222 results about "Reference array" patented technology

A method of automatically registering a surgical navigation system to a patient's anatomy is provided. The method comprises programming a surgical navigation system with a first spatial relationship between a surgical component and a reference array connected to the surgical component, programming the surgical navigation system with a second spatial relationship between an anatomical feature of a patient and the surgical component, installing the surgical component on the patient such that the surgical component engages the anatomical feature in the second spatial relationship, and locating the reference array with the surgical navigation system. The navigation system automatically recognizes the position of the reference array relative to the patient's anatomy.

Three-dimensional endoscopic measurements are made by adding an array of reference target points to the scene viewed by an endoscopic camera and characterizing the image formed by the camera when it views the scene from two or more viewing positions. Methods and apparatus are taught which allow one to make accurate measurements with any endoscope, without requiring any modification to the endoscope. Under certain circumstances, the measurements can be made without any pre-calibration of the endoscopic camera.A general measurement reference apparatus comprises a reference target array which is placed near to and fixed with respect to an object of interest inside an enclosure by means of a reference array holding apparatus and a reference array insertion apparatus. This measurement reference apparatus can be used to make either perspective dimensional measurements or to make conventional photogrammetric measurements of the object of interest.A general measurement apparatus to be used with the new methods comprises a reference target array which is placed near to and fixed with respect to an object of interest inside an enclosure by means of a reference array holding apparatus and a reference array insertion apparatus. In a version of this apparatus the reference array holding apparatus may attach the reference array directly to the object of interest and the combination may be inserted into the enclosure by the insertion apparatus. The general measurement apparatus also comprises an endoscopic camera located inside the enclosure. The camera is moved with respect to the object by a camera moving apparatus. Images formed by the camera are measured with an image measurement apparatus. These measurements are supplied to a computing apparatus which computes the desired three-dimensional distances. The measurement results are displayed to the user by a display apparatus.

The systems and methods disclosed herein employ a combination of digital three-dimensional modeling and rapid fabrication technologies to provide pre-indexed, pre-registered, and / or precut components for articulated dental models. Dental articulators and components of dental models as described herein use a positioning key to encode positional information for components of the dental model, and / or a reference grid on mounting surfaces to enforce local accuracy of fabricated parts against a fixed reference array.

The systems and methods disclosed herein employ a combination of digital three-dimensional modeling and rapid fabrication technologies to provide pre-indexed, pre-registered, and / or precut components for articulated dental models. Dental articulators and components of dental models as described herein use a positioning key to encode positional information for components of the dental model, and / or a reference grid on mounting surfaces to enforce local accuracy of fabricated parts against a fixed reference array.

A spreadsheet package allows a base formula to be copied to at least one adjacent cell to form a referencing array. The package maintains a list of bound arrays, at least one cell of a bound array being referred to from a referencing array formula. If a formula within a referencing array cell includes a reference to a cell outside a bound array, the package indicates an error in the formula.

Techniques and corresponding circuitry are presented for the detection of wordline leakage in a memory array. In an exemplary embodiment, a capacitive voltage divider is used to translate the high voltage drop to low voltage drop that can be compared with a reference voltage to determine the voltage drop due to leakage. An on-chip self calibration method can help assure the accuracy of this technique for detecting leakage limit. In other embodiments, the current drawn by a reference array, where a high voltage is applied to the array with all wordlines non-selected, is compared to the current drawn by an array where the high voltage is applied and one or more selected wordlines. In these current based embodiments, the reference array can be a different array, or the same array as that one selected for testing.

An auto-learned hierarchy algorithm that learns the hierarchical layout of a power monitoring system. Historical power data from each meter is received and placed into a data table. The main is assumed to be at the top of the hierarchy and is designated as the reference. A check matrix is developed indicating whether a possible connection exists between each meter pair combination. A correlation coefficient matrix (CCM) is calculated based on the data table, and entries in which no connection is possible are zeroed. The column for the reference meter from the CCM is copied to a correlation reference array (CRA), and the meter having the highest correlation with the reference meter in the CRA is marked as connected to the reference meter in a connection table. That meter's power is subtracted from the data table and the procedure is repeated until all meters have been analyzed.

A method for using a medical navigation system to identify an instrument to be navigated is provided, wherein the instrument includes a reference array having a plurality of markers that form a rigid body, and a location of the markers with respect to each other is not previously known in the navigation system as a characteristic arrangement for a particular instrument. The method includes measuring a distance of each marker relative to the other markers; identifying a spatial arrangement of the markers having the measured distance as an assignable marker array; assigning the assignable marker array to the instrument; and identifying the instrument based on the assigned marker array.

An auto-learned hierarchy algorithm that learns the hierarchical layout of a power monitoring system. Historical power data from each meter is received and placed into a data table. The main is assumed to be at the top of the hierarchy and is designated as the reference. A check matrix is developed indicating whether a possible connection exists between each meter pair combination. A correlation coefficient matrix (CCM) is calculated based on the data table, and entries in which no connection is possible are zeroed. The column for the reference meter from the CCM is copied to a correlation reference array (CRA), and the meter having the highest correlation with the reference meter in the CRA is marked as connected to the reference meter in a connection table. That meter's power is subtracted from the data table and the procedure is repeated until all meters have been analyzed.

The present invention provides systems and methods for determining the coordinates of a location element mounted on a medical probe. First and second signals are transmitted between the location element and a first and second reference transducers, which may be arranged in a reference array that can be attached to a patient's skin. A transit time difference between the first and second signals is determined, e.g., using a thresholding or correlation technique. A distance difference between a first distance extending from the location element to the first reference element and a second distance extending from the location element to the second reference element is then determined based on the transit time difference. An angle between the reference array and the location element can then be determined based on the determined distance difference and a known distance between the first and second reference transducers. The coordinates of the location element within a coordinate system are then determined based on the determined angle and the distance between the transducer array and the location element.

A method and system for calibrating molecular arrays to a reference molecular array, and for subsequently calibrating the molecular arrays to maintain a constant signal-intensity-to-label-concentration ratio. In the first step of the two-step calibration method, a reference array coated with the fluorophore or chromophore used to label probe molecules is employed, while in the second step of the two-step method, a reference array coated with a stable dye is employed.

The invention provides a method based on linear programming for locating near-field targets and a system thereof, particularly a method for locating near-field targets on the basis of the compressivesensing theory. The method comprises the following steps: selecting a reference array element under the condition that the signal form is unknown, allowing the reference array element to work at the normal sampling frequency, and the other array elements to work at far below the Nyquist sampling frequency; taking the output signal of the reference array element as the reference target signal, to acquire the sample data of all the array elements; generating a time-delay table and a sparse basis array; generating a random mapping array and obtaining a coefficient array; obtaining a sparse vectorby linear programming solution; and acquiring the location information of the near-field target from the predetermined location-distance collection on the basis of the acquired estimation results ofthe sparse vector. According to the invention, the sensor does not need to work beyond the Nyquist sampling frequency, thereby greatly reducing the sampling rate, reducing the operating energy consumption of the sensor and improving the resource utilization rate of the system; and the method has no limits to the target bandwidth, so that the method is applicable to the target location of both narrowband and wideband, and the method is further applicable to non-Gaussian target location.

Techniques and corresponding circuitry are presented for the detection of wordline leakage in a memory array. In an exemplary embodiment, a capacitive voltage divider is used to translate the high voltage drop to low voltage drop that can be compared with a reference voltage to determine the voltage drop due to leakage. An on-chip self calibration method can help assure the accuracy of this technique for detecting leakage limit. In other embodiments, the current drawn by a reference array, where a high voltage is applied to the array with all wordlines non-selected, is compared to the current drawn by an array where the high voltage is applied and one or more selected wordlines. In these current based embodiments, the reference array can be a different array, or the same array as that one selected for testing.

The invention provides a method for realizing wideband direction finding by utilizing three-dimensional orthogonal interferometer. Seven-array element three-dimensional orthogonal antenna array is utilized, a phase discriminator set is adopted to respectively detect phase differences of array elements 1-6 and a reference array element 0, according to cyclophysis of the phase difference, traversing searching is carried out on possible phase cycles and all the possible signal frequencies, azimuth angles and pitch angles are solved, and finally the signal frequency roughly measured by a receiver is taken as reference, one group of traversing values with minimum error are found, and the group of values are estimated signal frequency, azimuth angle and pitch angle. The method of the invention can be applied to place requiring frequency and angle estimation in the fields of communication, radar and wireless monitoring, calculated amount is less, no strict restriction on the position of antenna array element is required, and wideband angle estimation can be realized, thus having great application value.

A memory device as described herein includes a reference array of phase change memory cells and a memory array of phase change memory cells, where a difference between a current data set stored in the reference array and an expected data set is used to determine when to refresh the memory array. The high resistance state for the reference array is a “partial reset” state having a minimum resistance less than that of the high resistance state for the memory array. Sense circuitry is adapted to read the memory cells of the reference array and to generate a refresh command signal if there is a difference between a current data set stored in the reference array and an expected data set, and control circuitry responsive to the refresh command signal to perform a refresh operation on the memory cells of the memory array.

The invention relates to a phased array amplitude-phase error near-field calibration method based on one-dimensional rotation, and the method comprises the steps: S1, building a phased array amplitude-phase error testing system, enabling a phased array antenna to be fixed at an initial rotating angle, and measuring the initial position of a calibration source and the initial position of a reference array element; S2, measuring the receiving channel amplitude information and phase measurement information of the phased array antenna; S3, measuring the transmitting channel amplitude information and phase measurement information of the phased array antenna; S4, judging whether the measurement of all preset rotating angles is carried out or not: executing step S5 if the measurement of all preset rotating angles is carried out, or else enabling the phased array antenna to be rotated to another preset rotating angle, and executing step S2 and step 3; S5, calculating the calibration value of a phased array amplitude-phase error; S6, calculating the initial position of the calibration resource and the initial position of the reference array element through an optimization principle; S7, calculating the calibration value of the phased array amplitude-phase error. The method just needs to meet the far-field condition of a single antenna unit in the phased array antenna, is simple in calibration, is high in operability, is higher in measurement precision, and is easy in engineering realization.

An adaptor for attaching a reference array to a medical instrument, said instrument having a functional direction or plane includes a reference array mount for attaching the reference array to the adapter, an instrument engagement section for attaching the adaptor to the instrument, and a self-aligning coupling mechanism. The coupling mechanism is coupled to the reference array mount and to the instrument engagement section and is operative to move the reference array attached to the reference array mount to a predetermined location relative to the functional direction or plane of the instrument when the instrument engagement section is attached to the instrument.

The invention discloses a sparse L-shaped array and a two-dimensional DOA estimation method thereof and belongs to the technical field of wireless mobile communication. The sparse L-shaped array comprises a first subarray formed by a sparse uniform linear array, the array element space of which is equal to the wavelength, and an auxiliary array element, and a second subarray formed by an arbitrary sparse linear array, the minimum array element space of which is smaller than or equal to a half wavelength. The shared array element of the two linear arrays is a reference array element, and the distance between the auxiliary array element and the reference array element is the half wavelength. The two-dimensional DOA estimation method is characterized by, to begin with, calculating an autocorrelation matrix according to received data of the second subarray, carrying out characteristic decomposition on the autocorrelation matrix and then, estimating a corresponding second angle, and carrying out calculation to obtain an information source autocorrelation matrix based on the second angle; and obtaining an array manifold matrix of the first subarray according to a cross-correlation matrix of the received data of the two subarrays and the information source autocorrelation matrix, thereby finishing estimation of a first angle corresponding to the first subarray, and obtaining the two-dimensional DOA. Complexity is low, and DOA estimation precision is high.

An apparatus for use in tracking movement of a patella through a range of motion during a surgical navigation procedure, comprising a frame fixed in relation to the patella, a patella trial component associated with the frame for fixing the frame relative to the patella, and a reference array configured to attach to the frame, the reference array having first, second and third markers, the first, second and third markers being detectable by a surgical navigation system when exposed to a measurement field of the surgical navigation system.

The invention discloses a wideband digital wave beam forming method based on an all-pass type variable fractional delay filter. The problem that a needed filter in the prior art is large in order number and high in complexity is solved. The method comprises the steps that (1) according to radar system parameters, sampling rate fs and sampling time ts are determined; (2) according to the radar array geometric structure and the sampling time ts, a propagation time delay tau of each array element relative to a reference array element is calculated; (3) according to the sampling rate fs, an AD chip is selected to digitize analog signals received by the array elements; (4) according to the propagation time delay tau and the digitized received analog signals, the all-pass type variable fractional delay filter is designed; (5) the digitized received signals are filtered; (6) phase delay of the filtered signals is compensated for; (7) a window function is selected to conduct weighted summation on the filtered compensated signals to obtain a wave beam forming result. The wideband digital wave beam forming method can achieve wideband digital beam forming, saves hardware resources, improves instantaneity and can be used for wideband digital array radar.

The invention provides a digital beam forming and phase fitting method, and aims to provide a method capable of suppressing interference, improving the signal to interference and noise ratio and accurately controlling the phase of a beam forming signal. The method is implemented according to the technical scheme that a steering vector model obtains relative steering vectors by using online calibration, accurate absolute steering vectors are acquired by combining absolute phase responses, which are measured in a darkroom, of a reference array element, model parameters of the steering vector are fitted out by combining the existing absolute steering vectors, and an accurate spare steering vector of an antenna array in any direction is acquired; the second-order statistic of the array signal is iteratively calculated through an array signal statistic hardware calculation module, and sent to an array signal processing algorithm module together with an antenna array steering vector and a channel response to calculate an optimal beam weight; and finally, the array signal processing algorithm module imbeds the optimal beam weight into the digital beam forming module to perform real-time digital beam forming and phase fitting and process multi-channel array data and beam output in real time.

Provided is a parameter estimation method based on a virtual concentric annulus array. A receiving array is composed of actual array elements distributed on two concentric circular arcs, the number of the actual array elements is an even number, each concentric circular arc comprises an inner circular arc and an outer circular arc, each inner circular arc and each outer circular arc are arranged on the different sides of a coordinate original point, and do not overlap with each other, a connecting line between the end point of each inner circular arc and the end point, far away from the end point of each inner circular arc, of each outer circular arc penetrates through the coordinate original point, a reference array element is arranged on the coordinate original point, and a connecting line of each actual array element on each inner circular arc and each corresponding actual array element on each outer circular arc penetrates through the coordinate original point. The parameter estimation method based on the virtual concentric annulus array comprises the following steps of (1) measuring a measurement phase difference between each actual array element and the reference array element, (2) determining a measurement phase difference between each virtual array element and the reference array element, (3) determining a virtual short basic line theoretical phase difference of an incoming signal, (4) determining a phase ambiguity multiple of a long basic line theoretical phase difference through the virtual short basic line theoretical phase difference, and (5) determining a long basic line accurate estimation phase difference according to the phase ambiguity multiple, and obtaining an estimated value of a two-dimensional arrival angle of the incoming signal according to the accurate estimation phase difference of the incoming signal on a long basic line.

Techniques and corresponding circuitry are presented for the detection of wordline leakage in a memory array. In an exemplary embodiment, a capacitive voltage divider is used to translate the high voltage drop to low voltage drop that can be compared with a reference voltage to determine the voltage drop due to leakage. An on-chip self calibration method can help assure the accuracy of this technique for detecting leakage limit. In other embodiments, the current drawn by a reference array, where a high voltage is applied to the array with all wordlines non-selected, is compared to the current drawn by an array where the high voltage is applied and one or more selected wordlines. In these current based embodiments, the reference array can be a different array, or the same array as that one selected for testing.

A method and apparatus is disclosed herein for relative calibration of transceivers in a wireless communication system. In one embodiment, the method comprises transmitting multiple pilots from units in the first group; receiving, in response to the multiple pilots, a first set of pilot observations at each unit in the second group; transmitting a single pilot simultaneously from at least two units in the second group; in response to the single pilot, receiving a second set of pilot observations at each unit in the first group; and using the first and second sets of pilot observations to calibrate each of at least two units in the second group based on a reference array of transceivers in the first group of transceivers.

A method and testing circuit are provided for tracking transistor stress degradation. A first array of P-channel field effect transistors (PFETs) is connected in parallel. The first array of PFETs is stressed by applying a low gate input and a high source and a high drain to the PFETs during a stress period. The first array of PFETs is tested by operating the PFETs in a saturated region during a test period. A reference array of PFETs is not stressed during the stress period. The reference array of PFETs is activated for testing to compare a saturated drain current performance with the first array of PFETs during the test period.

The invention discloses a partial sparse L array and a two-dimensional DOA estimation method thereof. Two subarrays for the L array, the array element interval of the first subarray is half of a wavelength, and the array element interval of the second subarray is n times of the wavelength; and an auxiliary array element distanced half of the wavelength away from a reference array element is arranged on the second subarray. During DOA estimation processing, the subarrays are respectively placed on an x axis and a z axis, and by use of a feature that a cross-correlation matrix is not affected by noise, cross correlation of receiving data is solved, and a signal subspace is extracted; by use of translation invariability of a ULA and the signal subspace, a rotation matrix of a z-axis array flow type matrix is solved, possible pitch angle estimation values are obtained by performing feature value decomposition on the rotation matrix, and then defuzzificaiton processing is performed on estimation results based on the auxiliary array element; and then based on this, a source waveform and an x-axis array flow type matrix are estimated, and corresponding azimuths are solved. The partial sparse L array and the two-dimensional DOA estimation method thereof are applied to radar, sonar and the like, and have the advantages of low realization cost, low computation quantity and high direction finding precision.

A dual bit flash device comprising a core cell array, each cell of the core cell array is configured to store two bits of data, and a single reference array, each cell of the single reference array comprising a first bit programmed to a low threshold voltage and a second bit programmed to a high threshold voltage.

A radio measurement apparatus comprising: an array antennal selection unit selecting array antennas corresponding to received signals; a reference path selection unit selecting a reference array antenna; a signal processing unit selecting a reference antenna channel through analysis of signal characteristics measured through two reception channels; a sequential channel multiplex unit determining sequentially inputting received signals of remaining array antennas to output the sequentially input signals to a receiver; and a correction signal input unit compensating amplitude and phase characteristics of the respective reception channels.

The invention provides a two-dimensional arrival angle estimation method of an L-shaped array. Observation data vectors of the x axis and the y axis are constructed through an N-time snapshot data matrix receiving an array. A measuring matrix of the x-axis direction and a measuring matrix of the y-axis direction and corresponding sparse signal vectors are constructed. The direction cosine matrix estimated value of the x axis and the direction cosine matrix estimated value of the y axis are calculated by utilization of a minimum absolute contraction and selection algorithm. The direction cosine estimated value of the x-axis direction and the direction cosine estimated value of the y-axis direction are paired by utilization of reference array elements. A two-dimensional arrival angle of the signal is calculated by utilization of the paired direction cosine estimated value of the x-axis direction and the direction cosine estimated value of the y-axis direction. The a rough estimated values of the signal vectors are calculated by utilization of a minimum absolute contraction and selection algorithm, signal parameter pairing is carried out by utilization of power, and estimation precision of a signal arrival angle and power can be raised.