Commissariat a L'energie Atomique

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

Regis Guillemaud

Pierre Grangeat

Stephane Bonnet

Philippe Rizo

Yanis Caritu

A process for detecting activity of a person, in which movements of the person are measured by at least one sensor attached to the person, and respective components of the movements due to external activity and due to physiological activity are separated. The process obtains a signal of the sensor, filters the signal to derive a filtered signal, the filtering including partitioning the signal of the center into a low frequency component and high frequency component, and subtracts the filtered signal from the signal of the sensor. The filtering further variably extracts portions of the high frequency component according to a criterion of either a minimal level or a minimal instability of the signal of the sensor, and the filtered signal includes the low frequency component and the extracted portions of the high frequency components.

Method for measuring movements of a person wearing a portable detector

A sensor worn by a person measures movements of the person. Movements of orientation are not expressed by rotations leading from a stationary reference point to a reference point associated with the sensor, but by angles separating axes or planes of the stationary reference point and axes associated with the wearer, thereby making it possible to better identify his/her movements and his/her activity. The sensor can be applied to the monitoring of patients.

Method and device for determining a person's motions

A person under supervision wears a sensor consisting of at least one accelerometer () and a magnetometer (), oriented in his vertical direction. A fall event is picked up when a significant and rapid oscillation of the acceleration signal coincides with a shift in the ambient magnetic field between two levels (between t=4000 and t=5000). Additional criteria that may also make use of the magnetometer enable the diagnosis to be made, and it is easier and safer to establish this than with accelerometers alone.

Procedure and system for detecting a person's fall

The present invention relates to a method for determining the reference image of an image sensor comprising a matrix of detector pixels. The method comprises the acquisition of a black image Iand two images Iand Iacquired in linear detection zones of the sensor. The reference image is written: I=(R* I&#x2212;I)/(R&#x2212;1) with wherein I(i,j) represents the value of the pixel of the image Idetected by the pixel detector situated at the intersection of the row i and the column j of the detector pixel matrix, and N represents the total number of pixels in the matrix.

Method for determining image sensor reference image

Apparatus and process for obtaining three-dimensional images of an object by a planar array of detectors, whose focusing points are located on a circle. The advantage obtained is a wider detection field that in the case of focusing on a single point. Rules are given for using algorithms for inverting characteristic measurements of the conical focusing. Application to medicine and to non-destructive testing in industry.

Installation and process for the reconstruction of three-dimensional

A process provides a cartography of an emission of radiation by a body (2) that is corrected with respect to the attenuation of radiation by the body. A radiation transmissions source (3) is able to assume several positions with respect to the body and emits photons toward the body. The process includes: for each position of the radiation source, determining a transmission measurement (N) of the photons emitted by the radiation source and transmitted by the body and determining an emission measurement projection of the photons emitted by the body, the transmission measurement and the emission measurement projection being performed with the same geometry of the body. Determining, for each position of the radiation source, an attenuation correction coefficient C of radiation due to the body in order to correct the emission measurement projection (E6); and then constructing an emissions map (E2) on the basis of the attenuation-corrected, emission measurement projections.

Process for carrying out emission cartography of a body corrected with

Process for the reconstruction of three-dimensional images of an object (3), in which the reconstruction is obtained by calculating sums of projections on planes extracted from a conical attenuation radiation traversing the object, or an emission from the object in accordance with a conical collimation. The bidimensional detector array (4) used for this purpose has a random inclination (.xi.) with respect to the rotation axis defining the mark in which the image is reconstructed as a result of a voluntary choice. Formulas are given making it possible to obtain a limited distortion reconstruction after measuring the displacement parameters of the array and the conical radiation beam. The position errors resulting from construction defects are also taken into account in the calculations after measurement. A parameter measurement protocol and the associated calculation process are also described.

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La Tronche, France

Regis Guillemaud