Complex Residual Attention U-Net for Fast Ultrasound Imaging from a Single Plane-Wave Equivalent to Diverging Wave Imaging.

Plane wave imaging persists as a focal point of research due to its high frame rate and low complexity. However, in spite of these advantages, its performance can be compromised by several factors such as noise, speckle, and artifacts that affect the image quality and resolution. In this paper, we propose an attention-based complex convolutional residual U-Net to reconstruct improved in-phase/quadrature complex data from a single insonification acquisition that matches diverging wave imaging.

Towards markerless computer assisted surgery: Application to total knee arthroplasty.

Purpose: A new approach is proposed to localise surgical instruments for Computer Assisted Orthopaedic Surgery (CAOS) that aims at overpassing the limitations of conventional CAOS solutions. This approach relies on both a depth sensor and a 6D pose estimation algorithm.

Methods: The Point-Pair Features (PPF) algorithm was used to estimate the pose of a Patient-Specific Instrument (PSI) for Total Knee Arthroplasty (TKA).

FCN-based approach for the automatic segmentation of bone surfaces in ultrasound images.

Purpose: A new algorithm, based on fully convolutional networks (FCN), is proposed for the automatic localization of the bone interface in ultrasound (US) images. The aim of this paper is to compare and validate this method with (1) a manual segmentation and (2) a state-of-the-art method called confidence in phase symmetry (CPS).

Methods: The dataset used for this study was composed of 1738 US images collected from three volunteers and manually delineated by three experts.

Prediction of the pre-morbid 3D anatomy of the proximal humerus based on statistical shape modelling.

Aims: Restoring the pre-morbid anatomy of the proximal humerus is a goal of anatomical shoulder arthroplasty, but reliance is placed on the surgeon's experience and on anatomical estimations. The purpose of this study was to present a novel method, 'Statistical Shape Modelling', which accurately predicts the pre-morbid proximal humeral anatomy and calculates the 3D geometric parameters needed to restore normal anatomy in patients with severe degenerative osteoarthritis or a fracture of the proximal humerus.

Materials And Methods: From a database of 57 humeral CT scans 3D humeral reconstructions were manually created.

Design and evaluation of an actuated knee implant for postoperative ligament imbalance correction.

In Total Knee Arthroplasty (TKA), the collateral ligament tensioning stage cannot be standardised for all patients and relies heavily on the surgeon's experience and perception. Intraoperative inaccuracies are practically unavoidable and may give rise to severe postoperative complications, leading to the need for revision surgery already a few years after primary TKA. This work proposes a novel instrumented tibial component able to detect collateral ligament laxity conditions right after primary TKA and, if needed, to compensate for them in the postoperative period.

3D dento-maxillary osteolytic lesion and active contour segmentation pilot study in CBCT: semi-automatic vs manual methods.

Objectives: This study was designed to evaluate the reliability of a semi-automatic segmentation tool for dento-maxillary osteolytic image analysis compared with manually defined segmentation in CBCT scans.

Methods: Five CBCT scans were selected from patients for whom periapical radiolucency images were available. All images were obtained using a ProMax® 3D Mid Planmeca (Planmeca Oy, Helsinki, Finland) and were acquired with 200-μm voxel size.

A miniaturised actuation system embedded in an instrumented knee implant for postoperative ligament imbalance correction.

During Total Knee Arthroplasty surgery, the orthopaedic surgeon has to set up proper balance conditions for the two lateral ligaments of the knee. Such ligament tensioning procedure is performed manually and mainly depends on the surgeon's experience. Unfortunately, inaccuracies are unavoidable and may give rise to serious postoperative complications.

Automatic registration of pre- and intraoperative data for long bones in minimally invasive surgery.

The Minimally Invasive Procedures (MIP) in orthopedics have grown rapidly worldwide, as clinical results indicate that patients who undergo MIP typically experience minimized blood loss, smaller incision and shorter hospital stays. For most MIP, a preoperative 3D model of the patient anatomy is usually generated in order to plan the surgery. The challenge in MIP consists in finding the correspondence between the preoperative model and the actual position of the patient in the operating room, also known as image-to-patient registration.

Learning ultrasound gesture database: building and application to musculoskeletal ultrasound exams.

Our aim is to develop a frame work for virtually learning the ultrasound exams. In this paper we address the method used to build the image database required for this frame work. The used materiel and the proposed methodology are presented and explained.

Finite element lifetime prediction of a miniature adjustable orthopedic device.

In Total Knee Arthroplasty (TKA), accurate balancing of the medial and lateral collateral ligaments is considered by orthopedic surgeons as one of the most challenging and complicated tasks to achieve. Therefore, an efficient solution is needed to assist the surgeons in achieving this crucial task without resulting in tibiofemoral misalignment. The required solution consists in developing either a completely automated smart ligament balancer for intraoperative use or adjustable tibial implant for postoperative use.

Recognition-based segmentation and registration method for image guided shoulder surgery.

For any image guided surgery, independently of the technique which is used (navigation, templates, robotics), it is necessary to get a 3D bone surface model from CT or MR images. Such model is used for planning, registration and visualization. We report that graphical representation of patient bony structure and the surgical tools, interconnectively with the tracking device and patient-to-image registration are crucial components in such a system.

Ligament imbalance metrics and an autonomous measurement system for post TKA.

This paper describes two useful metrics to estimate the ligament imbalance for post Total Knee Arthroplasty (TKA) scenario: the center of pressure and the net moments (varus-valgus and anterior posterior). Both metrics have been evaluated using high level models and experimental measurement. Self-powered analog and digital architectures for the center of pressure are elaborated here and complies with the Medical Implant Communication Service (MICS) standard.

Self-powered instrumented knee implant for early detection of postoperative complications.

In-vivo measurement of tibiofemoral forces transmitted through Total Knee Replacement (TKR) during normal walking allows the early detection of postoperative complications such as the tibiofemoral misalignment and soft-tissue imbalance. In addition, the in-vivo data can help to improve the design of TKR in order to reduce polyethylene wear and consequently to increase the lifespan of knee implant. A self-powered custom-designed tibial implant instrumented with four piezoceramics has been developed in order to detect the aforementioned complications by measuring the relative change in pressure center (COP) position for different levels of eccentric compressive loading.

A self-powered telemetry system to estimate the postoperative instability of a knee implant.

Estimating in vivo the life span of a total knee replacement prosthesis is currently done by estimating the polyethylene (PE) wear rate from measurement of the femorotibial distance using X-ray photographies. This efficient method requires, however, waiting for few years to obtain a readout. This letter proposes using another metric that can be obtained within a couple of months of surgery, namely the center of pressure (COP).

Design and evaluation of instrumented smart knee implant.

The goal of ligament balancing in total knee arthroplasty (TKA) is to distribute the tibiofemoral compressive forces symmetrically between the medial and lateral compartments of a well-aligned prosthetic knee, as well as to reestablish a rectangular and identical tibiofemoral gap in both flexion and extension. Nowadays, the proper alignment of knee mechanical axis and the perfect equalization of flexion and extension gaps are ensured by computer-assisted TKA (CATKA). Nevertheless, any residual imbalance of collateral ligaments at the time of surgery can lead to an excessive imbalance in the postoperative period during the weight-bearing activities, which subject the knee collateral ligaments to increased loading.

Toward a dynamic approach of THA planning based on ultrasound.

The risk of dislocation after THA reportedly is minimized if the acetabular implant is oriented at 45 degrees inclination and 15 degrees anteversion with respect to the anterior pelvic plane. This reference plane now is used in computer-assisted protocols. However, this static approach may lead to postoperative instability because the dynamic variations of the pelvis influence effective cup orientation and are not taken into account in this approach.

A new optimization approach for the calibration of an ultrasound probe using a 3D optical localizer.

This paper describes a fast procedure for the calibration of an ultrasound (US) probe using a 3D optical localizer. This calibration step allows us to obtain the 3D position of any point located on the 2D ultrasonic (US) image. To carry out correctly this procedure, a phantom of known geometric properties is probed and these geometries are found in the US images.

A moment-based three-dimensional edge operator.

This paper presents a three-dimensional edge operator aimed at the detection of anatomical structures in medical imaging. It uses the spatial moments of gray level surface, and operates in three dimensions with any window size. It allows us to estimate the location and the contrast surface, as well as the surface orientation.