An implantable, rechargeable assembly comprised of an implantable device disposed within a living organism, an electrical storage device connected to the implantable device, and a thermoelectric charging assembly operatively connected to the electrical storage device. The thermoelectric charging assembly has devices for transferring thermal energy between the living organism and a thermoelectric module, for generating an electrical current from the thermal energy, for charging the electrical storage device with the electrical current, for determining the extent to which the electrical storage device is being charged with the electrical current, and for generating a signal whenever the extent to which the electrical storage device is being charged with the electrical current falls below a specified value.

Biothermal power source for implantable devices

An X-ray imaging method, and device for carrying out the method, utilizes a first imaging device to form and digitally store a series of two-dimensional X-ray images in which an object to be examined is projected onto an X-ray image pick-up device from different perspectives, and a second imaging device to form a three-dimensional image of the same object. Quasi three-dimensional reproduction of anatomic structures is achieved by extracting a relevant structure of the object to be examined from the three-dimensional image, calculating synthetic, two-dimensional projection images of the extracted structure, the structure being projected with the same geometrical parameters as used for the relevant structure during the formation of the individual X-ray images, forming superposition images by superposing the synthetic projection images and the X-ray images formed under the same geometrical conditions, and displaying the series of superposition images.

X-ray imaging method

A method is provided for reducing streak artifacts in images reconstructed from projections having significant discrepancies between the first and last scan views due to subject motion or to scan geometry aberrations during a typical 360° scan such as that utilized in computerized tomography. The views taken at the beginning and end of the 360° scan are taken far apart in time, but in the image reconstruction process, they are treated as being adjacent. The method recognizes that in a 360° scan each ray in a projection is scanned twice so that the data set contains redundant information. To reduce the inconsistencies, weights less than the nominal weight are assigned to original projections at the beginning and end of the scan, and the views near the middle of the scan containing corresponding redundant data are compensated so that the combined weights of all ray pairs are constant. In this manner, the inconsistency between the first and last views is feathered out, and the resulting image exhibits significantly reduced sensitivity to errors caused by the discrepancies. The method is effective regardless of the modality (for example, ultrasound, emission nuclear tomography, computerized tomography, nuclear magnetic resonance) used to obtain the projection data.

Method for reducing image artifacts due to projection measurement inconsistencies

A parallel-beam optical tomography system (4) for imaging an object of interest (1) includes a parallel ray beam radiation source (35) that illuminates the object of interest (1) with a plurality of parallel radiation beams (36). After passing through the object of interest (1) the pattern of transmitted or emitted radiation intensities is magnified by a post specimen optical element or elements. An object containing tube (2) is located within an outer tube (32), wherein the object of interest (1) is held within or flows through the object containing tube (2). A motor (34) may be coupled to rotate and/or translate the object containing tube (2) to present differing views of the object of interest (1). One or more detector arrays are located to receive the emerging radiation (68) from the post specimen magnifying optic. Two- or three-dimensional images may be reconstructed from the magnified parallel projection data.

Optical tomography of small objects using parallel ray illumination and post-specimen optical magnification

A system for three-dimensional diagnostic imaging generates a plurality of slice images of a specimen. A region of interest is selected from within a slice and is extrapolated to subsequent slices. A boundary indicative of a surface of interest is selected from within the region of interest to facilitate generation of an image representative of a three-dimensional surface of interest to be assembled from subsequent slices of the plurality. A viewing surface is defined in relation to a generated surface image which was selected from the boundary. A scaling means assigns a scaled gray level to the three-dimensional image to facilitate three-dimensional viewing of the object when it is projected on the viewing surface. Image information is selectably modified by data from the original slice images to add surface density visualization. Means is also provided to facilitate selective segmentation of a three-dimensional image along a plane or planes of interest. An interactive procedure is provided to facilitate cutting of a three-dimensional object from its perspective view (with or without density information).

System to reformat images for three-dimensional display using unique spatial encoding and non-planar bisectioning

A tomographic image of a X-ray tested tissue of body is reconstructed by calculating X-ray absorption coefficients of picture elements constituting a tomographic plane in reference to measured values produced by the first and second projectional distributions of X-ray produced by projecting X-ray. Accordingly, it becomes possible to reconstruct a clear tomographic image of a moving X-ray tested tissue and to make an X-ray exposure level very low by extremely shortening the time of the reconstruction of computed tomographic image. Moreover, a resolving power of measuring is substantially improved, resulting in that an accuracy of reconstructing the tomographic image may also be improved.

Reconstruction method of a computed tomographic image from a few X-ray projections

A method of reconstructing a computed tomographic image comprising projecting X-rays through material to be tested at a plurality of spaced positions, and measuring the X-ray density values of the X-rays projected through the material along the distribution of projected X-rays. The spaced positions at which the X-ray density values are measured are selected such that the tomographic plane of the material to be reconstructed is represented by a pseudo-tomographic plane comprised of an array of n rows of m columns of picture elements, each having a single piece of X-ray density information, and such that each X-ray beam passes through the lower left corner of a corresponding picture element. The X-ray absorption coefficient for each picture element is calculated from the measured values of X-ray density, and the computed tomographic image is reconstructed by positioning picture elements having the computed X-ray absorption coefficients in an array corresponding to the array in the pseudo-tomographic plane.

Method of reconstructing a computed tomographic image from a single X-ray projection

Verfahren zur rekonstruktion einer raentgentomographie

In the preceding paper, the authors reported that it was possible to get the spectral energy distributions of light sources or the spectral transmittances of optical filters by solving the matrices of which the elements were the relevant values of retarding potential characteristic curves of a photoelectric tube under illumination of tested lights or transmitted lights through tested filters. In those cases, the solutions were affected remarkably by the errors which were involved in measured values so that solutions which failed to meet the problems in physics or engineering were sometimes obtained. Then, in order to get good results, the only way was to measure the current of photoelectric tube with high accuracy.In this paper, first, we describe the principle to obtain the spectral energy distributions of light sources by means of linear programming applicable to retarding potential characteristics of a photoelectric tube. Next, we obtain the spectral transmittance of an optical interference filter as a practical example of the method above mentioned.In computation of it, two sorts of numerical values of the retarding characteristic of the photoelectric tube used in experiment are adopoted say, one is reduced from the theoretical equation and the other is a real measured value. The final results obtained linear programming agree fairly well with those obtained by the conventional spectrophotometric method.In general, careful efforts are made in experiments to minimize the errors involved in measured values and the least squares method is often used when unavoidable errors still exist. In some cases, however, it may be difficult to repeat the measurements many times or to measure with high accuracy. In those cases, linear programming may be useful for the data processing.(1) S. Yamaguchi, F. Kobayashi: J: Iluum. Engng Inst. Japan, vol.52, No.4 (1968) 108

Fujio Kobayashi

Papers

Reconstruction method of a computed tomographic image from a few X-ray projections

Method of reconstructing a computed tomographic image from a single X-ray projection

Verfahren zur rekonstruktion einer raentgentomographie

Applications of Linear Programming to the Spectrophotometry by Means of Retarding Potential Method

Analysis for Spectral Power Distributions of Fluorescent Lamps with Higher Efficacy and Color Rendering Indices