Optical fiber-based 3D positioning and tracking of patient body parts during x-ray

Abstract

A system (SYS) and related method for facilitating medical imaging of a patient by a medical imaging device (IA). The system comprises 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) may be arranged relative to the body of the patient, where the measurement is representative of a current posture of the body of the patient. A posture determiner (PD) of the system (SYS) calculates output data indicative of whether the patient's body is in a predefined target posture based on the measurements.

Description

Technical Field

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

[0002] Chest X-ray is one of the most established first-line imaging modalities for studying abnormalities, for example, in the chest area or for orthopedic (eg, limbs) or dental use cases, among others.

[0003] Patient position and patient rotation relative to the X-ray source and in particular the X-ray detector are two important quality aspects that have a major impact on chest radiograph interpretation and disease diagnosis.

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

[0005] Once a patient posture error is detected by whatever means, the next step is to correct the patient posture and perform imaging.

[0006] In the case of chest radiographs, the absence of rotational asymmetry (i.e., ensuring that the straight line formed by the spinous processes is equidistant from the clavicle or the medial end of the scapula) is important for biometry in the radiograph and for avoiding erroneous extrapolations. This may require a specific posture relative to the patient's torso. There may also be another specific posture required with respect to the patient's arms in order to rotate the scapula out of the lung field of view. Correct posture is even more important for limb radiographs, where incorrect positioning, for example, adversely affects the interpretation.

[0007] It is not uncommon to require multiple acquisitions before a diagnostic musculoskeletal image is achieved.

[0008] For radiation protection and to save time, it is desirable to be aware of any such posture errors and to correct the posture prior to imaging to "get it right the first time." Summary of the invention

[0009] An efficient imaging method may be needed, particularly in X-ray projection imaging or in other modalities (X-ray or non-X-ray).

[0010] The objects of the invention are achieved by the subject-matter of the independent claims, wherein further embodiments are incorporated in the dependent claims.It should be noted that the following described aspects of the invention apply equally to the associated method, imaging arrangement, computer program element and computer readable medium.

[0011] According to a first aspect of the present invention, there is provided a system for facilitating medical imaging of a patient by a medical imaging device, comprising:

[0012] an input interface for receiving measurements collected by a shape sensing sensor of an optical shape sensing device, the shape sensing sensor being positionable relative to a patient's body, wherein the measurements represent a current posture of the patient's body; and

[0013] A posture determiner is configured to calculate output data representing whether the patient's body is in a predefined target posture based on the measurement results.

[0014] The set of sensors may be arranged along the length of the elongated structure, for example along the length of an optical fiber, wire or other such structure. Preferably, optical shape sensing is used. Preferably, the elongated structure is deformable in response to a change in posture, which in turn causes a shape sensor reading or measurement result representing the change in posture. The set of sensors (sensor elements) may include one or more optical fiber cores and / or gratings (such as fiber Bragg gratings) or other arrangements capable of measuring shape changes included in a given optical fiber core. The set of sensors is arranged on the patient so that the relevant posture change causes a change in the shape of the elongated structure captured by the set of shape sensing sensors.

[0015] Target postures may include in particular "local" postures, i.e. spatial configurations of the anatomy and / or body parts of a given patient relative to each other. "Global" postures include relating "local" postures to an external coordinate system (such as a detector or other object, such as an X-ray source, etc.). Postures may relate to postures of arms, legs, torso, head, etc., but may also include postures such as the inhalation state, as this relates to specific postures of the chest.

[0016] In an embodiment, the system includes an output interface for providing the output data, the output data comprising one or more of: i) an indication of the current posture, ii) an indication of when the patient's body is determined to be in a predefined target posture, and iii) an indication of when there is a deviation between the predefined target posture and the current target posture.

[0017] In an embodiment, the output interface includes any one or more of the following: a display device, a tactile actuator. For example, the tactile actuator can be integrated into a sensor or attached to a sensor. Typically, the output interface is configured to support any one or more of a range of imaging tasks, including controlling the operation of the imaging device. Therefore, the output interface may include one or more suitable control interfaces. The output interface can be used to provide the user with preferably real-time feedback on all manner of patient postures and / or whether the posture is a target posture.

[0018] In an embodiment, the system includes logic configured to recommend a user to initiate imaging, or recommend that the logic automatically initiate the imaging, if the output data indicates that the patient's body is determined to be in a predefined target posture. The logic may prevent imaging until the output data indicates that the patient's body is determined to be in a predefined target posture. The logic may use a control interface to control tasks.

[0019] In an embodiment, the measurements comprise measurements collected by a further set of shape sensing sensors, which may be arranged in a predefined spatial relationship to a detector module of the medical imaging device.

[0020] In an embodiment, the further set of shape sensing sensors may be arranged in a layout defining a reference plane, which may be used as a reference system to determine the patient posture relative to the detector.

[0021] In embodiments, the further shape sensing sensor may be arranged in, at or on the detector module.

[0022] In an embodiment, the shape sensing sensor may be arranged on the body of the patient.

[0023] In an embodiment, the shape sensing sensors may be arranged at anchor points defining a region of interest.

[0024] In an embodiment, the shape sensing sensor may be included in or may be coupled to a wearable object such as a garment.

[0025] In an embodiment, the measurements include further measurements collected by further shape sensing sensors that may be arranged at the imaging device, wherein the system further comprises an imaging geometry determiner configured to determine a current imaging geometry of the imaging device based on the further measurements.

[0026] For example, the imaging geometry includes any one or more of the following: SID (source-detector distance), the tilt of the detector plane relative to the imaging axis of the imager, the focus of the source traveling from the center point of the detector plane to the imager. Thus, the logic can take such imaging geometry into account and only allow imaging when the correct imaging geometry is assumed. Thus, the system can monitor patient posture and imaging geometry. It is preferred to do both in combination, but in some cases, each can be done independently without the other.

[0027] In another aspect, an imaging arrangement is provided, comprising a medical imaging device and a shape sensing sensor arranged at the imaging device and supplying shape measurements to a system for determining a patient posture.

[0028] In an embodiment, the imaging device has a detector module on or at which the shape sensing sensor is arranged. Such an arrangement in particular allows definition of a (reference) plane / frame on / relative to the detector module and allows robust and accurate determination of the patient's posture relative to the detector for better image quality.

[0029] In yet another aspect, a wearable is provided comprising such a set of sensors (such as optical fibers) and a transmitter interface for sending readings to a system for processing the readings into posture changes associated with a patient wearing the wearable.

[0030] In another aspect, there is provided a computer-implemented method for facilitating medical imaging of a patient by a medical imaging device, comprising:

[0031] receiving measurements collected by a fiber-based shape sensing sensor of a fiber-based shape sensing device, the shape sensing sensor being positionable relative to the patient's body, wherein the measurements represent a current posture of the patient's body; and

[0032] Output data indicative of whether the patient's body is in a predefined target posture is calculated based on the measurement results.

[0033] The method may also include determining whether the patient's body is in a predefined target posture based on the output data.

[0034] The method may also include performing control tasks supporting imaging based on the established results.

[0035] References above to "the patient's body" may relate to the whole body or just one or more parts thereof.

[0036] In a further aspect, a computer program element is provided which, when run by at least one processing unit, is adapted to cause the processing unit to perform the method.

[0037] In a further aspect, at least one computer readable medium is provided, on which the program element is stored.

[0038] In yet another aspect, a wearable is provided that includes optical fibers and a transmitter interface for sending readings to a system for processing the readings into posture changes relative to a patient wearing the wearable.

[0039] In an embodiment, one or more groups of sensors are or include corresponding optical fibers. One or more optical fibers are used to collect data (curvature points) about the posture of (one or more) relevant anatomical regions of the patient's body, and in some embodiments, to collect data about the posture of the reference frame relative to the detector module of the imaging device. One group of sensors is at the patient, and another group of sensors is at the X-ray detector of the imaging device. The deviation of the current patient posture from the target posture can be measured in this way. Preferably, real-time feedback of posture deviation for posture correction can be provided by driving a display device, controlling a light, an acoustic transducer, a tactile transducer or any other suitable transducer. Feedback can be provided to the user and / or the patient.

[0040] In more detail, and in some embodiments, the system may include a set of such sensors, such as optical fibers (such as strips or other elongated forms). One or more of the optical fibers may be attached to the patient's body relative to the anatomical region to be imaged. This optical fiber ("patient optical fiber") is used for curvature sensing caused by patient movement. Another optical fiber may be arranged on the circumference of the detector module. The optical fiber provides a reference system for curvature sensing captured by the patient optical fiber. Preferably, the two optical fibers are attached to the same sensing system. Preferably, both are supplied from the same light source (emitter) of the shape sensing system. A LASER-based shape sensing system can be used. The use of the same light source allows a common coordinate system to be defined and allows the relative distance between any pair of points on the two optical fibers to be measured. For example, in a chest radiograph, one optical fiber is attached to the detector module and arranged along the circumference of the detector module. The patient optical fiber can be attached to the patient and can extend, for example, from the wrist of one hand to the wrist of the other hand through the shoulder region. Many other such arrangement layouts on the patient are contemplated in the embodiments. For example, the patient fiber(s) may be adhered to the patient's skin, or may be embedded within clothing (socks, shirts, headbands, etc.), or may be attached or otherwise secured to the patient using an elastic attachment system, etc. Imaging tasks other than chest imaging may require other placements. However, even in chest imaging, other fiber placements other than via the wrist and back are possible and are contemplated herein.

[0041] The described systems and methods allow for sufficiently accurate positioning of a patient's body part in 3D space relative to, for example, a detector, which in turn facilitates posture correction. However, in all embodiments, the use of a second set of shape sensors at the detector is not necessarily required herein, and shape sensing measurements collected at the patient alone may be sufficient, for example with suitable prior calibration. The use of a second set of sensors at the detector is preferred herein because this allows for a more robust and accurate determination of the correct patient posture relative to the detector (and optionally the X-ray source). It may also be possible to place (one or more) second sets of sensors at the X-ray source instead of at the detector. In another embodiment, at least two additional sensor groups may be used, one at the detector and one at the X-ray source.

[0042] The systems and methods presented herein allow for sufficiently accurate determination of patient posture (with respect to one or more body parts) before and during imaging (such as in radiography), wherein easy integration into current standards of care workflows.

[0043] Optionally, the posture 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 imaging geometry, such as changes in the posture of the detector (reorientation or repositioning).

[0044] Alternatively, real-time tracking of gestures can be accomplished by implementing the system on high performance computing equipment.

[0045] Due to the correct posture, ambiguity during the interpretation regarding the image appearance can be reduced or avoided, which in turn leads to correct findings. The likelihood of reshoots can be reduced, which saves dose and time, which is welcomed by users and patients.

[0046] The system has advantages over previous camera-based systems. Any camera can be avoided altogether, leading to better patient privacy. No sensitive data needs to be collected. Additionally, camera-based gesture control (such as RGB or depth cameras) is expensive, requires complex calibration and setup overhead, and its field of view is often limited, especially by occlusion. That said, the proposed system can be used together with or in combination with such camera-based systems, if desired.

[0047] The principles presented herein are applicable to either a reconfigurable setup (such as mobile X-ray) or a fixed setup.

[0048] A "user" refers to a person who operates the imaging device or oversees an imaging procedure, such as medical personnel, etc. In other words, a user is typically not a patient.

[0049] A "patient" is the object of imaging. Reference to a "patient" is not necessarily a reference to the patient as a whole, but may be a reference to a portion such as a body part, an anatomical feature, etc. Thus, the object of imaging may refer to such a portion, referred to herein as a region of interest (ROI). Patient as used herein is primarily for human patients, but animals (such as pets) in veterinary applications are not excluded herein.

[0050] "Posture / pose" are used interchangeably herein and relate to the position and orientation of a body part, organ, etc., or more generally anatomical feature, relative to a local or global coordinate system. Postures may include a plurality of different postures, one for each body region, which may or may not include the ROI itself. Postures / poses may in particular include "local" postures, i.e. the spatial mutual configuration of the anatomical structures and / or body parts of a given patient. A "global" posture comprises associating a "local" posture with an external coordinate system (such as a detector or other object). BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Exemplary embodiments of the present invention will now be described with reference to the following drawings, which are not drawn to scale unless otherwise specified, and in which:

[0052] Figure 1 A block diagram of an imaging arrangement including an imaging device is shown;

[0053] Figure 2 ac shows various embodiments as can be Figure 1 A block diagram of a shape sensing device used in an arrangement of apparatus.

[0054] Figure 3 a. Figure 3 b shows a shape sensing sensor arranged at the patient, at the detector or integrated in a wearable;

[0055] Figure 4 A block diagram of a computerized system for assisting patient posture tracking or facilitating patient posture control based on shape measurements that may be received from a shape sensing device is shown;

[0056] Figure 5 illustrates processing of shape sensing data;

[0057] Figure 6 illustrates the use of shape sensing sensors in orthopedic applications; and

[0058] Figure 7 A flow chart of a computer-implemented method for patient posture tracking or facilitating patient posture control based on shape measurements receivable from a shape sensing device is shown. DETAILED DESCRIPTION

[0059] First reference Figure 1 , which shows components of a medical imaging arrangement AR as envisaged herein in embodiments.

[0060] The arrangement AR preferably comprises an imaging device IA, such as an X-ray based imaging device of mobile or fixed type, a radiographic imager, a C-arm, etc. In this context mainly projection imaging is envisaged, but tomographic reconstruction such as via a CT scanner is not excluded in this context. The imager IA is operable to acquire medical images of the patient's PAT during an imaging session, for example to assist in treatment and / or diagnosis. An example of this is as in Figure 1 Schematically shown in Figure 1 is chest X-ray imaging, but imaging of other body parts or other purposes is also contemplated herein. Optical imaging as an alternative or supplement to X-ray imaging, such as for dermatological examinations, is not excluded herein.

[0061] Imaging arrangement device A1 includes a computing system SYS implemented by one or more fixed or mobile computing devices. Broadly, the computing system SYS preferably provides computer-assisted facilitation of patient posture control and / or tracking in 3D during or before an imaging session. The posture may involve one or more relevant body parts of the patient. The relevant body part may include a region of interest ROI, for example, one or more lungs of the patient. The region of interest may include features inside the patient's body, such as internal anatomical structures, organs, tissues, etc., but the relevant body part may also include external features such as limbs, trunk, head, etc. Facilitating the patient's body posture correction and / or tracking is beneficial for accurate imaging. It is preferred to ensure that the region of interest is within the field of view (FOV) of the imager IA. However, this is not always enough for good image quality. In addition, due to the system SYS, the present invention also ensures that the ROI is in the desired target body posture in the FOV. The posture may involve the position and / or orientation of the ROI, but also the position and / or orientation of one or more body parts including the ROI. In particular, the correct posture of the ROI is preferably combined with the correct posture 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, an arm posture may be preferred so that the shoulder blade is moved out of the field of view for better imaging of lung tissue.

[0062] The FOV is defined by an X-ray beam XB generated by an X-ray source XS of an imaging device IA ("imager"). Specifically, an X-ray generator G (such as an X-ray tube within a housing HS of the X-ray source) when electrically excited causes the beam XB to be emitted forward from a focal spot FS of the generator G, exit the housing HS through an exit window EW, and propagate along an optical axis through an open space through the examination region. The examination region ER includes a portion of the space defined between the X-ray detector DM and the X-ray source XS of the imager IA.

[0063] During imaging, the patient PAT resides in the examination region ER, as Figure 1 As shown. The patient PAT can squat, lie, sit, stand, or otherwise reside in the examination region ER. For example, the patient PAT can stand upright in the examination region, as is done according to some protocols in chest X-ray imaging, such as Figure 1As shown. The X-ray beam XB passes through the examination area and the patient tissue located therein. The X-ray beam interacts with the patient tissue and is then modified due to the interaction, and the thus modified X-ray beam is detected by the detector pixels of the module DM. The detector pixels are mounted inside the housing H of the detector module DM. The X-ray sensitive detector pixels are preferably arranged in a 2D manner, such as in a matrix layout. The X-ray sensitive pixels detect the impinging X-radiation in the form of intensity. The A / D conversion circuit of the detector module DM converts the intensity into a digital image, such as a projection image.

[0064] Image can for example help diagnosis by revealing the internal structure of lung, for example to help diagnose some lung conditions.Image can be stored in the image database MEM, and / or can be processed by visualizer VIZ to produce the visualization for displaying on display device DD.Image can be mapped to suitable gray value or palette, and this gray value or palette are used to drive video circuit, and this video circuit then makes display device display visualization.Additionally or alternatively, image can be processed in other ways.Mainly contemplate projection imaging based on attenuation in this article, yet, other modalities such as phase contrast and / or dark field imaging are not excluded in this article.

[0065] like Figure 1 The example imaging setup shown envisages a free-type imaging device IA, wherein there is no or 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 preferably each arranged so that the imaging geometry can be changed. For example, this may include modifying the position or orientation of the detector DM and / or the source XS. The position and / or orientation may be changed independently. It may be changed automatically or manually by the user depending on the protocol and the imaging task at hand. For example, the X-ray source and / or the detector module may each be subjected to, for example, Figure 1 Any one or more of the indicated yaw, pitch and roll movements independently. Figure 1 Examples of those degrees of freedom associated with the imaging geometry are illustrated by the curved or straight double arrows in . For example, the orientation, such as the direction of the imaging axis along which the beam XB propagates, can be changed. Additionally or alternatively, the direction of the normal vector of the detector plane can be changed. Additionally or alternatively, the source XS and / or the detector DM can undergo a translation. The mutual spatial configuration defined by the respective postures of the source XS and the detector DM may be referred to herein as the imaging geometry. The imaging geometry may also include a source-detector distance that may be changed as desired.

[0066] You can refer to Figure 1The imaging geometry of the X-ray source and the detector module is defined by the global coordinate system (X, Y, Z) shown in FIG. For example, directions (X, Y) perpendicular to each other generally indicate an image plane as defined by the X-ray sensitive pixel layout of the detector module DM. The Y direction extends to Figure 1 The drawing plane of . The direction Z generally indicates the imaging axis along which the X-ray beam propagates widely through space. The tilt or pitch of the X-ray beam can be changed in response to an appropriate pitch movement of the X-ray source as indicated by the vector α. However, similar degrees of freedom (DOF) of this type or more restricted degrees of freedom are not limited to free-type imagers, but can also be provided by imagers with a mechanical coupling arrangement (such as in a C-arm device) or by a radiographic device, etc.

[0067] The mentioned (optional but preferred) multiple DOF of the detector module DM and / or the X-ray source XS allows precise adjustment of the imaging geometry for the imaging task at hand to maximize the imaging value. Thus, it can be ensured that the region of interest is optimally exposed to the X-ray radiation. As required, intervening body parts, structures or anatomical structures are kept in a defined relationship inside or outside the FOV. In particular in projected images, intervening anatomical structures may result in overlapping imaging structures, thereby obscuring potentially important image information. This may be undesirable, in particular in diagnostic tasks. For example, it may be desirable to keep intervening structures, features outside the FOV as defined by the X-ray beam by requiring the patient to adopt a desired target posture specific to the imaging task at hand. However, such correct posture control (in particular with e.g. Figure 1 3D imaging (shown in Figure 3D) can be challenging because it requires good cooperation from the patient. The patient is expected to assume a predefined target body posture and maintain the predefined target body posture while he or she is exposed to radiation XB during the imaging session. Incorrect body posture may make the acquired images non-diagnostic, in other words, useless. Image retakes may be required, which consumes additional time and / or incurs additional dose costs for the patient and / or staff.

[0068] Therefore, the computerized system SYS is configured herein to assist body posture control or tracking during imaging in order to ensure that a target body posture is preferably always maintained during imaging. In particular and preferably, imaging can only start when the patient has assumed the target position. As will be explained in more detail below, the system uses measurements received by a shape sensing device SSD.

[0069] The measurements may include shape sensing measurements. The measurements are processed by the system SYS to produce, for example, an indication of the correct imaging target posture of the patient. A suitable such shape sensing measurement device SSD is preferably of a multi-channel type. Figure 2Examples are schematically shown in the block diagrams of a)-c).

[0070] The shape sensing device SSD is one embodiment of a posture measurement device configured to measure the current patient posture using sensors that will be described in more detail below. The measured current patient posture is preferably measured relative to the detector module DM. Additionally or alternatively, the shape sensing device SSD measures whether there is a deviation from an expected target posture envisioned for the imaging task at hand. The current measured patient posture or deviation may be provided by the device SSD as an output result indication.

[0071] The respective different predefined target postures may be saved in a memory and may be accessed by the system once the user specifies the intended imaging task type / protocol etc. on a user interface. The output results indicate said patient posture either by itself alone (with reference to a global coordinate system) or preferably with reference to a detector module, in particular a local coordinate detector coordinate system associated with the detector module DM.

[0072] The calculated results can be used to facilitate good image quality (IQ) since the feed of shape sensing readings allows for dynamic and preferably real-time monitoring of the patient's posture. The results can also be used to facilitate posture control or correction, such as by providing guidance via suitable transducers (such as acoustic, optical, tactile, etc.).

[0073] Broadly and preferably, optical shape sensing is preferred herein, but other non-invasive and non-ionizing shape sensing principles and techniques are not excluded herein. The shape sensing device SSD comprises a shape sensing processing unit SSP and a plurality of sensors S briefly mentioned above. The sensor S is preferably defined in or on a deformable elongated member (such as a probe, arm, etc.) of the sensor device, but in either case is defined along the deformable elongated member. The shape sensing device is preferably based on optical light, in which case the probe or arm may be implemented as a length of optical fiber F. Preferably, a plurality of such optical fibers may be used, each defining a separate set of sensors. Preferably, at least two, more than two or all optical fibers are coupled to the same shape sensing processing unit SSP, and their shape sensing readings are processed together to produce an output result. The optical fiber F may have a circular, elliptical or other such cross section, or may be arranged flat instead, for example as a ribbon, strip or strip. Suitable such optical fibers are described in the applicant's US2009 / 0137952.

[0074] One way in which posture may be measured is by arranging a first set of sensors Si (also referred to herein as "patient sensors") of a shape measurement device SSD relative to the patient, in particular spatially related to the region of interest.

[0075] Optionally, a second set of such 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 at or on the mobile DM, or may be integrated in the mobile DM. However, it may be sufficient that the sensors are arranged in a previously known spatial relationship, and the arrangement means of the second set of sensors Sj is not necessarily at the detector, but elsewhere in the examination room or at other parts of the X-ray imager IA. In the following, references to "optical fiber F" may additionally be regarded as references to the corresponding set of sensors constituting at least a part of the optical fiber F.

[0076] For example, the (first) optical fiber F, F1 (and therefore the first set of sensors Si) can be mechanically coupled to the patient at or around the region of interest. In particular, the first set of sensors Si / optical fibers F1 can be coupled to that part of the patient's body that at least partially includes the ROI, but can be arranged to extend beyond the (one or more) body parts. Typically, the sensors / optical fibers are spatially arranged in a manner that enables the sensors to respond with different shape sensing readings that vary with changes in the relevant posture. Therefore, preferably, any movement of the relevant body part or generally relevant posture changes are therefore applied to the optical fiber F1, which deforms in response to the patient's posture changes due to the mechanical coupling. The movement can be local or global. Local movement should preferably have a direct impact on certain pre-selected anchor points (to be described in more detail below) through which the optical fiber travels to convey movement information. Certain global movements may also affect the fiber anchor points. The main focus of this article is on movement relative to the field of view.

[0077] This deformation causes light traveling through the optical fiber to be internally reflected with a specific reflection pattern related to the deformation of the optical fiber F. Therefore, the reflection pattern can be related to the curvature experienced by the optical fiber along its length. As each sensor or point along the length of the optical fiber experiences its own positional curvature, a set of corresponding curvature values ​​(one for each sensor) can be provided as output.

[0078] The shape sensing processor may calculate 2D or preferably 3D point coordinates from the curvature values ​​as output. However, such conversion is not required and the output may instead be provided as curvature data. In practice, the format or nature of the output data is immaterial in this context, as long as the output data indicates deviations from the patient posture and / or target posture. The output data may relate to stress or strain measurements. Figure 2 The basic operation of the above optical shapes is illustrated in the block diagram of a).

[0079] The input signal X controls the light transmitter TX to emit light through the optical fiber F. A cross section of the core of such an optical fiber is shown, and it should be understood that there may be more than one such core wound, braided or bundled, so as to be combined in other ways to form an optical fiber. A cross section of an optical fiber having a core C and an optional cladding region buffer in which the core is coated is shown. The light traveling through the optical fiber F undergoes (internal) total reflection and is received at the light detector RX to produce an output measurement signal, which is representative of the reflection pattern experienced by the light and can be related to the shape of the optical fiber, and therefore to the body posture caused by the attachment of the optical fiber to the relevant body part as described above. The reflection pattern can be processed by the processor SSP into the indicative output signal. The processor SSP may include a solver to solve a set of Frenet-Serret equations based on the shape measurement results (stress, strain or curvature values) to obtain output data indicating the shape and / or 3D position of the representative posture.

[0080] Similar readings may be received from an optional second optical fiber F2 (e.g., coupled to a detector module) to provide a second shape sensing reading stream that may be processed together with the shape reading stream from the first optical fiber F1 to more robustly compute a pose relative to the detector module DM. It is also possible to use a single or multiple optical fibers arranged only at the patient, in which case the optical fiber(s) F2 need not be arranged relative to the detector module DM.

[0081] It will be appreciated that in some embodiments the sensors Si,j may be discretely arranged as a set of Fiber Bragg Grating (FBG) sensors, but this is not necessarily required in all embodiments as other techniques are also contemplated. For example, the sensors may comprise point locations or positions along the optical fiber and thus not necessarily discrete components / structures as in FBG or the like, but rather a quasi-continuous linear arrangement of point locations along the core C of the optical fiber.

[0082] In other arrangements, the FBGs of each core are not necessarily spread out uniformly over the length of the core, but are arranged towards the end portion of the respective core or elsewhere along the respective length of the respective core. Preferably, there are multiple fiber cores per optical fiber F, such as 2 or 3 or more. 3 cores are sufficient for good results in 3D, but 2 may be sufficient in some cases. Therefore, reference to a set of sensors S herein may be interpreted as reference to a respective plurality of cores of an optical fiber F and / or a plurality of FBGs in a core, or to other arrangements in or at (one or more) cores that enable shape measurement.

[0083] Reference numeral "S" is a general reference to, for example, a set of (one or more) shape sensing sensors, and reference numeral "F" is a general reference to such an optical fiber, regardless of where the set S / fiber F is located. Reference to an optical fiber is typically a common reference to the core(s) that make up the optical fiber.

[0084] Specifically, light transmitted through an optical fiber can be used to estimate the 3D curvature of the plane in which the fiber is placed. In this process, light of different wavelengths is transmitted through the fiber, and the phase difference and arrival time (TOA) are calculated. From these phase differences and TOA, an approximation of the curvature points of the plane is derived. Alternatively, the mentioned FBG-based sensors are used. Each point on the curvature can be defined by a tuple (x, y, z) representing the position vector in 3D space. Sending different wavelengths can be done in single mode ( Figure 2 c) (where a single light of a given wavelength is transmitted at a time) sequentially, or by using multimode fiber ( Figure 2 b) (wherein light of different wavelengths is simultaneously sent down along the optical fiber F) to accomplish this.

[0085] Typically, in a sensing operation, the reference point may include an inflection point on the fiber core. The shape sensing mechanism typically monitors the corresponding angle formed at the inflection point. If a second set of sensors at the detector is used as preferred herein, the alignment of the angle with the reference system is monitored. In addition to the set of sensors Si at the patient, the reference system is also defined by a second set of sensors Sj at the detector.

[0086] It should be understood that Figure 2 The embodiments of the shape sensing device SSD in ac are merely examples, and other arrangements are contemplated herein, provided that shape measurements that can be correlated to posture changes substantially as described herein can be obtained. Optical or infrared light is used herein, but other frequencies in the non-ionizing range are also contemplated herein.

[0087] Figure 3 a) shows an embodiment of how the optical fiber F1 can be arranged at the patient relative to the region of interest to be imaged (in this case the patient's torso or lungs). By selecting suitable anchor points AP1-3 (such as, for example, on the patient's spine and / or on the patient's elbows), a fiber layout can be defined that causes the optical fiber to deform in response to relevant posture changes of the patient. Three such anchor points API-3 are shown, but there may be more or fewer such anchor points. At least two anchor points are desirable, and these may be defined based on anatomical knowledge and the location of the region of interest.

[0088] For example, when the patient moves his torso, arms, shoulder blades, etc., the optical fiber F1, appropriately arranged as shown, will deform and thereby cause an indicative shape reading that can be associated with the correct target posture predefined by the imaging protocol. Thus, for example, the lung region can be imaged with the shoulder blade outside the FOV, or at least moved far enough away from the lung tissue to be imaged to avoid undesirable overlap in the projected image.

[0089] Anchor points on the patient's anatomy may include the spine and elbow joints for chest radiography. The set of anchor points API-3 will be predefined for atypical radiographic views, and preferably, bone landmarks with preferably low (such as minimal) relative motion between the skin and the bone may be selected. For example, this may include areas where the bone is subcutaneous, where there is no to minimal intervening soft tissue between the skin and the bone. Consideration of suitable anchor points may be such that a set of anatomical landmarks should enable unambiguous determination of the posture of the body part under study. Therefore, anchor points are preferably selected at suitable anatomical landmarks. The selection of such anchor points is based on anatomical knowledge and the type of posture one wishes to monitor. Some typical non-limiting examples may include the tips of the vertebral spinous processes, the olecranon and both epicondyles for the elbow joint, the medial and lateral malleolus and the calcaneal tuberosity for the ankle joint, etc. (see below Figure 6 ).

[0090] Also like Figure 3 As shown, an optional second set of optical fibers F2 can be arranged at the detector module DM, for example in a rectangular design extending along the edge of the detector module. In general, the optical fibers can extend to the outline of the FOV of the detector module, regardless of its shape, rectangular or not. As shown, the second set of optical fibers F2 can be arranged proximal to the patient on the patient-facing side of the detector module DM during imaging. Alternatively, the detector module DM can be arranged distally on the other side of the detector module directed away from the patient (not shown). Figure 3 The multiple sets of shape sensing sensors along the length of the optical fiber are schematically indicated in . Thus, Si and Sj act as two different sets of sensors, one in the detector fiber F2 and one in the optical fiber F1 attached to the patient.

[0091] Attaching the optical fiber F1 to the patient PAT can be accomplished in many ways, such as by a strap (e.g., a hook and loop fastener type), or by tape or by any other fastening means suitable for coupling to, for example, the patient's skin. However, direct coupling to the skin is not necessarily required, as the optical fiber F1 can be integrated into a wearable object WB such as clothing. For example, the optical fiber can be arranged at the back portion of a clinical gown, shirt, sweater, etc. worn by the patient PAT during imaging. For example, in Figure 3 In b) a wearable is schematically indicated, a garment with integrated optical fibers. It follows Figure 3 a) is defined in the API-3 layout of anchor points, and is therefore configured for chest X-ray imaging. Depending on the imaging task at hand, the garment WB may alternatively be embodied as a pair of trousers, a headdress, etc., for imaging an ROI located elsewhere. The garment may include multiple sets of optical fibers, each pre-positioned for a different imaging task / ROI, so that the same garment can be reused for such different ROIs. Alternatively, the garment includes appropriately positioned fabric loops, sleeves, or similar attachment devices, so that the garment can be reconfigured, for example, by rethreading the optical fiber F1 accordingly to achieve repositioning of the optical fiber F1. The garment WB may preferably include a wireless interface to wirelessly transmit shape readings to the interface IN of the system SYS for processing into patient posture output data. Bluetooth, WIFI IEEE 802.11 or other communication protocols may be used. However, tethered solutions are not excluded. They may provide less user comfort, but may help reduce signal interference.

[0092] Alternatively and separately, another set of sensors Sk, such as a third optical fiber F3 (not shown), may be arranged at the X-ray source XS housing HS to allow determination of the correct inclination of the X-ray beam, and hence its orientation. The optical fiber F3 is arranged so that its sensors respond to changes in the imaging geometry, such as a reorientation of the X-ray source XS.

[0093] This is particularly beneficial in free-type imaging settings (such as mobile imagers), where the detector is not mechanically coupled to the source. In such a setting, the central beam direction is not locked to hit the plane of the detector at an angle of 90 °, which is preferred in typical musculoskeletal or mobile chest examinations. There may be undesirable angles. The use of the third optical fiber F3 can allow the above-mentioned principles for tracking the direction of the X-ray beam to be applied. For example, the third optical fiber F3 can have one of its ends attached to one side of the tube housing HS and point in a direction parallel to the central beam. Knowing the offset of the focus FS position from the central beam, both the position of the focus FS and the central beam direction can be inferred based on the shape sensing readings received from the third optical fiber F3. This fiber-based focus position measurement can also be beneficial for, for example, a locked detector tube head configuration for measuring the source image receiver distance (SID). Therefore, the principles described herein can be used to measure imaging geometry. The imaging geometry so determined can be used to simulate "expected" X-rays, for example, based on a 3D model of the patient's PAT.

[0094] Now refer to Figure 4The block diagram of represents components of a patient posture tracker / control facilitator system SYS. The system SYS may include one or more input ports / interfaces IN at which shape sensing measurements / readings of a shape sensing device SSD are received. The input port IN may be arranged for wired or wireless communication as previously described.

[0095] Preferably, the system SYS is of a multi-channel type with a plurality of optical fibers providing different sets of readings according to their respective groups of sensors Si, Sj, Sk arranged at the patient, the detector module DM and the X-ray source, respectively, in relation to the region of interest. However, the detector fiber F2 and the source fiber F2 are optional, and a single-channel setup is also envisaged. That is, in some embodiments, it may be sufficient to calibrate the system to work only on local coordinates, so that measurements are collected only from a single or multiple optical fibers F1 arranged only at the patient. Fibers F2, F3 are not required at the detector DM or the source XS. That is, the fiber F2 comprising the second sensor group Sj arranged at the detector XD is optional, and the fiber F3 comprising the third sensor group Sk that can provide measurements related to posture changes of the X-ray source XS is also optional. However, as described above, a multi-channel setup is still preferred. This is because having separate sensor groups in separate optical fibers arranged at both the patient's ROI and the X-ray detector module DM, respectively, allows a more robust and accurate determination of the patient's posture relative to the X-ray detector, in particular relative to the imaging plane (X, Y) comprising the X-ray sensitive pixels.

[0096] The optical fiber F1 at the patient is arranged, for example, to partially or completely surround or encircle a region of interest, which may be an internal anatomical feature, such as one or more of the lungs. More than one optical fiber may be arranged at the patient, coupled to the skin, to form an imaginary geometric 2D surface in 3D, at least partially or possibly completely enclosing the region of interest therein. However, such at least partial enclosing is not necessary, and it may be sufficient for the optical fiber F1 to describe a curve through the ROI in 3D, such as Figure 3 Regardless of the geometrical layout of the patient fiber F1, it is preferred that its sensor be responsive to posture changes near or around a region of interest. The region of interest itself may not necessarily move during posture changes, but it may be surrounded by body parts (such as a shoulder blade or arm, etc.) that are intended to remain outside the field of view during lung imaging.

[0097] The second optical fiber F2 at the detector module DM (if used) may be arranged to define a plane including or at least parallel to the image plane (X, Y) of the detector pixels.

[0098] Shape measurements related to the patient PAT and at the detector module DM are received at the input port and processed by the posture determiner PD. An optional imaging geometry determiner IGD may process shape sensing readings Sk received about the X-ray source XS. The operation of the patient posture determiner PD and the imaging geometry determiner IGD may be similar, and the description below regarding the operation of the posture determiner PD is equally applicable to the operation of the imaging geometry determiner IGD.

[0099] The posture determiner PD output based on the measurements received from the sensors Si and optionally Sj is provided as output data at the output interface OUT. In the following, references to sensor data or sensor input data, sensor feeds, readings or the like are taken to include readings from the patient sensors Si and may optionally (but preferably) also include readings from the second sensor group Sj at the detector module DM.

[0100] The output data may indicate whether the target gesture has been achieved, or if the target gesture has been achieved before, the target gesture has been maintained. The logic L may be used to interpret the output data and issue, for example, control decisions based on the output data. The control decisions of the logic L may be implemented by suitable control interfaces IF, drivers, etc. The logic L is optional, and it is conceivable to use the output data itself without the logic L, such as to implement display of the output data on a display device DD, or for tasks other than display, such as recording, logging, or otherwise storing in a memory, etc.

[0101] In a preferred embodiment, the posture determiner PD preferably processes real-time sensor feeds from sensors Si (and optionally sensors Sj) to enable real-time tracking of the patient posture over a period of time, in particular during X-ray imaging or in a period prior to imaging. The latter mode / option is to promote that the current patient posture is at least within a predefined margin of the target posture. For example, logic L may allow imaging to be started only if this is indeed the case. The margin may be configured to reflect measurement error limits.

[0102] Thus, in some embodiments, the logic L may issue a binary control signal based on the output data of the posture determiner PD. The binary signal may depend on whether the output data indicates that the target posture is maintained or whether it has been achieved. The logic L may be arranged to process the output signal to determine whether the current posture is maintained or achieved.

[0103] The output data of the posture determiner PD or, optionally, the output signal generated by the logic L may be used to accomplish any one or more of a number of tasks. For example, in one embodiment, in a display task, an indication of the current posture and / or its deviation from the target posture is indicated in a graphical display on the display device DD or on a separate display device. The graphical display may include graphical or numerical elements (e.g., coordinates, etc.) or a combination thereof to visualize the current posture and / or deviation.

[0104] In some embodiments, the output interface OUT includes or is coupled to a control interface IF for controlling the imaging operation of the imager IA. The control interface IF can be coupled to a control interface circuit at the imaging device. The logic L can send a control signal to control, in particular, turning on / off the X-ray source XS. For example, if the patient's target posture is achieved or maintained, imaging is started, resumed or continued according to the situation. For example, if a sufficiently high deviation is found by the logic L, the imaging is delayed or interrupted. If such a deviation is not found, imaging is allowed to start, continue or restart. The on / off of the source XS can include a hard switch or a grid switch, and letters are preferred. In addition to any of the above, or alternatively, it is also envisioned that the output data of the posture determiner PD is controlled by the logic L for other imaging tasks or imaging support tasks. For example, an alarm signal can be generated as an option, which is controlled by the logic L based on the output date generated by the posture determiner PD. The alarm signal can be indicated on the screen DD to inform the user whether the target posture is achieved or maintained. Alternatively or in addition, the alarm signal can switch a light, emit a sound, etc.

[0105] More specifically, one or more tactile actuators H may be controlled by the logic L via control signals based on the output signal of the posture determiner PD. In particular, the tactile actuator H may be arranged at the patient, for example, may be integrated into the optical fiber F1 itself. It may be arranged as a mechanically actuatable elongated component extending alongside the optical fiber, such as a wire, cable, etc.

[0106] The actuator H may be attached independently and separately from the optical fiber F1. For example, the tactile indicator H may be arranged as an artificial muscle (also referred to as a "muscle-like actuator") that may be controlled to expand and contract with a range of techniques such as electric field actuation, pneumatic actuation (PAM), thermal actuation, etc.

[0107] The logic L can control the tactile actuator H based on the output signal provided by the posture determiner to encourage the patient PAT to correct / modify its current posture, thereby preferably pushing or guiding the patient to adopt the correct target posture in real time and preferably in a dynamic manner. Such an actuator H applies a force to the patient PAT to encourage the patient to change posture or remain in posture. This can be achieved by expansion or contraction or by changing the torsion or stiffness of a muscle-like actuator attached to the patient's skin. Therefore, using the actuator H in this way can be understood as mimicking the tactile cue guidance that is usually downward by a human user. Therefore, this arrangement can be used for robotized / autonomous imaging.

[0108] The use of the above feedback options managed by logic L may not be suitable for patients who cannot respond adequately to such approaches, such as frail, weak patients, such as elderly patients or trauma patients in the ICU, etc. In this case, the control tasks envisaged herein for logic L may include controlling actuators (not shown) based on the output from the posture determiner PD via a suitable interface, which actuates other hardware equipment of the imaging device to promote the correct posture. For example, the source XS and / or the detector DM can be equipped with motorized movement capabilities controlled by logic L. Alternatively or additionally, the patient support PS can be moved via actuators to move the patient so as to achieve the correct posture, or at least a better posture than the current posture.

[0109] Some or all components of the system SYS may be stored on one or more memory devices MEM. The system SYS may be composed of Figure 4 In particular, the posture determiner PD and the control logic L may be implemented on the same or different computing systems or devices. Each may be arranged in hardware, software, or both.

[0110] Reference now Figure 5 , Figure 5 The operation of the patient determiner PD is shown in more detail.

[0111] As explained above, in at least two-channel embodiments of the shape sensing device SSD, separate shape sensing readings are received from sensors Sj at the detector module DM and from a second set Si at the patient. Using this two-channel approach allows for a robust and accurate determination of the patient's posture versus the detector. However, this does not exclude alternative embodiments in which separate shape sensing devices SSD are used, each with its own set of sensors, and the measurements received therefrom are then later correlated.

[0112] In either case, the posture determiner PD may implement a function f that measures the current posture or, preferably, its deviation from a target posture. DEV The function f DEV The value of is preferably a scalar value that is appropriately calibrated so that one value (e.g., a target value of zero) indicates that the target posture has been achieved. Values ​​greater than or less than the target value indicate a deviation, and the function f DEV The value of varies with the amount of deviation.

[0113] The target pose preferably combined with the detector DM plane can be considered as a reference model. The deviation function f Dev The patient's curvature point vector is compared to this reference model to detect positional deviations.

[0114] Shape measurement results (X,Y,Z) Rj represents the reference frame measurements received, for example, from the detector sensor set Sj (fiber F2), while (X, Y, Z) pk represents the measurement results received from the first sensor group Si (optical fiber F1) arranged at the patient PAT. Figure 5 As shown, two sets of measurement results (X, Y, Z) Rj (X,Y,Z) pk Can be stored as a matrix and processed using matrix operations for efficient storage and processing. Shape measurements can include 3D points of curvature, stress / strain measurements, or any other quantity related to the shape of a corresponding optical fiber or optical fiber system used together (such as patient F1, detector fiber F2, and optional source fiber F3).

[0115] Through the function f DEV The two sets of shape measurements are combined appropriately to calculate the deviation value.

[0116] For example, to obtain a set of reference measurements [(X,Y,Z) Rj ,(X,Y,Z) Pk ] R , and this is consistent with the current measurement result [(X,Y,Z) Rj ,(X,Y,Z) Pk ] C This can then be compared using the distance function D([(X,Y,Z) Rj ,(X,Y,Z) Pk ] R ,[(X,Y,Z) Rj ,(X,Y,Z) pk ] C ) to obtain the deviation value f DEV For example, we can (by [(X,Y,Z) Rj ,(X,Y,Z) Pk ] R and [(X,Y,Z) Rj ,(X,Y,Z)Pk ] C , , preferably squared) to form the Euclidean component-wise difference. Higher moments may be used instead, or any other distance function may be used as desired.

[0117] Measurements (X,Y,Z) that can be collected at the detector module Rj is optional and may be based only on patient-side measurements (X, Y, Z) if, for example, no motion of detector DM is expected Pk To use the above formula.

[0118] As mentioned above, based on f DEV Similar calculations of can be done by the imaging geometry determiner IGD. The imaging geometry determiner IGD uses measurements collected by the sensor group Sk at the X-ray source, such as optical fiber F3. This can be combined with measurements collected by the group Sj at the detector, such as optical fiber F2. Thus, the imaging geometry determiner IGD can determine deviations from a target imaging geometry predefined for the imaging task at hand. The imaging geometry determination can be performed together with the patient posture determination. Thus, unintentional imaging geometry changes or incorrect imaging geometry settings caused by inexperienced or fatigued staff can be detected. Thus, the logic L can be used to determine the deviations from the target imaging geometry predefined for the imaging task at hand by checking f related to both the patient and the imaging geometry. DEV value to prevent imaging, and imaging is only allowed / recommended when both are on target.

[0119] In a calibration phase prior to imaging, the patient is asked to assume the correct target patient posture in front of the detector module DM, for example under the guidance of a medical practitioner. While remaining in this target position shape, measurements are recorded and these are stored as reference values ​​representing the target posture. This can be a one-off operation for a given patient and can be reused for other patients, or indeed for the same patient for later imaging sessions. Preferably, the calibration is done individually in a dedicated calibration phase for each patient. This individualized "customized" approach, although more time consuming, may be preferred because the target values ​​may deviate slightly for each patient given different biometric characteristics (such as gender, height, BMI, etc.). In a semi-customized approach, for groups of patients with different biometric characteristics, corresponding target values ​​may be stored in a database, stratified according to imaging task / target posture type. Then, at a later stage, for a given patient, the target values ​​can be calculated by the function f DEV Retrieve and apply target values ​​that match a given patient's biometrics.

[0120] In some embodiments, the setup phase may include "calculating the shape of the detector plane of the detector DM". This may be done by recording readings from the optical fiber F2 once it has been placed in place (e.g. by placing the optical fiber F2 along the circumference of the detector plane at its four corners (see again Figure 3 a)) is done. In the same way, when the patient is in the correct posture, sensor readings of the patient's PAT are received from fiber F1. This can be called "calculating the patient shape". In this way, a reference model can be established (optionally including detector readings from fiber F2 in this case).

[0121] During imaging, the current shape measurement is received in the stream at a certain sampling time. The shape measurement will change as the patient posture changes, for example due to involuntary movements (such as caused by coughing, etc.). Therefore, the function f DEV Can be configured to measure the difference between the target shape measurement and the current measurement to establish a deviation value.

[0122] In one embodiment, f can be calculated using the Hamiltonian quaternion setting DEV . Specifically, let (x1, y1) be the plane representing the reference frame as defined by detector fiber F2, and (x2, y2) be the plane representing the patient frame as defined by patient fiber F1. Let P1 denote the center of the reference frame at the detector, and let P2 denote the normal vector to the (x1, y1) and (x2, y2) planes, respectively. The quaternion Q(P1, P2) then represents the relationship between the P1 and P2 vectors, with one component of the quaternion (sometimes called "W") representing the angular relationship. This angular relationship can be projected onto other planes to find components θ, Φ, which together with r (the distance between the patient and the detector) define the complete set of polar coordinates of the patient frame.

[0123] As above Figure 5 A similar arrangement as discussed above can be used for the imaging geometry determiner IGT which processes the optional third set S at the source XS. k Sensor (X,Y,Z) Tj The collected measurements.

[0124] Continuing with reference to the control of the tactile actuator H, in order to guide the patient to achieve the target posture, the patient fiber F1 or the detector fiber F2 can be arranged along one or two of the three spatial directions. The function defined above can then allow not only the calculation of whether there is a deviation, but also the location of the deviation in 3D. Therefore, the deviation can be mapped to the three spatial axes as corresponding spatial components. The tactile actuator can also be arranged in a 3D layout and corresponding spatial components. Therefore, the corresponding spatial components can encode or indicate along which spatial action the user movement needs to be corrected and how much the user movement is corrected. The logic L can use the corresponding spatial components to generate a local control signal to drive the actuator H so as to tactilely indicate the directional action in 3D, thereby guiding the user to make a corrective movement to achieve the target posture.

[0125] For example, each spatial axis can be conceptually divided into a positive portion and a negative portion to define quadrants in this way. 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 particular tactile sensor is selected based on the sign of the X component. For example, the tactile duration can be based on the amplitude of X. The same operation can be performed for either of the other two axes. Again, a Hamiltonian quaternion setting can be used to formulate the location of the deviation and convert it into an appropriate correction vector, which can be voiced, displayed, or otherwise brought to the attention of the user and / or patient.

[0126] Figure 6 An alternative use of the above principles in an imaging session other than a chest X-ray is illustrated, in particular for orthopedic applications, for example, with respect to the human foot. Suitable anchor points API-3 at the foot may, for example, include any two or all of the following, as required: i) the mid-malleolar region, ii) the lateral malleolus, and iii) the calcaneal tuberosity. As can be seen, the optical fibers F1, F with a set of sensors S may be integrated into footwear, such as a sock WB. The optical fibers F1, F and therefore the sensors S may be integrated in such a way that the optical fibers F, F1 (and therefore their set of sensors S) pass through the anchor point API-3 when the sock is worn by the patient PAT during the imaging session.

[0127] Reference now Figure 7 The flowchart in Figure 7 The steps of a computer-implemented method for implementing the above-described system SYS are shown. However, it should be understood that the steps described below are not necessarily bound to the architecture shown above.

[0128] The method is a method for establishing the current patient posture and / or whether this deviates from a desired target posture, preferably in 3D or at least in 2D. The method is preferably applied during imaging of a patient in an imaging session, or before imaging occurs. The imaging can be done by an imaging device, preferably but not necessarily of the X-ray type. In embodiments, projection X-ray imaging such as in chest X-ray, orthopedic imaging, mammography, etc. is contemplated herein, and so is CT imaging, MRI or PET imaging.

[0129] At step S710, one or more sets of shape sensing measurements are received. Optical shape sensing is preferred in this article. A set of such measurements can be derived from a set of sensors. The sensors can be included in or part of a deformable probe of a shape sensing device (such as an optical fiber). The sensors / optical fibers / probes can be arranged at the patient relative to the region of interest. The measurements are collected in a manner that makes them correlated with posture changes about the region of interest and / or surrounding body parts or anatomical structures.

[0130] The shape sensing measurements are processed at step S720 to calculate output data, such as a value indicating whether there is any deviation of the current pose relative to a predetermined target pose, or where the value indicates the current pose, if desired.

[0131] At step S730, an output including output data is provided.

[0132] In step S740, an output signal is established based on the output data. The output signal can be used for any one or more of a plurality of processing or control tasks. Therefore, the method may also include a step S760 of controlling or executing such a control task based on the signal. Step S740 may be implemented by logic such as hardware, software, or both.

[0133] For example, one control task comprises the control of image acquisition. For example, an X-ray source is controlled based on a control signal. For example, the X-ray source is disabled or switched off so that no X-ray beam leaves the exit window of the source in the presence of such a deviation. Once the target posture is reached or the target posture is within a predefined margin thereof, imaging is resumed, i.e. the X-ray beam is allowed to leave the exit window. Alternatively or additionally, image acquisition is only allowed to start when the target posture is achieved. Thus, this step can be used as a delay switch to delay imaging until the target posture is achieved. Once the posture is no longer on target, control operations during imaging can be carried out in a monitoring operation to interrupt the imaging acquisition and / or issue an alarm signal to be used.

[0134] Control S760 may involve any one or more components of the imaging apparatus, such as actuators for moving the patient table, detectors, sources, and the like.

[0135] Preferably, the shape measurements received at step S710 include a second set of measurements collected from a second set of sensors arranged at the detector module. The sensors may be part of or included in a separate optical fiber (separate from the patient optical fiber) that is integrated or coupled to / at or in the X-ray detector module.

[0136] Optionally but less preferably, a second set of sensors is arranged elsewhere in the examination room or at the imaging device in a predefined known spatial relationship to the X-ray detector module DM. The use of such an optional second set of sensors on the detector side allows for a more robust determination of the patient's posture relative to the detector. Additionally, because two streams of measurements from two sets of sensors are considered, any changes (unintentional or not) in the posture of the X-ray detector can be picked up and fed back to steps S740, S760.

[0137] At optional step S750, the imaging geometry is determined. In particular, the inclination or SID of the X-ray beam may be determined as desired. This may be accomplished by arranging a separate third set of shape sensing sensors / optical fibers at the X-ray source as explained above. 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 and the target inclination) is calculated. The control task may include starting or resuming imaging only when the target imaging geometry is set. Thus, imaging is controlled so that both the patient posture and the imaging geometry are on target.

[0138] The order of steps S750 and S740 is interchangeable.

[0139] The method is preferably implemented in real time and in a dynamic manner at a suitable sampling rate to operate as required on the stream of shape measurements received from one or more sets of sensors at step S710.

[0140] For the present purpose, the above principle can also be used to track the respiratory cycle, since the movement of the chest during the respiratory cycle can be understood as a special case of the patent posture relative to the chest. For example, for a chest PA examination, full inspiration is important for the diagnostic quality. By tracking the change in the curvature of the optical fiber F1 attached to the patient's chest over time, it allows to infer the current inhalation state. For example, the optical fiber F1 can be bundled on the front of the chest. In this way, the user can check whether full inspiration is achieved to find the best moment to trigger the X-ray acquisition. The inspiration tracking can also be calibrated before the examination by asking the patient to fully inhale / exhale and recording the corresponding curvature.

[0141] The method may be used to issue an alarm for patient movement, for example to assist in acquisition timing. For example, after a target posture has been achieved, for example on instruction from a user, at least part of the above method may be used to monitor possible movements and thus deviations from the target posture, for example after the user leaves the acquisition room and is about to request an acquisition. By defining suitable margins on the maximum allowed deviations and thus movements, the control may include suppressing the requested acquisition if the deviation exceeds a safety margin.

[0142] Additionally or alternatively, the controlling step of the method may include triggering acquisition if the target gesture is achieved. This may be referred to as an "automatic acquisition" mode.

[0143] When the system is implemented on high performance computing equipment, such as those using parallel or multi-core processors, the automatic acquisition mode can be used to pick up the current pose while monitoring the flow / feed shape measurements even in volatile imaging conditions with fast, jerky, and frequent motion, such as when imaging children or pets.

[0144] The components of the system SYS may be implemented as one or more software modules running on one or more general purpose processing units PU, such as a workstation associated with the imager IA, or on a server computer associated with a group of imagers.

[0145] Alternatively, some or all components of the system SYS may be arranged in hardware integrated into the imager IA, such as a suitably programmed microcontroller or microprocessor, such as an FPGA (field programmable gate array) or a hardwired IC chip, an application specific integrated circuit (ASIC). In another embodiment, the system SYS may be implemented both partly in software and partly in hardware.

[0146] The different components of the system SYS may be implemented on a single data processing unit PU. Alternatively, some or more components are implemented on different processing units PU that may be remotely arranged in a distributed architecture and connectable in a suitable communication network, such as in a cloud environment or a client-server setup, etc. For example, the posture determiner PD and the logic L may run on different computing devices PU or on the same computing device PU.

[0147] One or more features described herein may be configured or implemented as or with circuits encoded in a computer readable medium and / or combinations thereof. The circuits may include discrete and / or integrated circuits, systems on a chip (SOCs) and combinations thereof, machines, computer systems, processors and memories, computer programs.

[0148] In a further exemplary embodiment of the present invention, a computer program or a computer program element is provided, which is characterized by being adapted to execute the method steps of the method according to one of the preceding embodiments on a suitable system.

[0149] Therefore, the computer program element can be stored on a computer unit, which can also be part of an embodiment of the present invention. The computing unit can be suitable for executing the steps of the method described above or inducing the execution of the steps of the method described above. In addition, it can be suitable for operating the parts of the device described above. The computing unit can be suitable for automatically operating and / or executing the user's command. The computer program can be loaded into the working memory of a data processor. The data processor can thus be equipped to perform the method of the present invention.

[0150] This exemplary embodiment of the invention covers both a computer program that right from the beginning uses the invention and a computer program that, by means of an up-date, turns an existing program into a program that uses the invention.

[0151] Furthermore, the computer program element can provide all necessary steps for implementing the procedures of an exemplary embodiment of the method as described above.

[0152] According to another exemplary embodiment of the present invention, a computer-readable medium, such as a CD-ROM, is proposed, wherein the computer-readable medium has a computer program element stored on the computer-readable medium, the computer program element being described in the preceding section.

[0153] The computer program may be stored and / or distributed on suitable media (specifically but not necessarily non-transitory media), such as optical storage media or solid-state media provided with or as part of other hardware, but the computer program may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

[0154] However, the computer program may also be present on a network such as the World Wide Web and can be downloaded from such a network into a working memory of a data processor. According to a further exemplary embodiment of the present invention, a medium for making a computer program element available for downloading is provided, the computer program element being arranged to perform a method according to one of the previously described embodiments of the present invention.

[0155] It must be noted that embodiments of the present invention are described with reference to different subject matters. Specifically, some embodiments are described with reference to method type claims, while other embodiments are described with reference to device type claims. However, it will be understood by a person skilled in the art from the above and following descriptions that, unless otherwise indicated, any combination of features belonging to one type of subject matter, in addition to any combination of features, any combination between features relating to different subject matters is also considered to be disclosed by the present application. However, all features can be combined to provide synergistic effects that exceed the simple sum of the features.

[0156] Although the present invention has been described and illustrated in detail in the drawings and the foregoing description, such description and illustration should be considered illustrative or exemplary rather than restrictive. The present invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments can be understood and implemented by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure, and the dependent claims.

[0157] In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. Although specific measures are recited in mutually different dependent claims, this does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope. Such reference signs may consist of numbers, letters or any alphanumeric combination.

Claims

1. A system (SYS) for facilitating medical imaging of a patient by a medical imaging apparatus (IA), comprising: An input interface (IN) for receiving a signal from a fiber-based shape sensing sensor (S j ) collects the measurement results of the shape sensing sensor (S j ) can be arranged relative to the patient's body, wherein the measurement result represents the current posture of the patient's body; and A posture determiner (PD) is configured to calculate output data representing whether the patient's body is in a predefined target posture based on the measurement results.

2. The system according to claim 1 comprises an output interface (OUT) for providing the output data, the output data comprising one or more of: i) an indication of the current posture, ii) an indication of when the patient's body is determined to be in the predefined target posture, and iii) an indication of when 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 (OU) comprises any one or more of the following: a display device (DD), a haptic actuator (H).

4. A system according to claim 1, 2 or 3, comprising logic (U), which is configured to recommend a user to initiate imaging if the output data indicates that the patient's body is determined to be in the predefined target posture, or to recommend that the logic (U) automatically initiate the imaging.

5. A system according to any one of the preceding claims, wherein: The measurements include those by an additional shape sensing sensor (S k ) collected by the further shape sensing sensor, the further shape sensing sensor being capable of being arranged in a predefined spatial relationship to a detector module (DM) of the medical imaging device.

6. The system according to claim 5, wherein: The additional shape sensing sensor (S k ) can be arranged in a layout that defines a reference plane.

7. A system according to any one of the preceding claims, wherein: The further shape sensing sensor can be arranged in, at or on the detector module.

8. A system according to any one of the preceding claims, wherein: The shape sensing sensor can be disposed on the patient's body.

9. The system according to any of the preceding claims, the shape sensing sensor being comprised in or coupled to a wearable (WB).

10. A system according to any one of the preceding claims, wherein: The measurement results include further measurement results collected by a further shape sensing sensor (Sl) that can be arranged at the imaging device, wherein the system also includes an imaging geometry determiner (IGD), which is configured to determine a current imaging geometry of the imaging device based on the further measurement results.

11. An imaging arrangement (AR) comprising a medical imaging device and a shape sensing sensor arranged at the imaging device and supplying shape measurements to the system according to any of the preceding claims.

12. Arrangement device according to claim 11, the imaging device (IA) having a detector module, the shape sensing sensor being arranged on or at the detector module.

13. A computer-implemented method for facilitating medical imaging of a patient (PAT) by a medical imaging device, comprising: receiving (S710) a fiber-based shape sensing sensor (S j ) collects the measurement results of the shape sensing sensor (S j ) can be arranged relative to the patient's body, wherein the measurement result represents the current posture of the patient's body; and Output data representing whether the patient's body is in a predefined target posture is calculated (S720) based on the measurement results.

14. A computer program element adapted, when run by at least one processing unit, to cause the processing unit (PU) to perform the method according to claim 13.

15. At least one computer-readable medium (MEM) on which a program element according to claim 14 is stored.

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