Fiber-optic based 3D positioning and tracking of a patient's body part during X-ray examination

Abstract

A system SYS and related method for facilitating medical imaging of a patient by a medical imaging device IA. The system includes an input interface IN for receiving measurements collected by a shape sensing sensor Sj of an optical shape sensing device SSD. The shape sensing sensor Sj is deployable with respect to the patient's body, and the measurements represent the current pose of the patient's body. A pose determiner PD of the system SYS calculates output data indicative of whether the patient's body is in a predefined target pose based on the measurements.

Description

Technical Field

[0001] The present invention relates to a system for facilitating medical imaging of a patient by a medical imaging device, an imaging apparatus using such a system, a related method, a computer program element, and a computer-readable medium.

Background Art

[0002] A chest X-ray examination is one of the most established and first imaging modalities used, for example, to investigate abnormalities in the chest region or for use cases in orthopedics (such as limbs) and dentistry.

[0003] The position and rotation of a patient relative to an X-ray source, particularly an X-ray detector, are two important quality aspects that have a significant impact on the interpretation of chest X-ray images and disease diagnosis.

[0004] In the current hospital and diagnostic center workflows, errors related to the position and orientation of a patient (hereinafter collectively referred to as the patient's pose or posture) can be detected, for example, by analyzing various image features, either before (e.g., using a camera) or after acquiring an image (X-ray). Feedback can be provided to correct such pose errors.

[0005] Once a patient pose error is detected by any means, the next step is to correct the patient's pose and perform imaging.

[0006] In the case of a chest X-ray, it is important to ensure no rotational asymmetry, i.e., that the line formed by the spinous processes is equidistant from the medial ends of the clavicles or scapulae, in order to avoid biometry and false inferences in the X-ray image. This requires a specific pose related to the patient's torso. There is also another specific pose required related to the patient's arms to rotate the scapulae outside the lung fields. The correct pose is even more important, for example, in X-ray images of limbs where incorrect positioning can adversely affect interpretation.

[0007] It is not uncommon to need to perform acquisition several times until a skeletal image for diagnosis is obtained.

Summary of the Invention

Problems to be Solved by the Invention

[0008] For radiation protection and time saving, it is desirable to recognize such a posture error and correct the posture before imaging in order to "make it correct from the beginning".

[0009] In particular, an efficient imaging method is required in other modalities regardless of whether it is X-ray projection imaging or an X-ray examination.

Means for Solving the Problems

[0010] The object of the present invention is achieved by the subject matter of the independent claims, and other embodiments are incorporated in the dependent claims. Note that the aspects of the present invention described below are similarly applicable to related methods, imaging devices, computer program elements, and computer-readable media.

[0011] According to a first aspect of the present invention, a system for facilitating medical imaging of a patient by a medical imaging device is provided. This system an input interface for receiving measurement values collected by a shape sensing sensor of an optical shape sensing device, the shape sensing sensor being deployable with respect to the patient's body, the measurement values representing the current posture of the patient's body, and a posture determiner configured to calculate output data representing whether the patient's body is in a predefined target posture based on the measurement values.

[0012] The sensor set can be arranged along the length of an elongate structure, such as along the length of an optical fiber, wire, or other such structure. Preferably, optical shape sensing is used. Preferably, the elongate structure is deformable to respond to changes in posture, thereby providing a shape sensor reading or measurement value representative of the posture change. The sensor set (sensor elements) may include one or more cores of an optical fiber, and / or gratings (such as fiber Bragg gratings), or other arrangements included within a given optical fiber core capable of measuring shape changes. The sensor set is arranged on a patient such that an associated posture change causes a change in the shape of the elongate structure captured by the set of shape sensing sensors.

[0013] The target posture includes, in particular, a "local" posture, i.e., the spatial mutual configuration of a given patient's anatomical structure or body part. The "global" posture includes associating the "local" posture with an external coordinate system, such as another object like a detector or an X-ray source. The posture is related to the posture of the arm, leg, torso, head, etc., but the posture may also include a posture such as an inhalation state because it is related to a specific posture of the chest.

[0014] In an embodiment, the system comprises an output interface for providing output data. The output data includes one or more of i) data representing the current posture, ii) data representing the case when the patient's body is determined to be in a pre-defined target posture, and iii) data representing the case when there is a deviation between the pre-defined target posture and the current target posture.

[0015] In an embodiment, the output interface includes any one or more of a display device and a tactile actuator. For example, the tactile actuator may be incorporated into or attached to the sensor. Generally, the output interface is configured to support any one or more of various imaging tasks, including the control of the operation of the imaging device. Therefore, the output interface can include one or more appropriate control interfaces. The output interface is used to provide the user, preferably in real time, feedback in any means regarding the patient's posture and / or whether this posture is the target posture.

[0016] In an embodiment, the system includes a logic circuit configured to recommend to the user to start imaging, or a logic circuit configured to automatically start messaging when the output data indicates that the patient's body is in a pre-defined target posture. The logic circuit stops imaging until the output data indicates that the patient's body is in a pre-defined target posture. The logic circuit may use the control interface for control tasks.

[0017] In an embodiment, the measurement values include measurement values collected by another set of shape sensing sensors that can be arranged in a pre-defined spatial relationship with respect to the detector module of the medical imaging device.

[0018] In an embodiment, the other set of shape sensing sensors can be arranged in a layout that defines a reference plane that functions as a reference frame for determining the patient's posture with respect to the detector.

[0019] In an embodiment, the other shape sensing sensors can be arranged within, on, or above the detector module.

[0020] In an embodiment, the shape sensing sensors can be arranged on the patient's body.

[0021] In an embodiment, the shape sensing sensor can be disposed at an anchor point that defines the region of interest.

[0022] In an embodiment, the shape sensing sensor can be included within a wearable such as clothing or can be attachable to the wearable.

[0023] In an embodiment, the measurement values include other measurement values collected by yet another shape sensing sensor that can be disposed on the imaging device, and the system further includes an imaging geometry determiner configured to determine the current imaging geometry of the imaging device based on the other measurement values.

[0024] For example, the above imaging geometry includes any one or more of the source-detector distance (SID), the inclination of the detector plane with respect to the imaging axis of the imager extending from the center point of the detector plane to the focal spot of the source of the imager. Therefore, the logic circuit takes such imaging geometry into account and permits imaging only when the correct imaging geometry is achieved. Accordingly, the system monitors the patient posture and the imaging geometry. It is preferable to perform both in combination, but in some cases each may be performed independently.

[0025] In another aspect, there is provided an imaging device including a medical imaging device and a shape sensing sensor disposed on the medical imaging device, and an imaging apparatus that supplies shape measurement values to a system for determining a patient posture.

[0026] In an embodiment, the imaging device has a detector module, and the shape sensing sensor is disposed on or in the detector module. This arrangement defines a (reference) plane / frame on or with respect to the detector module, and can robustly and accurately determine the patient posture with respect to the detector for better image quality.

[0027] In yet another aspect, a wearable is provided that includes a set of sensors, such as optical fibers, and a transmitter interface for sending readings to a system for processing the readings related to postural changes of a patient wearing the wearable.

[0028] In another aspect, a computer-implemented method is provided for facilitating medical imaging of a patient by a medical imaging device. The method includes receiving measurements collected by a shape sensing sensor of an optical shape sensing device, the shape sensing sensor being deployable with respect to a patient's body, the measurements representing a current posture of the patient's body, calculating output data representing whether the patient's body is in a pre-defined target posture based on the measurements.

[0029] The method may further include obtaining whether the patient's body is in a pre-defined target posture based on the output data.

[0030] The method may further include performing a control task for supporting imaging based on the obtained result.

[0031] The above reference to "the patient's body" may relate to the whole body or a part or multiple parts thereof.

[0032] In yet another aspect, a computer program element is provided that, when executed by at least one processing unit, is adapted to cause the processing unit to perform the above method.

[0033] In yet another aspect, at least one computer-readable medium storing the above program element is provided.

[0034] In yet another aspect, a wearable is provided that includes an optical fiber and a transmitter interface for sending readings to a system for processing the readings in relation to a postural change associated with a patient wearing the wearable.

[0035] In embodiments, the set of one or more sensors are each an optical fiber or include an optical fiber. The one or more fibers are used to collect data (curvature points) regarding the posture of a relevant anatomical region of the patient's body and, in some embodiments, are also used to collect data regarding the posture of a reference frame associated with the detector module of an imaging device. One sensor set is placed on the patient and another sensor set is placed on the x-ray detector of the imaging device. In this way, the deviation from a target posture of the current patient posture can be measured. Preferably, real-time feedback regarding the posture deviation for posture correction can be provided by driving a display device, by controlling a lamp, an acoustic transducer, a tactile transducer, or any other suitable transducer. The feedback can be provided to the user and / or the patient.

[0036] More specifically, and in some embodiments, the system can include such a set of sensors as an optical fiber (such as a strip, or other elongated form). One or more of the above fibers can be attached to the patient's body with respect to the anatomical region to be imaged. This optical fiber (the "patient fiber") is used for curvature sensing caused by the patient's movement. Another optical fiber can be placed around the detector module. This fiber provides a reference frame for curvature sensing captured via the patient fiber. Preferably, both fibers are attached to the same sensing system. Preferably, both are supplied from the same light source (transmitter) of the shape sensing system. A LASER-based shape sensing system may be used. By using the same light source, a common coordinate system can be defined and the relative distance between any pair of points on the two fibers can be measured. For example, in a chest X-ray, one optical fiber is attached to the detector module and arranged along the perimeter of the detector module. The patient fiber is attached to the patient and arranged, for example, from one wrist across the shoulder to the other wrist. In embodiments, many other such layouts for placement on the patient are envisioned. For example, the patient fiber can be adhered to the patient's skin, embedded in clothing items (such as socks, shirts, headbands, etc.), attached to the patient using a stretchable attachment system, or fixed in another manner. For imaging tasks other than chest imaging, other layouts may be required. However, even in chest imaging, fiber layouts other than those passing through the wrists or back are possible and are envisioned herein.

[0037] The described system and method enable, for example, sufficiently accurately identifying the position of a patient's body part relative to a detector in 3D space, thereby facilitating pose correction. However, the use of a second set of shape sensors in the detector is not necessarily required in all embodiments herein, and only the shape sensing measurements collected on the patient may be sufficient, for example, if appropriate pre-calibration is performed. Herein, it is preferred to use a second set of sensors in the detector, as it enables a more robust and accurate determination of the correct patient pose with respect to the detector (optionally the X-ray source). It is also possible to place a (one or more) second set of sensors on the X-ray source instead of the detector. In another embodiment, at least two additional sets of sensors can be used, one on the detector and the other on the X-ray source.

[0038] The system and method proposed herein can sufficiently accurately determine the patient pose (with respect to one or more body parts) before and during imaging (such as X-ray imaging) and can be easily integrated into the current standard treatment workflow.

[0039] Optionally, the pose of the patient relative to the X-ray detector can be determined by using a second set of sensors / second fibers in addition to the patient fibers. Such a system is more robust to changes in the imaging geometry, such as changes in the pose of the detector (change in orientation or position).

[0040] Optionally, by implementing the system on a high-performance computing device, real-time tracking of the pose can be performed.

[0041] Thanks to the correct pose, the ambiguity during reading regarding the image appearance is reduced or avoided, thereby enabling the obtaining of correct findings. It is welcomed by users and patients as it reduces the likelihood of re-imaging and can reduce the radiation dose and time.

[0042] The proposed system is superior to conventional camera-based systems. Since any camera can be completely avoided, it leads to better patient privacy. There is no need to collect confidential data. Also, camera-based pose control (such as RGB or depth cameras) is expensive, requires complex calibration and setup overhead, and the field of view is particularly prone to being limited by occlusion. That being said, the proposed system can be used, as needed, together with or in combination with such camera-based systems.

[0043] The principles proposed in this specification are applicable to reconfigurable setups (such as mobile X-rays) or fixed settings.

[0044] The term "user" relates to a person who operates an imaging device or supervises an imaging procedure, such as a healthcare professional. That is, the user is generally not the patient.

[0045] A "patient" is the object of imaging. A reference to a "patient" is not necessarily a reference to the entire patient, and may in some cases be a reference to a part such as a body part or an anatomical feature. Thus, the object of imaging may be related to such a part, which is referred to herein as the region of interest (ROI). The patients used in this specification are mainly human patients, but this specification does not exclude animals such as pets in veterinary applications.

[0046] "Posture / pose" is used herein in the same sense and is related to the position and orientation of body parts, organs, etc., or more generally anatomical features, with respect to a local or global coordinate frame. The posture may include a plurality of different postures, one for each body region, and may or may not include the ROI itself. In particular, the posture / pose may include a "local" posture that is the spatial interconfiguration of the anatomical structure and / or body parts of a given patient. The "global" posture includes associating the "local" posture with an external coordinate system such as a detector or other object.

[0047] Exemplary embodiments of the present invention will be described with reference to the following drawings. The drawings are not to scale unless otherwise specified.

Brief Description of the Drawings

[0048]

Figure 1

Figure 2a

Figure 2b

Figure 2c

Figure 3a

Figure 3b

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0049] First, refer to the block diagram of FIG. 1. FIG. 1 shows the components of the medical imaging device AR assumed in the embodiments in this specification.

[0050] For the configured AR, preferably, the imaging device IA such as a mobile or fixed X-ray-based imaging device, an X-ray imaging imager, and a C-arm is included. Although mainly assuming projection imaging in this specification, tomographic reconstruction using a CT scanner or the like is not excluded in this specification. The imager IA is operable to acquire medical images of the patient PAT during the imaging session, for example, to assist in treatment or diagnosis. As an example, there is a chest X-ray imaging schematically shown in FIG. 1, but in this specification, imaging for other body parts or other purposes is also assumed. In this specification, optical imaging for dermatological examinations or the like is not excluded as an alternative to or in addition to X-ray imaging.

[0051] The imaging device AI includes a computing system SYS realized by one or more fixed or mobile computing devices. Generally speaking, the computing system SYS facilitates and provides computer-assisted patient posture control and / or tracking, preferably in 3D, during or before the imaging session. The posture is related to one or more relevant body parts of the patient. The relevant body parts include the region of interest ROI such as one or more lungs of the patient. The region of interest includes internal features of the patient's body such as internal anatomical structures, organs, and tissues, but the relevant body parts also include external features such as limbs, torso, and head. Facilitating the modification and / or tracking of the patient's body posture is beneficial for accurate imaging. It is preferable to ensure that the region of interest is within the field of view (FOV) of the imager IA. However, this is not necessarily sufficient to obtain good image quality. Furthermore, in this specification, thanks to the system SYS, it is also ensured that the ROI is in the desired target body posture within the FOV. The posture is related not only to the position and / or orientation of the ROI but also to the position and / or orientation of one or more body parts including the ROI. In particular, the correct posture of the ROI preferably accompanies the correct postures of the anatomical features (anatomical structures, body parts, tissues, etc.) surrounding or adjacent to the ROI. As a specific example, in a chest X-ray examination, a posture of the arm in which the scapula is moved outside the field of view for better imaging of the lung tissue is preferred.

[0052] The FOV is defined by the X-ray beam XB generated by the X-ray source XS of the imaging device IA (the "imager"). Specifically, an X-ray generator G such as an X-ray tube within the housing HS of the X-ray source radiates the beam XB from the focal spot FS of the generator G when electrically energized, exits the housing HS through the exit window EW, and propagates along the optical axis through the open space across the inspection area. The inspection area ER includes a portion of the space defined between the X-ray detector DM and the X-ray source XS of the imager IA.

[0053] During imaging, the patient PAT is present in the inspection area ER as shown in FIG. 1. The patient PAT squats, lies down, sits, stands, or otherwise exists within the inspection area ER. For example, the patient PAT stands straight in the inspection area as performed according to the protocol for chest X-ray imaging schematically shown in FIG. 1. The X-ray beam XB traverses the inspection area and the patient tissue therein. The X-ray beam interacts with the patient tissue and changes due to the interaction. Therefore, the X-ray beam changed by the detector pixels of the module DM is detected. The detector pixels are mounted within the housing H of the detector module DM. The above X-ray sensitive detector pixels are preferably arranged in 2D, such as in a matrix layout. The X-ray sensitive pixels detect the impinging X-rays in the form of intensity. The intensity is converted into a digital image, for example a projection image, by the A / D conversion circuit of the detector module DM.

[0054] The image, for example, by revealing the internal structure of the lung, assists in diagnosing a specific lung condition, for example, to assist in diagnosis. The image can be stored in the image database MEM or processed by the visualizer VIZ to generate a visualization for display on the display device DD. The image is mapped to an appropriate gray value or color palette used to drive the video circuit, and the video circuit causes the visualization to be displayed on the display device. The image may be processed additionally or alternatively by another method. Although attenuation-based projection imaging is mainly assumed in this specification, other modalities such as phase contrast and / or dark field imaging are not excluded.

[0055] In an exemplary imaging setup as shown in FIG. 1, a free-type imaging device IA is assumed in which there is no permanent mechanical connection between the X-ray source and the detector module DM. The detector module DM and / or the X-ray source XS are each preferably arranged so that the imaging geometry can be changed. For example, this includes changing the position or orientation of the detector DM and / or the source XS. The position and / or orientation are changed individually. It can be changed automatically or manually by the user according to the protocol and the current imaging task. For example, as shown in FIG. 1, the X-ray source and / or the detector module are each independently affected by one or more of the yaw, pitch, and roll motions. Examples of these degrees of freedom related to the imaging geometry are indicated by the double arrows of the curves or straight lines in FIG. 1. For example, the orientation can be changed, such as the direction of the imaging axis along which the beam XB propagates. Additionally or alternatively, the direction of the normal vector of the detector plane can be changed. Further additionally or alternatively, the source XS and / or the detector DM may be translated. The mutual spatial configuration defined by the respective poses of the source XS and the detector DM is referred to herein as the imaging geometry. The imaging geometry may further include a source-detector distance that can be changed as needed.

[0056] Changes in the imaging geometry of the X-ray source and detector module can be defined with reference to the global coordinate system (X, Y, Z) shown in FIG. 1. For example, the directions (X, Y) perpendicular to each other generally indicate the image plane defined by the X-ray sensitive pixel layout of the detector module DM. The Y direction extends within the plane of the drawing in FIG. 1. The direction Z generally indicates the imaging axis along which the X-ray beam propagates widely in space. The inclination or pitch of the X-ray beam can be changed according to the appropriate pitch movement of the X-ray source indicated by the vector α. Similar degrees of freedom (DOF), or more restricted degrees of freedom, are not limited to free-type imagers, but can also be obtained by imagers with mechanically coupled setups such as C-arm devices and X-ray imaging devices.

[0057] Due to the aforementioned (optional but preferred) multiple DOFs of the detector module DM and / or the X-ray source XS, the imaging geometry can be accurately adjusted for the current imaging task in order to maximize the imaging values. Thus, it is possible to ensure that the region of interest is optimally exposed to X-ray irradiation. Intervening body parts, structures, or anatomical structures are maintained in a defined relationship inside or outside the FOV as required. Particularly in projection images, intervening anatomical structures will overlap with the imaging structures, potentially hiding important image information. This is particularly undesirable in diagnostic tasks. For example, it may be desirable to maintain intervening structures and features outside the FOV defined by the X-ray beam by asking the patient to assume a desired target posture specific to the current imaging task. However, as shown in FIG. 1, such correct pose control, especially in 3D, can be difficult because it requires good cooperation from the patient. The patient is required to assume a pre-defined target body posture and maintain this posture during the imaging session while being exposed to the radiation XB. If the body posture is incorrect, the acquired images will be undiagnosable, in other words, useless. Re-imaging of the images may be required, which takes extra time and incurs additional exposure cost for the patient and staff.

[0058] Accordingly, in this specification, the computerized system SYS is configured to assist in controlling or tracking the body posture during imaging to ensure that the target body posture is maintained during imaging, preferably always. In particular, preferably, imaging can be started only when the patient assumes the target position. As will be described in more detail below, the system uses the measurements received by the shape sensing device SSD.

[0059] The measurements include shape sensing measurements. The measurements are processed by the system SYS to generate data representing, for example, the correct imaging target posture of the patient. A suitable such shape sensing measurement device SSD is preferably of the multi-channel type. Embodiments are schematically shown in the block diagrams of FIGS. 2a)-2c).

[0060] The shape sensing device SSD is an embodiment of a posture measurement device configured to measure the current patient posture using sensors described in more detail below. The current patient posture to be measured is preferably measured with respect to the detector module DM. Additionally or alternatively, the shape sensing device SSD measures whether there is a deviation from the intended target posture assumed for the current imaging task. The currently measured patient posture or deviation is provided by the device SSD as an output result.

[0061] Each different predefined target posture is held in memory and accessed by the system after the user specifies, via the user interface, the type / protocol of the imaging task intended by the user. The output result indicates the patient posture, either in itself (with reference to the global coordinate frame) or preferably with reference to the local coordinate detector coordinate frame associated with the detector module, particularly the detector module DM.

[0062] By supplying the shape sensing readings, dynamic and preferably real-time monitoring of the patient's posture is possible, and the calculated results are used to promote good image quality (IQ). This result can also be used to facilitate posture control and correction, such as by providing guidance via appropriate transducers such as acoustic, optical, tactile, etc.

[0063] Broadly speaking, preferably, in this specification, optical shape sensing is preferred, but in this specification, other non-invasive and non-ionizing shape sensing principles and techniques are not excluded. The shape sensing device SSD includes a shape sensing processing unit SSP and the plurality of sensors S described above. The sensor S is preferably defined along the component within or on a deformable elongated component of a sensor device such as a probe, arm, etc. The shape detection device is preferably light-based, in which case the probe or arm described above is realized as the length of an optical fiber F of a certain length. Preferably, a plurality of such fibers may be used, each defining a separate set of sensors. Preferably, at least two, three or more, or all of the fibers are coupled to the same shape sensing processing unit SSP, and their shape sensing readings are processed together to generate an output result. The fiber F can have a circular, elliptical, or other such cross-section, or alternatively be arranged flat, such as in a band, strip, tape, etc. Such suitable optical fibers are described in the applicant's US2009 / 0137952.

[0064] As one of the methods for measuring the posture, the first sensor set Si (also referred to as the "patient sensor" in this specification) of the shape measurement device SSD may be arranged with respect to the patient, particularly in a spatial relationship with the region of interest.

[0065] Optionally, a second such set of sensors Sj (also referred to herein as "auxiliary sensors") is arranged in a spatial relationship with the detector module DM. The auxiliary sensors with respect to the detector module may be arranged on or in the mobile DM, or incorporated therein. However, it is sufficient to arrange the sensors in a pre-known spatial relationship, and they do not necessarily have to be detectors. The second sensor set Sj may be arranged at other locations in the examination room or other parts of the X-ray imager IA. Hereinafter, references to "fiber F" can also be considered as references to the corresponding set of sensors that make up at least a part of that fiber F.

[0066] For example, the (first) fibers F, F1 (and thus the first sensor set Si) are mechanically coupled to or around the region of interest of the patient. In particular, the first sensor set Si / fiber F1 is coupled to the part of the patient's body that at least partially includes the ROI, but may be arranged to extend beyond the said body part. Generally, the sensors / fibers are spatially arranged so as to be able to respond to various shape sensing readings that vary according to changes in the posture to which the sensors are related. Thus, preferably, the movement of the relevant body part, or a general change in the relevant posture, is imparted to the fiber F1 that deforms in response to the patient's posture change by mechanical coupling. This movement can be local or global. Local movement should preferably directly affect specific pre-selected anchor points (detailed below) along which the fiber extends to convey movement information. Certain global movements may also affect the above-mentioned fiber anchor points. Herein, the main concern is movement with respect to the field of view.

[0067] Due to this deformation, the light passing through the optical fiber is internally reflected in a specific reflection pattern that correlates with the deformation of the fiber F. Thus, the reflection pattern correlates with the curvature that the fiber experiences along its length. Since each sensor or point along the length of the fiber experiences its own local curvature, a set of corresponding curvature values (one for each sensor) can be provided as an output.

[0068] The shape sensing processor can calculate 2D or preferably 3D point coordinates as an output result from the curvature values. However, such a conversion is not necessarily required, and the output may be provided as curvature data. In fact, as long as the output data indicates the deviation of the above patient posture and / or target posture, the format and nature of the output data are not important here. The output data may be related to stress or strain measurement values. The block diagram of FIG. 2a shows the basic operation of the above optical shape.

[0069] The input signal X controls the optical transmitter TX to transmit light through the fiber F. A cross-section of the core of such an optical fiber is shown, and it will be understood that such a core is wound, braided, bundled, or otherwise combined one or more times to form the fiber. A cross-section of the fiber having the core C and an optional cladding zone buffer (in which the core is contained) is shown. The light ray passing through the fiber F undergoes (internal) total reflection and is received by the photodetector RX, representing the reflection pattern experienced by the light ray, and generating an output measurement signal that can be correlated with the shape of the fiber and thus the body posture due to the attachment of the fiber to the relevant body part as described above. The reflection pattern is processed by the processor SSP into the above output signal. The processor SSP includes the ability to solve a set of Frenet-Serret equations based on the shape measurement values (stress, strain, or curvature values) to obtain output data indicating the 3D position representing the shape and / or posture.

[0070] Similar readings can be received from an optional second fiber F2 (e.g., coupled to the detector module) to provide a second stream of shape sensing readings that can be processed with the stream of shape readings from the first fiber F1 to more robustly calculate the posture for the detector module DM. It is also possible to use a single or multiple fibers arranged only on the patient, in which case it is not necessary to arrange the fiber F2 relative to the detector module DM.

[0071] In some embodiments, sensors Si, Sj are discretely arranged as a set of fiber Bragg grating (FBG) sensors, but other techniques are envisioned, so it will be understood that this is not necessarily required in all embodiments. For example, since the sensor may include a point position or location along the fiber, the sensor does not necessarily have to be a discrete component / structure like an FBG, but rather a quasi - continuous linear array of point locations along the core C of the fiber.

[0072] In other arrangements, the FBGs for each core do not necessarily spread evenly over the length of the core. Instead, they are placed towards the ends of each core or at other locations along each length of each core. Preferably, there are multiple fiber cores, such as two, three, or more for each fiber F. Three cores are sufficient to obtain good results in 3D, but in some situations, two may be sufficient. Thus, the reference to the sensor set S herein can be interpreted as a reference to multiple cores of the fiber F and / or multiple FBGs within the core, or other arrangements within or in the fiber core that enable shape measurement.

[0073] Regardless of where the set S / fiber F is located, the reference sign "S" is a general reference to such a set of shape - sensing sensors, and the reference sign "F" is a general reference to such an optical fiber. The reference to the fiber is generally a collective reference to the cores that make up the fiber.

[0074] Specifically, the light transmitted through the optical fiber is used to estimate the 3D curvature of the plane in which the optical fiber is placed. In this process, lights of different wavelengths are transmitted through the optical fiber, and the phase difference and the time of arrival (TOA) are calculated. From these phase differences and TOA, an approximation of the curvature points of the plane is calculated. Alternatively, the aforementioned FBG-based sensors are used. Each point on the curvature is defined by a tuple (x, y, z) representing the position vector in 3D space. The transmission of different wavelengths is performed sequentially in a single mode (Figure 2c) where a single ray of light of a given wavelength is transmitted at a time, or by using a multimode optical fiber (Figure 2b) where lights of different wavelengths are transmitted to the fiber F simultaneously.

[0075] Generally, in the sensing operation, the reference point includes the refractive point on the fiber core. The shape sensing mechanism generally monitors each angle formed at the refractive point. As preferred in this specification, when a second sensor set in the detector is used, the angular alignment with the reference frame is monitored. The reference frame is defined by a second sensor set Sj in the detector in addition to the sensor set Si in the patient.

[0076] The embodiments of the shape sensing device SSD in Figures 2a to 2c are merely examples, and it will be understood that other arrangements are also envisioned in this specification as long as shape measurements correlatable to the change in posture can be obtained as substantially described herein. Although light or infrared light is used in this specification, other frequencies in the non-ionizing range are also envisioned.

[0077] Figure 3a) shows an embodiment of how the fiber F1 can be arranged on a patient with respect to the region of interest to be imaged (in this case the patient's torso or lungs). By selecting appropriate anchor points AP1 to AP3 such as the patient's spine or elbows, a fiber layout can be defined in which the fiber deforms in response to relevant posture changes of the patient. Three such anchor points AP1 to AP3 are shown, but there may be more or fewer such anchor points. At least two anchor points are recommended and can be defined based on anatomical knowledge and the location of the region of interest.

[0078] For example, when the patient moves their torso, arm, scapula, etc., the fiber F1 arranged appropriately as shown in the figure deforms, resulting in a clear-shaped reading value that can correlate with the correct target posture predefined by the imaging protocol. Thereby, for example, the lung region can be imaged by avoiding an undesirable overlap in the projection image when the scapula is outside the FOV or has moved sufficiently away from at least the lung tissue to be imaged.

[0079] Anatomical anchor points on the patient's body structure may include vertebral joints and elbow joints for chest X-rays. The set of anchor points AP1 to AP3 is predefined for common X-ray imaging views and preferably can select bone landmarks where the relative movement between the skin and the bone is appropriately low (such as minimal). For example, this includes areas where the bone is subcutaneous and there is no or minimal soft tissue intervening between the skin and the bone. Considering appropriate anchor points is to enable the pose of the body part being examined to be clearly determined by a series of anatomical landmarks. Therefore, the anchor points are preferably selected at appropriate anatomical landmarks. The selection of such anchor points is based on anatomical knowledge and the type of posture to be monitored. Some typical non-limiting examples include the tips of the spinous processes of the vertebrae, the olecranon, and the two epicondyles of the elbow joint, the medial and lateral malleoli of the ankle joint, and the calcaneal tuberosity (see Figure 6 below).

[0080] Also, as shown in FIG. 3, the optional second set of optical fibers F2 can be arranged in the detector module DM, for example, in a rectangular design extending along the edge of the detector module. Generally, the fibers, regardless of their shape, whether rectangular or not, extend to outline the FOV of the detector module. As shown in the figure, the second set of optical fibers F2 is arranged proximal to the patient on the side of the detector module DM facing the patient during imaging. Alternatively, the detector module DM may be arranged distally on the other side of the detector module not facing the patient (not shown). FIG. 3 schematically shows a set of shape sensing sensors along the length of the fiber. Thus, Si and Sj are two different sets of sensors, one in the detector fiber F2 and the other in the fiber F1 attached to the patient.

[0081] The attachment of the fiber F1 to the patient PAT can be done in various ways, such as by a strap (such as a hook-and-loop type), adhesive tape, or any other fixing method suitable for attachment to the patient's skin, for example. However, since the fiber F1 may sometimes be incorporated into a wearable WB such as clothing, it is not always necessary to directly attach it to the skin. For example, the fiber can be placed at the back of a clinical gown, shirt, sweater, etc. that the patient PAT wears during imaging. Figure 3b) schematically shows such a wearable, i.e., clothing with the fiber incorporated. It can be seen that the layout of the anchor points AP1 - AP3 defined in Figure 3a) is configured for chest X-ray imaging. Depending on the current imaging task, the clothing WB can be embodied as trousers, headgear, etc. to image ROIs in other locations. The clothing may contain multiple fiber sets, each pre-positioned for different imaging tasks / ROIs, so the same clothing can be repeatedly used for such different ROIs. Alternatively, the clothing may contain appropriately placed loops, sleeves, or similar attachment means, so that the clothing can be reconfigured, for example, by sewing the fiber F1 again accordingly to reposition the fiber F1. The clothing WB may preferably also contain a wireless interface for wirelessly transmitting the shape reading values to the interface IN of the system SYS for processing into patient posture output data. Bluetooth, WIFI IEEE802.11, or other communication protocols can be used. However, tethered solutions are not excluded. These may reduce user comfort but may help reduce signal interference.

[0082] Optionally and separately, another sensor set Sk, such as a third optical fiber F3 (not shown), can be placed in the housing HS of the X-ray source XS to verify the correct inclination and thus the direction of the X-ray beam. The fiber F3 is arranged such that its sensor reacts to changes in the imaging geometry, such as a change in the orientation of the X-ray source XS.

[0083] This is particularly beneficial in a freestanding type of imaging setup such as a mobile imager where there is no mechanical coupling between the detector and the radiation source. In such a setup, the direction of the central beam is not locked to impinge on the plane of the detector at the preferred 90° angle as in a normal musculoskeletal examination or a mobile chest examination. There may be unwanted angulation. Using a third fiber F3, the above principle can be applied to track the direction of the x-ray beam. For example, one end of the third fiber F3 is attached to the side of the tube housing HS and points in a direction parallel to the central beam. By knowing the offset from the central beam with respect to the location of the focal spot FS, both the position of the focal FS and the direction of the central beam can be inferred from the shape sensing readings received from this third fiber F3. Such fiber-based measurement of the focal position is also beneficial for a locked detector tube-head configuration for measuring, for example, the source-to-image distance (SID). Thus, the imaging geometry can be measured using the principles described herein. Using the imaging geometry so determined, for example, "expected" x-rays can be simulated based on a 3D model of the patient PAT.

[0084] The block diagram of FIG. 4, which is referred to next, depicts the components of a patient pose tracker / control facilitator system SYS. System SYS includes one or more input ports / interfaces IN that receive measurements / readings from a shape sensing device SSD. The input ports can be configured for wired or wireless communication as described above.

[0085] Preferably, system SYS is of the multi-channel type, where multiple fibers provide different sets of readings in a patient in relation to the region of interest, detector module DM, and X-ray source, according to respective sensor sets Si, Sj, Sk each arranged in the patient. Detector fiber F2 and source fiber F2 are optional, but a mono-channel setup is also envisioned. That is, in some embodiments, it may be sufficient to calibrate the system to operate only in local coordinates, collecting only measurements from single or multiple fibers F1 arranged only in the patient. Fibers F2, F3 at the detector DM and source XS are not needed. That is, fiber F2 including a second sensor set Sj arranged at detector XD is optional, and fiber F3 including a third sensor set Sk that provides measurements in relation to changes in the orientation of X-ray source XS is also optional. However, the multi-channel setup as described above is still preferred. This is because having separate sensor sets in separate fibers arranged respectively at both the patient's ROI and the X-ray detector module DM allows for a more robust and accurate determination of the patient's orientation with respect to the X-ray detector, particularly the patient's orientation with respect to the imaging plane (X,Y) including X-ray sensitive pixels.

[0086] The fiber F1 in the patient is arranged, for example, to partially or completely surround or enclose a region of interest that is an internal anatomical feature such as one or both lungs. Multiple fibers are arranged in the patient and coupled to the skin to form an imaginary geometric 2D surface in 3D that at least partially or, in some cases, completely surrounds the region of interest therein. However, such at least partial surrounding is not necessarily required, and as shown in FIG. 3, fiber F1 is sufficient to trace a 3D curve through the ROI. Regardless of the geometric layout of the patient fiber F1, preferably its sensors are made responsive to changes in orientation in the vicinity or surrounding the region of interest. The region of interest itself does not necessarily move during a change in orientation, but the region of interest may be surrounded by body parts that should be kept out of the field of view during lung imaging, such as the scapula or arm.

[0087] When used, the second fiber F2 in the detector module DM is arranged to define a plane that includes or is at least parallel to the image plane (X,Y) of the detector pixel.

[0088] In connection with the patient PAT, also, the shape measurement values in the detector module DM are received at the input port and processed by the pose determiner PD. The optional imaging geometry determiner IGD processes the shape sensing readings Sk received in connection with the X-ray source XS. Since the operations of the patient pose determiner PD and the imaging geometry determiner IGD are similar, the following description of the operation of the pose determiner PD applies equally to the operation of the imaging geometry determiner IGD.

[0089] The output of the pose determiner PD is based on the measurements received from the sensor Si and optionally the measurements received from the sensor Sj, and is provided as output data at the output interface OUT. Hereinafter, references to sensor data or sensor input data, sensor feeds, readings, etc. are to be interpreted as including readings from the patient sensor Si and also optionally (but preferably) readings from the second sensor set Sj in the detector module DM.

[0090] The output data indicates whether the target pose has been achieved or, if previously achieved, is being maintained. A logic circuit L is used to interpret the output data and issue control decisions, for example, based on the output data. The control decisions by the logic circuit L are effected via an appropriate control interface IF, driver, etc. The logic circuit L is optional, and it is assumed that the output data itself can be used without the logic circuit L, such as displaying the output data on a display device DD or, for non-display tasks, recording in memory, logging, or storing by other means.

[0091] In a preferred embodiment, the posture determination device PD preferably processes real-time sensor feeds from sensors Si (and optionally sensor Sj) in order to be able to track the patient's posture in real time for a certain period, particularly during or for a certain period before X-ray imaging. The latter mode / option is for facilitating that the current patient posture is within a predefined margin of the target posture. For example, the logic circuit L then only permits the start of imaging. The margin is set to reflect the boundaries of measurement errors.

[0092] Accordingly, in some embodiments, the logic circuit L can issue a binary control signal based on the output data of the posture determination device PD. The binary signal depends on whether the output data indicates that the target posture is being maintained or whether it has been achieved. The logic circuit L is arranged to process the output signal to determine whether the current posture is being maintained or has been achieved.

[0093] The output data of the posture determination device PD, or optionally the output signal generated by the logic circuit L, is used to accomplish one or more of several tasks. For example, in one embodiment, in a display task, data representing the current posture and / or the deviation from the target posture is graphically displayed on a display device DD or another display device. The graphical display may include graphical or numerical elements (e.g., coordinates, etc.) or combinations thereof for visualizing the current posture and / or the deviation.

[0094] In some embodiments, the output interface OUT includes or is coupled with a control interface IF for controlling the imaging operation of the imager IA. The control interface IF may be coupled with the control interface circuit of the imaging device. The logic circuit L issues a control signal for controlling, in particular, the on / off switching of the X-ray source XS. For example, when the target posture of the patient is achieved or maintained, imaging is started, resumed, or continued. For example, if the logic circuit L detects a sufficiently high deviation, imaging is delayed or interrupted. If there is no such deviation, imaging is permitted to start, continue, or resume. The above on / off switching of the source XS includes hard switching or grid switching, with the latter being preferred. In addition to or instead of any of the above, control by the logic circuit L of other imaging tasks or imaging support tasks based on the output data of the posture determiner PD is also contemplated. For example, an alert signal can be generated as one option and is controlled by the logic circuit L based on the output data generated by the posture determiner PD. The alert signal can be shown on the screen DD to inform the user whether the target posture has been achieved or maintained. Alternatively, or furthermore, the alert signal can switch a lamp or make a sound.

[0095] Even more specifically, one or more tactile actuators H can be controlled by the logic circuit L through a control signal based on the output signal of the posture determiner PD. In particular, the tactile actuator H may be arranged on the patient or, for example, incorporated in the fiber F1 itself. The tactile actuator H may be arranged on a mechanically actuable elongated component such as a wire or cable extending along the fiber.

[0096] The actuator H may be separately attached independently of the fiber F1. For example, the tactile indicator H is arranged as an artificial muscle (known as a "muscle-like actuator") that can be controlled to expand and contract using various techniques such as electro-field actuation, pneumatic actuation (PAM), and thermal actuation.

[0097] Based on the output signal provided by the posture determiner, the logic circuit L controls the tactile actuator H to prompt the patient PAT to straighten / correct the current posture, thereby prompting and guiding the patient to assume the correct target posture, preferably in real time and preferably dynamically. Such an actuator H applies a force to the patient PAT to prompt the patient to change or maintain the posture. This can be achieved by changing the expansion and contraction, torsion, or hardness of the actuator like muscles attached to the patient's skin. Therefore, it can be understood that such use of the above actuator H mimics the tactile indication guidance usually performed by human users. Therefore, this setup can be used for robotic / autonomous imaging.

[0098] The use of the above-described feedback option performed by the logic circuit L may not be suitable for patients who are frail and weak, such as elderly patients or trauma patients in the ICU, who may not be able to respond appropriately to such closures. In this case, the control tasks of the logic circuit L assumed in this specification include controlling an actuator (not shown) that operates other hardware devices of the imaging device to correct the posture via an appropriate interface based on the output from the posture determiner PD. For example, the linear source XS and / or the detector DM are equipped with an electric moving function controlled by the logic circuit L. Alternatively, or further, the patient support PS can be moved via an actuator to move the patient, thereby achieving the correct posture or at least a better posture than the current posture.

[0099] Some or all of the components of the system SYS can be stored in one or more memory devices MEM. The system SYS can be realized by one or more processing devices PU as shown in the lower left of FIG. 4. In particular, the posture determiner PD and the control logic circuit L can be implemented on the same or different computer systems or devices, and each can be arranged in hardware, software, or both.

[0100] Next, refer to FIG. 5. FIG. 5 shows the operation of the patient determiner PD in more detail.

[0101] As described above, in at least a 2-channel embodiment of the shape sensing device SSD, separate shape detection readings are received from the sensors Sj in the detector module DM and the second set Si in the patient. By using such a 2-channel approach, a robust and accurate measurement of the patient's posture relative to the detector becomes possible. However, this does not exclude alternative embodiments where separate shape sensing devices SSD, each having its own set of sensors, are used and the measurements received therefrom are later correlated.

[0102] In either case, the posture determiner PD can implement a function f that measures the current posture, or preferably the deviation from a target posture. DEV function f DEV Since the value of function f is preferably a properly calibrated scalar value, one value, for example a target value of 0, indicates that the target posture has been achieved. A value greater than or less than the target value indicates a deviation, and the value of function f DEV varies according to the amount of deviation.

[0103] The target posture is preferably considered as a reference model in combination with the detector DM plane. In the deviation function f Dev the curvature point vectors of the patient are compared with this reference model to detect a position deviation.

[0104] Shape measurements (X, Y, Z) Rj represent, for example, the reference frame measurements received from the detector sensor set Sj (fiber F2), and (X, Y, Z) pk represent the measurements received from the first sensor set Si (fiber F1) arranged on the patient PAT. As shown in FIG. 5, the two sets of measurements (X, Y, Z) Rj (X, Y, Z) pkIt is stored as a matrix and processed using matrix operations for storage and processing. The shape measurement values include 3D curvature points, stress / strain measurement values, or other quantities related to the shape of each fiber or fiber system, such as patient F1, detector fiber F2, and optionally source fiber F3, are collectively used.

[0105] Two sets of shape measurement values are appropriately combined by the function f DEV to calculate the deviation value.

[0106] For example, a set of reference measurement values [(X,Y,Z) Rj ,(X,Y,Z) Pk R is obtained and compared with the current measurement values [(X,Y,Z) Rj ,(X,Y,Z) Pk C This is then processed by the distance function D([(X,Y,Z) Rj ,(X,Y,Z) Pk R ,[(X,Y,Z) Rj ,(X,Y,Z) Pk C ) to reach the deviation value f DEV . For example, the difference based on the Euclidean components is preferably squared and formed from ([(X,Y,Z) Rj ,(X,Y,Z) Pk R and [(X,Y,Z) Rj ,(X,Y,Z) Pk C . Instead, higher moments can be used or other distance functions can be used as needed.

[0107] The measurement values (X,Y,Z) Rj that can be collected in the detector module are optional, and the above formula can be used based only on the patient-side measurement values (X,Y,Z) Pk (for example, when the movement of the detector DM is not expected).

[0108] f DEV ​​​​​​Similar calculations based on the above can be performed by the Imaging Geometry Determinator IGD. The Imaging Geometry Determinator IGD uses the measurements collected by the sensor set Sk (such as fiber F3) at the X-ray source. These can be combined with the measurements collected by the set Sj (such as fiber F2) at the detector. Thus, the Imaging Geometry Determinator IGD can determine the deviation from the target imaging geometry predefined for the current imaging task. The determination of the imaging geometry can be performed together with the determination of the patient's posture. For this reason, it is possible to detect inadvertent changes in the imaging geometry or inaccurate settings of the imaging geometry by inexperienced or tired staff. Thus, the logic circuit L inspects the f DEV value for both the patient and the imaging geometry to prevent imaging and only permits / recommends imaging when both are within the target.

[0109] In the pre-imaging calibration phase, the patient is asked to assume the correct target patient posture in front of the detector module DM, for example under the guidance of medical staff. The measurements are registered in this target position shape and saved as reference values representing the target posture. This is a one-time operation for a given patient and may be reused for other patients or in later imaging sessions for the same patient. Preferably, the calibration is performed in a dedicated calibration phase individually for each patient. This individually "tailored" approach is preferred although it takes more time because the target values may deviate slightly for each patient if biological characteristics such as gender, height, BMI, etc. are different. In the semi-tailored approach, for patient populations with different biological characteristics, the respective target values are saved in a database and stratified according to the imaging task / target posture type. At a later stage, for a given patient, the target value corresponding to the biological characteristics of the given patient is retrieved and applied by the function f DEV thereby.

[0110] In some embodiments, the setup phase includes "calculating the shape" of the detector surface of detector DM. This can be done, for example, by placing fiber F2 along the perimeter of a detector surface having four endpoints (see FIG. 3a), recording the readings from fiber F2 after placing the fiber F2 in a predetermined position. Similarly, sensor readings for patient PAT from fiber F1 when the patient is in the correct position are received. This is referred to as "calculating the patient shape". In this way, a reference model (optionally including the detector readings from fiber F2 in this case) is established.

[0111] During imaging, the current shape measurements are received in a stream at a specific sampling time. The shape measurements change due to changes in the patient's posture caused by involuntary movements such as coughing. Thus, the function f DEV is configured to measure the difference between the target shape measurement and the current measurement to obtain a deviation value.

[0112] In one embodiment, a Hamilton quaternion setup can be used to calculate f DEV Specifically, let (x1,y1) be the plane representing the reference frame defined by detector fiber F2, and (x2,y2) be the plane representing the patient frame defined by patient fiber F1. Let P1 be the center of the reference frame at the detector, and P2 be the normal vectors to the (x1,y1) plane and the (x2,y2) plane respectively. Then, the quaternion Q(P1,P2) represents the relationship between the P1 vector and the P2 vector, and one component of the quaternion (sometimes called "W") represents the angular relationship. This angular relationship can be projected onto other planes to find the components θ, Φ, which together with r (the distance between the patient and the detector) define a complete set of polar coordinates for the patient frame.

[0113] A setup similar to that described above with respect to FIG. 5 can be used for the imaging geometry determiner IGT. The imaging geometry determiner IGT includes an optional third sensor (X,Y,Z) at the radiation source XS TjProcess the measurement values collected by the set Sk.

[0114] Continuing to refer to the control of the tactile H actuator, in order to guide the patient to the target posture, one or both of the patient fiber F1 or the detection fiber F2 are arranged along three spatial directions. The function defined above can not only calculate whether there is a deviation, but also locate the deviation in 3D. Therefore, the deviation is mapped as respective spatial components on the three spatial axes. The tactile actuators can also be arranged in a 3D layout and respective spatial components. Therefore, each spatial component encodes or indicates which spatial component the user's movement needs to be corrected along and by how much. The logic circuit L uses each spatial component to generate a localized control signal to drive the actuator H, thereby tactually indicating the instructed action in 3D to guide the user for the corrective movement to achieve the target posture.

[0115] For example, to define a quadrant, each spatial axis is conceptually divided into a positive part and a negative part. For example, "patient left" is encoded as negative and "patient right" is encoded as positive (-|+). Assuming that the X component of the correction vector represents the horizontal position from left to right, the activation of a specific tactile sensor is selected based on the sign of the X component. For example, the duration of the tactile sensation is based on the magnitude of X. The same can be done for either of the other two axes. Again, use the quaternion setup of Hamilton to formulate the location of the deviation and convert this into an appropriate correction vector. This vector can make a sound, display, or otherwise draw the attention of the user and / or patient.

[0116] Figure 6 shows an alternative use of the above principle in an imaging session other than a chest X-ray examination, in particular, for example, in an imaging session for orthopedic applications related to a human foot. Appropriate anchor points AP1 to AP3 of the foot may include, for example, any two or all of i) the medial malleolus, ii) the lateral malleolus, and iii) the calcaneal tuberosity, as required. As shown, the fibers F1, F with the sensor set S may be incorporated into footwear such as socks WB. The fibers F1, F, and thus the sensors S, may be incorporated such that the fibers F, F1 (and thus the sensor set S) pass through the anchor points AP1 to AP3 when the patient PAT wears the socks during the imaging session.

[0117] Next, refer to the flowchart of FIG. 7. FIG. 7 shows the steps of a computer-implemented method for implementing the above system SYS. However, it will be understood that the steps described below are not necessarily tied to the above architecture.

[0118] This method is preferably in 3D or at least 2D and is a method for obtaining the current patient posture and / or whether the current patient posture deviates from a desired target posture. This method is preferably applied during or before imaging of the patient during an imaging session. Imaging is preferably performed by an X-ray type imaging device, but not necessarily so. In the embodiments herein, projection X-ray imaging such as chest X-ray examination, orthopedic imaging, mammography, etc. is assumed, but CT imaging, MRI or PET imaging is also assumed.

[0119] In step S710, a set of one or more shape sensing measurements is received. In this specification, optical shape sensing is preferred. One such set of measurements is provided from a sensor set. The sensor may be included in or be part of a deformable probe of a shape sensing device such as an optical fiber. The sensor / fiber / probe can be placed on a patient in relation to the region of interest. The measurements are collected to correlate with changes in posture regarding the region of interest and / or surrounding body parts or anatomical structures.

[0120] The shape sensing measurements are processed in step S720 to calculate output data such as a value indicating whether there is a deviation of the current posture with respect to a predetermined target posture, or, if necessary, a value indicating the current pose.

[0121] In step S730, an output including the output data is provided.

[0122] In step S740, an output signal is generated based on the output data. The output signal can be used for any one or more of several processing or control tasks. Thus, this method further has step S760 of controlling or performing such control tasks based on this signal. Step S740 is implemented by a logic circuit, such as in hardware, software, or both.

[0123] For example, one control task includes the control of image acquisition. For example, the X-ray source is controlled based on a control signal. For example, if there is such a deviation, the X-ray source is disabled or turned off so that the X-ray beam does not exit from the output window of the source. When the target pose is achieved or within a predefined margin thereof, imaging is resumed. That is, the X-ray beam can exit from the output window. Alternatively, or further, image acquisition is permitted to start only when the target pose is achieved. Therefore, this step functions as a delay switch that delays imaging until the target pose is achieved. The control operation during imaging proceeds with a monitoring operation, and when the pose is not as expected, the imaging acquisition is interrupted or an alert signal is issued for use.

[0124] Controlling (S760) may be related to one or more components of the imaging device, such as an actuator that moves the patient table, detector, source, etc.

[0125] Preferably, the shape measurement value received in step S710 includes a second set of measurement values collected from a second sensor set arranged in the detector module. The sensor is incorporated in the X-ray detector module, is part of another fiber (separate from the patient fiber) coupled thereto, or is included therein.

[0126] Optionally, and less preferably, the second sensor set is arranged in a known spatial relationship predefined with the X-ray detector module DM in the examination room or other location of the imaging device. By using such an optional second sensor set on the detector side, the patient pose with respect to the detector can be determined more robustly. Further, since the streams of measurement values from both sensor sets are considered, changes in the pose of the X-ray detector (whether due to carelessness or not) are captured and fed back to steps S740, S760.

[0127] In the optional step S750, the imaging geometry is determined. In particular, the inclination of the X-ray beam and, if necessary, the SID can be determined. This can be done, as described above, by placing another third shape sensing sensor / fiber set at the X-ray source. This step is similar to step S740 above, and a value representing the deviation between the current imaging geometry and the target imaging geometry, such as the current beam inclination from the target inclination, is calculated. The control task includes starting or resuming imaging only when the target imaging geometry is set. Thus, imaging is controlled so that both the patient's posture and the imaging geometry are as desired.

[0128] The order of step S750 and step S740 may be reversed.

[0129] This method is preferably implemented in real time and dynamically at an appropriate sampling rate and acts on the stream of shape measurement values received in step S710 from one or more of the sensor sets as required.

[0130] For this purpose, the movement of the chest during the breathing cycle is understood as a special case of the patient's posture regarding the chest, so the above principle can also be used for tracking the breathing cycle. For example, in a chest PA examination, full inspiration is important to improve the quality of the diagnosis. By tracking the change in the curvature of the fiber F1 attached to the patient's chest over time, the current inspiration state can be estimated. For example, the fiber F1 is fixed to the front of the chest with a string. In this way, the user can check whether full inspiration has been achieved in order to find the optimal timing to start X-ray collection. Also, by instructing the patient to inhale / exhale completely and recording the corresponding curvature, the inspiration tracking can be calibrated before the examination.

[0131] This method can be used, for example, to issue alerts about the patient's movement in order to assist in timing the collection. For example, after achieving the target posture under the instruction from the user, at least a part of the above method can be used when monitoring possible movements, and thus the deviation from the target posture, such as when the user tries to leave the collection room and request collection. By defining the maximum allowable deviation, and thus the appropriate margin of movement, the control includes stopping the requested collection when the deviation exceeds the safety margin.

[0132] The control step of this method further or alternatively includes starting the collection when the target posture is achieved. This is called the "automatic collection" mode.

[0133] When this system is implemented on high-performance computing devices such as those using parallel processors or multi-core processors, even under unstable imaging conditions with quick and jerky active movements like when imaging children or pets, the current posture can be captured while monitoring the stream / feed shape measurement values using the automatic collection mode.

[0134] The components of system SYS are implemented as one or more software modules executed on one or more general-purpose processing units PU, such as a workstation associated with imager IA, or on a server computer associated with a group of imagers.

[0135] Alternatively, some or all of the components of system SYS may be arranged in hardware such as a properly programmed microcontroller or microprocessor, such as an FPGA (Field Programmable Gate Array), or may be arranged as a hardwired connection IC chip that is an application-specific integrated circuit (ASIC) integrated into the imaging IA. In other embodiments, system SYS may be realized partly in software and partly in hardware.

[0136] The various components of system SYS may be implemented on a single data processing unit PU. Alternatively, some or multiple components may be implemented on different processing units PU that are, in some cases, remotely located in a distributed architecture and connectable in a suitable communication network such as a cloud setting or a client-server setup. For example, the posture determiner PD and the logic circuit L may be executed on different computing devices PU or on the same computing device PU.

[0137] One or more features described herein are configured or implemented as, and / or using, circuits encoded within a computer-readable medium, and / or combinations thereof. Circuits include discrete circuits and / or integrated circuits, system-on-chip (SOC), and combinations thereof, machines, computer systems, processors and memories, computer programs.

[0138] In another exemplary embodiment of the present invention, there is provided a computer program or computer program element adapted to execute the method steps of a method according to one of the above embodiments on a suitable system.

[0139] Thus, the computer program element may be stored in a computer unit that may be part of an embodiment of the present invention. This computing unit may execute or induce the execution of the steps of the above method. Further, it may operate the components of the above device. The computing unit may operate automatically and / or execute user instructions. The computer program may be loaded into the working memory of a data processor. Thus, the data processor is ready to execute the method of the present invention.

[0140] This exemplary embodiment of the present invention covers both computer programs that use the present invention from the beginning and computer programs that convert existing programs, via updates, into programs that use the present invention.

[0141] Moreover, the computer program element may provide all the steps required to carry out the procedures of the exemplary embodiments of the methods described above.

[0142] According to another exemplary embodiment of the present invention, a computer readable medium, such as a CD-ROM, is presented having stored thereon computer program elements, as described in the previous section.

[0143] The computer program may be stored / distributed on a suitable medium (in particular, but not necessarily a non-transitory medium), such as an optical storage medium or a solid-state medium, supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless communication systems.

[0144] However, the computer program may also be presented via a network such as the World Wide Web and downloaded from such a network into the working memory of a data processor. According to another exemplary embodiment of the invention, a medium is provided making available a computer program element for downloading, the computer program element being configured to perform a method according to one of the aforementioned embodiments of the invention.

[0145] Note that the embodiments of the present invention are described with reference to different subjects. In particular, some embodiments are described with reference to method-type claims, while other embodiments are described with reference to device-type claims. However, those skilled in the art can presumably infer from the above and the following descriptions that, unless otherwise specified, in addition to any combination of features belonging to one type of subject, any combination of features related to different subjects is also considered to be disclosed in this application. However, all features can be combined if they provide a synergistic effect greater than a mere collection of features.

[0146] Although the present invention has been illustrated and described in detail in the drawings and the above description, such illustration and description should be considered exemplary or exemplary and not limiting. The present invention is not limited to the disclosed embodiments. Other modifications of the disclosed embodiments can be understood and implemented by those skilled in the art when implementing the invention according to the claims from the consideration of the drawings, the disclosure, and the dependent claims.

[0147] In the claims, the term "comprising" does not exclude other elements or steps, and a singular element does not exclude a plurality. A single processor or other unit can perform the functions of several items described in the claims. The mere fact that certain means are described in different dependent claims does not mean that a combination of these means cannot be used advantageously. Any reference signs in the claims should not be construed as limiting the scope. Such reference signs may be composed of numbers, letters, or any combination of alphanumeric characters.

Claims

1. A system for facilitating medical imaging of patients using a medical imaging device, wherein the system is An input interface for receiving measurements collected by an optical fiber-based shape sensing sensor of an optical fiber-based shape sensing device, wherein the shape sensing sensor is positionable relative to the patient's body, and the measurements represent the current posture of the patient's body; A posture determiner that calculates output data indicating whether the patient's body is in a predefined target posture based on the measured values, Equipped with, The measurement values ​​include measurements collected by other shape-sensing sensors that can be positioned in a predefined spatial relationship with respect to the detector module of the medical imaging device configured to determine the patient's posture relative to the detector module. system.

2. The system according to claim 1, comprising an output interface for providing the output data, wherein the output data includes one or more of the following: i) data representing the current posture; ii) data representing a case in which the patient's body is determined to be in the predefined target posture; and iii) data representing a case in which there is a deviation between the predefined target posture and the current target posture.

3. The system according to claim 2, wherein the output interface includes one or more of a display device and a tactile actuator.

4. The system according to claim 1, further comprising a logic circuit for recommending to the user to start imaging, or a logic circuit for automatically starting imaging when the output data indicates that the patient's body has been determined to be in the predefined target posture.

5. The system according to claim 1, wherein the other shape sensing sensors can be arranged in a layout that defines a reference plane.

6. The system according to claim 1, wherein the other shape sensing sensor can be placed in the detector module, on the detector module, or on the detector module.

7. The system according to claim 1, wherein the shape sensing sensor is capable of being placed on the patient's body.

8. The system according to claim 1, wherein the shape sensing sensor can be included in a wearable or can be coupled to a wearable.

9. The system according to claim 1, wherein the measurement includes further measurement collected by further shape sensing sensors that can be placed in the imaging device, and the system further includes an imaging geometry determiner that determines the current imaging geometry of the imaging device based on the further measurement.

10. An imaging device comprising a medical imaging device and a shape sensing sensor disposed on the medical imaging device, wherein the system comprises receiving the shape measurement value according to any one of claims 1 to 9.

11. The imaging device according to claim 10, wherein the medical imaging device has a detector module, and the shape sensing sensor is located on or in the detector module.

12. A computer-based method for facilitating medical imaging of a patient using a medical imaging device, A step of receiving measurements collected by an optical fiber-based shape sensing sensor of an optical fiber-based shape sensing device, wherein the shape sensing sensor is positionable relative to the patient's body, and the measurements represent the current posture of the patient's body; The steps include: calculating output data that indicates whether the patient's body is in a predefined target posture based on the measured values; It has, The measurement values ​​include measurements collected by other shape-sensing sensors that can be positioned in a predefined spatial relationship with respect to the detector module of the medical imaging device configured to determine the patient's posture relative to the detector module. Computerized implementation method.

13. A computer program that, when executed by at least one processing unit, causes the at least one processing unit to perform the computer implementation method described in Claim 12.

14. At least one computer-readable medium on which the computer program described in claim 13 is stored.

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