of the first markers 610 on the tracking element 600.The tracking system software compares the detected distance for the at least one pair and the corresponding reference value. The tracking system 10 verifies the probe 700 based upon the comparison. When the determined/detected distance matches with the corresponding reference value, it is determined that the length of the probe 700 is correct, i.e., the length of the probe 700 is verified correctly. In other words, the tracking system is configured to provide an indication indicative of whether the length of the registration probe 700 is correctly verified or not. When there is a deviation between the determined distance and the corresponding reference value, it is determined that the length of the registration probe 700 is not correct – either because the registration probe 700 that is inserted has a different length than the preset length value, the shaft 720 of the registration probe 700 is bent and/or the tip 733 of the registration probe 700 is damaged. This is illustrated using two examples visually depicted in Figs. 10a and 10b.
[114] Example 1:
[115] In this example, a predefined distance between one first marker (indicated by M1) of the first markers 610 provided on the tracking element 600 and one second marker (indicated by M2) of the second markers 713 provided on the registration probe 700, as shown in Fig. 10a, is used to verify the length of the registration probe 700. Consider, for example, that the predefined distance, i.e., the reference value, for the distance between the markers M1 and M2 is X.
[116] In one example situation, the detected distance between the first marker (M1) and the second marker (M2) is X, as shown in Fig 10a. In this example, the detected distance between the markers M1 and M2 matches with the corresponding reference value predefined in the tracking application.. The tracking system 10 therefore determines that the tip 733 of shaft 720 is intact and the length of the registration probe 700 is accurate. In an embodiment, the tracking system 10 provides an indication (e.g., textual, visual, audio or the like) to the user on a navigation user interface that the probe 700 is correctly verified. For example, the tracking system 10 may display a green flag on the user interface indicating that the verification is successful.
[117] Example 2:
[118] Similar to the Example 1, the predefined distance between the first marker (M1) and the second marker (M2) is used for the verification step. As described earlier, the reference value for this distance is X. Unlike the Example 1, in this example, the detected distance between the markers M1 and M2 is X1, as shown in Fig. 10b. The tracking application determines that X1 is shorter than the reference value X preset in the tracking application. This deviation in the distance between the first marker (M1) and the second marker (M2) indicates that either the probe 700 has a different length and/or the tip 733 of the probe 700 is damaged and/or the shaft 720 may be bent. Consequently, the tracking application determines that the probe 700 is not verified correctly. Accordingly, the tracking system 10 may provide an indication (e.g., display a red flag) on the navigation user interface to indicate that the verification of the probe 700 has failed.
[119] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. , Claims:WE CLAIM:
1. A tracking assembly (100) for a robotic surgery, the tracking assembly (100) comprising:
a. a coupling element (300) comprising:
i. a holder (310) removably coupled to a tool guider (200) of a surgical robot,
ii. a block (320) coupled to the holder (310), the block (320) comprising a slot (321) extending between a top end (300a) and a bottom end (300b) of the coupling element (300);
b. a tracking element (600) comprising:
i. a frame (620) coupled to the block (320) of the coupling element (300); and
ii. a plurality of first markers (610) couple to the frame (620) and arranged in a predefined geometry; and
c. a registration probe (700) comprising:
i. a shaft (720) at least partially disposed within the slot (321) of the block (320) and having a tip (733););
ii. a plurality of second markers (713) coupled to the shaft (720) and arranged in a predefined geometry, each second marker (713) is at a predefined distance from the tip (733);
wherein, each second marker (713) is at a respective predetermined distance from each of the first markers (610) when the registration probe (700) is disposed within the slot (321) of the coupling element (300).
2. The tracking assembly (100) as claimed in claim 1, wherein the holder (310) of the coupling element (300) is removably disposed in a cavity (211) of a sleeve (210) of the tool guider (200).
3. The tracking assembly (100) as claimed in claim 2, wherein the tracking assembly (100) comprises:
a. a locking element (400) comprising:
i. a shank (420) disposed within a channel (331) provided in the holder (310); and
ii. a cap (410) coupled to the shank (420) at a first end (400a) of the locking element (400) and disposed on a rim (335) provided on the holder (310) at the top end (300a) of the coupling element (300);
b. a locking key (500) coupled to a second end (400b) of the locking element (400) and disposed out of the channel (331);
wherein, the rim (335) is configured to abut a top surface of the sleeve (210) of the tool guider (200);
wherein, in a locked state, the locking key (500) is configured to abut a bottom surface of the sleeve (210).
4. The tracking assembly (100) as claimed in claim 3, wherein the shank (420) comprises a projection (430) provided at the second end (400b) of the locking element (400) and configured to engage with an aperture (500a) of the locking key (500).
5. The tracking assembly (100) as claimed in claim 3, wherein the tracking assembly (100) comprises a resilient member (350) disposed around the shank (420) towards the first end (400a), and disposed between a bottom surface of the cap (410) and a ledge (340) provided in the channel (331).
6. The tracking assembly (100) as claimed in claim 2, wherein the tool guider (200) comprises:
a. a stem (220);
b. a connector (230) coupled to a second end (220b) of the stem (220) and an end effector (50) of the surgical robot; and
wherein the sleeve (210) is coupled to a first end (220a) of the stem (220) and comprises a gap (215) between a first edge (213a) and a second edge (213b) of the sleeve (210););
wherein, the block (320) is disposed within the gap (215).
7. The tracking assembly (100) as claimed in claim 1, wherein the coupling element (300) comprises a plug (325) having:
a. a first portion (327) disposed within and coupled to the slot (321);); and
b. a second portion (329) abut a bottom surface of the block (320);
wherein, the tip (733) of the registration probe (700) is configured to rest on a top surface (330) of the first portion (327).
8. The tracking assembly (100) as claimed in claim 1, wherein the frame (620) comprises a pointer (650) representing a center of a frame of reference of the plurality of first markers (610).
9. The tracking assembly (100) as claimed in claim 1, wherein the tracking element (600) comprises a plurality of first marker caps (640) coupled to the frame (620), each of the plurality of first marker caps (640) comprises a cavity (640a) configured to receive a respective first marker (610).
10. The tracking assembly (100) as claimed in claim 1, wherein the registration probe (700) comprises a plurality of second marker caps (715) coupled to a probe head (710) coupled to the shaft (720), each of the plurality of second marker caps (715) comprises a cavity (715a) configured to receive a respective second marker (713).
11. The tracking assembly (100) as claimed in claim 1, wherein the block (320) comprises
a. a protrusion (333) provided on a face (A) of the block (320) and configured to mate with a groove (665) provided on a back surface (620b) of the frame (620); and
b. at least one hole (360) provided on the protrusion (333) aligned with at least one hole (660) provided on the frame (620), each of the aligned holes (360, 660) configured to receive a respective fastener (550).
12. The tracking assembly (100) as claimed in claim 1, wherein the holder (310) comprises a cut-out (337) extending for at least a partial length of the holder (310).
13. A calibration method (900) for a robotic surgery, the method (900) comprising:
a. coupling a coupling element (300) of a tracking assembly (100) to a tool guider (200) of a surgical robot;
b. coupling a tracking element (600) of the tracking assembly (100) to a block (320) of the coupling element (300);
c. inserting the registration probe (700) into a slot (321) of the block (320);
d. determining a distance between at least one of a plurality of second markers (713) provided on the registration probe (700) and at least one of a plurality of first markers (610) provided on the tracking element (600);
e. verifying a length of the registration probe (700) based upon the determined distance between the at least one second marker (713) and the at least one first marker (610) and a corresponding predefined reference value; and
f. providing an indication indicative of whether the length of the registration probe (700) is correctly verified or not.
14. The method as claimed in claim 13, wherein the step of coupling the coupling element (300) with the tool guider (200) comprises:
a. inserting the holder (310) into a cavity (211) of a sleeve (210) of the tool guider (200); and
b. rotating a locking element (400) in a first direction to lock the coupling element (300) and the sleeve (210) of the tool guider (200).
15. The method as claimed in claim 13, wherein the step of coupling the tracking element (600) with the block (320) of the coupling element (300) comprising:
a. mating a protrusion (333) provided on the block (320) and a groove (665) provided on a frame (620) of the tracking element (600); and
b. inserting a fastener (550) through a hole (660) provided on the frame (620) and a corresponding hole (360) provided on the block (320).
16. The method as claimed in claim 13, wherein the step of verifying the length of the registration probe (700) comprises:
a. comparing the determined distance between the at least one second marker (713) and the at least one first marker (610) and the corresponding predefined reference value;
b. determining that the length of the registration probe (700) is correctly verified when the determined distance between the at least one second marker (713) and the at least one first marker (610) matches with the corresponding predefined reference value; and
c. determining that the length of the registration probe (700) is not correctly verified when the determined distance between the at least one second marker (713) and the at least one first marker (610) deviates from the corresponding predefined reference value.