DE102012217077A1 - Arrangement for positioning and aligning e.g. movable C-arm for diagnostic and therapeutic operation to patient, has ultrasound unit formed with marker, where ultrasound unit with sensors and markers is inserted within sterile region - Google Patents

Abstract

The arrangement has an ultrasound unit (U) formed with a navigation marker (NMU). Position and/or alignment of the ultrasound unit are determined and used for positioning and alignment of a controllable medical device (MR) if an ultrasound image recorded by the ultrasound unit comprises a selected area in a patient (P). A navigation system (NSY) comprises an evaluation and drive unit (AWS) for determination of position and/or orientation data from the marker and others navigation markers (NMR, NMRS). The ultrasound unit with sensors and the markers is inserted within a sterile region. An independent claim is also included for a method for positioning and alignment of a controllable medical device.

Description

The invention relates to a device and a method for positioning and alignment of a medical device unit

For diagnostic and therapeutic uses, for example, imaging units are used. By way of example, an X-ray unit arranged on a C-shaped support can be used as the imaging unit. This C-arcuate carrier may be disposed on a mobile chassis. With this X-ray unit, for example, X-rays must be taken before an intervention on a patient. In addition, during surgery, u.U. perform a repeated positioning and / or alignment of the X-ray unit on the patient to create X-ray record of the surgical progress. In particular, a selected orientation or positioning of the C-arm is required for each X-ray image in order, for example, to align the X-ray source of an X-ray unit so that a doctor can make a targeted diagnosis or perform an intraoperative check.

So far, it is common that the mobile X-ray machine is positioned by the assistant or by the attending physician himself at the patient, to then align the X-ray unit manually on the patient. This entails, in addition to a possible contamination of a region to be kept sterile around the area of the procedure, the additional disadvantage that due to inaccurate knowledge of the location and location of the area to be imaged, an X-ray must be repeated, exposing the patient to a renewed X-ray exposure ,

The invention has for its object to provide a further arrangement and an associated method for eliminating the disadvantages listed.

The object is solved by the features specified in claim 1 or 7 features.

In the arrangement and the associated method according to the invention, the position of an ultrasound unit provided with at least one sensor and / or with navigation markers is detected in the presence of a meaningful ultrasound image of an application area to be assessed by the doctor. The orientation and position of the ultrasound unit is stored and aligned the X-ray unit according to the orientation of the ultrasound unit and / or the orientation of the ultrasound image. Further parameters, such as, for example, the depth resolution of the ultrasound waves emitted by the ultrasound unit, which led to the creation of the ultrasound image, can be used to determine an isocenter in the creation of a 3D data volume set from the area of use.

An evaluation and control unit is designed such that the alignment of the ultrasound unit is detected and the medical device is aligned thereon by means of a device axis associated with the medical device or the central beam of the x-ray source.

In a further refinement, the position of the patient and the orientation of the lying unit on which the patient is placed are likewise detected by means of sensors and / or navigation markers and taken into account in a positioning and alignment of the x-ray source.

The invention has the advantage that, because of the targeted alignment of the X-ray source of the X-ray unit for an X-ray, the patient is exposed only once to the X-ray radiation necessary for this purpose.

The invention has the advantage that the orientation of the X-ray device can be based on the orientation and position of the ultrasound unit.

The invention has the advantage that a or rotation center can be fixed for a 3D data record.

The invention has the advantage that the ultrasound unit formed with sensors and / or navigation markers can also be used within a sterile area and an alignment of the X-ray unit provided with electrical drive means takes place without manual use.

The invention has the advantage that the movement and the positioning and alignment of the device is collision-monitored.

The invention has the advantage that the orientation and the location coordinates of a positioned ultrasound unit and / or an ultrasound image can be stored and / or a relative movement of the patient and / or the couch during a repositioning can be taken into account.

The invention will be explained in more detail below by means of an embodiment shown in a drawing.

The invention is based on the idea to view a medical imaging unit, in particular the X-ray source of a mobile C-arm, as a device to be navigated. Through this Consideration can be achieved that an exact positioning of the X-ray source by the orientation of the ultrasound unit and / or the ultrasound image can be derived.

Particularly often, a C-arm is used as a carrier of a medical imaging device. Especially when this is mobile, the degrees of freedom in the movement of the C-arm are particularly large. This brings a particularly high flexibility in terms of positioning and alignment possibilities with it.

In a further embodiment, a positioning of the imaging device from image data of a recording, in particular a Ultraschallaufname is calculated from the intervention area on the patient.

In this arrangement and the associated method for positioning devices, in particular a C-arm, the position and orientation of an ultrasound device are detected by means of a navigation system and implemented to align the C-arm, when there is an interventional imaging in a patient ultrasound recording. In a 2D image, the position and orientation of the central beam of the X-ray source can be determined based on the ultrasound image. When offsetting several 2D X-ray images to a 3D X-ray image, an associated rotation center can be determined on the basis of the present ultrasound image.

The following exemplary embodiment relates, for example, to a mobile device, in particular to an X-ray device with a C-arm, at whose ends an X-ray source RS and an X-ray detector RD are arranged. In this arrangement and a related method, the positioning of the X-ray source RS and / or a device system by the positioning and alignment of an ultrasound unit U. This device system, in addition to the already mentioned mobile C-arm, e.g. also a kidney stone smashing device or an X-ray system formed with a robotic arm. The arrangement and / or method comprises navigation markers, in particular optical navigation markers, a navigation system NSY designed with a stereo image camera, a screen unit B for acquiring the ultrasound image, an evaluation and control unit AWS comprising processing modules V1, V2, a conversion unit UE and a mobile x-ray unit MR with a control unit SS on. The navigation system NSY, for example, works with infrared light. As a further embodiment of the navigation markers, these can be designed as sensors or in the form of transmitting / receiving units. The location coordinates are determined by the different navigation markers of the positioning systems. Angle sensors or acceleration sensors could also be used as sensors and / or high-frequency signals emitting transmitting units with corresponding receiving units and RFID units could be used.

In this exemplary embodiment, the ultrasound unit U is designed such that it has at least one optical navigation marker NMU. The activation of the drive means of the mobile X-ray unit MR can be done by control functions. The control functions may also cause, for example, a lifting, lowering, turning, tilting or movement in the plane of the C-arm according to the movement directions indicated in the drawing.

After evaluation of the ultrasound unit U moving in space with respect to location and orientation, servo motors can be actuated via the control systems SS assigned to the C-arm and an X-ray unit R formed from the X-ray source RS and an X-ray detector RD can be aligned exactly on the patient. Between the evaluation unit AWS and the device units MR to be aligned, a signal conversion unit UE for voltage level adaptation between the evaluation unit AWS and the system control SS is provided.

The navigation system NSY is based on a first coordinate system K1. The navigation system has, for example, a stereo camera system SK with infrared cameras. The ultrasound unit U is formed at least with a first navigation marker NMU. The mobile X-ray unit MR has at least one second navigation marker NMR, NMRS. The couch L is at least a third navigation marker NML and / or the patient is assigned at least a fourth navigation marker NMP. By means of the at least first navigation marker NMU its positioning and orientation in space can be determined. The navigation system NSY detects the cited first, second, third and fourth navigation markers NMU, NMR, NMRS, NML, NMR and determines at least their respective positions in the first coordinate system K1. Due to the position and orientation of the first navigation marker NMU and the calculated current position and orientation of the second navigation markers NMR, NMRS, the positioning and alignment of the C-arm or the X-ray source RS can take place according to the position and orientation of the ultrasound unit U. In order to take into account the position of patient P and couch L in the orientation of the X-ray source at least the location coordinates of the third and fourth navigation markers are detected by the navigation system NSY and stored in the positioning of the C-arm and in the repositioning of the X-ray source RS considered. Instead of the Infrared cameras can also be used high-resolution video cameras KA. The first, second, third and fourth navigation markers NM are each adapted to the sensitivity of the camera systems used. When using transmitting units with high-frequency signals, the orientations of the alternating electromagnetic fields of the transmitting units used are calculated by suitable sensors.

The evaluation and control electronics AWS has a first processing module V1 for determining the position of the ultrasound unit U. The position of the ultrasound unit U can be reproduced by means of the first navigation marker NMU and its orientation on the basis of a direction vector RVZ associated therewith. In addition to the alignment of the ultrasound unit U, the coordinates of an isocenter and the vertices of the ultrasound image can be determined and buffered. To determine the isocenter, the penetration depth or depth resolution of the ultrasonic waves emanating from the ultrasound unit U is used. The coordinates of the isocenter may also be used to position the center beam of the x-ray source RS. The coordinates of the vertices of the ultrasound image can be used to adjust the aperture of the X-ray unit and to align the X-ray source. The various calculations for the positioning and alignment and adjustment of parameters at the X-ray source can be done in the already mentioned evaluation and control unit AWS and in the control unit SS. The orientation of the X-ray source RS and the corresponding detector unit RD are calculated on the basis of a device axis RA connecting the two units in a second processing module V2. The connection axis RA is aligned with the direction vector RVZ or the alignment of the ultrasound unit U and control signals for positioning and orientation of the C-arm are initiated.

If an X-ray is needed at the beginning of a surgical procedure to be performed by the patient, the C-arm of the mobile X-ray unit MR is moved up to the area to be imaged on the patient P. This can be done manually or remotely. In both cases, an activated collision monitoring, a collision with other people or objects by signaling and / or by blocking the C-arm receiving mobile chassis can be avoided. The alignment of the wheels of the C-arm can be done with a manual displacement of the mobile X-ray unit due to a desired location specification by the ultrasound unit U. The process of the C-arm takes place in defined paths along the degrees of freedom D, H, K or directions of movement of the C-arm, which are indicated, for example. A collision is also monitored here by means of a collision detection module K. At this the signaling of the at the C-arm, in particular at the outer edges of the X-ray source RS and the X-ray detector RD, attached sensors S are forwarded. If a critical distance is reached and the C-arm continues to collide, the continuation of the C-arm is stopped.

Optionally, a camera system KA with object recognition algorithms can monitor the movement of the C-arm and a collision with other objects by the collision detection module K can be avoided. In the collision detection module K, objects are detected, their direction of motion is determined and possible collision points are calculated and collisions are avoided. When falling below a predefinable allowable approach of objects is controlled in the movement path of movable objects, in particular in the movement of the mobile C-arm, intervened.

If the mobile X-ray unit MR is positioned at the predetermined location, the X-ray source and / or the X-ray detector is aligned. The device axis RA of the mobile X-ray unit MR can be aligned by the orientation predetermined by the ultrasound unit U if the present ultrasound image has all the necessary details for the assessment for the physician.

If the X-ray unit R has taken the X-ray recording unit RD corresponding thereto for X-ray recording, the optimized recording position predetermined by the ultrasound unit U, the X-ray radiation can be triggered by means of a footswitch or trip unit, for example, from an adjacent spatiality.

If the doctor requires a further X-ray image during or after an intervention for the purpose of checking, the orientation of the X-ray source can be determined on the basis of the position and orientation data already determined for a preoperative X-ray image. Must be checked and taken into account a possible change in the position and orientation of the patient P and / or the couch L before another X-ray.

As a parameter value, as already mentioned above, for example, the penetration depth of the ultrasonic waves can be used to determine a possible isocenter in the creation of a 3D data volume set. The navigation marker NMU arranged on the ultrasound unit U is recorded continuously by the stereo camera SK. In the navigation system NSY, the position and orientation of the ultrasound unit U and the orientation of the C-arm are detected and evaluated in the first and second processing units V1, V2. If the ultrasound unit U is directed onto the C-arm R, for example, this is detected by the navigation system NSY and the control electronics are activated by the mobile C-arm MR. The activation could be visually displayed on the C-arm, for example. After the C-arm has been selected, appropriate control functions can be initiated. The process of the C-arm could also be monitored by a camera system KA and stopped on a collision course. The trigger pulses for aligning the device axis RA to the direction vector RVU of the ultrasound unit U can be triggered and / or delivered by actuating a footswitch. The orientation and position of the ultrasound unit U in the room determines the direction and position from which the X-ray is to be taken.

The position and orientation of the ultrasound unit U, as described above, detected by the navigation system NSY. The navigation system can take place on an optical, acoustic or electromagnetic navigation and / or via line-bound or line-free connections. As a wired connections, for example, fiber optic, electrical or mechanical connections can be used. The position and evaluation of the navigation markers can be adjusted with respect to the first coordinate system K1. In an electromagnetic navigation system, a field generator of an electromagnetic system is located directly in the C-arm and / or alternatively in the ultrasound unit U. Alternatively, the position or orientation of the ultrasound unit U relative to the C-arm via acceleration or angle sensors in the ultrasound unit U be determined. In a further refinement, the determination of the position and orientation of the ultrasound unit U can also take place via a cable-bound glass fiber system. In a further alternative embodiment of the navigation system, an orientation of ultrasound unit U and C-arm, e.g. done by measuring axial inclinations.

With the help of the ultrasound unit, a trajectory can also be defined and a sequence of X-ray images can be created.

LIST OF REFERENCE NUMBERS

ABY

navigation system

SK

stereo camera

KA

camera

U

ultrasound unit

K1

first coordinate system

NMU

first navigation marker

NMR, NMRS

second navigation marker

NML

third navigation marker

NMP

fourth navigation marker

MR

mobile x-ray unit

R

X-ray equipment

RD

X-ray detector

RS

X-ray

RA

Device axis / central beam of the X-ray unit

D, K, H

Degrees of freedom of the X-ray device

BE

operating element

AWS

Evaluation and control unit

B

Monitor / computer unit

V1

first processing module

V2

second processing module

K

Collision detection module

S

sensor

SS

control system

L

lounger

P

Object / patient

RVU

Direction vector of the first navigation marker

of the

 ultrasound unit

Claims (9)

Arrangement for positioning and alignment of a controllable medical device (MR), characterized in that an ultrasound unit (U) is formed with at least one first navigation marker (NMU) whose position and / or orientation can be determined and these for the positioning and alignment of the medical device (MR) are used when an ultrasound image taken by the ultrasound device (U) has a selected area at an object (P). Arrangement according to claim 1, characterized in that a navigation system (NSY) an evaluation and control unit (AWS) for determining position and / or alignment data from the at least first navigation marker (NMU) and the medical device (MR) associated second navigation markers ( NMR, NMRS). Arrangement according to one of the preceding claims, characterized in that a navigation system (NSY) an evaluation and control unit (AWS) for determining position and / or alignment data of a third Liegeeinheit (L) and fourth an object (P) associated navigation markers ( NML, NMP). Arrangement according to one of the preceding claims, characterized in that the evaluation and control unit (AWS) at least one first and / or second processing module (V1, V2) for evaluating the alignment of the first to fourth navigation markers (NMU, NMR, NMS, NML, NMP), wherein the positioning and alignment of the medical device (MR) on the basis of the ultrasound device (U) arranged navigation marker (NMU) takes place. Arrangement according to one of the preceding claims, characterized in that the medical device (MR) is a mobile C-arm with an X-ray source (RS) and an X-ray detector (RD) having X-ray device (R). Arrangement according to one of the preceding claims, characterized in that the evaluation and control unit (AWS) is designed such that the alignment of the ultrasound unit (U) detected and with the medical device (MR) associated with device axis (RA) or an outgoing central beam the X-ray source (RS) is brought to coincide. Method for positioning and alignment of a controllable medical device (MR), characterized in that data for the position and orientation of an ultrasound unit (U) detected and its position and / or alignment data for the positioning and alignment of the medical device (MR) are used when an ultrasound image taken by the ultrasound device (U) is from a selected area in a patient. A method according to claim 7, characterized in that position and / or alignment data from the first and the medical device (MR) associated second navigation markers (NMU, NMR, NMS) are determined. Method according to one of the preceding claims, characterized in that position and / or alignment data of third of a lying unit (L) and fourth an object (P) associated navigation markers (NML, NMP) are determined.

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