Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Minmaxmedical

Advanced Magnetic Interaction, Ami

Saifeddine Aloui

Tristan Hautson

Franck Vial

Timothée Jobert

Andréa Vassilev

Rabeb Aloui

Francois Bertrand

Stephane Lavallee

Matthieu Le Prado

Christelle Godin

Dominique David

Mathieu Grossard

Sébastien Brulais

Vincent Josselin

François Bertrand

David Dominique

Mickael Chave

Jean-Marie Dupre La Tour

Etienne Labyt

Simon Thomas

Jerome Paulet

Laure Peris Y Saborit

Myrna Jaillet-Casillas

Stéphane Lavallée

Jean-Marie Dupré La Tour

Adrien Bardet

Antoine Viana

Guilhem Sauvagnac

Clément Rolinat

Mickaël Chave

Jérôme Paulet

The invention relates to a method of localisation of vector magnetometers arranged in a network, comprising the following steps: The invention also includes a magnetic field measurement instrument that includes a network of vector magnetometers and is capable of implementing the localisation method. Application to the imagery of biomagnetic fields, for example in magnetocardiography or in magnetoencephalography.

Vector magnetometers network and associated positioning method

A force sensor includes at least one cavity defining at least two surfaces having different orientations. On each of said surfaces is disposed at least one respective detection structure sensitive to a pressure exerted on the corresponding surface. A resiliently deformable medium at least partially fills the cavity by coming into contact with the surfaces and defines a detection surface, on which a force to be detected is likely to be exerted. The application of this force is likely to generate stresses on each detection structure due to the transmission of forces by the medium.

Force sensor

The invention relates to a system for recording a track comprising: a utensil comprising a tip and equipped with a magnetic object; a device for locating the magnetic object configured to determine an estimated reference position on a writing surface; and a matrix-array touch sensor configured to define a set of M pixels, among N pixels, at least partially encircling the estimated reference position, and to detect the contact of the tip on the writing surface on the basis of the electrical signals generated by said set of M pixels.

System for recording a track traced by a utensil over a writing surface

The method relates to a synchronization of a magnetic locating system including a first device and a second device each including an oscillator, a time counter clocked by the oscillator, and a radiocommunication module. The locating system also includes a device for emitting and receiving alternating magnetic fields, the device being configured to allow a propagation of alternating magnetic fields between the first and second devices, the device for emitting and receiving alternating magnetic fields being connected to the oscillators of the first and second devices. The synchronizing method includes a synchronizing step that is configured to synchronize the oscillators of the first and second devices by adjusting, by servo-controlling the oscillator of the second device, the operation of the time counter of the second device to the operation of the time counter of the first device.

Method for synchronizing a magnetic locating system

A method for estimating an angular deviation between a reference axis of a magnetic object and a magnetic axis co-linear to a magnetic moment of the magnetic object, including: a) positioning the magnetic object facing at least one magnetometer; b) rotating the magnetic object about the reference axis; c) measuring, during the rotating, the magnetic field, using the magnetomenter; and d) estimating the angular deviation from the magnetic field measurements.

Method for estimating an angular deviation between the magnetic axis and a reference axis of a magnetic object

A method of calibrating a network of magnetometers (C, Ci) including the displacement of a magnet holder tool () above the network, and solving an optimisation problem to determine a localisation of the magnetometers in the network. This localisation minimises based on an optimisation criterion, the difference between a real attribute (D, m1, m2) of the magnet holder tool and an estimate of the attribute determined without knowledge of the displacement, starting from the localisation and measurements made by the magnetometers in the network during the displacement.

Method of calibrating a network of magnetometers

A method for detecting an anomaly, associated with a magnetic locating device including a first magnetic element and a second magnetic element that are associated with a first object and with a second object, respectively. The first object includes a first movement sensor configured to determine a first datum dependent on inclination of the first object in a basic reference frame, or the terrestrial reference frame. The method includes: determining the first datum from the first movement sensor; determining a second datum dependent on inclination of the second object in the basic reference frame; determining at least one orientation parameter with the magnetic locating device using the first and second magnetic elements; using the at least one orientation parameter and the first and second data to generate an indicator of presence of the anomaly.

Method for detecting an anomaly in the context of using a magnetic locating device

A method for recognizing a magnetic object includes holding the object immobile in front of an array of N (where N is &#x3e;five) tri-axial magnetometers (M) linked with no degree of freedom. There is a fixed distance between two consecutive magnetometers less than the maximum separation between the magnetic parts of the magnetic object furthest away from one another. The method includes measuring by each magnetometer a vector bof which each coordinate represents the value of the magnetic field projected onto a respective measurement axis of the magnetometer, and a union of vectors bforming a measured magnetic signature S, where the index 'i' is an identifier of the magnetometer. The method includes computing of a deviation E between the magnetic signature Sand a prerecorded magnetic signature Sof a known magnetic object. The method includes comparing E to a predetermined threshold and recognizing the magnetic object.

Method for automatically recognising a magnetic object

Locating a moving magnetic object includes determining its position or orientation from measurements from an array N tri-axial magnetometers (N&#x3e;5) mechanically linked to one another with 0-DOF by repeatedly estimating its position relative to the array from measurements made either in a preceding iteration or from a sensor distinct from the array's magnetometers before making a new measurement using the array's magnetometers; computing the distance between each magnetometer and the object's estimated position; eliminating Ni magnetometers closest to this estimated position, where Ni&#x3c;N; using the remaining magnetometers, making a new measurement of the field generated or modified by the object; and determining its new position or orientation from the new measurements so as to obtain the object's new location.

Method and device for locating a magnetic object

An automatic recognition method includes the calculation of an error representative of the difference between an estimate of the values of the magnetometer measurements when the positions, orientations and amplitudes of the magnetic moments of the P dipoles are equal to those determined, and the values of the magnetometer measurements taken. There is the selection of another system of equations linking each measurement of a triaxial magnetometer to the position, orientation and amplitude of the magnetic moment of P' magnetic dipoles. The method includes the calculation of at least one distinctive feature of the object presented from the position, orientation, or amplitude of the magnetic moment of each dipole determined with the system of equations that minimizes the error calculated. The method includes the recognition of the magnetic object presented if the calculated distinctive features correspond to those of a known object, otherwise the lack of recognition of this object.

Method for automatic recognition of a mobile magnetic object

A method of detecting a point of contact between a tip of an instrument and a writing support, the instrument being one of a pen and an eraser, and the method comprising determining, with the aid of a magnetic object fixed without any degree of freedom on the instrument, the height of a point of the instrument with respect to a bearing face of a tablet. The bearing face constituting the writing support or supporting the writing support. The method further includes: comparing the height determined with a preconfigured contact threshold, and detecting a point of contact between the tip of the instrument and the writing support if the height determined is less than the contact threshold and, in the converse case, detecting no point of contact between the tip of the instrument and the writing support.

Method of detecting point of contact between a tip of a utensil and writing support

Growing community of inventors

Grenoble, France

Saifeddine Aloui