A plurality of imaging regions (104, 105 and 106) capture a plurality of images, respectively, via a plurality of imaging optical systems (101, 102 and 103) corresponding one to one to the plurality of imaging regions. An image combining means (115) eliminates a difference among the plurality of images and combines the plurality of images into a single image. Thereby, it is possible to obtain a combined image of high quality.

As the principle method of obtaining a single high definition image by combining a plurality of images obtained using a plurality of imaging optical systems (multiple-lens imaging system), for example, the method disclosed in "Acquisition of Super High Definition Pictures" (Kiyoharu Aizawa et al., the Journal of the Institute of Image Electronics Engineers of Japan, 90-03-04, p 23 to 28) is known. According to this method, a single high definition image is obtained by superimposition of two images obtained using two imaging optical systems such that the pixels of one image are interposed between the pixels of the other image.
The same applies when this principle is applied to color images. Specifically, as the method of obtaining high definition color images, there are the following methods: one is to employ a plurality of imaging optical systems equipped with color filters arranged in the Bayer arrangement, a stripe arrangement or the like; and another is to employ a plurality of imaging optical systems having different chromatic sensitivity characteristics.
A typical multiple-lens image pickup device will be described with reference to FIG. 15. In FIG. 15, a plurality of imaging optical systems 101, 102 and 103 form object images on a plurality of image sensors 104, 105 and 106, respectively. The plurality of image sensors 104, 105 and 106 have different imaging and light-receiving characteristics. The image sensor 104 captures a red (R) wavelength region, the image sensor 105 captures a green (G) wavelength region, and the image sensor 106 captures a blue (B) wavelength region. A plurality of images captured by the plurality of image sensors 104, 105 and 106 are image-processed by an R signal processing circuit 107, a G signal processing circuit 108 and a B signal processing circuit 109, respectively, and combined and outputted as a color image by an image combining process circuit 110.
In this multiple-lens image pickup device, the plurality of imaging optical systems 101, 102 and 103 have different optical axes, and they are arranged to be symmetrically inclined at an angle θ (radiation angle) with respect to the normal line of the object placed at a predetermined position. For example, with the radiation angle θ being set and fixed to be optimal for the object position b of FIG. 15, if an object placed at the position a or c is captured, because the radiation angle θ for the object position a or c is different from the optimal radiation angle, a shift occurs among the images captured by the image sensors 104, 105 and 106.
This will be described with reference to FIGS. 16A, 16B and 16C. FIGS. 16A, 16B and 16C are diagrams showing combined images obtained by the multiple-lens image pickup device shown in FIG. 15. FIG. 16A is a combined image obtained when the object placed at the position a is captured. FIG. 16B is a combined image obtained when the object placed at the position b is captured. FIG. 16C is a combined image obtained when the object placed at the position c is captured. In this example, the object is assumed to be a white circular object captured on a black background.
When the object is placed at the position a, because the radiation angles of the plurality of imaging optical systems101, 102 and 103 are not appropriate, the red image (R) and the blue image (B) shift to the right and left from the green image as shown in FIG. 16A. The shifted portions are outputted as color drift in the combined image. More specifically, the portion from which the blue image has shifted becomes yellow (Ye) due to the combination of the green image and the red image. The portion from which the red image has shifted becomes cyan (Cy) due to the combination of the green image and the blue image. The portion from which the blue image and the red image have shifted becomes green (G). In this example, because the optical axes of the plurality of imaging optical systems 101, 102 and 103 are arranged one-dimensionally, in the combined image, a one-dimensional shift occurs along the arrangement direction, but when they are arranged two-dimensionally, a two-dimensional shift occurs. When a two-dimensional shift occurs in a combined image, the portion from which the green image has shifted becomes magenta (Mg) due to the combination of the red image and the blue image.
When the object is placed at the position b, because the radiation angles of the plurality of imaging optical systems101, 102 and 103 are appropriate, a high definition image without color drift as shown in FIG. 16B is outputted.
When the object is placed at the position c, a combined image as shown in FIG. 16C is obtained in which the red image and the blue image are shifted in the opposite direction to that of the combined image (see FIG. 16A) obtained when the object is placed at the position a.
Moreover, if there is even a slight difference (e.g., a variation in magnification, inclination, distortion, etc.) among a plurality of images obtained by the image sensors 104, 105 and 106, it will be difficult to correct the parallax accurately, and the image quality, particularly, the resolution of the combined image, will be very poor.
To cope with this, Japanese Patent No. 3397758 discloses, in order to prevent the variation in magnification, to set the focal length of a first imaging optical system corresponding to a first wavelength and that of a second imaging optical system corresponding to a second wavelength to be equal. However, from the actual production point of view, it would be extremely difficult to set the focal lengths to be exactly equal, and particularly when the optical systems correspond to different wavelength bands, it is essentially impossible.


A three-dimensional map of the probability of brain or heart functional states is obtained based on electric or magnetic signals, or a combination of both measured in the surface of body. From signals, the statistical descriptive parameters are obtained and a map of its distribution is calculated. The map is the inverse solution of the problem based upon: a) the restriction of the solution to structures with high probability of generating electric activity using for this restriction an Anatomical Atlas and b) imposing that the solution belong to a pre-specified functional space. The probability is determined that this map belongs to a test group. The spatial and temporal correlations of the map are modeled as well as their dependence on experimental covariables. The resulting probabilities are coded in a pseudocolor scale and they are superimposed on a Anatomical Atlas for their interactive three-dimensional visualization.

1. Field of the Art
The present invention consists of a system and method for obtaining Tomographic Images of the Primary Electric Currents (PEC) produced by the neurons of the brain and the muscle cells of the heart.
2. Description of the Prior Art
In this invention reference will be made to phrases and terms used of art that will be defined as follows:
Vectors will usually be denoted with boldface lowercase letters and matrices usually with uppercase boldface letters. 1N is the vector of dimension N of ones. In denotes the identity matrix of order n.  is the matrix Kronecker product. ".*" is the Hadamaard product and o represents the dyadic product among vectors. If x is a matrix or a vector, then xt denotes x transposed x; x* denotes x conjugate transposed. The operation vech(X) applied to X consists of forming a vector with the columns of X, eliminating repeated elements or those considered constant in the context of the problem.
Primary Electric Current (PEC) jP(r,t): is the macroscopic magnitude obtained by the spatial and temporal average of the post-synaptic activity of a group of nervous or heart cells at the position {right arrow over (r)} and the instant of time t.
Volume Conductor ΩV: the region inside the body that will be the object of study (e.g., the head and/or the torso.
Generating Volume Ωg: the subset of ΩV where the PEC originates (i.e., the brain or the heart).
Lattice of the Volume Conductor V: the discrete group of NV points rvεΩV.
Lattice of the Generating Volume g: the discrete group of Ng points rgεΩg.
Lattices of Time Instants ℑm(tI,I=1, . . . ,NIm): time scale for which each selected functional image m has been sampled.
Analysis Interval ℑ=[0,T] is the period defined from a reference fixed arbitrarily at the instant 0 until time T.
PEC Tomographic Image (TPEC): vector j(t)=└jP({right arrow over (r)}g,t)┘1≦g≦Ng defined at the points rgεΩg, and for each instant tεℑ of time.
Electro-encephalogram (EEG) and Electro-cardiogram (EKG): time series obtained by measuring, on the head and the thorax respectively, the voltage difference Ver(t) that is created in a pair of electrodes localized on the body in the positions re (recording electrode) and rr (reference). Ver(t) is measured at Ne sites on the body. A vector of measurements of this type will be denoted by v(t).
Magneto-encephalogram (MEG) and Magneto-cardiogram (MKG): time series obtained by measuring the projection bcn(t) of the magnetic field density vector at the center rc of a simple coil on nc, the perpendicular vector to the plane that contains it. These simple coils are connected to Superconducting Quantum Interference Devices (dc SQUID) by means of a group of magnetic flow detection transformers. bcn(t) are measured at Nc sites of the body. The vector of measurements of this type will be denoted by b(t).
Anatomical Images: type of medical images that offer structural information about the body such as Computed Axial Tomography (CAT), Magnetic Resonance Images (MRI), post-mortem sections of the head using cryotomy, etc.
Anatomical Atlas: is an anatomical image of the brain or of the heart in a reference system of the head or the torso, respectively. A particular instance of a reference system for the brain is the "Talairach" international system. Possible types of anatomical atlases are:                Individual: structural images of the subject under study (FIG. 1); and        Probabilistic: a composite statistical image that summarizes the inter-individual variability of normal or pathological morphologies of anatomical images in a given population (Valdés P. and Biscay R. The statistical analysis of brain images. In: Machinery of the Mind, E. Roy John et al. the. (ed.), (1990). Birkhauser, pp. 405–434.; Collins D L, Neelin P, Peter T M, Evans A C (1994) Automatic 3D registration of MR volumetric dates in standardized talairach space. J Comput. Assist. Tomogr. 18(2): 192–205; Evans A C, Collins D L, Mills S R, Brown E D, Kelly R L, Peters T M (1993) 3D statistical neuroanatomical models from 305 MRI volumes. Proc. IEEE-nuclear Science Symposium and Medical Imaging Conference: 1813–1817; Evans, A. C., Collins, D. L., Neelin, P., MacDonald, D., Kambei, M., and Marret, T. S. (1994) Three dimensional correlative imaging: Applications in human brain mapping. In R. Thatcher, M. Hallet, T. Zeffiro, E. Roy John and M. Huerta (Eds.) Functional neuroimaging technological foundations. (Academic Press).
Functional Images: types of medical images that offer information on the hemodynamics corporal metabolism such as: Functional Magnetic Resonance (fMRI), Positron Emission Tomography (PET), and the Single Photon Emission Tomography (SPECT).
Observations o(t)=[o(t)m]1≦m≦M the group of M measurements of different modalities (EEG, MEG, and functional image) that will be used for the construction of the TPEC. All the measurements are referred to the reference system of the selected anatomical atlas. The EEG/EKG (o1(t)) and/or the MEG/MKG (o2(t)) and optionally the fMRI, PET, and SPECT (om(t), m>2) will be always included in o(t). These observations are defined for the lattices of sensor positions m as the set of Cartesian coordinates that define the position and orientation of each sensor in a predefined common body reference system, said lattices being designated 1, 2, 3, 4, and 5 for the EEG/EKG, MEG/MKG, fMRI, PET, and SPECT, respectively. Alternatively, o(t) may be defined for the coordinates yεΔm, where Δm is the Space of Measurement of the modality m.
Multivariate Z Transform of the vector of random variables xΘx={μx, Σx}, their mean vector and matrix of population covariances is defined
      z    X    =            (              x        -                  μ          x                    )        ·                            ∑          x                          -                      1            2                              .      In this last expression one of the square roots of Σx is selected and, if this is not of complete range, a pseudoinverse is used. In the case that x is of dimension 1, its Z Transform has the simple expression
      z    X    =                    x        -                  μ          x                            σ        x              .
Generalized Gaussian Distribution Ntk,p(μx,Σx): is a probability density proportional to exp(−β∥x−μx∥Σxp), where k is the dimension of the distribution, p the order of the norm in the exponent ∥x−μx∥Σxp=|zx|p, β a proportionality constant, and t is the numeric variable type (i.e., R—real or C—complex). For example, the notation x˜NR2,p(μx,Σx) is used to express that x is a sample from a multivariate real gaussian distribution.
Functional Space: is a set of functions with common properties (Triebel, H. 1990. Theory of Function Spaces II. Basel: Birkhauser). Membership in a function space is used to specify desirable properties in the TPEC under consideration. The function spaces are considered to be consisting of the combination of atoms.
Dictionary of Atoms: is a collection of atoms with properties such that all element of a function space can be expressed as
      f    =                  ∑        k                                    F          k                ·                  ψ          k                      ,where ψk are the atoms. Examples are: "Wavelets", (Meyer, Y. 1992. Wavelets and Operators. Cambridge: Cambridge University Press), the Fourier base of complex exponential, the collection of Dirac deltas in a space of generalized functions, etc. A Megadictionary is the union of several dictionaries of atoms.
Besov Space Bn,sm(Ω→Rn): is a collection of functions defined on the space Ω and taking values in Rn that possess a degree of smoothness specified by means of the triple (m, n, s) (Triebel, H. 1990. Theory of Function Spaces II. Basel: Birkhauser). The requirement that any given function f belongs to Bn,sm shall be imposed by means of penalization with the metric
                                        f                                    B                      n            ,            s                    m                    ≈                                  f                                    b                      n            ,            s                    m                      =                  ∑        k                                    a          k                ·                                                        F              k                                            m                      ,that is to say the norm of weighted combination of the atoms (De Vore R. A. and Popov V., (1988) Interpolation of Besov Spaces, Transactions of the American Mathematical Society 305, 397–414). These spaces allow the modeling of functions with controllable degree of spatial inhomogeneity. Particular cases are:                Sobolev Space: B2,2m=Hm, of maximum smoothness (with respect to derivatives of order m); and        The "algebra of bumps": B1,s1 that allows modeling both of point sources (dipoles) and distributed sources in a common framework. (Meyer Y., (1992) Wavelets and Operators, Cambridge: Cambridge University Press).
Reference group: consists of a reference group, the membership to which is to be established for a given TPEC image.
Classical Quantitative Electrophysiology (qEEG/qEKG)
This invention has as antecedents the work directed to quantify and to make objective the detection of abnormal states of the brain and heart by applying multivariate statistical analysis to the EEG and EKG. These methods are known as quantitative electroencephalography and quantitative electrocardiography (abbreviated respectively as qEEG and qEKG). Systems and methods for qEEG were described in the patents U.S. Pat. No. 4,846,190; U.S. Pat. No. 4,913,160; U.S. Pat. No. 5,282,474 and U.S. Pat. No. 5,083,571. Methods for qEKG were described in the U.S. Pat. No. 4,974,598. These patents specify recording of the EEG and/or EKG (v(t)) by means of a plurality of sensors.
Optionally, instead of analyzing the v(t) recorded originally, pre-processed series (PPS) are obtained by means of the calculation of the cross-covariance function of v(t) with respect to a time series s(t), marker of external events. In the case of the EEG, s(t) may be taken as a sequence of Dirac delta functions indicative of the moments at which certain stimuli are presented to the subject examined. The resulting time series is known as the Average Evoked Potential (AEP). In the case of the EKG, s(t) may signal the occurrence of the R wave of the EKG itself and the resulting PPS is the average EKG (AEKG).
The extraction of Descriptive Parameters (DP) from these time series are statistical summarizations of the recorded time series designed to reflect variations in normal and pathological physiological activity.
In the above-mentioned patents, the DP specified for the EEG are the averages in broad bands of the frequency of spectrum, and elementary transformations of these DP are also included. The DP of the Broad Band Spectral Analysis (BBSA) are defined formally as follows: SO(ω) is the crosspectral or variance and covariances matrices of the coefficients of Fourier of V(t) (where ω denotes frequency). The DP-BBSA are:
            ∫      a      b                                    s                      O            ,            ij                                            (          ω          )                                  ⅆ        ω              ,where a and b specify the limits of the broad band and sO,ij(ω) is the element i, j of the matrix SO(ω).
In the patents cited, the DP for the AEP and AEKG are defined as the coefficients of a Karhunen-Loeve bases. These parameters are known as Factorial Analysis loadings.
In the patents cited, transformations of the DP are carried out to guarantee their gaussianity. In the description of this invention a generic transformed scalar DP will be denoted with the letter x=T(DP) and a vector with the notation x=T(DP), after the transformation x˜NR2,p(μx,Σx).
In the patents cited, a comparison of the DP is carried out with respect to the normal variability (inferred from normative databases) by means of the univariate z transform that expresses the DP as a deviation measured in units of standard deviation σx, with respect to the populational average μx. In the calculation of the zx based on the normative database, the effect of concomitant variables that originate variability that is not of diagnostic interest (as is the case of the subject's age), is eliminated by means of homoscedastic polynomial regression.
In the construction of brain and heart Topographic Maps (TM), the degree of deviation of the subject with respect to the norm is coded by means of a color scale. The TM is an image interpolated between the measurements of the sensors, which represents a schematic two-dimensional projection of the head or of the torso.
Cluster analysis is used to define groups of similar subjects according to the values of their DP (see U.S. Pat. No. 5,083,571).
Linear discriminant analysis is used to classify a subject examined as belonging to a test group or a test group previously defined by cluster analysis on the basis of predefined values of their DP (see U.S. Pat. No. 5,083,571).
The measurement of the statistical distances of a subject with respect to his own previous states is carried out at selected moments. This offers information on the subject's physiological state, for example, in the following conditions: during an operation, while in intensive therapy, or while in evaluation for the evolution of pathology (U.S. Pat. Nos. 4,545,388; 4,447,270; 4,815,474; 4,844,086 and 4,841, 983).
The utility of these methods has been confirmed in several studies (John, E. R.; Harmony, T. Valdés-Sosa and, P. (1987b): The uses of statistics in electrophysiology. In: Gevins, A. S. and Rémond, A. (Eds), Handbook of Electroencephalography and Clinical Neurophisiology. Revised Series. Volume 1, Elsevier, The Netherlands, 497–540 and John, E. R.; Prichep, L. S. and Easton, P. (1987a): Normative data bases and neurometrics. Basic concepts, methods and results of norm construction. In: Gevins, A. S. and Rémond, A. (Eds), Handbook of Electroencephalography and Clinical Neurophisiology. Revised Series. Volume 1, Elsevier, The Netherlands, 449–496).
However, these methods have the following limitations:
The DP-BBSA are insufficient as descriptive parameters for the quantification of many types of activities of the EEG. This is due to the loss of resolution caused by the averaging over bands in frequency, with the resulting loss of sensitivity and specificity in diagnoses (Szava, S.; Valdés, P.; Biscay, R.; Galán, L.; Bosch, J.; Clark, I. and Jiménez, J. C.: High Resolution Quantitative EEG Analysis. Brain Topography, Vol. 6, Nr. 3, 1994, pp. 211–219).
The analysis of a group of DP by use of TM is hindered by the high correlation among the variables. To overcome this difficulty, Galán et al. (Galán, L.; Biscay, R.; Valdés, P.; Neira, L. and Virués T. (1994): Multivariate Statistical Brain Electromagnetic Mapping. Brain Topography, vol 7. No.1) introduced the Multivariate TM by means of the use of the multivariate Z transform.
The evaluation of the normality of the TM is carried out by means of univariate statistics without taking into account the need for the control of Type I errors caused by the multiple comparisons for all point of the map. This increases to uncontrollable levels the probability of false anomaly detection.
The procedure for the statistical classification of subjects is based on the assumption that x˜NR2,p(μx,Σx). This implies that the decision frontiers between the groups are linear which is too restrictive. In addition, optimal procedures for the selection of the DPs with highest classification power have not been applied.
The use of magnetic measurements b(t) are not included, in spite of the fact that these add additional information to that provided by v(t).
The analysis of physiological information is limited to v(t), without there being any inference about j(t). Therefore, none of these methods constitutes a modality of TPEC. They are merely an analysis of projections of j(t) on the surface of the body after being distorted by the tissues of the subject interposed between the generators of the neural/cardiac PEC and the sensors. In fact, the relationship between the PEC and the EEG/MEG/EKG/MKG depends on the conductor properties of the head and the torso (e.g. geometry, conductivity, electric and magnetic permeability, etc.).
Cerebral and Heart Multivariate Statistical Maps
Some of these limitations were overcome by the U.S. Pat. No. 5,282,474 of Pedro Valdés-Sosa et al. In this patent the use of statistical methods is claimed for the evaluation of the abnormal activity of the brain and of the heart with the following innovations:
(1) b(t) is added as an optional source of physiological information.
(2) Additional components of the time series s(t) are included in the form of markers of external events of more general type such as can be derived from the subject's own voluntary or involuntary reactions, or those obtained by the analysis of their own o(t). The series derived by such a pre-processing are the Event Related Components (ERC) derived from o(t).
(3) Expansion of the ERC in tensor products of functional space-time bases. These include not only the basis of Fourier, but also wavelets (for the description of non-stationary processes) among other sets of DP that increase flexibility in the description of physiological processes.
(4) Summarize inclusive of these DP by means of the use of higher order statistical moments and different parametric time series models. In particular the coefficients of linear autorregresive are included.
(5) The introduction as DP of High Resolution Spectral Analysis (HRSA) consistent in the use of SO(ω) for all the frequencies ω according to the one transformed of discrete Fourier; and
(6) The introduction in the TM of color scales based on the empirical probability distribution of the global maxima and global minima of the DP. This scale exercises an effective control of the probability of false pathology detection.
The improvements for the evaluation of brain activity introduced in the Sosa et al. '474 patent were exemplified as follows:
(1) By means of the construction of norms of HRSA for the Cuban population from 5 to 97 years (Valdés, P.; Biscay, R.; Galán, L.; Bosch, J.; Szava, S.; and Virues, T.: High Resolution Spectral EEG norms for topography. Brain Topography, 1990, vol. 3, pp. 281–282 and Valdés, P.; Bosch, J.; Serious of it Banks, R.; Hernández, J. L.; Pascual, R. and Biscay, R.: Frequency domain models for the EEG. Brain Topography, 1992a, vol. 4, pp. 309–319); and
(2) By the showing that the DP-HRSA achieve a higher sensitivity and specificity than the DP-BBSA for the detection of neurological and psychiatric pathology (Szava, S.; Valdés, P.; Biscay, R.; Galán, L.; Bosch, J.; Clark, I. and Jiménez, J. C.: High Resolution Quantitative EEG Analysis. Brain Topography, Vol. 6, Nr. 3, 1994, pp. 211–219).
However, the construction of DP of o(t) used in the Sosa et al. '474 patent is limited to such parametric models as the DP-HRSA. These are only a complete description of o(t) for stationary and linear stochastic signals or those signals with limited types of nonlinearity. The inadequacy of such DP for the study of the EEG of some types of patient (i.e., those with epilepsy) was demonstrated by Hernández, Valdés-Sosa and Vila (Hernández, J, L., Valdés, P. A., and Vila, P. (1996) EEG spike and wave modeled by to stochastic limit cycle. NeuroReport, 7: 2246–2250).
Moreover, qEEG methods and qEKG are not applied to estimates of j(t). For this reason, they are not true variants of TPEC.
Tomography of Cerebral and Heart Primary Electric Currents
As in all type of Tomography, the starting point for the development of the TPEC is the establishment of a model that relates the observed data with the quantity to estimate, this model is known as the Direct Problem. In the TPEC, the direct problem postulates how the o(t) are generated the from j(t). This model has two components:
(1) The specific model of Volume Conductor assumed, that is to say, of the conductive properties of the head and the torso, in particular their geometry, conductivity, electric and magnetic permeability, etc; and
(2) The model that is assumed for j(t), or source model; and
The properties of the Volume Conductor are summarized in the electric kE(r) and magnetic kM(r) Lead Fields (LF). These are the kernels of Fredholm integral equations of the first kind that establish direct relationships between the PEC jP(r,t) with Ver(t) and bcn(t).
                                          V            er                                          (            t            )                          =                              ∫                          Ω              v                                                                                k                  E                                                                  (                  r                  )                                            ·                                                j                  P                                                                  (                                      r                    ,                    t                                    )                                                                                ⅆ                              r                3                                                                        (        1        )                                                      b            cn                                          (            t            )                          =                              ∫                          Ω              v                                                                                k                  M                                                                  (                  r                  )                                            ·                                                j                  P                                                                  (                                      r                    ,                    t                                    )                                                                                ⅆ                              r                3                                                                        (        2        )
The discretization of the terms expressed in equations (1) and (2) lead to the following formulation of the direct problem:o(t)=K·j(t)+e(t)  (3)where K is the discretized LF and e(t)˜.Ntk,p(0,ΣEE), being the error introduced at the sensors in the moment of the measurement.
The use of the LFs to formulate the Direct Problem instead of using the classic Green formulation results in remarkable advantages according to Rush and Driscoll (Rush S. and Driscoll D. A. EEG electrode sensitivity—an application of reciprocity. IEEE Trans. on Biomed. Eng., vol. BME-16, pp. 15–22, 1969) and Plonsey (Plonsey R. Capability and limitations of electrocardiography and magnetocardiography. IEEE Trans. Biomed. Eng., vol. BME-19, not. 3, pp. 239–244, 1972). This is mainly because all the conductive properties of the head or the thorax can be summarized in these magnitudes without assuming a specific model for the PEC.
However, it is well-known that the conductivity in the body is non homogeneous and non isotropic (Hoeltzell P. B. and Dykes R. W. Conductivity in the somatosensory cortex of the cat. Evidence for cortical anisotropy. Brain Research, 117, pp. 61–82, 1979), a fact that complicates the calculation of the LFs considerably. Nevertheless, a substantial simplification is possible when the conductivity is considered constant and isotropic in each tissue type, which constitute a compartment (Schwan H. P. and Kay C. F., The conductivity of living tissues. Ann. N.Y. Acad. Sci., vol. 65, pp. 1007–1013, 1957). This model of Volume Conductor is denominated Isotropic and Piecewise Homogeneous Volume Conductor (IPHC). In general, two types of model IPHC are in use for the head or the torso:
(1) Spherical: the simplest model that specifies that the surfaces defining the different compartments are concentric spheres. For this model explicit formula exist to evaluate K. This model is easy to evaluate but not very exact, mainly for the temporal regions of the head; and
(2) Realistic: in which the surfaces of the compartments are obtained from an anatomical atlas. For this model numeric methods have been developed by Fletcher et al. (Fletcher D. J., Amir A., Jewett D. L. and Fein G. Improve method for the calculation of potentials in a realistic head shape model. IEEE Trans. Biomed. Eng., vol 42, not. 11, pp. 1094–1104, 1995) and Oostendorp and van Oosteroom (Oostendorp T. and van Oosterom A. The potential distribution generated by surface electrodes in homogeneous volume conductive of arbitrary shape. IEEE Trans. Biomed. Eng., vol. BME-38, pp. 409–417, 1991). However, this procedures is based on a boundary element method (BEM) for the calculation of the potential difference on the surfaces that limit the compartments produced by energizing the sensors.
The expression:RO=∥o(t)−K·j(t)∥ΣEEpO  (4)is the functional of the Direct Problem in the norm pO. l(o(t)|(t),ΣEE)=CO exp[−Ro] is defined as the likelihood corresponding to equation (3), being C0 the constant of normalization of the density. In what follows, unless otherwise stated, pO=2.
The central objective of the TPEC is the estimation of j(t) by means of the minimization of RO=∥o(t)−K·j(t)∥ΣEEpO, which is the "Inverse Problem". It is well known that RO=∥o(t)−K·j(t)∥ΣEEpO lacks, in general, a unique solution since the LF operator has a non-trivial null space, even when simultaneous electric and magnetic measurements are available.
Estimation of the PEC is possible only if a priori information is contributed in the form of a model for j(t) that impose a series of restrictions. These may be classified as:
Extrinsic: consisting of requiring the compatibility of the desired solution with information provided from other types of neuroimages. About the cerebral anatomical neuroimages, typical requirements are: (1) that j(t) be estimated only inside the spherical Volume Conductor that models the head; and (2) that j(t) be restricted to the cortical surface of the of the subject with an orientation perpendicular to said cortex (Dale, A. M., and Sereno and, M. I., J. Cognit. Neurosc., 1993, 5:2, pp. 162–176).
Intrinsic: consisting of requirements about the shape and extent of areas of activated tissue. It is required that the activated areas are as small as possible while maintaining compatibility of the model with the data (simplicity). As for the variation in the shape in the space, j(t), this requirement has ranged from minimal smoothness (collections of Dirac deltas corresponding to current dipoles) to functions that are maximally smooth.
All the above stated conditions are imposed on the solution in two equivalent ways:
Regularization: Adding to RO=∥o(t)−K·j(t)∥ΣEEpO a non-negative functional RJ=RJ(j(t)|Θ) and minimizing RO+λ·RJ(j(t)|Θ).
Bayesian estimation: Maximizing the a posteriori distributionP(j(t),ΣEE|o(t))∝l(o(t)|j(t),ΣEE)·π(j(t)|Θ)  (6)where π(j(t)|Θ)=CJ exp[−RJ] is the a priori probability of j(t).
The fundamental differences in the different methods that have been developed to estimate the generators of o(t) are in the model specified for j(t). These are reviewed as follows:
When RJ(j(t)|Θ) is a functional that guarantees that Ng<Θo, where Θo is a constant that assures the uniqueness of the solution of RO=∥o(t)−K·j(t)∥ΣEEpO. This class of models for j(t) is denominated current dipoles (Scherg, M. and Ebersole, J. S. (1993): Models of Brain Sources. Brain Topography. Vol. 5, Nr. 4, pp. 419–423).
                              j                                (                          r              ,              t                        )                          =                              ∑                          g              =              1                                      N              g                                                                                α                  g                                                                  (                  t                  )                                            ·                                                μ                  g                                                                  (                  t                  )                                                                                δ                                            (                                  r                  -                                      r                    g                                                  )                                                                        (        7        )
Where αg(t) is the activity of the generator g and μg(t) its orientation. A model of this type was described in the U.S. Pat. Nos. 4,949,725; 5,285,385; 5,524,086, and 5,361,774. The advantages of these models are: (1) they are effective for modeling situations in which a small group of regions is producing PEC, all of small extent, (2) the formulation leads to simple least squares estimation methods, (3) the set of resulting DP of the estimates is very compact, comprising the positions and orientations of each current dipole, and (4) due to the simplicity of the model, it is easy to include additional restrictions to the estimation of this model of PEC (Scherg, M. and Ebersole, J. S. (1993): Models of Brain Sources. Brain Topography. Vol. 5, Nr. 4, pp. 419–423). For example a certain degree of smoothness may be imposed on αg(t) and the requirement that, μg(t)=μg does not depend on time. These requirements stabilize the estimated DP.
Nevertheless, the dipolar models discussed have the following limitations:
(1) When the number of possible generators of PEC (Ng) becomes too large, this type of model requires of an excessive manual intervention of the operator. For this case, the inverse problem becomes again ill determined. In fact, these models do not include a statistical approach for determining Ng.
(2) When the different regions of tissue that generate PEC are distributed in extensive areas, the dipolar model estimates an equivalent dipole located at the center of mass of the actual region, and therefore produces an artifact
(3) The smoothness of αg(t) has been imposed by use of a spline basis, that limits its possible forms of the amplitude of the activity to belong to a Sobolev functional Space W2(L2), (second derivative integrable Lebesgue).
This type of model has been used solely to describe the AEP or AEKG.
This model for generators has been applied using spherical and realistic models of the Volume Conductor. However, the LF methodology has not been used, which necessitates the use of numerical algorithms for the realistic case that are not very practical since they require the evaluation of a step of the BEM in each iteration.
A TPEC was proposed for the first time in the U.S. Pat. No. 5,307,807 of Valdés-Sosa et al., providing a new modality of medical image. This invention consists on a method and system to create three-dimensional maps of the amplitude, orientation and connectivity of the generators of neural/cardiac PEC with the following innovations:
(1) An estimate of j(t) on a three-dimensional lattice inside the body is carried out.
(2) DPs of the PEC of the CRE is considered.
(3) The information available from other types of Structural Medical Images is used to specify the conductive properties of the subject's body. It is also used to define the spatial extent of a lattice for which PEC are defined (thus limiting the possible sites where the PEC are to be estimated) and to determine the orientation of the PEC. The subject's corporal geometric characteristics are incorporated in the TPEC in a quantitative manner with the use of parametric models.
(4) The use of information on the metabolism of the subject under study, available from other types of functional medical images, in order to limit even further the lattice on which j(t) is to be estimated.
(5) The generators that are modeled include not only discrete sources (dipoles) but also diffuse generators that desribe background generator noise, in occasions of higher amplitude than the discrete generators.
(6) Frequency domain estimation is introduced for the generators of CRE, in particular the cross-spectral matrix, Sj(ω), of the generators is introduced.
The improvements for the evaluation of brain activity introduced in the Valdés-Sosa et al. '807 patent were later verified by studies on the origin of abnormal electric activities in patient with focal neurological lesions. See for example Harmony, T.; Fernández-Bouzas, A.; Marosi, E.; Fernández, T.; Valdés, P.; Bosch, J.; Riera, J.; Rodriguez, M.; Reyes, A.; Silva, J; Alonso, M. and Sánchez, J. M. (1995): Frequency Source Analysis in Patients with Brain Lesions. Brain Topography, vol 8. No.2.
However, the clinical works mentioned previously and others (Valdés, P.; Carballo, J. A.; Alvarez, A.; Diaz, G. F.; Biscay, R.; Pérez, M. C.; Szava, S.; Virués, T. and Quesada, M. E.: qEEG in to public Health System. Brain Topography, Vol. 4, Nr. 4, 1992b, pp. 259–266) showed that the inventions described in the patents U.S. Pat. No. 5,282,474 and U.S. Pat. No. 5,307,807 did not take into consideration the following aspects, necessary for a more complete methodological elaboration of the TPEC:
(1) The statistical procedures described in the U.S. Pat. No. 5,282,474 were not extended for use in the TPEC. In particular, the sample space of the TPEC is a stochastic field defined on a 4 dimensions space time manifold, thus requiring for its analysis specific methods which were not taken into consideration in said patent.
(2) The regression methods used in the U.S. Pat. No. 5,282,474 to eliminate the effect of experimental concomitant variables are of a parametric global polynomial type. These are not sufficiently flexible for the description of the variations at multiple scales typical for electrophysiologicalal data.
(3) In the case of the Valdés-Sosa et al. '807 patent, the only regularization resource consists of the control of the number of dipoles whose parameters are considered. This is an implicit use of the functional RJ(j(t)|Θ) that guarantees that Ng<Θo, which is not very flexible and requires excessive human intervention.
(4) The solution for the direct problem that relates the activity of the generators with the observable signals is achieved with anatomical deconvolution. This method does not adapt to general configurations of generators and is only an inexact numeric approximation to the optimal solution.
(5) The parametric description employed to characterize the geometry of the subject's body is based on the use of quantitative descriptors of a functional form that are not sufficiently flexible to adequately describe inter-individual morphometric variability. In particular this method does not allow the inclusion of probabilistic anatomical information in those cases for which the acquisition of structural images of the particular subject under study is either undesirable or impracticable.
(6) The metabolic information available from other image modalities is only integrated as a restriction to the regions in which active dipoles will be allowed. Thus this information is not used in a statistically optimal estimation procedure.
Since the publication of the two aforementioned patents, a series of works have appeared, that while not totally solving the problems outlined above, have contributed to the elaboration of the solutions that are claimed in the present invention. The relevant developments are enumerated next, accompanied by an evaluation of their advantages and inadequacies.
The DPs used in the construction of all the TPEC until the moment are either the raw data or sufficient statistics, derived from the data, almost always some of the lower order statistical moments in the time or frequency domain. Recent works (Hernández, J, L., Valdés, P. A., and Vila, P. (1996) EEG spike and wave modeled by to stochastic limit cycle. NeuroReport, 7: 2246–2250) demonstrate the need for flexible non-parametric descriptions for the temporal sequence of the EEG/MEG/EKG/MKG that allow the description of the dynamic activity, essentially nonlinear, that is characteristic of masses of neural and heart tissue.
The formula RJ(j(t)|Θ)=∥j(t)∥ΣEEpJ includes classical regularization, which allows models of j(t) in which the activated areas can be extensive and with smooth contours. In particular Linear Distributed Solutions are limited to estimate j(t) for each time t separately. They assume that R(t)˜NRk,po(0,ΣEE) and that j(t)˜NRk,ps(0,ΣJ) with pO and pJ=2. In consequence, the estimator of generic TPEC is formulated as a Spline type solution (Riera, J. J., Aubert, E., Valdés, P., Casanova, R. and Lins, O. Discrete Spline Electric-Magnetic Tomography (DSPET) based on Realistic Neuronatomy. To appear in the proceedings of The Tenth International Conference on Biomagnetism, BIOMAG '96, Santa Fe, N. Mex., February 1996) where the smoothness of the solution is specified by the matrix ΣJJ. The estimator of the PEC has, in this case, an explicit expression that is:ĵ(t)=ΣJJ·Kt·(K·ΣJJ·Kt+ΣEE)−1·v(t)  (8)
The most significant representatives in this family of TPEC are characterized by assuming that ΣEE=σ2EEI, where σ2EE is a variance common to the sensors of the same type. The different linear solutions are characterized by the Σj postulated as indicated below.
Minimum Norm TPEC (MN) for which ΣJ=σJ2·I3·Ng. This solution requires that the configuration of generators has minimum energy (Wang J. Z., Williamson S. J. and Kaufman L. Magnetic source images determined by lead-field analysis: the unique minimum-norm least squares estimation. IEEE Trans. Biomed. Eng., 39, 7, 665–667, 1992) compatible with the likelihood. This method produces spatially widespread estimates that do not localize discrete sources correctly. Variants of this methodology were presented in the U.S. Pat. No. 5,228,443.
Weighed Minimum Norm TPEC (WMN), ΣJ=σJ2·W−2I3, where the matrix W=diag(wi)
      w    i    =                    ∑                  d          =          1                          N          d                                                      K                                                •            i                              d                2            W is diagonal and it contains weights. These counteract a bias that distributed solutions have of concentrating solutions near the sensors (George, J. S, P. S Lewis, H. A Schlitt, L. Kaplan, I. and C. C Wood (1993) Strategies for source space limitation in tomographic inverse procedures. In: Proc. 9th Int. Conf. On Biomagnetism, Vienna). It has been demonstrated that this method avoids spurious superficial solutions but it does not localize discrete sources with more precision.
Low resolution electric Tomography (LORETA) where:ΣJ=σJ2·(Λm·L2·Λm)−1I3 Λm=W, L3=LI3, L being the matrix of the discretized Laplacian. This solution imposes the maximum spatial smoothness compatible with the likelihood term (Pascual-Marqui, R. D., 1994. Low resolution electromagnetic tomography: a new method for localizing electrical activity in the brain, Int. J. Psychophysiol. 18:49–65. LORETA). This method localizes a single point source accurately in any part of the brain or heart. LORETA has been extended for the estimation of the cross-spectrum of the generators of the EEG. (see Casanova, R., Valdés P., Garcia F. M., Aubert E., Riera, J. J., Korin W. and Lins O. Frequency domain distributed inverse solutions. To appear in the proceedings of The Tenth International Conference on Biomagnetism, BIOMAG '96, Santa Fe, N. Mex., February 1996). This is based on the following estimator:SJ1/2(ω)=ΣJ·Kt·(K·ΣJ·Kt+ΣE)−1·Sv1/2  (9)
However, SJ1/2(ω)=ΣJ·Kt·(K·ΣJ·Kt+ΣE)−1·Sv1/2 does not correspond to a complete Bayesian model, since an a priori probability is specified for j(t), but not for Σj.
In some cases, additional restrictions can be imposed to obtain the well-known Backus and Gilbert solution, as described in U.S. Pat. No. 4,977,896.
All these Spline methods specify the membership of j(t) to a Sobolev Space Hq(L2), for integer q, which is too restrictive since the estimation of dipolar types of PEC are not allowed. In fact, the Raleigh limit is valid which states the impossibility of discriminating nearby point sources. This limit is the cause, additionally, of the appearance of "ghost" solutions that are interference artifacts due to the limited resolution of linear methods.
In search of less widespread solutions, several authors have proposed non-linear estimators of j(t). Among these (1) Matsuura and Okabe (Matsuura K. and Okabe Y. (1995) Selective Minimum-Norm Solution of the Biomagnetic Inverse Problem. IEEE Trans. BME Vol. 43 not. 6 pp. 608–615) have varied of po and pj in the Generalized gaussian distributions that define the inverse problem with the consequence that the inverse solution must now be estimated non-linearly; (2) Gorodnitsky and Bhaskar (Gorodnitsky, I. and Bhaskar D. R. 1997. Sparse signal reconstruction from limited data using FOCUSS: a reweighted minimum norm algorithm. IEEE Trans. Signal Proc. Vol. 45 (3) pp 600–616) have proposed to apply iteratively the estimator of RO+λ·RJ(j(t)|Θ) weighting each lattice point proportionally to the j(t) value estimated in the previous step. Both proposals converge algorithmically to a number of discrete generators equal to the number of sensors, therefore being in effect a more elaborate form of dipole fit. In consequence, they share with these dipolar models the defect that they can not estimate spatially distributed sources.
Philips et al. (Philips J W, Leahy R M and Mosher J C. MEG based imaging of focal neuronal current sources. (1997). IEEE trans Medical Imaging, Volume 16: 338–348) introduced for P(j(t),ΣEE|o(t))∝l(o(t)|j(t),ΣEE)·π(j(t)|Θ) the functionalRJ(j(t)|Θ)=∥ψ(t)∥Σψψpψ+V(z(t))  (10)where j(t)=ψ(t).*(z(t)13). This functional penalizes the lack of smoothness of Ψ(t) in the metric of ΣΨΨ,. It also imposes the additional requirement that there are few active Zi (which is controlled by the weights αI) which will be concentrated in neighborhoods ξI (whose dispersion is controlled by means of the parameters Q and the weights βi). This is accomplished by means of the term
      V              (              z                          (          t          )                    )        =            ∑              i        =        1                    N        g                        {                                    α            i                    ·                                    Z              i                                                  (              t              )                                      +                              β            i                    ·                                    [                                                ∑                                      i                                                                                ∈                                                                                ξ                      i                                                                                (                                                                                Z                          i                                                                                (                          t                          )                                                                    -                                                                        Z                          i                                                                                (                          t                          )                                                                                )                                    2                                            ]                        Q                              }      The resulting Bayesian hierarchical model is estimated by using the method of "Mean Field Annealing." This model, although potentially very flexible it has only been described for the case ΣΨ=σΨ2·W−2I3.
None of the methods described above models the temporal dependencies of j(t), which is equal to the use of the implicit assumption that j(t) is independent for each t. This assumption can cause considerable bias in the statistical estimates.
It should be mentioned that numerous works carry out processing of o(t) images, sometimes taking into account information contributed by other neuroimage modalities, that however do not have as an objective the estimation and ulterior use of j(t). Such is the case of the patent from Finland 925,461 and the U.S. Pat. No. 5,331,970. Since these patents do not having as an objective the obtaining of a TPEC, these types of antecedents will not be included in this analysis of the art.

System and method for the tomography of the primary electric current of the brain and of the heart

Centro Nacional de Investigaciones Cientificas (CNIC)


A power converting apparatus controls switching of self turn-off type semiconductor devices so as to perform power conversion. The apparatus comprises a plurality of switch units each having first and second self turn-off type semiconductor devices, first and second diodes, and a capacitor. The cathode of the first self turn-off type semiconductor device is connected to the anode of the first diode, and the cathode of the second diode is connected to the anode of the second self turn-off type semiconductor device. The capacitor is connected between a common junction between the cathode of the first self turn-off type semiconductor device and the anode of the first diode and a common junction between the cathode of the second diode and the anode of the second self turn-off type semiconductor device.

1. Field of the Invention
This invention relates to a power converting apparatus using self turn-off type semiconductor devices.
2. Description of the Related Art
FIG. 21 is a circuit diagram, showing a conventional power converting apparatus. In this apparatus, an AC voltage supplied from a first AC system 1 is transformed by a first transformer 2, and the transformed voltage is applied to a first converter 3A, where it is converted to a DC voltage.
The first converter 3A has self turn-off type semiconductor devices, e.g., gate turn-off thyristor (hereinafter referred to as "GTO") switches 69-74, and di/dt suppressor circuits 75-80 connected in series to the switches 69-74, respectively. Each of the GTO switches 69-74 consists of a GTO 93, diodes 94 and 95, a capacitor 96, and a resistor 97. Each of the suppressor circuits 75-80 consists of a diode 99, a resistor 100, and a reactor 98.
The DC voltage obtained by the converter 3A is smoothed by a capacitor 68, and is converted again to an AC by a second converter 5A, and is applied to a second AC system 7 after being transformed by a second transformer 6.
Like the first converter 3A, the second converter 5A consists of GTO switches 81-86 and di/dt suppressor circuits 87-92 connected to the switches. Each element has a structure similar to that of the first converter 3A.
In the structure as above, the diode 94 serves as a free-wheel diode for feeding back a circuit current obtained when the GTO switch 72 is turned off. The diode 95 serves to guide a current, having been flowing through the GTO 93 before the GTO 93 was turned off to the capacitor 96.
The capacitor 96 serves as a so-called snubber condenser for suppressing below an allowable value the rate dv/dt of the increase of the forward voltage of the GTO 93 which will occur as a result of turn off thereof. The resistor 97 is discharge resistor which relieves the charge of the capacitor 96 when the GTO 93 is turned on. These elements 93-97 constitutes the GTO switch 69.
The reactor 98 suppresses below an allowable value the rate di/dt of the increase of the forward current of the GTO 93 which will occur as a result of turn on thereof. The diode 99 serves to guide a current, having been flowing through the reactor 98 before the GTO 93 was turned off, to the resistor 100. The electromagnetic energy trapped by the reactor 98 is consumed by the resistor 100.
The above-described conventional device, however, has the following disadvantages:
(1) The charges of the capacitor 96 charged when the GTO 93 is in the off-state, will be discharged by the resistor 97 when the GTO 93 is turned on, resulting in heat loss. Thus, the efficiency of the power converting apparatus is deteriorated.
(2) The current flowing through the reactor 98 when the GTO 93 is turned on, is discharged by the resistor 100 when the GTO 93 is turned off, resulting in heat loss. Thus, the efficiency of the power converting apparatus is deteriorated.
(3) For example, if the GTO switch 72 is erroneously turned on where the GTO switch 69 is in the on-state, the DC circuit will short. Thus, it is difficult to protect the apparatus from excessive current. The apparatus must have a complicated structure.


Various embodiments described herein provide shoreline restoration modules which may be anchored together along a shoreline of a body of water, such as a lake or pond, to facilitate restoration of the shoreline. The shoreline restoration modules may include a photodegradable material selected to degrade over a period of years, such as four years or five years, while maintaining strength over the period of years to prevent breakdown of a media enclosed by the shoreline restoration modules. In some embodiments, the shoreline restoration modules also provide beneficial run off nutrient, silt, and other particulate matter trapping and filtering.

Shorelines surrounding many bodies of water have become unhealthy in recent years. The unhealthy nature of shorelines, such as shorelines surrounding ponds and lakes have suffered due to many reasons such as residential and commercial development, increased amounts of runoff dues to non-permeable surfaces, loss and removal of native shoreline vegetation, and many other reasons.
Unhealthy shorelines often result in deteriorating water conditions that are harmful to aquatic life. Absent healthy shorelines, silt, nitrates, phosphates, and other soluble and particulate matter are often able to flow unrestricted in bodies of water. These bodies of water may fill with silt and particulate matter, which may damage the ecosystem for aquatic life. Aquatic ecosystems may also be damaged, or otherwise altered form a healthy state, increasing algae growth and other invasive plants and aquatic life to flourish. The result is often an unhealthy body of water that not only disrupts or destroys naturally occurring aquatic ecosystems, but also disrupts recreation and other uses of these altered bodies of water.

Shoreline stabilization, restoration, and runoff filtration


A stent, an intermediate article in the manufacture of a stent, and a method of forming a stent from a workpiece are disclosed. A portion of the wall thickness of a workpiece may be removed, demarcating the structural framework of a stent from the remainder of the workpiece material during a cutting process. In some embodiments, a residuum layer of material remaining after a cutting process may have a recessed surface in relation to a first surface of the structural framework of the stent formed in the workpiece. In some embodiments, a plurality of kerf channels may be cut in a workpiece to demarcate a structural framework of a stent from waste material of the workpiece. In some embodiments, a series of perforations may, at least in part, demarcate the structural framework of a stent from the remainder of the workpiece material. The waste material and/or residuum material may be removed from the structural framework of a stent during a post-cutting process.

Stents are expandable endoprosthetic devices adapted to be placed in a body lumen in order to maintain the patency of a body lumen by providing a flow pathway and/or structural support, for example. Stents are typically used in the treatment of atherosclerotic stenosis in blood vessels and the like to reinforce body vessels and to prevent restenosis following angioplasty in the vascular system. Additionally, stents may be used in the treatment of aneurysms, such as aortic aneurysms, by providing strength to a weakened vascular wall. They have also been implanted in other body lumens, such as urinary tracts and bile ducts. Stents are generally tubular structures that may be radially expandable between an unexpanded size and an expanded size greater than the unexpanded size. Therefore, a stent may be inserted through a body lumen in an unexpanded state and then expanded at a specific location within the lumen to an expanded state.
Stents, as well as other medical devices, are commonly intricately laser cut from a workpiece. The intricate nature of a stent is formed by removing large quantities of material from the workpiece, leaving a delicate structural framework of the stent. The structural framework may then be subjected to additional processes to generate a finished product. The intricate and delicate characteristics of the structural framework greatly reduce the dimensional and structural integrity of the stent, which may compromise subsequent manufacturing processes.
As the use of stents in a variety of medical procedures is gaining widespread acceptance, it is desirable to provide improved methods of manufacturing stents in order to increase efficiency, maintain structural integrity, and/or reduce dimensional inaccuracies. The disclosed stents and accompanying methods of manufacturing a stent may be deemed advantageous in view of the increased usage of stents during medical procedures.


The present invention provides an image forming apparatus that includes a first system and a second system, wherein the permission/prohibition of access to a storage unit provided in the first system is controlled appropriately based on a signal transmitted from the second system, and a control method thereof. To accomplish this, the image forming apparatus of the present invention includes the first system and the second system, and permits access to the storage unit only when executing a program that includes a predetermined process to activate the apparatus using an external storage apparatus.

1. Field of the Invention
The present invention relates to an image forming apparatus and a control method thereof.
2. Description of the Related Art
In recent years, demand for image forming apparatuses is shifting from printing apparatuses intended only for printing to multi-function peripherals that implement multiple functions such as scanning and faxing. Operating systems are widely used in order for such image forming apparatuses to execute application programs to implement multiple functions. As image forming apparatuses become more advanced, systems that allow maintenance workers to activate the image forming apparatuses using storage apparatuses (e.g., removable media) for maintenance purposes are beginning to be incorporated into image forming apparatuses. It is very advantageous, in terms of maintenance of the image forming apparatuses, to activate an image forming apparatus into an operational state by loading an operating system from a storage apparatus. However, if an inappropriate operating system is stored in the storage apparatus, it can cause problems such as system crashes, data leakage, and so on. Further, a situation may also occur in which the inappropriate application program stored in the storage apparatus is transferred into another storage apparatus (e.g., hard disk) provided in the image forming apparatus. In this case, problems such as system crashes, data leakage, and so on can occur as a result of executing the inappropriate application program.
Japanese Patent Laid-Open No. 2004-303216 discloses a method for suppressing activation from a removable medium other than those whose serial numbers are registered in advance. Specifically, according to the method disclosed in Japanese Patent Laid-Open No. 2004-303216, the serial number of a removable medium is registered in an apparatus that activates a program from the removable medium. The apparatus performs the activation process only when the removable medium having the registered serial number is used, thereby suppressing inappropriate access to the apparatus.
The method of the related art, however, has the following problems. For example, in the case of the method disclosed in Japanese Patent Laid-Open No. 2004-303216, it is necessary to associate the image forming apparatus with a specified removable medium. Accordingly, when conducting maintenance on a plurality of image forming apparatuses using removable media, it is necessary to register the serial numbers of all removable media that may be used in each image forming apparatus. Therefore, the method according to the related art is problematic in that as the number of image forming apparatuses that need maintenance increases, the amount of work that has to be done by the administrator increases.
Further, the method of the related art does not prevent the inappropriate application program from being stored into another storage apparatus (e.g., hard disk) that is provided in the image forming apparatus.

Image forming apparatus and control method thereof


A defective focusing coil, impregnated with and held in place with epoxy is removed from its inner lead liner and its outer brass housing by immersing the assembled parts in a bath of liquid nitrogen until the temperature of the assembly is reduced to the temperature of the liquid nitrogen, about -350.degree. F. The assembly is then removed from the bath and a series of sharp blows are then directed to the side of the brass housing to break the bond between the super cooled epoxy and the housing. Axial pressure is then applied to the coil, to remove the coil and liner. The coil is then cut longitudinally into two half cylinders, whereupon the coil is split from the liner, all without injury to either the liner or the housings.

This is a adaptation of my inventions disclosed in U.S. Pat. Nos. 5,070,063, issued Dec. 10, 1991 and 5,199,159, issued Apr. 6, 1993. My prior U.S. Pat. No. 5,070,063 related generally to a method of separating printed circuit wiring boards and, more particularly, to a method of cyrogenically separating multi-layer printed circuit wiring boards without damaging the printed circuit on the individual layers. My prior U.S. Pat. No. 5,199,159 involved the cryogenic removal of the field windings of a generator or motor. This invention involves the method of removing focusing coils from their rigid housings without damaging the housings.
Focusing coils are comprised of an assembly including an inner lead liner, an epoxy encapsulated coil, and an outer brass housing. During manufacture, the epoxy on the coil bonds the coil to both the liner and the housing. If the coil becomes defective, it is desirable to re-use the liner and housing, since these are expensive items to replace. In the past, the outer brass housing with the focusing coil in place, and containing the inner lead liner along with a brass rear flange were placed in a burn out furnace. The furnace was then heated to 500.degree. F. for 20 hours. This was done in a reducing environment (without oxygen). The toxic gases and the ash resulting from this burn out were released into the environment via the foundry chimney. In some cases, the epoxy was not completely ashed, and the apparatus was put through a second heating cycle. The coil was then removed from the outer housing by hand. The personnel were required to wear a respirator, gloves, coveralls, and other protective gear. The whole operation was labor intensive, and in some cases the lead shield melted so that additional precautions had to be taken to protect the personnel. In addition, the venting of the ash and gases up the foundry stack created an environmental hazard.

Cryogenic removal method for epoxy impregnated coils from rigid outer housings

The United States of America as represented by the Secretary of the Air Force


A satellite-based imaging system (100) is used to provide imaging services to users located anywhere on the earth. The surface of the earth is imaged, and the resulting images are geolocated using stars as registration marks on the images. The imaging system comprises a scene imaging system (120) which forms an image of a scene on a first section of a focal plane system (150), a second group of imaging systems (122-128) that form images of unmoving objects, that geolocate the scene on a second group of sections of the same focal plane system (150), and an internal self-consistent system timing mechanism. The satellite-based imaging system (100) stores the images and transmits the images to earth-based processing centers.

Since humans began making recordings there has been an interest in map making. That interest continues today in the form of a major industry involved in the acquisition of land data, and the creation and distribution of maps of the earth and its features. To a smaller extent there is interest in the mapping of other celestial bodies. Most earth feature maps are described with surface distances. This is true even if the map is topographical. However, there are a growing number of applications where the features need to be described with respect to a coordinate system located at a position defined to be the center of the earth. Identifying features and correlating them to this earth-centered coordinate system can be a difficult, expensive operation. Sometimes radio frequency signaling equipment, such as the Global Positioning System (GPS), is used to facilitate geolocating. The coordinate system adopted by GPS is both earth centered and fixed to the earth.
What are needed are a system and method for geolocating images using a less complex, but accurate satellite-based imaging system. What are further needed are a system and method for geolocating images using the optics contained in the main telescope.

System and method for accurate geolocation of images


Disclosed is a document generator which comprises a memory unit for storing a digital picture signal obtained by picking up an image of a surface of a distributed object in which code information such as an ID number peculiar to the distributed object is provided by a notation tool including a bar code, a code information reading unit for selectively reading code information from the picture signal, and a retry unit for code information reading.

The present invention relates to a document generator for generating documents to clarify, delivery and receipt of distributed objects in a delivery service business and to improve the efficiency of acceptance, relay, conveyance and delivery of distributed objects, such as mail items, packets, or parcels.
FIG. 1 shows a conventional delivery certificate generator for registered mail. FIG. 2 shows a flow of documents in a registered mail delivery service using the delivery certificate generator.
In a registered mail delivery service, a delivery certificate is generated for the purpose of managing the delivery business. The delivery certificate is used for receiving the receipt sign (or seal) of a recipient when a registered mail item is delivered to the recipient. The delivery certificate is prepared in duplicate. One of the duplicate copies is used as a delivery certificate for receiving the receipt sign (or seal) from the recipient to certify the receipt of the mail. After receiving the receipt sign (or seal), that duplicate copy is returned to the post office and kept in custody therein. The other of the duplicate copies is reserved in the post office to confirm the delivery by collation with the delivery certificate returned after receiving the receipt sign (or seal) certifying the end of the delivery. The contents required to be written in the delivery certificate are the recipient address, the recipient name, the accepting office symbol, the acceptance number, the special consignment character, the generating date and time zone, the receipt sign (or seal) column, the character string "delivery certificate", etc.
A conventional example of a mail treater will be described hereunder with reference to FIGS. 1 and 2. In FIG. 1, the reference numeral 1 designates the mail treater having a copying function, 2 a copying table for mounting a mail item to be copied, 3 a display means for displaying information of the number, characters and the like required for treating the mail, 11 a controller section for setting the contents of information displayed by the display means 3 and for monitoring the contents of the information, 12 a copying means constituted by an electrostatic charge process, an exposure process, a development process and a fixing process, 13 light sources for illuminating the copying table 2 and the display surface of the display means 3 with brightness required for copying, and 14 a focusing lens. The operation of the conventional example of the mail treater will be described hereunder. In FIG. 1, necessary information, such as the generating date and the serial number, is set to the display means 3 by operating the control section 11. Then, the distributed object 4 is placed on the copying table 2, so that the distributed object 4 is irradiated with the light emitted from the light sources 13. As a result, a copied image of the distributed object 4 is focused on the image-forming surface 15 of the copying means 12 by the focusing lens 14, as well as on the display surface of the display means 3. The copied image is outputted as a hard copy after the development process and the fixing process. As described above, the copied image of the mail provided with necessary information such as the generating date and the serial number can be produced as a hard copy even in the conventional mail treater.
A conventional example of a registered mail delivery service using the above mail treater having a copying function will be described hereunder with reference to FIG. 2. In FIG. 2, the reference numeral 1 designates the mail treater having the copying function. The mail treater 1 includes two reduced scale optical systems. The copying table 2 and the display portion 3 are provided so as to be located on the document surface of the mail treater 1. The display portion 3 is located in the interior of the copying table 2 so that the contents of displayed information can be changed. The reference numeral 4 designates a registered mail item. When the registered mail item 4 is copied after it is set on the copying table 2 with its front surface turned up, two scale-reduced images relative to the surface of the mail and the contents of information displayed on the display portion 3 are produced as a delivery certificate 5 and a delivery certificate reserve 6. In each of the delivery certificate 5 and the delivery certificate reserve 6, not only the information such as the recipient address and name, the accepting office symbol, the acceptance number, and the special consignment character, is described as the image of the surface of the mail but also the information such as the generating date, time zone, the receipt sign (or seal) column, the character string "delivery certificate", the serial number, etc., is described as the image of information displayed on the display portion 3.
The delivery certificate 5 is stuck onto the registered mail 4 before the registered mail 4 is delivered to the recipient. The delivery certificate reserve 6 is reserved in the post office. The delivery certificate 5 is removed from the registered mail 4 when the registered mail 4 is delivered to the recipient 7. The delivery certificate 5 is returned to the post office after receiving the receipt sign (or seal) 8 from the recipient 7. The delivery certificate 5 thus returned is collated with the delivery certificate reserve 6 to confirm the completion of the delivery and then kept in a depository 9 after being classified by the date, the time zone and the delivery section number. When some user makes an inquiry at the time of occurrence of accidents, the depository 9 in the post office is searched for the target delivery certificate 5 with the receipt sign (or seal) 8 to give an answer to the user.
For a large user such as a governmental office or a large business office, the delivery certificate may be generated in a manner so that the information such as the recipient address and name, the generating data and time zone, etc. is described in a multiple entry type sheet in which the character string "delivery certificate" and the receipt sign (or seal) column are described in advance, and the information such as the accepting office symbol and the acceptance number for each of a plurality of mails is further described in the multiple entry type sheet.
In the conventional delivery certificate generator for registered mail, however, the scale of the copied image of the mail is reduced. Accordingly, there arises a problem that the characters mechanically printed by a printer or the like are so small that the delivery certificate cannot be read easily. If the scale reducing rate is decreased to solve this problem, there arises another problem that the size of the delivery certificate becomes so large that not only the running cost becomes high but also the handling efficiency at the time of the sticking or keeping of the delivery certificate becomes poor. Further, many hands are required for searching for a delivery certificate in response to an inquiry about accidents from a user or for confirmation of the completion of the delivery. Consequently, speedy response to such an inquiry is impossible.

Document generator including a pickup means for detecting picture information and code information

Matsushita Electric Industrial Co., Ltd.


A cutting tool assembly adapted to be coupled to a cutter head for manufacture of a gear. The cutting tool assembly includes a cutting insert and a holder adapted to couple the cutting insert to the cutting head. The holder includes a pocket defined by a back surface and at least one lip member that provides a force directed against the cutting insert toward the back surface to thereby retain the cutting insert within the pocket during cutting operations.

Gear milling tool assemblies have been developed for the manufacture of gears, such as bevel and hypoid gears with curved flank lines. Many face mill cutter assemblies, for example, include a disk-shaped cutter head that attaches to the milling machine and a plurality of cutting blades that are coupled to the cutter head. The cutting blades are arranged about a center point of the cutter head at varying radial positions. The cutting blades are arranged in groups, with usually two or three cutting blades per group. In two-blade groups, the blade pair comprises an inner cutting blade and an outer cutting blade. In the three-blade group, a "bottom" cutting blade is included with the inner and outer cutting blades. Typically, one tooth slot is formed in the work piece with each plunge of the cutter assembly. The cutter assembly is then withdrawn, and the work piece is indexed to the next tooth slot position in order to form the next tooth slot as is widely known in the art.
During typical face hobbing processes, the cutter and the work piece rotate independently in a timed relationship with each other, thereby allowing continual indexing of the work piece and continual formation of each tooth slot of the gear. Each successive group of cutting blades passes through successive tooth slots with each blade in the group forming a cut completely along the longitudinal portion of the tooth slot. Thus, in most face hobbing processes, a single plunge of the cutting tool results in all tooth slots of the work piece being formed.
In many prior art gear milling tool assemblies, the cutting blades are elongate stick-type members that are disposed in slots in the disk-shaped cutter head. The cutting blades are typically made from bar stock high speed steel (HSS). To form a gear within high tolerances, it is preferable if each of the cutting blades are uniform. However, after prolonged use of the gear milling tool assembly, one or more of the cutting blades wear, and the cutting blades typically require sharpening. However, sharpening the cutting blades can be time-consuming and costly.
U.S. Pat. No. 6,609,858 to Francis et al. discloses a gear hobbing cutter system with a cutter head body that receives a plurality of supporting blocks (i.e., holders). Each of the holders includes a pocket that receives a cutting insert. The cutting insert is indexable to at least two cutting edges. When one of the cutting edges becomes worn, the cutting insert can be indexed for use of the sharper cutting edge, thereby possibly providing cost savings.
One drawback of the device of the Francis et al. '858 patent, however, is that the cutting inserts may not be adequately supported within the pocket of the respective holder. Forces generated during the formation of a gear may shift the cutting insert relative to the supporting block, thereby causing the work piece to be out of tolerance. For instance, the pocket of the holders is substantially open on one side—the side facing the head of the fastener. Because this side is open, the cutting insert may not be adequately supported and the cutting inset may shift out of tolerance, especially considering the high loads on the cutting insert during the gear manufacturing process.
Accordingly, there remains a need for an improved gear milling tool assembly with a holder that receives a cutting insert. More specifically, there remains a need for an improved gear milling tool in which the cutting inserts are better supported by the holder.

Gear milling tool with replaceable cutting inserts


A session identification unit (11) determines a session to which an incoming packet belongs, while a session relay unit (12-1-12-N) relays between a session with a transmission terminal and a session with a reception terminal. A packet scheduler (13) instructs and controls the delivery of packets from each session relay unit (12-1-12-N), and a delivery control unit (14) delivers packets from each session relay unit (12-1-12-N) based on the instruction. In the session relay unit (12-1), a transmission session processing unit (121-1) processes a session for transmitting data to the reception terminal, and a transmission buffer (122-1) stores received data until the end of a transmission. A reception session processing unit (123-1) processes a session for receiving data from the transmission terminal.

Generally, in communication applications, a communication session is established between a transmission terminal and a reception terminal, and communication is made on the established session. However, when a propagation delay time is very long between the transmission terminal and the reception terminal, or when communication is made across networks which differ in characteristics such as wired and wireless ones, the communication throughput degrades between the transmission terminal and the reception terminal.
As methods for solving this problem, there exist systems as disclosed in the following Documents 1-3. In this system, instead of making communication between a transmission terminal and a reception terminal in a single session, a relay apparatus is installed between the transmission terminal and the reception terminal. Then, communication is made by relaying data in two sessions, i.e., a session from the transmission terminal to the relay apparatus and a session from the relay apparatus to the reception terminal.
Document 1: JP-A-11-252179
Document 2: JP-A-2002-281104
Document 3: Bakre and B. R. Badrinath, "I-TCP; Indirect TCP for Mobile Host", Department of Computer Science Rutgers University, DSC-TR-314, 1994 (http://www.it.iibt.ac.in/it644/papers/i-tcp.pdf)
A relay apparatus that has a large transmission buffer in order to prevent the throughput from degrading even if a propagation delay time is very long is known to be effective. However, when a large transmission buffer is contained, packets are delivered in a burst manner particularly when the TCP session starts slowly which causes congestion on a network, resulting in a lower throughput.
As a method for solving such a problem, there is a method which adjusts intervals at which packets are delivered in such a manner that the packets are not delivered in a burst manner from a TCP session, as disclosed in the following Document 4:
Document 4: A. Aagarwal, S. Savage, and T. Anderson, "Understanding the Performance of TCP Pacing", in proceedings of IEEE INFOCOM' 2000
Also, as another method, output packets from a TCP session are placed in a queue and controlled to be delivered by a scheduler, thereby making it possible to deliver packets in an arbitrary bandwidth, to limit the throughput of another TCP session, and to improve the throughput of a particular session as well.
For relaying a session, the most frequent problem is that a processing load is generally high in processing of the TCP session so that fast relay processing is difficult. Also, when an adjustment is made for a packet delivery interval from the TCP session, the processing load becomes even higher.
As a system for speeding up the processing of the TCP session, there exist systems as described below. As a first system, there is a system for reducing the processing load on a relay apparatus by using a zero copy method for data transfer between the kernel of OS (Operating System) and an application program. In this first system, when data is passed between a kernel program for actually performing data transmission/reception processing and an application program for performing data relay processing, virtual data movement is performed through page mapping without performing a physical data copy.
As a second system, there is a system which only conducts retransmission control when relay processing is performed. In this second system, a session is not terminated in a relay apparatus, but one session is set between a transmitting and a reception terminal. Then, in the relay apparatus, when a packet received from the transmission terminal is delivered to the reception terminal, the packet is not only transferred, but is also saved in the relay apparatus.
The relay apparatus monitors an ACK (acknowledgement) packet returned from the reception terminal to the transmission terminal, delivers the saved packet to the reception terminal upon detection of a discarded packet between the relay apparatus and the reception terminal, to prevent a retransmission of the packet from the transmission terminal and to prevent a lower throughput between the transmission terminal and the reception terminal due to the discarded packet.
In this second system, relay processing is not performed between sessions, the retransmission processing alone is performed, so that the load on the relay apparatus can be reduced, as compared with the case where relay processing is performed.
As a third system, there is a system which performs relay processing only for a session which requires a relay, without performing the relay processing for a session which does not require a relay, thereby reducing the processing load on a relay apparatus. For example, as an illustration of this system, there is a system which measures the throughput of a session, and performs the relay processing only for selected sessions which allow for an improved throughput, if the relay processing is performed therefor, as described in the following Document 5.
Document 5: JP-A-11-112576
Also, as the aforementioned system, there is a system which does not perform relay processing when an HTTP (Hyper Text Transfer Protocol) request is transmitted, but performs the relay processing only when data is transferred, as disclosed in the following Document 6.
Document 6: JP-A-2002-312261
In the aforementioned conventional session relay systems, the first system has the problem that the processing load is also high besides the data copies. When delivery control is conducted in accordance with a TCP pacing system or a scheduler, a load for packet delivery control is added, in addition, to a TCP processing load, resulting in a higher overall processing load.
Also, when relay processing is performed for an upper layer protocol such as, for example, iSCSI (internet Small Computer System Interface), as well as for a relay of TCP sessions, packet delivery control is further added on the basis of congestion control on an upper layer, resulting in a yet higher processing load. Particularly, when there are a large number of sessions to be relayed, a higher processing load is required for conducting delivery control for packets between sessions.
Further, in conventional session relay systems, the first system has a problem in that the packet length is limited. To move virtual data between a TCP layer and an application in accordance with page mapping, the page size of a CPU (central processing unit) must match the packet length.
Generally, a session relay apparatus exists independently of transmitting and reception terminals, and the packet length cannot be previously assumed for use by the transmission terminals and reception terminals, so that no reduction in processing load can be expected by eliminating copies for those transmission and reception terminals which employ a packet length different from the page size of a bandwidth control apparatus.
On the other hand, in the conventional session relay systems, the second system has a problem in that it cannot improve a reduction in the throughput due to factors other than discarded packets. When session relay processing is performed, the session relay apparatus immediately returns an ACK packet to a transmission terminal in response to packets received from the transmission terminal, that area intended for confirming the reception. However, in this second system, a reception terminal simply returns an ACK packet to a transmission terminal, whereas the session relay apparatus itself does not return an ACK packet. For this reason, the second system provides a smaller throughput improving effect in an environment in which a propagation delay is large.
Also, in the conventional session relay systems, the third system has a problem in that the processing load is not reduced when there are a large number of sessions which must be relayed.

Session relay apparatus for relaying data, and a data relaying method


In embodiments, an apparatus for computing includes a protection key register (PKR) having 2N bits, where N is an integer, to store a plurality of permission entries corresponding to protected memory domains, and a protected memory domain controller, coupled to the PKR. In embodiments, the memory domain controller is to: obtain protection key (PK) bits from a page table entry for a target page address; obtain one or more additional PK bits from a target linear memory address; and combine the PK bits and the additional PK bits to form a PK domain number to index into the plurality of permission entries in the PKR to obtain a permission entry for a protected memory domain.

Speculative execution is one of the main techniques used by modern high end processors to improve performance. The concept behind speculative execution is that instructions are executed ahead of knowing that they are required. Without speculative execution, the processor might need to wait for prior instructions to be resolved before executing subsequent ones. By executing instructions speculatively, performance can be increased by minimizing latency and extracting greater parallelism. However, speculative execution is vulnerable to a relatively new form of attack, known as "speculative execution side-channel (SESC) attacks."
For example, "Spectre" is a vulnerability that affects processors that perform speculative execution based on branch prediction. On many processors, speculative execution resulting from a branch "mis-prediction" may leave observable side effects which reveal private data to attackers. For example, if the pattern of memory accesses performed by the speculative execution depends on private data, the resulting state of the data cache might be accessible via a side channel, through which an attacker may be able to extract information about the private data. While some mechanisms for SESC mitigation have been proposed, the performance overhead is often costly, especially as regards Spectre v1. For example, full prevention of a Spectre v1 attack requires adding memory fences (lfence/mfence) after every branch instruction, which is a major cause of performance slow down.

Memory domains protection method and apparatus with composite protection key numbers


This invention provides a storage module formed using a plurality of storage cells. The each storage cell includes a storage unit that stores a charge, a polyhedral container that houses the storage unit and has two opposing surfaces, and a pair of electrode terminals that output and input the charge of the storage unit. The electrode terminals include a positive electrode terminal that projects externally from an end portion of the container and has a joint surface that is formed to be substantially coplanar with one of the two opposing surfaces of the container and joined to an electrode terminal of an adjacent storage cell, and a negative electrode terminal that projects externally from the end portion of the container and has a joint surface that is formed to be substantially coplanar with another of the two surfaces and joined to an electrode terminal of an adjacent storage cell.

Patent Documents 1 to 8, published by the Japan Patent Office, propose using a lithium battery or an electric double layer capacitor as a storage cell that can be charged and discharged repeatedly.
Referring to FIGS. 33 and 34, an example of a storage cell will be described. A storage cell 100 includes a storage unit 111 that stores a charge, and a container 112 that houses the storage unit 111.
The storage unit 111 includes a positive electrode body, a negative electrode body, and a separator interposed between the positive electrode body and the negative electrode body. The storage unit 111 is formed from an angular laminated body. The positive electrode body and negative electrode body are constituted by an electrode layer that stores a charge, and a collector layer that outputs and inputs the charge. The positive electrode body and the negative electrode body are respectively formed by bundling together identical poles of the collector layer and then joining and electrically connecting an electrode terminal 113 of a corresponding polarity to a resulting bundled portion.
The electrode terminal 113 is formed from a metal plate in a shape having a short length. A first end portion of the electrode terminal 113 is positioned in the interior of the container 112. The bundled portion of the identical poles of the collector layer is joined to the first end portion of the electrode terminal 113. A second end side of the electrode terminal 113 is drawn directly out to the exterior of the container 112. The container 112 is formed from a laminate film, or more specifically a resin film having a laminated structure and including a metallic intermediate layer. The container 112 is tightly sealed while housing the storage unit 111 so that a tip end side of each electrode terminal 113 projects partially to the outside.
The container 112 is constituted by a pair of container members, for example. When the pair of container members are combined, a chamber for housing the storage unit 111 is defined. The storage unit 111 is housed in the interior of the chamber in the container such that the tip end side of the electrode terminal 113 projects to the outside from a flange surrounding the chamber. As shown in FIG. 34, the container 112 is sealed by thermally bonding flanges 112a to each other, whereby the storage unit 111 is housed and tightly sealed such that the tip end side of each electrode terminal 113 partially projects to the outside from a sealing surface of the container 112, or in other words substantially in a thickness direction center of the container 112. In the figure, A, B, and C respectively denote a front surface, a left side surface, and an upper surface of the container 112.