Abstract: A pipe repair device includes a body defining a first body end, a second body end, and a middle body section therebetween; a foldable arm pivotably attached to the body to radially reposition the foldable arm relative to the body, the foldable arm comprising a first segment and a second segment, the first segment extending between the body and the second segment, wherein the second segment is substantially parallel to the body; and a locomotion subsystem configured to drive the pipe repair device through a pipe, the locomotion subsystem mounted to the second segment of the foldable arm and configured to engage an inner surface of the pipe.

Abstract: Disclosed herein are radiotherapy systems and methods that can display a workflow-oriented graphical user interface(s). In an embodiment, a system comprises a first display in communication with a server, the first display configured to display a first graphical user interface; a second display in communication with the server, the second display configured to display a second graphical user interface, wherein the server is configured to: present the first graphical user interface for displaying on the first display, wherein the first graphical user interface contains one or more pages corresponding to one or more stages of a radiotherapy treatment, wherein the server transitions from a first page of the one or more pages representing a first stage to a second page of the one or more pages representing a second stage responsive to an indication that at least a predetermined portion of tasks associated with the first stage has been satisfied.

Abstract: Methods, devices, apparatuses and systems are disclosed for performing mammography, such as utilizing tomosynthesis in combination with breast biopsy.

Abstract: Systems and methods are disclosed for use in electronic guidance systems for surgical navigation. A sensor is provided with an optical sensor, to provide optical information, and a measuring sensor, to provide measurements for determining a direction of gravity. The sensor communicates optical information and measurements to an inter-operative computing unit. In an embodiment, the inter-operative computing unit receives first optical information for a registration device and a patient anatomy and a measurement to determine a direction of gravity to perform a registration step. The inter-operative computing unit receives second optical information for the patient anatomy and an object and determines and presents measurements relative to the anatomy. The measurements relative to the anatomy are determined from the second optical information, and in relation to the registration of the anatomy of the patient.

Abstract: Systems and methods are disclosed for use in electronic guidance systems for surgical navigation. A sensor is provided with an optical sensor, to provide optical information, and a measuring sensor, to provide measurements for determining a direction of gravity. The sensor communicates optical information and measurements to an inter-operative computing unit. In an embodiment, the inter-operative computing unit receives first optical information for a registration device and a patient anatomy and a measurement to determine a direction of gravity to perform a registration step. The inter-operative computing unit receives second optical information for the patient anatomy and an object and determines and presents measurements relative to the anatomy. The measurements relative to the anatomy are determined from the second optical information, and in relation to the registration of the anatomy of the patient.

Abstract: Medical software tools platforms utilize a surgical display to provide access to specific medical software tools, such as medically-oriented applications or widgets, that can assist surgeons or surgical team in performing various procedures. In particular, an endoscopic camera may register the momentary rise in the optical signature reflected from a tissue surface and in turn transmit it to a medical image processing system which can also receive patient heart rate data and display relevant anomalies. Changes in various spectral components and the speed at which they change in relation to a source of stimulus (heartbeat, breathing, light source modulation, etc.) may indicate the arrival of blood, contrast agents or oxygen absorption. Combinations of these may indicate various states of differing disease or margins of tumors, and so forth. Also, changes in temperatures, physical dimensions, pressures, photoacoustic pressures and the rate of change may indicate tissue anomalies in comparison to historic values.

Abstract: Methods for identifying a disease state in a patient and/or for treating a patient having the identified disease state are disclosed and can be based on characteristics identified through machine learning models such as deep learning convolutional neural networks and that are associated with video recordings, audio recordings, infrared images, photographs, and/or radiologic patient images.

Abstract: An end effector for a computer-assisted surgical system includes a mount configured to be coupled to an arm and a housing coupled to the mount and configured to interchangeably support a first operating member and a second operating member. When the housing supports the first operating member, the housing is configured to prevent translation of the first operating member relative to the mount. When the housing supports the second operating member, the housing is configured to allow translation of the second operating member relative to the mount along a first axis.

Abstract: An example computer-implemented method for tuning a beam spot in a radiation therapy system based on radiation field measurements has been disclosed. The example method includes configuring an electron beam to generate a first beam spot on an electron-beam target of the radiation therapy system, determining a value for one or more radiation field quality metrics for a first radiation beam that originates from the first beam spot, and based on the value, determining whether the first radiation beam is outside a specified quality range.

Abstract: Provided is a method of generating a virtual x-ray image, the method including: obtaining a 3-dimensional (3D) image of a patient; determining a projection direction of the 3D image in consideration of a position relationship between an x-ray source of an x-ray device and the patient; and generating a virtual x-ray image by projecting the 3D image on a 2D plane in the determined projection direction.

Abstract: The present disclosure relates to a system and method for locating a target subject associated with an X-ray system. The X-ray system may include an X-ray source, a detection component, an arm, and a platform. The X-ray system may also include a first positioning component, a second positioning component, or a third positioning component. The first positioning component may be configured to determine a target point where a region of interest (ROI) of the target subject locates. The second positioning component may be configured to locate the target subject. The third positioning component may be configured to obtain location information of a target device associated with the target subject in real-time.

Abstract: The present disclosure relates to systems and methods for scanning a patient in an imaging system. The imaging system may include at least one camera directed at the patient. The systems and methods may obtain a plurality of images of the patient that are captured by the at least one camera. Each of the plurality of images may correspond to one of a series of time points. The systems and methods may also determine a motion of the patient over the series of time points based on the plurality of images of the patient. The systems and methods may further determine whether the patient is ready for scan based on the motion of the patient, and generate control information of the imaging system for scanning the patient in response to determining that the patient is ready for scan.

Abstract: The present disclosure relates to a method for scanning a patient in an imaging system. The imaging system may include one or more cameras directed at the patient. The method may include obtaining a position of each of the camera(s) relative to the imaging system. The method may also include obtain image data of the patient captured by the camera(s), wherein the image data may correspond to a first view with respect to the patient. The method may further include generating projection image data of the patient based on the image data and the position of each of the camera(s) relative to the imaging system, wherein the projection image data may correspond to a second view with respect to the patient different from the first view. The method may further include generating control information for scanning the patient based on the projection image data of the patient.

Abstract: The present invention is a method of radiation position, which includes: placing a locking bar member on a proper position of a treatment bed; selecting positions respectively on two sides of the treatment bed to be joined with two ends of the locking bar member; and providing a calibration device, wherein the calibration device is provided with at least one positioning point, so that the bottom part of the calibration device is buckled with at least two positioning elements on the locking bar member; and calculating an offset distance between an irradiation point of a radiation and the at least one positioning point of the calibration device to obtain a value, wherein if the value is less than a deviation value, it represents completion of a positioning. The purpose of the present invention is to provide a method of quick and precise radiation position, which can not only reduce time cost but also increase the daily use frequency of a radiological apparatus to facilitate cost recovery.

Abstract: Receiving a dataset and parsing from the dataset an XP coordinate value on an x-axis, a YP coordinate value on a y-axis, and a ZP coordinate value on a z-axis all within a domain having 3-dimensional features. The x-axis and y-axis are perpendicular and define a horizontal earthbound main surface. The ZP coordinate value is on the z-axis perpendicular to the horizontal earthbound main surface. The XP, YP and ZP define a place associated with a 3-dimensional feature. Stored resource rules for places in the domain are accessed that indicate a first resource if the ZP has a first value, and a second resource if the ZP has a second value. One of the resource rules that applies to the place is identified based on XP, YP and ZP. A resource for the dataset is determined by applying the identified rule. The resource is caused to be transmitted.

Abstract: Patient misidentification errors in medical imaging can result in serious consequences, such as the misdiagnosis of a disease state or the application of an inappropriate treatment regimen. Systems, methods, and apparatuses disclosed herein can properly and consistently identify, adjust, and/or correlate radiologic images with the correct patient. Systems and methods for automated and robust image capture are also provided. Methods for identifying a disease state in a patient and/or for treating a patient having the identified disease state are disclosed and can be based on characteristics identified through deep learning convolutional neural networks and that are associated with photographic and radiologic patient images.

Abstract: Radiation therapy delivery system, including X-ray source, magnetic body rotation fixation node and/or mechanical body rotation fixation node; filter unit with a plurality of filters and a plug that circle a cylindrical element; drive unit for rotating filter unit; collimation elements in a collimation unit body, that includes collimation element fixation device and collimation photoelectric identification system; and processor controlling the filter unit to adjust X-ray filtration characteristics. The filter unit includes filter photoelectric identification system, controller, and photoelectric sensors. The cylindrical element includes slits located on rings that run along outer surface. Photoelectric sensors are triggered by a light beam that passes through the slits to identify/position filters.

Abstract: A method of planning an image-guided interventional procedure to be performed on a patient, where expected motion of the patient, such as that of a breathing cycle, is determined on a sequence of preoperative images, and the procedure trajectory is planned accordingly. The method takes into account the initial positions of the interventional entry, the target region, and any obstructions or forbidden regions between the entry point and the target region, and uses object tracking methods of image processing on the preoperative images to determine how the positions of these three elements change relative to each other during the patient's motion cycle. The method may automatically search in at least some of the preoperative images taken at different temporal points of the motion cycle, for a path connecting the entry point with the target and avoiding the obstacles, which provides minimal lateral pressure on the patient's tissues.

Abstract: Methods and apparatuses for performing patient registration. 3D scan data from a 3D scanner, preoperative image data, first tracking data from a first tracking system, and second tracking data from a second tracking system are mapped to a common coordinate space. The 3D scan data and the first tracking data are mapped to each other using a transformation that is determined based on a calibration relating the 3D scan coordinate space and the tracking coordinate space. The 3D scan data and the preoperative image data are mapped to each other using a surface matching algorithm. The first tracking data and the second tracking data are mapped to each other based on tracking of the patient reference device.

Abstract: An augmented reality system for viewing a static physical object includes a movable unit receiving signals from, a static tracking base station for obtaining the six-dimensional absolute position of the movable unit. The relative position of the movable unit relatively to the static physical object is calculated from the absolute positions of the movable unit and the static physical object. The relative unit-object position is then used for rendering and displaying an augmented image or projecting a virtual object on the static physical object.

Abstract: A surgical monitoring system including a machine vision sensor, an electronic controller communicatively coupled to the machine vision sensor, the electronic controller including a processor and a memory storing a computer readable instruction set, where, when the computer readable instruction set is executed by the processor, the electronic controller, detects a position of a subject with the machine vision sensor, detects a position of a person support apparatus, compares the detected position of the subject with the detected position of the person support apparatus, and determines if the detected position of the subject and the detected position of the person support apparatus indicates that the subject is not aligned with the person support apparatus.

Abstract: Systems, devices, and methods for imaging-based calibration of radiation treatment couch position compensations.

Abstract: A system of this invention is directed to a bone cutting support system that properly indicates a bone cutting plane determined in advance to a doctor during surgery. The bone cutting support system includes a storage that stores 3D shape data of a surgery target bone in association with position data of a marker fixed to the surgery target bone, a bone cutting plane determiner that determines, based on the 3D shape data of the surgery target bone, a position and direction of a bone cutting plane or a bone cutting guide plane representing a plane to guide for cutting the surgery target bone, and a bone cutting plane display that displays the determined bone cutting plane based on an image obtained by capturing the marker fixed to the surgery target bone.

Abstract: A fixture for a fluoroscopic x-ray imaging system is discussed, wherein the fluoroscopic imaging system includes a C-arm, an x-ray source at a first end of the C-arm, and an x-ray detector at a second end of the C-arm. The fixture includes a processor and memory coupled with the processor. The memory includes instructions that are executable by the processor so that the processor is configured to detect an x-ray emission from the x-ray source toward the x-ray detector, determine an offset of the x-ray source relative to the x-ray detector responsive to detecting the x-ray emission, and provide an indication of the offset of the x-ray source to a medical navigation system. Related methods and robotic systems are also discussed.

Abstract: A system for intra-operatively registering a pelvis comprising an acetabulum with a computer model of the pelvis in a coordinate system. The system may include: a) a surgical navigation system including a tracking device; and b) at least one computing device in communication with the surgical navigation system. The at least one computing device: i) receiving first data points from first intra-operatively collected points on an articular surface of the acetabulum, the first data points collected with the tracking device; ii) receiving a second data point from a second intra-operatively collected point on the pelvis, the second data point collected with the tracking device, the second data point corresponding in location to a second virtual data point on the computer model; and iii) determining an intra-operative center of rotation of the femur relative to the pelvis from the first data points.

Abstract: According to one embodiment, an X-ray computed tomography apparatus includes a gantry body, a column, and fixing equipment. The gantry body includes a bore to form a field of view, and also includes an X-ray tube and an X-ray detector. The column supports the gantry body so that the gantry body is vertically movable with a central axis of the bore extending vertically to a floor face. The fixing equipment fixes a subject holder so that the subject holder is located on a passage of the bore and partially in the bore in a phase of attaching a subject to the subject holder.

Abstract: Described are various embodiments of a mobile surgical imaging sensor and display unit, and surgical navigation system associated therewith, in which the mobile unit may be disposed to provide line-of-sight or near line-of-sight imaging and display capabilities to an operator thereof during a surgical procedure, while a position and/or orientation of the mobile unit is tracked relative to a surgical site to associate a surgical site location with images captured and rendered by the mobile unit.

Abstract: Disclosed herein are methods, compositions and tools for repairing articular surfaces repair materials and for repairing an articular surface. The articular surface repairs are customizable or highly selectable by patient and geared toward providing optimal fit and function. The surgical tools are designed to be customizable or highly selectable by patient to increase the speed, accuracy and simplicity of performing total or partial arthroplasty.

Abstract: An apparatus for medical imaging of a patient, including an object of interest, is provided. The apparatus comprises a patient support unit, a processor, and a display. The patient support unit is configured to receive a patient. The processor is configured to receive scout images of the patient acquired in respective positions of the apparatus. Each respective position is represented by a position parameter. The processor is further configured to select at least one iso-centering image from the scout images by geometrical calculation using the position parameter of each scout image and a position parameter representing a present position of the apparatus. The processor is further configured to adapt the appearance of the at least one iso-centering image according to the present position of the apparatus. The display is configured to present the at least one adapted iso-centering image.

Abstract: A subject support includes a fixed portion and a moveable portion coupled to the fixed portion and configured to move along at least one axis relative to the fixed portion, and the coupling includes one or more points of friction that move during movement of the moveable portion and which wear due to at least movement by the moveable portion. The moveable portion receives and supports at least one of an object or a subject during an imaging procedure with an imaging device. One or more inertial measurement units (IMUs) are affixed to or embedded in the moveable portion that directly measure acceleration of translation of the moveable portion along one or more axes.

Abstract: A method is disclosed for adjusting a collimator of an X-ray source. In an embodiment, the method includes detecting an arrangement of an X-ray detector with respect to the X-ray source; automatically determining an adjustment for the collimator based on the detected position of the X-ray detector with respect to the X-ray source; and automatically adjusting the collimator based on the determined adjustment for the collimator. An X-ray device and computer readable medium are also disclosed.

Abstract: A method and system for accurately localizing a wireless radiographic detector in a radiography system, based on a method to accurately determine distances between a set of generator arrays and sensor arrays. The generator arrays and sensor arrays are preferably orthogonally arranged magnetic field generators and sensors, that allow measurements of distances without being affected by presence of human tissue between the generator and sensor arrays.

Abstract: The present invention relates to a magnetic holder for immunoelectron microscopy grids. The holder comprises a frame, a magnet and a hydrophobic layer. The device can use a magnetic force to simultaneously attach the outer rings of nickel grids to the frame, so that a batch operation (such as rinsing, immunolabeling and dyeing) of the nickel grids can be realized. In addition, due to the hydrophobic effect of the hydrophobic layer, the holder can reduce the amount of the liquid carried by the nickel grids in the process of continuously transferring the nickel grids between different types of liquids to almost zero. Compared with the prior art, the magnetic holder effectively reduces the probability of cross-contamination between reagents.

Abstract: A radiographic image capturing apparatus includes: a radiation detector in which a plurality of pixels for accumulating electric charges corresponding to emitted radiation are arranged in a two-dimensional manner; a control unit that controls the radiation detector; a radiation emission unit that emits radiation; a changing unit that integrally changes angles of the radiation detector and the control unit with respect to a predetermined direction; a heat sink in which a guiding unit for guiding an air flow in a predetermined guiding direction is provided and which dissipates heat of the control unit; and a housing unit in which the radiation detector, the control unit, and the heat sink are housed and which has a radiation detection surface irradiated with the radiation emitted from the radiation emission unit.

Abstract: An x-ray backscattering imaging system creating a backscatter image representing a structure is disclosed. The system includes a drum rotatable about an axis of rotation at a rotational speed, a radioactive source, a container, at least one collimator, at least one light emitting element, and a plurality of backscatter detectors. The radioactive source is connected to the drum and generates x-ray beams. The container houses the radioactive source and is constructed of a material that substantially blocks the x-ray beams generated by the radioactive source. The collimator is defined by the container and has a length and an aperture, where the collimator filters a stream of x-rays generated by the radioactive source such that the x-ray beams traveling substantially parallel with respect to the length of the collimator pass through the aperture. The light emitting element generates visible light and is positioned to direct the visible light into the collimator.

Abstract: Methods, apparatus, systems and articles of manufacture to correct the measurement of water equivalent diameter in Computed Tomography (CT) imaging when patients are miscentered are disclosed. A disclosed example apparatus includes a patient size characteristic calculator to calculate a set of patient size characteristics for a set of axial slices along a height of the patient. The apparatus further includes a patient size characteristic corrector module to calculate a set of correction factors for the set of patient size characteristics and apply the set of correction factors to the set of patient size characteristics. The apparatus further includes a computation manager to utilize a set of corrected patient size characteristics for the set of axial slices along the height of the patient to perform a CT scan on the patient by modulating an X-ray current to control a radiation dose applied to the patient.

Abstract: The patient specific instrument (PSI) assembly for guiding a surgical tool on a tibia during a knee replacement surgery includes an extra-medullary portion at a distal end, an elongated rod connected at a distal end to the extra-medullary portion and extending in a direction along a mechanical axis of the tibia, and an upper mounting portion at a proximal end. The extra-medullary portion has a pair of spaced apart malleoli clamping elements with a size and/or relative position that is patient-specific for engaging respective ones of the lateral and medial malleoli. The upper mounting portion including a base body connected to a proximal end of the elongated rod and a surgical guide having guide openings extending therethrough and anchor element(s) on the upper mounting portion in locations adapted to overlay a peripheral contour of the tibia. The peripheral contour of the tibia including an anterior surface of the proximal tibia.

Abstract: Methods and apparatuses for performing patient registration. 3D scan data from a 3D scanner, preoperative image data, first tracking data from a first tracking system, and second tracking data from a second tracking system are mapped to a common coordinate space. The 3D scan data and the first tracking data are mapped to each other using a transformation that is determined based on a calibration relating the 3D scan coordinate space and the tracking coordinate space. The 3D scan data and the preoperative image data are mapped to each other using a surface matching algorithm. The first tracking data and the second tracking data are mapped to each other based on tracking of the patient reference device.

Abstract: A modular specimen holder (10?) for high pressure freezing and/or X-ray crystallography of a specimen has a specimen holding element (100?) and an extension element (200?) connectable with and separable from each other; the specimen holding element (100?) including a tubule (120?) adapted to hold the specimen and a base element (110?) adapted to hold the tubule (120?), wherein a distance from a bottom of the base element (110?) to a top of the tubule (120?) is a first distance (d1); the extension element (200?) being connectable with the base element (110?), wherein, when the extension element (200?) and the base element (110?) are connected with each other, a second distance (d2) from a bottom of the extension element (200?) to the top of the tubule (120?) is larger than the first distance (d1).

Abstract: A method of calibrating a system for imaging a subject is provided. The method includes determining a position of an X-ray source of the system operative to transmit X-rays through the subject; and calibrating the position of the X-ray source with respect to a detector of the system, based at least in part on a field of view of the X-ray source, the detector operative to receive the X-rays transmitted by the X-ray source. In embodiments, the method includes positioning an X-ray source of the system via a controller at one or more calibration positions based at least in part on at least one camera of the system. In such embodiments the X-ray source is disposed on a mobile arm and operative to transmit X-rays through the subject, and a field of view of the X-ray source is directed substantially towards the detector at each of the calibration positions.

Abstract: A dental radiographic positioner and film holder assembly has a film plane reference component (2) configured to detachably affix to a shaft (1a) extending from the edge of the film holder (1). Affixing surfaces (1b, 2b) are provided between the shaft (1a) and film plane (2) to enable longitudinal movement and restrict rotational movement. A teeth plane reference component (3) is detachably affixed to the shaft (1a). A bisecting angle reference component (4) is detachably affixed to the shaft (1a). Both the bisecting angle plane (4) and teeth plane (3) are attached to allow for longitudinal motion along the shaft (1a) as well as rotational motion around the axis of the shaft (1a).

Abstract: A radiation imaging apparatus performs pre-shot imaging while considering the imaging condition on the tomosynthesis imaging which can be performed right thereafter without repeating a positioning of the radiation irradiation unit on the tomosynthesis imaging. The protocol for the per-shot imaging is read out. Reading out the protocol is executed by that the operator of operation unit of the console and the console 1 reads out the protocol for the pre-shot imaging from the radiology department information system along with the patient information. Therefore, the imaging condition of the protocol for the continuously executed tomosynthesis imaging is read out while linking the protocol of the pre-shot imaging.

Abstract: A system for imaging is provided. The system includes an x-ray source, a detector, and a controller. The x-ray source is operative to transmit x-rays through a subject while the x-ray source continuously travels along a path defined by a sweep angle. The detector is operative to receive the x-rays after having passed through the subject. The controller is operative to: acquire preliminary data regarding the subject via the x-ray source and the detector; determine at least one acquisition parameter from the preliminary data; and acquire one or more projections of the subject via the x-ray source and the x-ray detector based at least in part on the acquisition parameter.

Abstract: A method of creating a patient specific instrument (PSI) for use in knee replacement surgery is described which includes performing at least two two-dimensional X-ray scans of a bone, each of the X-ray scans being taken from different angular positions, generating a digital bone model of the bone based on the X-ray scans, planning the PSI based on the digital bone model, including determining locations for one or more anchor points on the PSI which are adapted to abut a surface of the bone, the determined locations of the anchor points being disposed on the PSI at locations corresponding to areas of expected high accuracy on the digital bone model generated by the X-ray scans. The areas of expected high accuracy include at least a peripheral bone contour in at least one of the angular position of the X-ray scans. A suite of such PSI instruments is also described.

Abstract: An object is to provide a radiation therapy system which can easily and accurately set an X-ray irradiation range. A movable X-ray diaphragm unit 6 has, in its configuration, an X-ray shielding unit configured with a plurality of members, a driver for the X-ray shielding unit, and a position detector for acquiring a position of the X-ray shielding unit. It has displays 8 and 9 which display a transmission image of a subject based on an output of an X-ray detection unit and a simulation image when the X-ray shielding unit is projected on the X-ray detection unit 2 based on an output of the position detector.

Abstract: A method for positioning an emitter relative to a detector includes determining the position of the detector relative to the emitter, changing the position of the detector and measuring the change in position using a measuring device located in the detector. Data related to the change in position of the detector is then supplied to a device for positioning the emitter, and the position of the emitter is changed in accordance with the data. An image capture device is also provided.

Abstract: A gauge assembly includes a distal femur gauge including medial and lateral condyle paddles each having a shape and size corresponding to a pre-operative planned distal resection of a patient's femur, and a tibial cutting block connected to the distal femur gauge. The condyle paddles include features, for example, pin-receiving holes, that permit intra-operative anterior-posterior and/or internal-external adjustment of the position of the distal femur gauge. The tibial cutting block includes features, for example, pin-receiving slot and holes, that permit fixing of the varus-valgus and flexion-extension degrees of freedom prior to fixing the internal-external and medial-lateral degrees of freedom.

Abstract: A method and device for operating an x-ray device including an x-ray emitter and an x-ray detector are provided. An alternating magnetic field is produced and emitted at the x-ray emitter. At least two sensors are included for capturing at least one physical variable correlating with the alternating magnetic field. An alignment of the x-ray detector relative to the x-ray emitter is determined based on the measurement.

Abstract: A processing device determines a plurality of angles from which tracking images can be generated by an imaging device. The processing device generates a plurality of projections of a treatment planning image of a patient, the treatment planning image comprising a delineated target, wherein each projection of the plurality of projections has an angle that corresponds to one of the plurality of angles from which the tracking images can be taken. The processing device determines, for each angle of the plurality of angles, a value of a tracking quality metric for tracking the target based on an analysis of a projection generated at that angle. The processing device selects a subset of the plurality of angles that have a tracking quality metric value that satisfies a tracking quality metric criterion.

Abstract: A system for intra-operatively registering a pelvis comprising an acetabulum with a computer model of the pelvis in a coordinate system. The system may include: a) a surgical navigation system including a tracking device; and b) at least one computing device in communication with the surgical navigation system. The at least one computing device: i) receiving first data points from first intra-operatively collected points on an articular surface of the acetabulum, the first data points collected with the tracking device; ii) receiving a second data point from a second intra-operatively collected point on the pelvis, the second data point collected with the tracking device, the second data point corresponding in location to a second virtual data point on the computer model; and iii) determining an intra-operative center of rotation of the femur relative to the pelvis from the first data points.