Danilo Franchi

Characterization of a simmechanics model for a virtual glove rehabilitation system

Hand rehabilitation, is a repetitive and long duration therapy that can be facilitated with the assistance of gloves based on sensors. These devices can be substituted by the Virtual Glove, a simple and low-cost system based on the images acquired by four cameras and numerical analysis. In this paper the implementation of the numerical hand model used in this system has been characterized in term of errors in joints position calculation and inverse kinematics. The first preliminary experimental data to test the proposed model have also been reported.

A shape-based segmentation algorithm for X-ray digital subtraction angiography images

We present an efficient algorithm for vessel segmentation of digital subtraction angiography (DSA) images. Continuous DSA images (projections), obtained by X-ray fluoroscopy with contrast-media, are normally used as road maps in vessel catheterization. A more efficient technique would consist in the use of a 3D model reconstruction of the vascular tree, instead of continuous X-ray scans, as a map. By separating vessel information from the undesired background (noise and signals coming from other organs and motion artefacts), efficient segmentation can play a key role in reducing the number of projections (X-ray scans) necessary to reconstruct a 3D vascular model. In what follows, the proposed method is described and some experimental results are reported, thus illustrating the behaviour of the algorithm when compared to other segmentation methods, ideated for the same application. The automatic calculation methods for some of the parameters used are also reported and discussed.

Review on Patents about Magnetic Localisation Systems for in vivo Catheterizations

Abstract: in vivo Catheterizations are usually performed by physicians using X-Ray fluoroscopic guide and contrast-media. The X-Ray exposure both of the patient and of the operators can induce collateral effects. The present review describes the status of the art on recent patents about magnetic position/orientation indicators capable to drive the probe during in-vivo medical diagnostic or interventional procedures. They are based on the magnetic field produced by sources and revealed by sensors. Possible solutions are: the modulated magnetic field produced by a set of coils positioned externally to the patient is measured by sensors installed on the intra-body probe; the magnetic field produced by a thin permanent magnet installed on the intra-body probe is measured by magnetic field sensors positioned outside the patient body. In either cases, position and orientation of the probe are calculated in real time: this allows the elimination of repetitive X-Ray scans used to monitor the probe. The aim of the proposed systems is to drive the catheter inside the patient vascular tree with a reduction of the X-Ray exposure both of the patient and of the personnel involved in the intervention. The present paper intends also to highlight advantages/disadvantages of the presented solutions.

A numerical hand model for a virtual glove rehabilitation system

Hand rehabilitation, following stroke or hand surgery, is a repetitive and long duration therapy that can be facilitated with the assistance of gloves based on sensors. These devices can be substituted by a simple and inexpensive system based on the images acquired by 4 cameras and numerical analysis. In this paper we present a numerical hand model used in this system which describes the kinematic of the hand. Preliminary experimental data to test the proposed model have also been reported.

An optimized Java based software package for biomedical images and volumes processing

Digital image processing is fundamental for several biomedical applications. In this paper, we describe an efficient software package, developed in Java, for advanced visualization and processing of biomedical images and volumes. Actually, a great part of biomedical applications is covered by specific software packages: they have a lot of graphical and processing functions in common and not any has been really optimized. The novelty of our system, when compared to other software developed to deal with biomedical applications, is that it is designed to provide a unifying software solution for potentially all biomedical applications. Another important point is the accurate choice of the development tools which we used for our project: ImageJ and Visualization Toolkit. A detailed description of the usage of these tools into the project is reported. Moreover, a case study is presented and discussed.

A novel acquisition-reconstruction algorithm for surface magnetic resonance imaging

In U-shaped, hand-size magnetic resonance surface scanners, imaging is performed along only one spatial direction, with the application of just one gradient (one-dimensional imaging). Lateral spatial resolution can be obtained by magnet displacement, but, in this case, resolution is very poor (on the order of some millimeters) and cannot be useful for high-resolution imaging applications. In this article, an innovative technique for acquisition and reconstruction of images produced by U-shaped, hand-size MRI surface scanners is presented. The proposed method is based on the acquisition of overlapping strips and an analytical reconstruction technique; it is capable of arbitrarily improving spatial lateral resolution without either using a second magnetic field gradient or making any assumptions about the imaged sample extension. Numerical simulations on synthetic images are reported demonstrating the method functionalities. The presented method also makes it possible to use U-shaped, hand-size MRI surface scanners for high-resolution biomedical applications, such as the imaging of skin lesions.

Numerical methods for the semi-automatic analysis of multimodal wound healing images

Wound healing problem requires the analysis of tens of images from different microscopic systems. We describe a set of semi-automatic algorithms to analyze a variety of microscopy images used to study the wound healing process. The proposed suite, beside the phase contrast images, allows analyzing fluorescent microscopy images, inverted light microscopy images at different magnification and staining methods, or images obtained by scanning electron microscopy. The proposed software is designed in Matlab®. It is suggested to integrate it into the CellProfilerTM software, thus introducing new functionalities without losing the CellProfiler existing capabilities. The approach is efficient, easy-to-use, and enables biologists to comprehensively and quantitatively address many questions of the wound healing problem.

A Novel Segmentation Algorithm for Digital Subtraction Angiography Images: First Experimental Results

We present an efficient algorithm for vessel segmentation of Digital Subtraction Angiography (DSA) images. Continuous DSA images (projections), obtained by X-ray fluoroscopy with contrast-media, are normally used as road maps in vessel catheterization. A more efficient technique would consist in the use of a 3D model reconstruction of the vascular tree, instead of continuous X-ray scans, as a map. By separating vessel information from the undesired background (noise and signals coming from other organs and motion artefacts), efficient segmentation can play a key role in reducing the number of projections (X-ray scans) necessary to reconstruct a 3D vascular model. In what follows, the proposed method is described and some experimental results are reported, thus illustrating the behaviour of the algorithm when compared to other segmentation methods, ideated for the same application. The automatic calculation methods for the parameters used are also reported and discussed.

A Novel Acceleration Coding/Reconstruction Algorithm for Magnetic Resonance Imaging in Presence of Static Magnetic Field In-Homogeneities

In Magnetic Resonance Imaging (MRI), magnetic field spatial variations are used to spatially codify the signal. The presence of static magnetic field in-homogeneities introduces distortions and artefacts in the images. To reduce these effects, an innovative coding/reconstruction algorithm for MRI, based on the assignment of different time varying frequencies (accelerations) to different spatial positions, is presented. The technique is used both for coding and decoding the signal. Numerical simulations of the 1D case are reported and compared with conventional MRI results to demonstrate its applicability and efficacy. The adoption of the proposed algorithm could reduce the costs of magnet construction and shimming; allow the construction of more accessible magnets; increase the Field of View (FOV) of existing scanners; reduce chemical shift and magnetic susceptibility effects. It can be considered to be a revolutionary approach to Magnetic Resonance Image acquisition/reconstruction.

Design of a Magnetic Localisation System for In-Vivo Endovascular Interventions

Endovascular catheterisation is performed by an interventional radiologist using fluoroscopic guide and contrast-media. The X-Ray exposure both of the patient and of the operators can induce heavy collateral effects. The present paper describes an innovative magnetic position/orientation indicator capable to drive the endovascular probe during in- vivo medical diagnostic or interventional procedures. It uses the magnetic field produced by a thin permanent magnet installed on the endovascular probe and magnetic field sensors positioned outside the patient body: this allow the elimination of repetitive X-Ray scans used to monitor the probe position. The aims of the proposed system are: to drive the catheter inside the patient vascular tree with a reduction of the X-Ray exposure both of the patient and of the personnel involved in the intervention; to allow a more comfortable operative condition for the personnel due to the reduction of the time they wear X-Ray protective systems. The paper reports the mathematical problem formulation, the numerical simulations for the magnetic field calculation produced by the thin endovascular permanent magnet and the system design of the usable hardware.