WO2015079456A2

WO2015079456A2 - An optical needle tracking system and method for image guided percutaneous biopsy procedure

Info

Publication number: WO2015079456A2
Application number: PCT/IN2014/000735
Authority: WO
Inventors: Anand Jayanthi; Gururajan Kumar; Roy Santosham Dr.
Original assignee: Tuscano Equipments Private Limited
Priority date: 2013-11-28
Filing date: 2014-11-27
Publication date: 2015-06-04
Also published as: IN2013CH03823A; WO2015079456A3

Abstract

The embodiments herein provide an optical needle tracking system and a method for image guided percutaneous biopsy procedure with little patient compliance, minimal radiation exposure and reduced needle pass. The optical needle tracking system comprises a plurality of cameras, a processor, a display unit, a plurality of markers, medical imaging equipment such as a CT scanner and a camera positioning system. The plurality of markers is placed on the ROI of the patient's body which assists in acquiring the breathing pattern of the patient. The plurality of cameras captures the real time images and is controlled by the camera positioning system. The processor controls the entire operation of the optical needle tracking system.

Description

AN OPTICAL NEEDLE TRACKING SYSTEM AND METHOD FOR IMAGE GUIDED PERCUTANEOUS BIOPSY PROCEDURE

A) CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the priority of the Indian Provisional Patent Application entitled, "Optical Needle Tracking System and Method for Image Guided Percutaneous Biopsy Procedure" with serial number 3823/CHE/2013, filed on August 28, 2013, post-dated to 28 November, 2013, the content of which is incorporated by reference herein.

B) TECHNICAL FIELD

[0002] The embodiments herein generally relate to medical devices and particularly relate to an improved system and method for a percutaneous biopsy. The embodiments herein more particularly relate to a real time needle tracking system and a method for performing a percutaneous biopsy procedure with a minimal patient compliance, reduced radiation exposure and reduced needle pass.

C) BACKGROUND OF THE INVENTION

[0003] A Percutaneous biopsy is recognized to be a safe, effective procedure. Successful percutaneous needle biopsy has been applied in most of the organs with excellent results and few complications. The key to the percutaneous biopsy procedures has been the use of imaging guidance systems, such as Computer Tomography (CT), Magnetic Resonance Imaging (MRI), ultrasound, etc., which allows for a safe passage of a needle into an organ or mass, to obtain a tissue for the cytologic or histologic examinations. The image guided percutaneous biopsy is less invasive than an open exploration performed to obtain the same tissues.

[0004] In the developing countries like India, nearly 71 % of deaths occurred in people at the age group of 30 - 69 are due to Cancer. The three most common fatal cancers found at the age of 30-69 years, are oral (including lip and pharynx) cancer with 22.9%, stomach cancer with 12.6%, and lung (including trachea and larynx) cancer with 1 1.4% in men, and cervical cancer with 17.1%, stomach cancer with 14.1 %, and breast cancer with 10.2% in women. Because of the lower morbidity and mortality of the non-invasive procedures, they can be applied to the patients easily in the above age group. Among the existing imaging guidance systems, CT guided needle biopsy is the most dominant method of obtaining tissue samples from the organs in a patient.

[0005] A tissue sampling accuracy and a patient safety are the critical issues in the CT biopsy. An accurate needle placement depends on the skill of the radiologist, patient compliance (breathing) and a size & location of an organ itself. The complications due to an inaccurate needle placement are bleeding, infection, peritonitis in case of abdominal procedure etc. Moreover, it is necessary for the patient to repeatedly hold his breathing during a needle insertion process to achieve a safe & accurate biopsy. Breath holding and remain still during a procedure can be significant problem, when the lesion is smaller. Respiratory motion poses a considerable problem in the CT-guided biopsy of the lung or upper abdomen in which the structures can vary in position from 1 to 6 cm in the superior-to-inferior direction during a normal breathing. In spite of following the specific breath-hold instructions, the ability to reproduce the consistent levels of suspended inspiration or expiration on command is a challenge for many patients and especially for the people above 50 yrs.

[0006] In most of the conventional systems, breathing is not monitored and as a result the radiologist has to ensure a needle entry point and the needle angulations by means of repeated check scans which result in more radiation exposure and needle pass. In addition to this, it is necessary for the patient to repeatedly hold his breathing and not to make any bodily movement (physical movement) during every check scan and needle insertion, which is difficult for 90% of patients especially for elderly and paediatric patients.

[0007] Most of the existing systems lack a real time tracking mechanism for the patient body plane movements due to breathing. As a result, the radiation exposure is increased and the number of needle pass is also increased especially for moving targets. There also exist a lot of image guided robots to assist the image guided percutaneous procedures which provide a robotic needle alignment but only a few systems are equipped with a respiratory tracking mechanism. But these tracking mechanism are confined to a single plane movement and do not measure all body plane movements.

[0008] Hence, there is a need for a system for tracking the alignment of needle in an image guided percutaneous biopsy. Also, there is a need for a system and method for monitoring and tracking a breath movement of a patient in all planes for an effective biopsy procedure. Further, there is a need for a system and method for tracking a needle angulation and deciding an insertion depth based on the patient breathing phase. Still further, there is a need for a system and method to perform a biopsy procedure with little patient compliance, reduced radiation exposure and reduced needle pass.

[0009] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.

D) OBJECT OF THE INVENTION

[0010] The primary object of the embodiments herein is to provide a real time optical needle tracking system and a method for aiding a medical practitioner in an image guided percutaneous biopsy.

[001 1] Another object of the embodiments herein is to provide a method and system for tracking a breath movement of a patient in a plurality of body planes and guiding the medical practitioner for inserting a needle.

[0012] Yet another object of the embodiments herein is to provide a method and system for tracking the needle angulations and estimating an insertion depth based on the patient breathing phase.

[0013] Yet another object of the embodiments herein is to provide a plurality of cameras for capturing the images of a region of interest (ROI) at different field of views (FOV) and constructing a three dimensional (3D) image. [0014] Yet another object of the embodiments herein is to provide a method and system for performing the biopsy procedure with a little patient compliance, reduced radiation exposure and reduced needle pass.

[0015] These and other objects and advantages of the embodiments herein will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

E) SUMMARY OF THE INVENTION

[0016] The embodiments herein provide a real time optical needle tracking system and method in a percutaneous biopsy procedure.

[0017] According to an embodiment herein, a real time optical needle tracking method in a percutaneous biopsy procedure is provided. According to one embodiment herein, the method comprises the following steps. A patient is subjected to X-ray sonogram to obtain a scanogram image to localize body structures or a region of interest (ROI) for subsequent computer tomography (CT) scans and to display the locations of acquired CT slices. A desired ROI is selected from the scanogram. The selected ROI of the patient is aligned to a field of view (FOV) of a plurality of cameras. A plurality of first reference markers is pasted in the selected ROI region on a body of the patient body. The patient is instructed to do breathing and to hold the breath at a comfort level. A movement of the plurality of the first reference markers is captured by the plurality of cameras in a plurality of planes. A movement of the plurality of the first reference markers is captured by the plurality of cameras in all planes during normal breathing. The patient is scanned at the selected ROI with an imaging process. A slice number and an entry point are input in an imaging device based on the imaging process. A couch is moved and positioned to a required slice by the imaging system. A needle insertion point is marked with a second marker in the patient body by a radiologist. A check scan is performed to validate a position of the second marker, a needle trajectory and needle angles are calculated from a DICOM image based on the first reference markers and second marker. The calculated needle trajectory and needle angles information is communicated from the imaging device to a processor of an optical tracking system. The calculated needle trajectory and needle angles information is overlaid on a display monitor. The second marker is aligned with the needle entry point either by moving a camera or the couch, based on the calculated needle trajectory and needle angles information displayed on the display screen. The needle orientation is adjusted using a real time image displayed on the display screen, after adjusting the needle insertion point. A needle insertion depth is computed with the processor to guide a medical practitioner to reach a target location, after matching the needle orientation.

[0018] According to an embodiment herein, the selected ROI of the patient is aligned to the field of view (FOV) of the plurality of cameras manually.

[0019] According to an embodiment herein, the movement of the plurality of the first reference markers is captured by the plurality of cameras in a plurality of planes that are mutually different to one another during the breath hold process.

[0020] According to an embodiment herein, the movement of the first reference markers during a normal breathing is captured in all planes by the plurality of cameras, when the patient is unable to hold the breath. [0021] According to an embodiment herein, the imaging process is selected from a group consisting of CT, Magnetic Resonance Imaging (MRI) and ultrasound, and the number of slices depends on the selected imaging process.

[0022] According to an embodiment herein, the second marker is contrast in color, size and shape to the first marker.

[0023] According to an embodiment herein, the needle trajectory and needle angles are calculated from a DICOM image based on the first reference markers and second marker for mutually different planes.

[0024] According to an embodiment herein, the second marker is aligned with the needle entry point by the user either by moving a camera or the couch, based on the calculated needle trajectory and needle angles displayed on the display screen.

[0025] According to an embodiment herein, the needle orientation is adjusted by the user using real time image displayed on the display screen, after adjusting the needle insertion point.

[0026] According to an embodiment herein, a real time optical needle tracking system in a percutaneous biopsy procedure is provided. The system comprises an imaging system for taking an image of a patient, a processor, a plurality of cameras for taking a real time image of the patient in a plurality of planes, a camera positioning system for positioning the plurality of cameras in a mutually perpendicular planes and to adjust a field of view of the plurality of cameras and a display device. The processor calculates a needle orientation angle and trajectory based on a movement of reference markers pasted on the body of the patient during a breathing phase to compute a needle insertion depth to guide a medical practitioner to reach a target location.

[0027] According to an embodiment herein, the imaging system is selected is selected from a group consisting of CT, Magnetic Resonance Imaging (MRI) and ultrasound. The imaging system is configured to obtain a scanogram image to localize body structures or a region of interest (ROI) for subsequent computer tomography (CT) scans and to display the locations of acquired CT slices. The number of slices depends on the selected imaging system.

[0028] According to an embodiment herein, the selected ROI of the patient is aligned to the field of view (FOV) of the plurality of cameras manually.

[0029] According to an embodiment herein, the patient is selected at the selected ROI with the imaging system.

[0030] According to an embodiment herein, the plurality of reference markers comprises a first reference marker and a second reference marker. The first reference marker is pasted in the selected ROI region on a body of the patient body. The second reference marker is pasted in the patient body by a radiologist to mark a needle insertion point. The second marker is contrast in color to the first marker.

[0031] According to an embodiment herein, the plurality of cameras is configured to capture a movement of the plurality of the first reference markers during a normal breathing process and during a breathing hold process.

[0032] According to an embodiment herein, the plurality of cameras is configured to capture a movement of the plurality of the first reference markers in a plurality of planes that are mutually different to one another during the breath hold process.

[0033] According to an embodiment herein, the plurality of cameras is configured to capture a movement of the plurality of the first reference markers during a normal breathing process in all the planes, when the patient is unable to hold the breath.

[0034] According to an embodiment herein, the processor is configured to calculate the needle trajectory and needle angles from a DICOM image based on the first reference markers and second marker for mutually different planes.

[0035] According to an embodiment herein, the camera or a couch is moved by a user to align the second marker with the needle entry point based on the calculated needle trajectory and needle angles displayed on the display screen.

[0036] According to an embodiment herein, the processor is configured to enable the User to adjust a needle orientation using real time image displayed on the display screen, after adjusting the needle insertion point.

[0037] The embodiments herein provide an optical needle tracking system for an image guided percutaneous biopsy procedure. The embodiments herein provide a method for operating a needle tracking system in real time with the use of an imaging guidance system which allows a medical practitioner to perform the biopsy procedure with a little patient compliance, reduced radiation exposure and reduced needle pass. The imaging technology comprises a CT, MRI, Ultrasound, etc. The optical needle tracking system comprises a plurality of markers, medical imaging equipment preferably a CT scanner, a plurality of cameras, a processor, a display unit and a camera positioning system. The plurality of markers is placed on the region of interest (ROI) of the patient's body which assists in acquiring the breathing pattern of the patient. The plurality of cameras captures the real time images and is controlled by the camera positioning system. The processor controls the entire operation of the optical needle tracking system.

[0038] According to an embodiment herein, a real time optical tracking mechanism is provided for aligning the needle to a preplanned needle path with very little patient compliance. The needle is aligned with the help of the plurality of markers pasted in the region of interest (ROI) on the patient skin surface. When the patient is lying on a CT patient couch (table), the optical needle tracking system tracks the patient breathing movement in all body planes as well as needle angulations. The tracked and captured image information is overlaid on the selected CT DICOM image. The optical tracking mechanism also tracks the needle angulations and insertion depth to improve the biopsy sampling accuracy. The optical needle tracking system allows the radiologist to know about a current patient breathing level and also any bodily movement (physical movement) that is bound to happen when the patient lies on the table. The optical needle tracking system guides the radiologist to reach the target point by providing the required needle angulationsand as well as the needle depth based on the estimated current patient breathing level so that the needle procedures are performed easily even in the case of patients with a breathing difficulty (not able reproduce same breath holding). When a patient movement is observed, the optical needle tracking system allows the clinician/radiologist to decide a further course of action. [0039] According to an embodiment herein, a method for improving the accuracy of the biopsy sampling procedure is provided. The method comprises monitoring the critical parameters of the percutaneous biopsy procedure. The accuracy of the biopsy procedure depends mainly on the factors including but not limited to a needle placement and orientation, a sample collection from a right location using the needle, number of samples/size, a patient compliance (breathing) / movement of patient during the procedure and a size and location of the organ. The needle placement and orientation factor is dependent on the skill of the radiologist. The embodiments herein monitor the crucial factors in real time and thereby improve the accuracy of the biopsy procedures.

[0040] According to an embodiment herein, a processor of the optical needle tracking system correlates the attached markers to a skin displacement and overlay the correlated information on the 3D reconstructed images of CT. The processor is a computer system with processing software. The processor receives the DICOM images from the CT Console by means of a wired or wireless connection which includes but not limited to LAN, WAN, MAN, Wireless- Fidelity (Wi-Fi), Bluetooth communication, etc. Based on the Region of Interest (ROI), the processing software computes the co-ordinates for each camera and sends the information to the camera positioning system to position the individual cameras. Once the camera positioning system ensures the position and orientation of the camera and establishes the relationship of the patient position with respect to the plurality of cameras, the processor starts receiving the images from the cameras. The correlation is performed in the processing software and real time information about a patient breath and a needle position are displayed on the monitor.

[0041] According to an embodiment herein, the markers used for correlating the information are of any type, size and shapes. The markers when pasted/placed on the patient skin surface are visible in the CT scan image. Thus, the image allows the radiologist to correlate the skin surface and the CT image. The real time 3D reconstructed images guide a radiologist to reach a target area in the body of the patient with a limited number of the needle pass and reduced check scans.

[0042] According to an embodiment herein, the plurality of cameras is mounted inside the area where the patient undergoes scanning through any one of the medical imaging procedures such as CT, MRI, Ultrasound, etc. The plurality of cameras captures the real time images of the patient with respect to the OI. The pluralities of cameras are mounted in such a way that they are perpendicular to each other. A camera positioning system is provided which ensures the pluralities of cameras are perpendicular to each other with the respective adjustable field of view (FOV). The cameras images of the skin are overlaid on the 3D reconstructed images of CT in each plane to assist the radiologist. The pluralities of cameras are placed near the patient couch so that the movements in all planes are captured. The entire assembly of the plurality of cameras is mounted on the floor. Alternately, the entire assembly of the plurality of cameras is suspended from the ceiling. The mounting shaft of each camera has freedom to move in the respective planes. The movement of each mounting shaft is done by means of a stepper motor which is controlled by a control mechanism. A relationship is established between the plurality of mounted cameras and the CT patient couch. This relationship is constant at all times for each site.

[0043] According to an embodiment herein, the camera positioning system controls at least three positional cameras comprising a side camera, a front camera and a top camera. The three positional cameras capture the movement of the patient in a supine and a prone position. When the patient is in supine position, the side camera captures anterior, superior and inferior images, while the front camera captures lateral, median and anterior images, and the top camera captures lateral, median, inferior and superior images of the patient. Every movement is captured by two cameras to keep the error at a minimal level. When the patient lies in the prone position, then the side camera captures and shows the posterior region. The part of the patient's body which is in contact with the couch experiences a negligible movement due to contact with the couch.

[0044] According to an embodiment herein, the plurality of positional cameras are mounted perpendicular to each other and placed near the couch of the patient so that the information regarding the patient contour in all the planes are captured. A relationship between the patient couch and the cameras is established. The relationship indirectly establishes and defines a relationship between the plurality of cameras and the patient. A surface contouring software processes the captured image and creates the 3D images of the patient surface from the information acquired with the camera in all the planes. Further the surface contouring software enables to overlay the same with the CT images. relationship is established between the plurality of mounted cameras and the CT patient couch. This relationship is constant at all times for each site.

[0042] According to an embodiment herein, the camera positioning system controls at least three positional cameras comprising a side camera, a front camera and a top camera. The three positional cameras capture the movement of the patient in a supine and a prone position. When the patient is in supine position, the side camera captures anterior, superior and inferior images, while the front camera captures lateral, median and anterior images, and the top camera captures lateral, median, inferior and superior images of the patient. Every movement is captured by two cameras to keep the error at a minimal level. When the patient lies in the prone position, then the side camera captures and shows the posterior region. The part of the patient's body which is in contact with the couch experiences a negligible movement due to contact with the couch.

[0043] According to an embodiment herein, the plurality of positional cameras are mounted perpendicular to each other and placed near the couch of the patient so that the information regarding the patient contour in all the planes are captured. A relationship between the patient couch and the cameras is established. The relationship indirectly establishes and defines a relationship between the plurality of cameras and the patient. A surface contouring software processes the captured image and creates the 3D images of the patient surface from the information acquired with the camera in all the planes. Further the surface contouring software enables to overlay the same with the CT images.

13 [0044] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating the preferred embodiments and numerous specific details thereof, are given by way of an illustration and not of a limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

E) BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:

[0046] FIG. 1 illustrates a block diagram of an optical needle tracking system used in image guided percutaneous biopsy, according to an embodiment herein.

[0047] FIG. 2 illustrates a schematic arrangement of the three positional cameras in an optical needle tracking system for capturing the movement of the patient in a plurality of planes, according to an embodiment herein.

[0048] FIG. 3 illustrates a flow chart explaining a method of estimating needle depth and needle insertion position in the image guided percutaneous biopsy procedures using the optical needle tracking system, according to an embodiment herein.

14 [0049] FIG. 4 illustrates a CT DICOM image displayed along with planned and real time needle angulations on a display screen, according to an embodiment herein.

[0050] Although the specific features of the embodiments herein are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the embodiments herein.

F) DETAILED DESCRIPTION OF THE INVENTION

[0051] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.

[0052] The various embodiments herein provide a real time optical needle tracking system and method in a percutaneous biopsy procedure.

[0053] According to an embodiment herein, a real time optical needle tracking method in a percutaneous biopsy procedure is provided. According to one embodiment herein, the method comprises the following steps. A patient is subjected to X-ray sonogram to obtain a scanogram image to localize body structures or a region of interest (ROI) for subsequent computer tomography (CT)

15 scans and to display the locations of acquired CT slices. A desired ROI is selected from the scanogram. The selected ROI of the patient is aligned to a field of view (FOV) of a plurality of cameras. A plurality of first reference markers is pasted in the selected ROI region on a body of the patient body. The patient is instructed to do breathing and to hold the breath at a comfort level. A movement of the plurality of the first reference markers is captured by the plurality of cameras in a plurality of planes. A movement of the plurality of the first reference markers is captured by the plurality of cameras in all planes during normal breathing. The patient is scanned at the selected ROI with an imaging process. A slice number and an entry point are input in an imaging device based on the imaging process. A couch is moved and positioned to a required slice by the imaging system. A needle insertion point is marked with a second marker in the patient body by a radiologist. A check scan is performed to validate a position of the second marker. A needle trajectory and needle angles are calculated from a DICOM image based on the first reference markers and second marker. The calculated needle trajectory and needle angles information is communicated from the imaging device to a processor of an optical tracking system. The calculated needle trajectory and needle angles information is overlaid on a display monitor. The second marker is aligned with the needle entry point either by moving a camera or the couch, based on the calculated needle trajectory and needle angles information displayed on the display screen. The needle orientation is adjusted using a real time image displayed on the display screen, after adjusting the needle insertion point. A needle

16 insertion depth is computed with the processor to guide a medical practitioner to reach a target location, after matching the needle orientation.

[0054] According to an embodiment herein, the selected ROI of the patient is aligned to the field of view (FOV) of the plurality of cameras manually.

[0055] According to an embodiment herein, the movement of the plurality of the first reference markers is captured by the plurality of cameras in a plurality of planes that are mutually different to one another during the breath hold process.

[0056] According to an embodiment herein, the movement of the first reference markers during a normal breathing is captured in all planes by the plurality of cameras, when the patient is unable to hold the breath.

[0057] According to an embodiment herein, the imaging process is selected from a group consisting of CT, Magnetic Resonance Imaging (MRI) and ultrasound, and the number of slices depends on the selected imaging process.

[0058] According to an embodiment herein, the second marker is contrast in color, size and shape to the first marker.

[0059] According to an embodiment herein, the needle trajectory and needle angles are calculated from a DICOM image based on the first reference markers and second marker for mutually different planes.

[0060] According to an embodiment herein, the second marker is aligned with the needle entry point by the user either by moving a camera or the couch, based on the calculated needle trajectory and needle angles displayed on the display screen.

17 [0061] According to an embodiment herein, the needle orientation is adjusted by the user using real time image displayed on the display screen, after adjusting the needle insertion point.

[0062] According to an embodiment herein, a real time optical needle tracking system in a percutaneous biopsy procedure is provided. The system comprises an imaging system for taking an image of a patient, a processor, a plurality of cameras for taking a real time image of the patient in a plurality of planes, a camera positioning system for positioning the plurality of cameras in a mutually perpendicular planes and to adjust a field of view of the plurality of cameras and a display device. The processor calculates a needle orientation angle and trajectory based on a movement of reference markers pasted on the body of the patient during a breathing phase to compute a needle insertion depth to guide a medical practitioner to reach a target location.

[0063] According to an embodiment herein, the imaging system is selected is selected from a group consisting of CT, Magnetic Resonance Imaging (MRI) and ultrasound. The imaging system is configured to obtain a scanogram image to localize body structures or a region of interest (ROI) for subsequent computer tomography (CT) scans and to display the locations of acquired CT slices. The number of slices depends on the selected imaging system.

[0064] According to an embodiment herein, the selected ROI of the patient is aligned to the field of view (FOV) of the plurality of cameras manually.

[0065] According to an embodiment herein, the patient is selected at the selected ROI with the imaging system.

18 [0066] According to an embodiment herein, the plurality of reference markers comprises a first reference marker and a second reference marker. The first reference marker is pasted in the selected ROI region on a body of the patient body. The second reference marker is pasted in the patient body by a radiologist to mark a needle insertion point. The second marker is contrast in color to the first marker.

[0067] According to an embodiment herein, the plurality of cameras is configured to capture a movement of the plurality of the first reference markers during a normal breathing process and during a breathing hold process.

[0068] According to an embodiment herein, the plurality of cameras is configured to capture a movement of the plurality of the first reference markers in a plurality of planes that are mutually different to one another during the breath hold process.

[0069] According to an embodiment herein, the plurality of cameras is configured to capture a movement of the plurality of the first reference markers during a normal breathing process in all the planes, when the patient is unable to hold the breath.

[0070] According to an embodiment herein, the processor is configured to calculate the needle trajectory and needle angles from a DICOM image based on the first reference markers and second marker for mutually different planes.

[0071] According to an embodiment herein, the camera or a couch is moved by a user to align the second marker with the needle entry point based on the calculated needle trajectory and needle angles displayed on the display screen.

19 [0072] According to an embodiment herein, the processor is configured to enable the user to adjust a needle orientation using real time image displayed on the display screen, after adjusting the needle insertion point.

[0073] The various embodiments herein provide an optical needle tracking system for an image guided percutaneous biopsy procedure. The embodiments herein provide a method for operating a needle tracking system in real time with the use of an imaging guidance system which allows a medical practitioner to perform the biopsy procedure with a little patient compliance, reduced radiation exposure and reduced needle pass. The imaging technology comprises a CT, MRI, Ultrasound, etc. The optical needle tracking system comprises a plurality of markers, medical imaging equipment preferably a CT scanner, a plurality of cameras, a processor, a display unit and a camera positioning system. The plurality of markers is placed on the region of interest (ROI) of the patient's body which assists in acquiring the breathing pattern of the patient. The plurality of cameras captures the real time images and is controlled by the camera positioning system. The processor controls the entire operation of the optical needle tracking system.

[0074] According to an embodiment herein, a real time optical tracking mechanism is provided for aligning the needle to a preplanned needle path with very little patient compliance. The needle is aligned with the help of the plurality of markers pasted in the region of interest (ROI) on the patient skin surface. When the patient is lying on a CT patient couch (table), the optical needle tracking system tracks the patient breathing movement in all body planes as well as needle angulations. The tracked and captured image information is overlaid on the

20 selected CT DICOM image. The optical tracking mechanism also tracks the needle angulations and insertion depth to improve the biopsy sampling accuracy. The optical needle tracking system allows the radiologist to know about a current patient breathing level and also any bodily movement (physical movement) that is bound to happen when the patient lies on the table. The optical needle tracking system guides the radiologist to reach the target point by providing the required needle angulations and as well as the needle depth based on the estimated current patient breathing level so that the needle procedures are performed easily even in the case of patients with a breathing difficulty (not able reproduce same breath holding). When a patient movement is observed, the optical needle tracking system allows the clinician/radiologist to decide a further course of action.

[0075] According to an embodiment herein, a method for improving the accuracy of the biopsy sampling procedure is provided. The method comprises monitoring the critical parameters of the percutaneous biopsy procedure. The accuracy of the biopsy procedure depends mainly on the factors including but not limited to a needle placement and orientation, a sample collection from a right location using the needle, number of samples/size,a patient compliance (breathing) / movement of patient during the procedure and a size and location of the organ. The needle placement and orientation factor is dependent on the skill of the radiologist. The embodiments herein monitor the crucial factors in real time and thereby improve the accuracy of the biopsy procedures.^■

[0076] According to an embodiment herein, a processor of the optical needle tracking system correlates the attached markers to a skin displacement and

21 overlay the correlated information on the 3D reconstructed images of CT. The processoris a computer system with processing software. The processor receives the DICOM images from the CT Console by means of a wired or wireless connection which includes but not limited to LAN, WAN, MAN, Wireless- Fidelity (Wi-Fi), Bluetooth communication, etc. Based on the Region of Interest (ROI), the processing software computes the co-ordinates for each camera and sends the information to the camera positioning system to position the individual cameras. Once the camera positioning system ensures the position and orientation of the camera and establishes the relationship of the patient position with respect to the plurality of cameras, the processor starts receiving the images from the cameras. The correlation is performed in the processing software and a real time information about a patient breath and a needle position are displayed on the monitor.

[0077] According to an embodiment herein, the markers used for correlating the information are of any type, size and shapes. The markers when pasted/placed on the patient skin surface are visible in the CT scan image. Thus, the image allows the radiologist to correlate the skin surface and the CT image. The real time 3D reconstructed images guidea radiologist to reach a target area in the body of the patient with a limited number of the needle pass and reduced check scans.

[0078] According to an embodiment herein, the plurality of cameras is mounted inside the area where the patient undergoes scanning through any one of the medical imaging procedures such as CT, MRI, Ultrasound, etc. The plurality

22 of cameras captures the real time images of the patient with respect to the ROI. The pluralities of cameras are mounted in such a way that they are perpendicular to each other. Acamera positioning system is provided which ensures the pluralities of cameras are perpendicular to each other withthe respective adjustable field of view (FOV). The cameras images of the skin are overlaid on the 3D reconstructed images of CT in each plane to assist the radiologist. The pluralities of cameras are placed near the patient couch so that the movements in all planes are captured. The entire assembly of the plurality of cameras is mounted on the floor. Alternately, the entire assembly of the plurality of cameras is suspended from the ceiling. The mounting shaft of each camera has freedom to move in the respective planes. The movement of each mounting shaft is done by means of a stepper motor which is controlled by a control mechanism. A relationship is established between the plurality of mounted cameras and the CT patient couch. This relationship is constant at all times for each site.

[0079] According to an embodiment herein, the camera positioning system controls at least three positional cameras comprising a side camera, a front camera and a top camera. The three positional cameras capture the movement of the patient in a supine and a prone position. When the patient is in supine position, the side camera captures anterior, superior and inferior images, while the front camera captures lateral, median and anterior images, and the top camera captures lateral, median, inferior and superior images of the patient. Every movement is captured by two cameras to keep the error at a minimal level. When the patient lies in the prone position, then the side camera captures and shows the posterior region. The

23 part of the patient's body which is in contact with the couch experiences a negligible movement due to contact with the couch.

[0080] According to an embodiment herein, the plurality of positional cameras are mounted perpendicular to each other and placed near the couch of the patient so that the information regarding the patient contour in all the planes are captured. A relationship between the patient couch and the cameras is established. The relationship indirectly establishes and defines a relationship between the plurality of cameras and the patient. A surface contouring software processes the captured image and creates the 3D images of the patient surface from the information acquired with the camera in all the planes. Further the surface contouring software enables to overlay the same with the CT images.

[0081] FIG. 1 illustrates a block diagram of an optical needle tracking system used in an image guided percutaneous biopsy, according to an embodiment herein. The optical needle tracking system 100 comprises a processor 101, a plurality of positional cameras 103, a camera positioning system 104, a medical imaging device 105 and a displayscreen 102. The processor 101 controls the operation of all the components of the optical needle tracking system 100. The processer 101 also computes the data provided by the connected components and displays the result on the display screen 102. The medical imaging device such as a CT console 105 is used to scan the body of the patient to produce the images at different slices with respect to the region of interest (ROI).The processor 101 also controls the pluralities of positional cameras 103 with the help of the camera positioning system 104. The camera positioning system 104 ensures that the

24 plurality of positional cameras 103 are arranged perpendicular to each other and performs the necessary correction automatically through the processor. The pluralities of positional cameras 103 are preferably but not limited to three in number. The plurality of positional camerasl 03 captures the movement of the patient body in different planes and helps in constructing a 3D image. The generated 3D image assists a medical practitioner to perform the biopsy.

[0082] FIG. 2 illustrates a schematic arrangement of the three positional cameras in an optical needle tracking system for capturing the movement of the patient in a plurality of planes, according to an embodiment herein. The three positional cameras comprise a side camera 203, a front camera 202 and a top camera 201. The three positional cameras 201-203 capture the patient movement in different planes and create 3D images of the ROl. The generated 3D image assist the medical practitioner by providing a guidance to perform needle biopsy with minimal insertion, less patient compliance and less number of needle passes. For a patient lying in supine position (facing upwards),the side camera 203 captures and displays the anterior, superior and inferior images of the ROI. The front camera 202 captures and shows the lateral, median and anterior images of the ROI. The top camera 201 captures and shows the lateral, median, inferior and superior images of the ROI. Every movement is captured by the positional cameras to keep the error to minimum. For a patient lying in the prone position (facing downwards), the side camera 203 shows the posterior areaof the ROI. The part of the patient body which is in contact with the couch has negligible movement due to contact with the couch.

25 [0083] FIG. 3 illustrates a flow chart explaining a method of estimating needle depth and needle insertion position in the image guided percutaneous biopsy procedures using the optical needle tracking system, according to an embodiment herein. A patient undergoes an X-ray scanogram before a biopsy procedure for the examination of tissues or cells. The images obtained from the X- ray scanography is used to determine the ROI (301). The images obtained in this process are similar in general appearance to a conventional projection radiography image. The scanogram has lower spatial resolution but much wider dynamic range. Scanograms are used primarily to localize body structures (Region of interest ROI) for subsequent CT scans and to display the locations of acquired CT slices. A plurality of positional cameras is mounted near a couch.The patient undergoing the needle biopsy procedure or the scanning process lies on the couch. The couch is adjusted in such a manner that the ROI of the patient is in within the Field Of View (FOV) of the plurality of mounted positional cameras. This is done manually by the patient with the help of the technicians. Further, the FOV of the plurality of positional camera are ensured to be perpendicular to each other by a camera positioning system (302). After the patient has lied down on the couch and the pluralities of cameras are mounted at the preferred positions, a plurality of reference markers are pasted on the skin surface of the patient. The reference markers are pasted to indicate the ROI and compute the breathing movement of the patient (303). Now the patient undergoes a medical imaging procedure based on the instructions given to the patient by the medical practitioner regarding the holding of the breath. When the patient is instructed not to hold any breath, then

26 the movement of the reference markers during the holding of the breath is captured by the mounted positional cameras (304). When the patient is instructed to hold the breath, then the movement of the reference markers during the holding of the breath is captured by the mounted positional cameras (305). When the patient is instructed not to hold any breath, then the patient is scanned normally at the ROI without holding the breath. In the case of no breath holds or free breathing, the plurality of positional cameras indicate the movement of the reference marker and the same isused as a reference during the biopsy procedure (306). If the patient is unable to hold the breath, then in such case, the movement of reference markers during normal breathing is captured in all planes by multiple cameras. Once the camera capturing is completed, the patient is scanned at ROI with a suitable imaging procedure. After obtaining the images of the patient from the CT scan medical imaging procedure, a slice number and a specific entry point of the needle is planned and determined in the CT console (307). The number of slices obtained depends on the imaging procedure. Later, the slice number and entry point are planned in the CT image of the CT console. Based on the determined slice number, the couch is moved to the required slice as per the instruction from the medical practitioner (308).

[0084] An insertion or entry point for the needle is marked on the patient surface with a second contrast marker (309). Also, a check scan is performed for the patient to validate the second marker position corresponding to skin surface (310). After a successful validation of the markers positions, the needle insertion trajectory and angles in the different planes are calculated based on the Digital

27 Imaging and Communications in Medicine (DICOM) image in the CT console

(31 1) . The calculated angles and trajectory of the needle is fed to the processor

(312) . The processor overlays the received information in the display (313). Based on the displayed information, the needle entry point is aligned with the DICOM image by moving the plurality of positional cameras or the couch (313). Once the entry point is adjusted, the medical practitioner adjusts the needle orientation based on the images acquired with an image guidance system. The second marker is aligned with the needle entry point in DICOM image by moving camera or couch based on feedback from camera image guidance (314). The user adjusts the needle orientation using camera image guidance (315). Once needle orientation matches, the processor computes the insertion depth and guides the medical practitioner to insert the needle at a right position with the help of the reference marker during a breath hold condition. Thusa medical practitioner is able to perform a percutaneous biopsy procedure with minimal patient compliance, reduced radiation exposure and reduced needle pass (316).

[0085] FIG. 4 illustrates a CT DICOM image displayed along with planned and real time needle angulationson a display screen, according to an embodiment herein. A display screen 401 is provided for displaying the image captured by a suitable medical imaging procedure and real time mage during the biopsy.In the display screen, a CT scan slice 404 is exhibited to depict the ROI of the patient, where the biopsy is to be conducted.The objects in solid lines correspond to the planned image and planned needle angulations whereas the real time information is overlaid in dotted lines. The radiologist is guided to insert the

28 needle at the entry point 402 to the target organ 406 in the ROI. By using the side and front cameras, needle angulations along Y&X axis are tracked respectively. The real time angulations guide the radiologist to align the needle angulationsaccording to the planned path. The plurality of cameras has a relationship with the CT patient table in each plane. The relationship is definitive for each site.

[0086] According to an embodiment herein, the optical needle tracking system monitors the patient breathing in real time and displays the information thereby allowing the radiologist to reach the target point without any subsequent check scans.

[0087] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications.

29 [0088] Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the embodiments herein with modifications.

30

Claims

CLAIMS What is claimed is:

1. A real time optical needle tracking method in a percutaneous biopsy procedure, the method comprises:

subjecting a patient to X-ray sonogram to obtain a scanogram image to localize body structures or a region of interest (ROI) for subsequent computer tomography (CT) scans and to display the locations of acquired CT slices;

selecting a desired ROI from the scanogram;

aligning the selected ROI of the patient to a field of view (FOV) of a plurality of cameras;

pasting a plurality of first reference markers in the selected ROI region on a body of the patient body;

instructing the patient to do breathing and to hold the breath at a comfort level;

capturing a movement of the plurality of the first reference markers by the plurality of cameras in a plurality of planes;

capturing a movement of the plurality of the first reference markers by the plurality of cameras in all planes during normal breathing;

scanning the patient at the selected ROI with an imaging process; inputting a slice number and entry point in an imaging device based on the imaging process;

31 moving and positioning a couch to a required slice by the imaging system;

marking a needle insertion point with a second marker in the patient body by a radiologist;

performing a check scan to validate a position of the second marker;

calculating a needle trajectory and needle angles from a DICOM image based on the first reference markers and second marker;

communicating the calculated needle trajectory and needle angles from the imaging device to a processor of an optical tracking system; overlaying the calculated needle trajectory and needle angles information on a display monitor;

aligning the second marker with the needle entry point either by moving a camera or the couch, based on the calculated needle trajectory and needle angles displayed on the display screen;

adjusting the needle orientation using real time image displayed on the display screen, after adjusting the needle insertion point; and

computing a needle insertion depth with the processor to guide a medical practitioner to reach a target location, after matching the needle orientation.

2. The method according to claim 1, wherein the selected ROI of the patient is aligned to the field of view (FOV) of the plurality of cameras manually.

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3. The method according to claim 1, wherein the movement of the plurality of the first reference markers is captured by the plurality of cameras in a plurality of planes that are mutually different to one another during the breath hold process.

4. The method according to claim 1 , wherein the movement of the first reference markers during a normal breathing is captured in all planes by the plurality of cameras, when the patient is unable to hold the breath.

5. The method according to claim 1, wherein the imaging process is selected from a group consisting of CT, Magnetic Resonance Imaging (MRI) and ultrasound, and wherein the number of slices depends on the selected imaging process.

6. The method according to claim 1, wherein the second marker is contrast in color, size and shape to the first marker.

7. The method according to claim 1, wherein the needle trajectory and needle angles are calculated from a DICOM image based on the first reference markers and second marker for mutually different planes.

8. The method according to claim 1, wherein the second marker is aligned with the needle entry point by the user either by moving a camera or the couch, based on the calculated needle trajectory and needle angles displayed on the display screen;

9. The method according to claim 1, wherein the needle orientation is adjusted by the user using real time image displayed on the display screen, after adjusting the needle insertion point.

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10. A real time optical needle tracking system in a percutaneous biopsy procedure, comprising:

an imaging system for taking an image of a patient;

a processor;

a plurality of cameras for taking a real time image of the patient in a plurality of planes;

a camera positioning system for positioning the plurality of cameras in a mutually perpendicular planes and to adjust a field of view of the plurality of cameras; and

a display device;

wherein the processor calculates a needle orientation angle and trajectory based on a movement of reference markers pasted on the body of the patient during a breathing phase to compute a needle insertion depth to guide a medical practitioner to reach a target location.

1 1. The system according to claim 10, wherein the imaging system is selected is selected from a group consisting of CT, Magnetic Resonance Imaging (MRI) and ultrasound, and wherein the imaging system is configured to obtain a scanogram image to localize body structures or a region of interest (ROI) for subsequent computer tomography (CT) scans and to display the locations of acquired CT slices, and wherein the number of slices depends on the selected imaging system.

12. The system according to claim 1 1, wherein the selected ROI of the patient is aligned to the field of view (FOV) of the plurality of cameras manually.

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13. The system according to claim 11, wherein the patient is selected at the selected ROI with the imaging system.

14. The system according to claim 10, wherein the plurality of reference markers comprises a first reference marker and a second reference marker, and wherein the first reference marker is pasted in the selected ROI region on a body of the patient body and wherein the second reference marker is pasted in the patient body by a radiologist to mark a needle insertion point, and wherein the second marker is contrast in color, size and shape to the first marker.

15. The system according to claim 10, wherein the plurality of cameras is configured to capture a movement of the plurality of the first reference markers during a normal breathing process and during a breathing hold process.

16. The system according to claim 10, wherein the plurality of cameras is configured to capture a movement of the plurality of the first reference markers in a plurality of planes that are mutually different to one another during the breath hold process.

17. The system according to claim 10, wherein the plurality of cameras is configured to capture a movement of the plurality of the first reference markers during a normal breathing process in all the planes, when the patient is unable to hold the breath.

18. The system according to claim 10, wherein the processor is configured to calculate the needle trajectory and needle angles from a DICOM image

35 based on the first reference markers and second marker for mutually different planes.

19. The system according to claim 10, wherein the camera or a couch is moved by a user to align the second marker with the needle entry point based on the calculated needle trajectory and needle angles displayed on the display screen.

20. The system according to claim 10, wherein the processor is configured to enable the user to adjust a needle orientation using real time image displayed on the display screen, after adjusting the needle insertion point.

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