Patent Application
20230130653
This application claims the benefit of European Patent Application No. 21204576.9, filed Oct. 25, 2021, which is incorporated herein by reference in its entirety.
The invention relates to an arrangement for positioning a patient's body and tracking the patient's position during surgery.
U.S. Pat. No. 9,433,387 B2 discloses a system for obtaining cranial or other scans from a patient. The system comprises a diagnostic scanning table and a mold that conforms to a portion of a patient's body contour. In one embodiment a mask for encompassing the patient's head is provided. Sensors are placed within the mold or mask for obtaining pressure readings, which may indicate movements of the patient such as a swallowing action. The signals of the sensors may be used for avoiding inaccuracies during the scan due to movements of the patient. For doing so, the sensors are coupled to the scanning system.
Furthermore, US 2019/0105423 A1 discloses the support for a patient's limb. This support comprises a network of flexible multi lumen tubing interlaces, which form a lattice structure. By inflating the multi lumen tubing a limp says within the support may be immobilized.
The article V. Edward, C. Windishburger et al., Quantification of fMRI Artifact Reduction by a Novel Plaster Cast Head Holder (published online September 2000), Wiley-Liz, Inc. discloses a plaster cast head holder for immobilization and repositioning a patient's head during an fMRI scan. The plastic cast head holder will decrease the magnitude of unintentional head movements and reduce movement artifacts. The plastic cast head holder comprises a head mask with malleable fixation material, which is stiff in its fully hardened state.
While there is a wide variety of techniques for acquiring images from patient's body before surgery, as for example ultrasonic imaging radioscopy, computer tomography (CT), or magnetic resonance imaging (MRI), the surgeon may still have problems with identifying objects and tissues viewed with the camera during surgery.
In US 2016/0249987 A1 a sensor is attached to an anatomy of the patient before the surgery whereas during surgery a computing unit is in communication with the sensor enabling to register the patient's anatomy during surgery. The patient's anatomies used for attaching the sensor are for instance bones or relatively rigid organs. This approach, however, requires additional invasive surgical interventions before the actual surgery, which means additional costs as well as additional physical strain for the patient. Also the patient's soft tissues such as muscles, tendons, ligaments, fat, fibrous tissue, lymph and blood vessels can deform during a repositioning of the patient's body, viz. a change of the position and/or orientation of the patient's body or parts of the patient's body. A repositioning can result in a redistribution of weights, which in turn can result in deformation of the patient's body. Therefore, there is a strong desire to obviate the above-mentioned problems and help the surgeon to orientate during surgery.
This objective is solved by the arrangements and by the methods disclosed herein.
The inventive arrangement comprises a body shape capturing device, a processing unit, a 3D shape generating device and a localization or detection system. The body shape capturing device is adapted to acquire a (outer contour) shape of at least a part of the patient's body. The processing unit is adapted to generate a data representation of the patient receiving device adapted to at least partially receiving a patient's body. The data representation of the receiving device is generated based on the patient's shape. The term patient's shape may be understood as the outer contour of his or her body. The 3D shape generating device is adapted to additively manufacture at least parts of the patient receiving device based on the data representation. For example, the shape generating device can be a 3D printing device. The patient receiving device comprises at least one tracker element that is connected to the (patient receiving) device and adapted to indicate the position and orientation of the patient receiving device. The localization or detection system is adapted to capture data indicating the at least one tracker element's position and/or orientation during surgery. The patient's body shape scan can be performed before any medical scan or live scan is performed gathering the (outer contour) shape of at least a part of the patient's body.
Alternatively, the shape of the patient's body part can be directly obtained from a medical scan without the necessity of performing a shape scan beforehand, e.g. utilizing an automatic skin segmentation of the body part in the medical scan. Obtaining the shape of the patient's body part directly from a medical scan can reduce the risk of further changes of the position of the patient's body part from the medical scan to the surgery. A mechanical scanner, a laser scanner, structured light illumination and camera system, a stereoscopic or multi camera system or any other suitable shape acquiring device can be used for scanning the shape of the body or at least a part thereof. The so acquired data characterizing the patient's body shape are used in a processing unit to generate a data representation of the patient receiving device. An inner shape of the patient receiving device can be adapted to the (outer counter) shape of the patient's body. Alternatively or additionally, at least parts of the inner shape of the patient receiving device can deviate from the precise outer contour shape of the patient's body enabling to reposition at least parts of the patient's body and/or or redistribute the weight of the patient's body e.g. by reforming parts of the patient's soft tissue.
The 3D shape generating device can in particular print a plaster, a fiber glass or a resin based cast creating a three-dimensional structure. This process can enable a better fitting of the patient receiving device to the patient's body by removing constructional limitations in designing the patient receiving device. The inventive concept can further enable including movably connected structures/parts such as cover structures for surgical windows and/or joints enabling easy attachment and removal of the patient receiving device from the patient's body.
The patient receiving device will be used for positioning and/or shaping the patient during the surgical procedure in the same shape or in a corrected shape as it was during a medical imaging.
The at least one tracker element is connected to the patient receiving device and is adapted to indicate the position and orientation of the patient receiving device. In other words, the at least one tracker element is adapted to indicate the location (X, Y, Z) of at least one point in space of the receiving device in combination with free orientations (angular orientation around axes X, Y, Z). Alternatively, two or more tracker elements may be provided for indicating the spatial position and orientation of the patient receiving device.
Furthermore, the arrangement comprises a localization or detection system for capturing data indicating the position and orientation of any of the tracker elements in example cameras, a CT scanner, an x-ray apparatus or any other arrangement or medical imaging device.
In a second embodiment the arrangement further comprises:
A medical imaging system, a live imaging device and a computation unit. The medical imaging system is adapted to acquire at least one at least two dimensional medical image of the patient's region of interest in relation to the at least one tracker element. The images may be acquired in a preoperative scan or even during surgery. The tracker's attachment to the patient receiving device may be localized or detected therewith. A medical imaging device may comprise a processing unit, which generates the scan image within a coordinate system with that tracker elements located in the same coordinate system.
At the operation site the localization or detection system is provided for capturing data indicating the tracker's position and/or orientation during surgery. The data regarding the position and/or orientation of the trackers may be captured by at least one tracking camera. The camera might or might not be close to the surgical site but kept at a distance. However, line of sight visibility should be ensured.
Alternatively, an active tracking method may be used where the patient receiving device may emit at least one signal such as a radio frequency (RF) signal, a light signal or an ultrasonic signal. The signal of the patient receiving device can be received and used for capturing/obtaining the patient receiving device position and/or orientation during surgery. For example RF trackers can be embedded in the patient receiving device during or after manufacturing. In that case the data are captured/transmitted from the site the trackers are placed.
Since the patient is placed within the same individually shaped portion of the patient receiving device as he or she was during the medical imaging process, the patient's body will take the same shape surgery as it had during the medical scan. Therefore, the data captured by the localization or detection system precisely indicates the position and orientation of the patient receiving device and hence the position of tissue structures of the patient. The shape adaptive receiving device will now reshape the patient's body and make sure that all tissues of the patient are in the same place as they have been during the medical scan. This is in particular important for surgical operations on or in soft tissues with high flexibly and with no specific natural or artificial landmarks. The computation unit may register and blend the scan image and the live image and provide perfect orientation for the surgeon. In particular, the inventive system provided the following advantages:
1. There is no need for preoperative interventions for implanting tracking markers or markings inside the patient's body.
2. There is no need for using screws, pins or the like in bones or target structures. Therefore, additional surgical procedure and potential complications can be avoided.
3. There is reduced or even no need for using additional medical imaging devices during the surgical operation.
4. The inventive method and system do not rely on rigid anatomies (as there are bones) or organs with though deformation.
The invention avoids changes in the contour of a patient's torso due to redistribution of the weight caused by changing the patient's outer contour or position. Therefore, the invention allows for acquiring medical images and performing the surgical procedure afterwards. The surgical procedure may be performed in a position of the patient different from the position during medical imaging.
In particular, the processing unit is further adapted to compute the at least one outer contour shape using the medical scan image so that a separate shape scanning of the patient's body can be avoided.
Preferably, the patient receiving device comprises a movable table and an additively manufactured structure that is placeable on, and connectible to, the movable table. The additively manufactured structure may be removably connected to the movable table. The movable table can support the patient's body.
In particular, the 3D shape generating device is adapted to additively build the additively manufactured structure which can be placed on and removably connected to an upper surface of the movable table. Alternatively, the additively manufactured structure is built separately in several pieces and assembled together after building.
Preferably, an inner shape of the additively manufactured structure is at least partly adjusted to the patient's outer contour shape. This allows the patient's position and/or orientation from the medical scan to be maintained and/or re-established for surgery.
Additionally or alternatively, an inner shape of the additively manufactured structure may at least partially deviate from the outer contour shape bringing the patient's body into a desired position, orientation, and/or shape. This allows for bringing the patient's body or at least parts of the patient's body into a position, orientation and/or shape that in turn allows the surgeon to have better access to regions of interest during surgery compared to the original position, orientation and/or shape.
Moreover, the additively manufactured structures may comprise at least two pieces that are configured to be assembled, disassembled, and/or reassembled. So a faster building process and lower complexity of the individual parts results. A receiving structure may also be easier removed or reassembled.
Preferably, the receiving device may comprise an opening that exposes the surgical sites. The opening allows for easy access to the surgical site. The opening may comprise a cover flap that enables to open or close the opening.
Preferably the tracker element is adapted to indicate the position and orientation of the patient receiving device in space. The at least on tacker element is firmly connected to the receiving device. The detection system may be placed at the surgical site of the arrangement and comprises preferably at least two cameras or other positional detectors for trigonometrically determining the place (and if necessary the orientation) of the at least one tracker element in space. The detection system can be adapted for performing a triangulation measurement determining the tracker element's position in space. Moreover, an imaging system may comprise at least one tracker element or any other sensor connected to a detection system adapted to detect localization and orientation of the camera. The detection system may be connected to the computation unit, which accordingly may register the live image and the scan image.
Furthermore, the computation unit may comprise a structure detecting unit for generating graphical representations of tissue structures. The graphic representations may be obtained from the medical images. The graphical representations may be lines, symbols, colored areas or anything else adapted to indicate regions or tissues the surgeon shall distinguish from other regions or tissues. These graphical structures may be blended into the live images, which helps the surgeon to find structures to be treated within the region of interest.
Preferably, the 3D shape generating device is adapted to additively build the at least one tracker element, wherein the at least one tracker element is connectable to a (upper surface) of the movable table and/or a (upper) surface of the additively manufactured structure. Alternatively, if the tracker element is an active tracker, the at least one tracker element may be embedded in the patient receiving structure. If the tracker element is a passive tracker, the tracker element may comprise reflector elements that are spaced apart one from another and detectable by the detection system.
Preferably, the detection system comprises at least two cameras for trigonometrically determining the place and the orientation of the at least one tracker element and space. Alternatively, the detection system may comprise a 3D camera acquiring image as well as depth information.
In a specific embodiment, the arrangement may involve an instrument for treating the patient's body in the region of interest. The instrument may be any type of RF surgical, cryosurgical, plasma surgical or any other surgical instrument. In particular, the instrument is adapted to be placed within the field of view of the live imaging device. The live imaging device may be part of the instrument, a separate camera inserted into a trocar, or a separate camera placed at, on, or in the patient's body.
The inventive method comprises the steps of:
Preferably, the manufacturing of the patient receiving device comprises additively building an additively manufactured structure comprising an inner shape that is at least partly adjusted to the (outer contour) shape of the patient's body and/or partly deviates from the (outer contour) shape bringing the patient's body into a desired position, orientation and/or shape.
The features and advantages that are mentioned with respect to the arrangement also apply to the inventive method.
Further details and features may be found in the drawings, the description and the claims as well.
The patient receiving device 14 comprises at least one tracker element 16 that is firmly connected to the patient receiving device 14. The tracker element 16 is adapted to indicate the positon and orientation of the patient receiving device 14. In the present example there are three tracker elements 17, 18, 19, which in the present case are balls fixed at the ends of a tree 20 in known distances one from another. Balls 17a, 18a, 19a may be light reflecting or light absorbing balls visible ball the imaging system 21. In the present case three tracking elements 17, 18, 19 are provided for unambiguously indicating the location and orientation of the patient. However, while three balls 17a, 18a, 19a placed on the ends of the tree 20 give a fairly good indication of the location and orientation of the patient it is also possible to place three different balls independent from one another at different places of the patient receiving device 14.
If the tracker elements 17, 18, 19 will be optically detected they will be placed at a visible side of the patient receiving device 14. Furthermore, it is possible to use only one item as a tracker element 16 e.g. one cube firmly connected to the receiving device 14. Other tracker elements having different designs are also well applicable.
After manufacturing, the patient receiving device 14 can be put on or around the desired region of the patient's body so that the patient's body is brought into a desired position, orientation and/or shape. For instance, the desired region of the patient's body 13 may be marked before the shape scan with reference markers 27 that are affixed and/or painted on the patient's body 13. The desired region of the patient's body is the torso of the patient in
In
A medical imaging system 24 may additionally be used as a means for capturing data indicating the portions of the tracker elements 17, 18, 19 during operation of the imaging system in example during the scanning of the patient's body 13. Alternatively, a separate detection system may be provided for detecting and locating the tracking elements 17, 18, 19 and bringing the images 25 into special relation to the tracking elements 17, 18, 19.
Part of the arrangement may be an operation site 28 illustrated in
At the operation site 28, a localization or detection system 29 is provided for capturing data fed into a localization or detection processing unit 30 connected to the storage 26. The localization or detection processing unit 30 may be identical with the image processing unit 24 of
Part of the arrangement is a live imaging device 33 which can be another camera for acquiring live images as separately illustrated in
The live image 36 may be fed to the processing units 24, 30 as illustrated in
In
The so far described arrangement operates as follows:
Before surgery the patient will be placed on the table 23 and the body shape capturing device 11 acquires a shape S of the patient's body 13 as illustrated in
After the patient receiving device 14 is manufactured and put on or around the patient, the imaging system 21 may acquire scan images 25a to 25z, which images are stored by processing unit 24 in the storage 26. Afterwards the patient may leave the receiving device 14 and prepare for surgery, which may follow within a short period of time and sometimes within hours or days.
For surgery the patient reenters the patient receiving device 14 as illustrated in
At the beginning or before the beginning of the surgery the detection system 29 will be activated which captures position of the tracking elements 17, 18, 19. So the processing unit 24, 30 will be registered the position of the patient's body to the scan images 25a to 25z as illustrated in
The detection system 29 or any other tracking system for determining the position and orientation of the camera 33 continuously processes data from which a processing unit 24, 30 determines the place and orientation of the field 34 of the camera 33 and hence the place of the live image 36 and the viewing direction to the live image. As illustrated in
The processing unit 24, 30 will then merge and blend the live image 42 (
Furthermore, the processing unit 24 or 30 may alternatively or additionally use graphical presentations 48 of tissue structures and blend those graphic representations 48 into the live image. Any of the scan images 25 the image obtained by intersecting the volume model 41, and a graphic representation 48 obtained from at least one of the scan images or from the volume model 41 are considered being a “scan image” for blending with the “live image”. The arrangement further comprises an image display 49 for reproducing the blended image. The display 49 may be a screen, a virtual reality head set or another means for showing the blended image.
The inventive system uses a body shape capturing device for acquiring a patient's body shape and a 3D shape generating device for additively manufacturing a patient receiving device that is at least partially adapted to the patient's body shape or at least partially deviates from the patient's body shape bringing the patient's body into a desired shape so that the outer shape of the patient's body during surgery is identical to the outer shape of the body during shape capturing. The patient receiving device comprises at least one tracker element that is detectable by a detection system. The detection system is adapted to capture data indicating the at least one tracker element's position and/or orientation during surgery enabling in particular important for surgical operations on or in soft tissues with high flexibly and with no specific natural or artificial landmarks the surgeon to orientate/navigate in live images from the surgical site.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21204576.9 | Oct 2021 | EP | regional |
