TECHNICAL FIELD

This disclosure relates to a laser projection apparatus, a control method thereof, and a laser guidance system including the laser projection apparatus, and more particularly, to a laser projection apparatus for projecting an insertion location and posture of a fixing screw, a drill, a guide, or the like onto an affected part during a surgical operation, a control method thereof, and a laser guidance system including the laser projection apparatus.

BACKGROUND ART

Though a surgical operation using an image device is planned, it is difficult to proceed with the operation as planned at an actual operation site. As a simple example, in the case of the osteotomy, if the osteotomy is planned to take place at 5 cm lower than the knee joint, it is necessary to perform incision by 5 cm using a ruler at the actual knee, which is exposed by incision of the skin, and then perform a surgical operation accordingly. However, there are many differences between the real surgery and the plan depending on the position and angle of the ruler.

In particular, when marking a surgical perforation point using a writing instrument based on the manual work of a medical staff, especially when a perforation is necessary, the medical staff must rely on a 2D image of a fluoroscopy device (or, a C-armed fluoroscopy). However, the fluoroscopy device does not provide any important information as to whether to enter the affected part at the skin of the patient perpendicularly or at a slanted angle. Therefore, the surgical operation has to be inevitably performed depending on the surgical experience or intuition of the medical staff.

Moreover, the results of the surgery in the operating room depend largely on the surgical experience of the medical staff performing the surgery or the medical interpretation ability on the affected part image information. Thus, in the case of a medical staff with insufficient surgical experience, a continuous preparation training for accurate surgical performance is required for a considerable period of time, and as a result, there is a problem of increased expenditure of human labor and material expenses for the required training.

Accordingly, guidance for accurately performing a planned surgery is required. Conventionally, an image of a patient is acquired by using equipment such as a computed tomography (CT) or a magnetic resonance (MR) device, and a marker or the like is installed in a certain place, such as the leg of a patient, in the operating room (the marker is an auxiliary tool for aligning coordinates), and the image taken through MRI in the operating room must be matched (coordinate matching) using the corresponding marker.

Therefore, since two processes of displaying the marker on the human body of the patient and matching the marker with the image are required, there is a problem in that the surgical process is complicated and real-time guidance is not provided. In addition, since the matching of the marker and the image is not precise, there is a risk of adversely affecting the surgical operation that demands a high degree of accuracy.

In particular, in the orthopedic surgery, a mobile C-arm fluoroscopy (hereinafter, referred to as a C-arm) is frequently used to check the condition of bone, establish a surgical plan such as osteotomy and alteration correction, and then perform the surgery. To this end, a k-wire (stainless-steel wire) is placed on the affected part, a C-arm image is taken, and a location between the bone and the k-wire is measured to make a surgical plan.

The laser projection apparatus is a device that displays lines planned in the C-arm image directly on the affected part, and it is essential to accurately match the positions of the C-arm and a laser target device required to use the apparatus.

DISCLOSURE

Technical Problem

According to an aspect of the present disclosure, there is provided a laser projection apparatus which matches a position with a C-arm in order to project a line laser to a position according to operation information planned on a C-arm image.

According to another aspect of the present disclosure, there is provided a control method of the laser projection apparatus for generating a line laser to display the operation information planned on the C-arm image to the affected part.

According to another aspect of the present disclosure, there is provided a laser guidance system for displaying operation information of an insertion location and an insertion angle planned on the C-arm image directly to the affected part as an intersection point of two-line lasers.

Technical Solution

A laser projection apparatus according to an embodiment of the present disclosure in order to solve the above object, which projects operation information of an insertion location and an insertion angle planned on a C-arm image photographed using a C-arm fluoroscopy (hereinafter, a C-arm) directly to an affected part, comprises: a line laser module configured to generate a line laser to form a plane by rotating around an origin; a matching unit configured to calculate a coordinate representing the insertion location in a C-arm coordinate system based on the C-arm, calculate an insertional vector according to the coordinate representing the insertion location and the insertion angle, and calculate a vector perpendicular to the plane formed by the line laser in the C-arm coordinate system according to the insertional vector; and a control unit configured to control the line laser module based on the vector perpendicular to the plane formed by the line laser.

Meanwhile, the matching unit may be configured to calculate a coordinate representing the origin in the C-arm coordinate system, and calculate the vector perpendicular to the plane formed by the line laser by performing vector product to a vector connecting the coordinate representing the insertion location and the coordinate representing the origin and the insertional vector.

In addition, the matching unit may be configured to transform the vector perpendicular to the plane formed by the line laser in the C-arm coordinate system into a line laser module coordinate system based on the line laser module.

In addition, the matching unit may be configured to calculate an extrinsic parameter of a C-arm marker located at the line laser module in the C-arm image, derive a transformation matrix between the C-arm coordinate system and a C-arm marker coordinate system based on the C-arm marker, derive a transformation matrix between the C-arm marker coordinate system and a line laser module coordinate system based on the line laser module, and derive a transformation matrix between the C-arm coordinate system and the line laser module coordinate system.

In addition, the line laser module may include: a green laser configured to generate a laser beam; a rotation line generator configured to transform the laser beam into a line laser rotating around the origin; a rotating mirror configured to change a rotation central axis of the line laser; a first motor connected to the rotation line generator to operate under the control of the control unit; and a second motor connected to the rotating mirror to operate under the control of the control unit.

In addition, the control unit may be configured to control the first motor and the second motor by calculating steering angles of the first motor and the second motor, respectively, from the vector perpendicular to the plane formed by the line laser.

In addition, the line laser module may further include a calibration tool to which a calibration pattern is attached, and the calibration tool may be located between the line laser module and the C-arm.

Meanwhile, a control method of a laser projection apparatus according to another aspect of the present disclosure, which projects operation information of an insertion location and an insertion angle planned on a C-arm image photographed using a C-arm fluoroscopy (hereinafter, a C-arm) directly to an affected part, comprises: calculating a coordinate representing the insertion location in a C-arm coordinate system based on the C-arm; calculating an insertional vector according to the coordinate representing the insertion location and the insertion angle; calculating a vector perpendicular to a plane formed by a line laser generated by the laser projection apparatus in the C-arm coordinate system according to the insertional vector; and controlling the line laser to be generated based on the vector perpendicular to the plane formed by the line laser.

Meanwhile, said step of calculating a vector perpendicular to a plane formed by a line laser generated by the laser projection apparatus in the C-arm coordinate system according to the insertional vector may include calculating a coordinate representing an origin for rotation of the line laser in the C-arm coordinate system, and calculating the vector perpendicular to the plane formed by the line laser by performing vector product to a vector connecting the coordinate representing the insertion location and the coordinate representing the origin and the insertional vector.

In addition, the control method may further comprise transforming the vector perpendicular to the plane formed by the line laser in the C-arm coordinate system into a line laser module coordinate system based on the line laser module.

In addition, the control method may further comprise calculating an extrinsic parameter of a C-arm marker located at the line laser module in the C-arm image, deriving a transformation matrix between the C-arm coordinate system and a C-arm marker coordinate system based on the C-arm marker, deriving a transformation matrix between the C-arm marker coordinate system and a line laser module coordinate system based on the line laser module, and deriving a transformation matrix between the C-arm coordinate system and the line laser module coordinate system.

In addition, the line laser module may include: a green laser configured to generate a laser beam; a rotation line generator configured to transform the laser beam into a line laser rotating around an origin; a rotating mirror configured to change a rotation central axis of the line laser; a first motor connected to the rotation line generator to operate under the control of the control unit; and a second motor connected to the rotating mirror to operate under the control of the control unit, and said step of controlling the line laser to be generated based on the vector perpendicular to the plane formed by the line laser may include controlling the first motor and the second motor.

In addition, said step of controlling the line laser to be generated based on the vector perpendicular to the plane formed by the line laser may include controlling the first motor and the second motor by calculating steering angles of the first motor and the second motor, respectively, from the vector perpendicular to the plane formed by the line laser.

Meanwhile, a laser guidance system according to another aspect of the present disclosure comprises: a C-arm fluoroscopy (hereinafter, a C-arm); a display device configured to display an image photographed using the C-arm and receive operation information of an insertion location and an insertion angle from a user; and at least two laser projection apparatuses configured to project the operation information directly to an affected part, wherein the laser projection apparatus may include: a line laser module configured to generate a line laser to form a plane by rotating around an origin; a matching unit configured to calculate a coordinate representing the insertion location in a C-arm coordinate system based on the C-arm, calculate an insertional vector according to the coordinate representing the insertion location and the insertion angle, and calculate a vector perpendicular to the plane formed by the line laser in the C-arm coordinate system according to the insertional vector; and a control unit configured to control the line laser module based on the vector perpendicular to the plane formed by the line laser.

Meanwhile, the operation information may be displayed as an intersection point of line lasers generated from the at least two laser projection apparatuses.

In addition, the matching unit may be configured to calculate a coordinate representing the origin in the C-arm coordinate system, and calculate the vector perpendicular to the plane formed by the line laser by performing vector product to a vector connecting the coordinate representing the insertion location and the coordinate representing the origin and the insertional vector.

In addition, the line laser module may include: a green laser configured to generate a laser beam; a rotation line generator configured to transform the laser beam into a line laser rotating around the origin; a rotating mirror configured to change a rotation central axis of the line laser; a first motor connected to the rotation line generator to operate under the control of the control unit; and a second motor connected to the rotating mirror to operate under the control of the control unit.

In addition, the control unit may be configured to control the first motor and the second motor by calculating steering angles of the first motor and the second motor, respectively, from the vector perpendicular to the plane formed by the line laser.

In addition, the line laser module may further include a calibration tool located between the line laser module and the C-arm so that a calibration pattern is attached thereto.

In addition, the display device may include: a panel configured to display an image photographed using the C-arm; and an interface unit configured to provide a user interface allowing a touch input of a user to the panel and detect a touch input applied by the user.

Advantageous Effects

According to the present disclosure, since the operation information of the insertion location and the insertion angle planned on the C-arm image is directly displayed on the affected part as an intersection point of two line lasers, it is possible to help a the user (for example, a doctor) to precisely and easily perform a surgical operation.

