System for surgical tracking

FIELD OF THE INVENTION

The present invention relates to system for surgical tracking. More particularly, the invention discloses a system for surgical tracking of predetermined target in a reference object using novel tracker.

BACKGROUND OF THE INVENTION

The success of surgical procedure lies on various factors which includes minimum invasiveness and accurate positioning of the surgical instruments and implants with respect to the patient anatomy. In order to achieve accuracy during surgery, a surgeon often takes the assistance of surgical navigation systems.

Surgical navigation involves real time computerized monitoring of the spatial position as well as orientation of the tracking elements around implantation site with respect to certain key anatomical landmarks during surgery. The minimum invasiveness and ability to correctly pinpoint the position of the surgical object with respect to the patient at any instant of time are the hallmark of these surgical navigation systems.

Surgical navigation systems generally comprise of computer systems which include sensors to detect, track or monitor the tracking elements attached in predetermined relationship with regard to the surgical site. Surgical navigation system usually employs markers which are fixed on the surgical instruments as a reference marker in order to ascertain their position in the complex background of the implantation site. These markers may be passive markers which are essentially reflecting or retro- reflecting markers, and active markers which include light emitting markers, or magnetic markers which are constantly sending information to the main system.

The advantage of an active marker over the passive marker is that it allows communication directly from the sterile area to capture discrete point / area of an anatomy without the need of an additional person at the computer station(outside the sterile field) to manually accept the comment and feed the input.

The state-of-art tracking technologies employing active tracking (as described in US 20010034530 Al) typically uses infra-red or other non- visible optical tracking technology. However active tracking requires power inputs typically a sterile battery which adds cost and complexities to the surgery.

Another US patent application "US 20110254922" discloses a system for detecting a position of an object such as a surgical tool in an image guidance system which includes a camera system with a detection array for detecting visible light, a processor arranged to analyze the output from the array. Each object to be detected carries a single marker with a pattern of contrasted areas of light and dark intersecting at a specific single feature point thereon. The pattern includes components arranged in an array around the specific location arranged such that the processor is able to detect an angle of rotation of the pattern around the location and which are different from other markers of the system such that the processor is able to distinguish each marker from the other markers.

The main disadvantage of this method is that the pattern of contrast is always visible to the camera system at all time. This causes a problem to the surgeon to identify and detect the trackers specific to the surgical target. There is neither the provision to detect and input a discreet event nor does a possibility of providing input by the surgeon during surgery. This therefore requires an additional person to manually input the data to record the discrete position of the tracker.

OBJECT AND SUMMARY OF THE INVENTION:

In order to obviate the drawbacks of the current state of the art, the main object of the present invention is to provide system for surgical tracking/ navigation which is capable of identifying and capturing the desired or predetermined target point in reference object such as position of the surgical object specific landmarks of patient anatomy, position of surgical instruments at any instant during surgical procedure..

Accordingly, the present invention provides system for surgical tracking, system comprising of surgical tracking unit and trackers. The tracker may be complex 2D image sticker or may be simple or complex image sticker or may be representation of the image displayed on the electronic display screen. These trackers can be a multilayer image that can be modified via mechanical means to display a specific pattern at any given time in the surgery. The tracker can be of multiple layer sterile sheets, with the lower sticker sheet opaque and upper sheet partially transparent so as the lower sheet information can be revealed when the trigger is pressed.

The trackers can also be made of all metal or plastic such that when the lower and the upper layer are aligned at a specific location, a pattern is generated that is recognizable by the tracking unit. The marking on these patterns can be made of but not limited to laser marking, embossing, window opening and could be of different colors for easy detection. The trackers are also capable of taking inputs from the surgeon at any given time to record or capture a specific position at any moment during surgery.

These trackers may be passive trackers, wherein they have inbuilt mechanism to change their image shape so that they may show a particular tracking pattern or tracker shape at any instant of time to identify the target which could have been lost in the image of neighboring tracker in the vicinity of target scheduled for surgery, this can be similar to but not limited to Quick Response (QR) code image.

The surgical navigation/ tracking unit is capable of identifying or recognizing the particular tracking pattern on the tracker. When that particular pattern appears on tracker, surgical tracking unit detects the target position which may be a landmark on anatomy or specific position of surgical instrument.

Accordingly the present invention relates to system for surgical tracking to identify the predetermined target point in the reference object. The system is comprises of at least one surgical tracking unit and at least one tracker. The surgical tracking unit comprises of at least one sensor, at least one processing unit and at least one memory unit. The said system further comprises of tip to identify the specific target point of reference object. The tracker having at least two tracking pattern one being unrecognizable to surgical tracking unit, another being recognizable to the surgical tracking unit. At any instant only one pattern is exposed to surgical tracking unit. The tracker further has one inbuilt mechanism which is having at least one trigger. The inbuilt mechanism can alter or change the tracking pattern of the tracker. The said system further may have tip to identify the specific target point. The trigger provides input of the target point of reference object to the surgical tracking unit via inbuilt mechanism by altering tracking pattern to new tracking pattern which is recognizable to the sensor. Upon recognition, the surgical tracking unit captures the positional information of the tip of the tracker in its memory by determining the relative location of tip of the tracker and the sensor in its processing unit thereby enabling it to record at least one target point with in sterile environment during surgical procedure.

BRIEF DESCRIPTION OF THE DRAWINGS:

Fig.lA shows the schematic illustration of tracker as visible by the tracking unit in which the tracker pattern is such that it is not being detected by the tracking unit.

Fig. IB shows the schematic illustration of tracker as visible by the tracking unit in which the tracker pattern is such that it is being detected by the tracking unit and thereby the position of a landmark on patient's anatomy is captured by the tracking system.

Fig.2A shows the schematic illustration of tracker as visible by the tracking unit in which the tracker pattern is such that it is not being detected by the tracking unit.

Fig. 2B shows the schematic illustration of tracker as visible by the tracking unit in which the tracker pattern is such that it is being detected by the tracking unit and thereby the position of a specific landmark on patient's anatomy is captured by the tracking unit.

Fig. 2C shows the schematic illustration of tracker as visible by the tracking system in which the tracker pattern is such that it is being detected by the tracking unit and thereby the position of another landmark on patient's anatomy is captured by the same tracking unit. DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE DRAWINGS AND ILLUSTRATED WITH EXAMPLES:

The present invention relates to system for surgical tracking which comprises of surgical tracking unit and tracker. The tracker can be used to accurately detect the surgical objects which may be important reference of patient anatomy or may be specific instrument position or position of implant with reference to the anatomy of the patient during surgery.

The term "tracking pattern" herein interchangeably referred as trackable element and/ or pattern. The term "surgical navigation unit" herein interchangeably referred to as surgical tracking unit or navigation unit or tracking unit. The term "trackers" herein interchangeably referred as "novel trackers" or tracking unit. The term "Reference object" is used interchangeably with the surgical objects.

In a preferred embodiment, the present invention discloses a tracker having trackable element. The tracker is capable of being connected to an anatomical part of body of a patient. Further it can be attached to an instrument to be used by the surgeon during a surgical procedure as well as can act as an independent tracker to identify discrete landmarks of patient's anatomy. The trackers are passive and the surgeon may configure multiple said trackers to capture important information about patient's anatomy and / or implant system position information.

The trackers of the present invention may be similar in configuration and features. The trackers of the present invention has the capability of displaying a unique pattern which is recognizable to the tracking unit for a given time duration. This makes the trackers capable of communicating wirelessly to the tracking unit sensors without the use of any energy. Further, the trackers also have the capability of displaying multiple such patterns allowing it to communicate with the tracking unit for multiple anatomical landmarks of the patients or surgical instrument position.

In another embodiment the present invention may be used for various surgical procedures including but not limited to arthroplasty, sinus surgery, spinal surgery, trauma surgeries, brain surgery, as well as Neuro surgery

In yet another embodiment, the trackers of the present invention may also capture one or more patient position information during the surgery and use that information at a later state to accurately position the implant systems.

In yet another embodiment, the present invention may also be used for diagnostics either alone or in combination.

The process of the present invention may also be configured to be used for various diagnostic procedures.

The systems and the devices of the present invention can be easily placed in a sterile zone. Further, the systems and the devices of the present invention require minimal set up.

Fig 1A, IB, 2A, 2B and 2C depict the schematic view of the system for surgical tracking. As depicted in Figure 1A , IB, 2A, 2B and 2C system for surgical tracking comprises of surgical tracking unit(200) and tracker (100,400).

The surgical navigation/ tracking unit (200) comprises of at least one sensor (201) which may inbuilt digital camera sensor, at least one processor (202), least one memory unit (203), at least one display unit (204) and at least one input unit (205).

Fig 1A illustrates the tracker (100) having tracking pattern (120) which is unrecognizable to surgical tracking unit (200) indicating its non-active state while Fig IB illustrates the same tracker (100) having tracking pattern (121) which is recognizable to surgical tracking unit (200) indicating its active state. The tracker (100) may further comprise of holding grip (104), a tip (101) to identify the target point such as anatomical landmark (301) for the patient anatomy (300) and sliding mechanism (102) underneath the pattern (120), such that part of pattern is hidden until the trigger (103) is activated.

As shown in Fig IB, during surgery surgeon provides the input of specific landmark (301) of the patient's anatomy (300) to the sensor (201) of the surgical tracking unit (200) by pressing the trigger (103). On activation, the sliding mechanism (102) repositions to create a new pattern (121) which is recognizable to the sensor (201) of the surgical tracking unit (200). Once detected, the surgical tracking unit (200) using its processing unit (202) and its memory (203) determines the relative location of sensor (200) and the tip (101) of the tracker (100). The surgical tracking unit (200) captures this positional information of tip (100) into its memory (202) which in turn enables it to identify and record specific surgical land mark (301) of the patient anatomy (300). The recorded information or runtime information of about the specific landmark or position of the instrument can be accessed by the surgeon at any instant of time using display (204) and input (205).

Fig. 2A illustrates another tracker (400) with another tracking pattern (420). The sensor (201) of the surgical tracking unit (200) is not able to recognize this pattern (420). Fig 2B and Fig 2C illustrate the tracker (400) with tracking pattern recognizable to surgical tracking unit (200).

The tracker may comprise of a tip (401) to identify the anatomical landmark (301) and sliding mechanism (402) underneath the pattern (420) such that part of the pattern is hidden until the trigger (403) is activated. As shown in Fig 2B the surgeon provides input of a specific landmark (301) of the patient's anatomy (300) to the sensor (201) of the surgical tracking unit (200) by pressing the trigger (403) of the tracker in one direction. On activation, the sliding mechanism (402) of the tracker (400) repositions to create a new pattern (421) which is recognizable to sensor (201) of the surgical tracking unit (200). Upon detection, the surgical tracking unit using it's processing unit (202) and its memory (203) determines the relative location of sensor (201) and the tip (401) of the tracker (400).

The surgical tracking unit (200) stores this positional information of tip (401) into its memory (202) which enables it to identify and record the specific land mark (301) of the patient anatomy (300).

In another embodiment the same tracker (400) can be used to determine multiple landmarks of the patient's anatomy. As shown in Fig 2C, surgeon provides the input by pressing the trigger (403) in another direction, due to which the sliding mechanism (402) repositions to create a new pattern (422) which is also recognizable to the sensor (201) of the surgical tracking unit (200). Once detected, the surgical tracking unit (200) using it's processing unit (202) and memory (203) determines the relative location of sensor (200) and the tip of the tracker (401). The surgical processing unit stores this positional information in its memory and utilizes the same to identify and record another specific landmark (302) of the patients anatomy (300).

This tracker may contain a static component of the pattern and a movable component of pattern, such that when an input is provided by the surgeon using any type of mechanism (102,402), it moves the movable component to the specified location thereby creating new recognizable pattern.

Tracker pattern (120) (121) (420) (421) (422) can be made of sterile plastic or stickers that can be used only once or can have multiple usage. The pattern can also be made of metal with certain portion etched or embossed or laser marked or processed to create a contrast onto the surface such that it is visible by the sensor of the tracking system. The pattern which is formed by metal or plastic sheet, the tracker comprising of at least two layers : upper layer and lower layer each bearing sticker in a manner that upper layer is partially transparent and lower layer is opaque such that when trigger is pressed either said upper layer or lower layer repositions to expose the said lower layer thereby generating new pattern which is recognizable to the surgical tracking unit.

BEST MODE OF OPERATION:

In hip arthroplasty procedure, alignment of the cup implant that is received by the pelvic bone is very critical. Any in correct position of cup may lead to dislocation of joint, leg length discrepancy, poor loading condition and thereby resulting into failure of the implant system and require expensive and extremely skilled revision surgery by expert surgeons. To accurately place the cup into pelvis, mechanical instrument is used, however the accuracy of these mechanical instruments is limited. Navigation systems do provide some accuracy but are expensive and cumbersome to use.

The cup placement procedure is divided into two or three stages depending upon the type of implant used. In case of cemented cup implant, the acetabulum is reamed using a reamer as a first step and then a cup is placed along with cement. While in un-cemented press-fit implant, the acetabulum is reamed and then the cup is press-fitted onto the bone using an impaction.

In the present invention, surgeon identifies and registers the key landmark (301,302) of patient anatomy (300) such as the patient's neutral pelvic plane, acetabulum rim and other key anatomical landmarks in the surgical tracking unit (200) with the help of novel trackers (100,400). These landmarks are then processed by tracking unit to better understand the patient's anatomy and spatial location relative to the sensor such as camera, this in turn helps to determine the optimal position of the implant for that patient.