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Compact Air Coupled 2 D Ultrasound Computed Tomography (Uct) System

Patent Information

Application #
Patent Number
Invention Field
PHYSICS
Publication Type
INA
Publication Number
05/2022
Status
Legal Status
Filing Date
20 January 2022
Grant Date
2024-02-07
Renewal Date

Abstract

Abstract: The invention relates to the field of Non-Destructive evaluation. A compact air-coupled 2D UCT system and its scanning method are presented. The system is automated to produce specimen's inner profile in a single push of button, non-invasively. Existing ultrasound CT require a medium or couplant between object and ultrasound transducers. This system scans a specimen in air. It employs a parallel beam geometry to scan the specimen. The automatically controlled mechanical assembly of the scanner is integrated with its synchronized data acquisition, complex signal processing and inverse problem based image reconstruction software. The system also provides the functionality to view the scanning process and analysis in real time.

Applicants

1. INDIAN INSTITUTE OF TECHNOLOGY ROORKEE
ROORKEE

Inventors

1. DR. MAYANK GOSWAMI
Department of Physics, Indian Institute of Technology Roorkee, Roorkee- 247667
2. ANKUR
Department of Physics, Indian Institute of Technology Roorkee, Roorkee- 247667

Eregister



Year CBR Date CBR Number Renwal Amount Renwal Date Normal Due Date Renwal To Renwal From Due Date with Extension Reneal Certificate Number
3rd year 03/05/2024 31348 800 03/05/2024 07/05/2024 20/01/2025 20/01/2024 07/11/2024 120533
4th year 03/05/2024 31348 800 03/05/2024 20/01/2025 20/01/2026 20/01/2025 20/07/2025 120534
5th year 03/05/2024 31348 800 03/05/2024 20/01/2026 20/01/2027 20/01/2026 20/07/2026 120535
6th year 03/05/2024 31348 800 03/05/2024 20/01/2027 20/01/2028 20/01/2027 20/07/2027 120536
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Documents

Application Documents
Name Date
1 202211003424-IntimationOfGrant07-02-2024.pdf 2024-02-07
2 202211003424-PatentCertificate07-02-2024.pdf 2024-02-07
3 202211003424-ABSTRACT [14-09-2022(online)].pdf 2022-09-14
4 202211003424-CLAIMS [14-09-2022(online)].pdf 2022-09-14
5 202211003424-CORRESPONDENCE [14-09-2022(online)].pdf 2022-09-14
6 202211003424-FER_SER_REPLY [14-09-2022(online)].pdf 2022-09-14
7 202211003424-FORM-8 [14-09-2022(online)].pdf 2022-09-14
8 202211003424-FER.pdf 2022-06-21
9 202211003424-FORM 18 [25-01-2022(online)].pdf 2022-01-25
10 202211003424-FORM-9 [25-01-2022(online)].pdf 2022-01-25
11 202211003424-COMPLETE SPECIFICATION [20-01-2022(online)].pdf 2022-01-20
12 202211003424-DECLARATION OF INVENTORSHIP (FORM 5) [20-01-2022(online)].pdf 2022-01-20
13 202211003424-DRAWINGS [20-01-2022(online)].pdf 2022-01-20
14 202211003424-EDUCATIONAL INSTITUTION(S) [20-01-2022(online)].pdf 2022-01-20
15 202211003424-EVIDENCE FOR REGISTRATION UNDER SSI(FORM-28) [20-01-2022(online)].pdf 2022-01-20
16 202211003424-FIGURE OF ABSTRACT [20-01-2022(online)].jpg 2022-01-20
17 202211003424-FORM 1 [20-01-2022(online)].pdf 2022-01-20
18 202211003424-FORM FOR SMALL ENTITY(FORM-28) [20-01-2022(online)].pdf 2022-01-20
19 202211003424-STATEMENT OF UNDERTAKING (FORM 3) [20-01-2022(online)].pdf 2022-01-20
Search Strategy
1 search_strategy_424E_20-06-2022.pdf

Specification

The present invention relates to the field of non-destructive evaluation system. The present invention in particular relates to a system and method for two dimensional (2D) ultrasound computed tomography (UCT) scanner.
DESCRIPTION OF THE RELATED ART:
[002] The ultrasound modalities have been actively used for decades for various non-destructive evaluations/testing. Generally, an ultrasound based NDT system consists of either a transducer or a number of transducers. The Ultrasonic modalities are classified under Ultrasound A-Scan Testing (USAT), Doppler Ultrasonography (DU), B-Scan Ultrasonography (USG), C-Scan Ultrasonography (USC) and Ultrasound Computed Tomography (UCT). The applications are related to the material testing/inspection, visualization of specimen’s inner profile, diagnosis and intervention techniques for guiding purposes in the medical field. A typical UCT system consists of either transducer pairs/arrays, an imaging platform, data acquisition and a processing system. The emitting transducers are configured to emit and receive ultrasound waves transmitted/reflected through the specimen. The contact transducers comprising of single or several piezoelectric crystals are dominantly used in UCT systems. These systems require the use of medium or/and couplant for their operation. The recent development in the non-contact ultrasound (NCU) transducer technology enabled their use for 1D crack detection, 2D surface and transmission imaging (raster scanning). Commercially available 2D Ultrasound Computed Tomography (UCT) system designs consist of several contact ultrasound transducers (or array of transducers) with the essential requirement of a couplant. Operation of these UCT require the use of coupler and/or medium for operation. A consistent layer needs to be maintained in real-time, or an object has to be submerged inside a tank filled with a coupling medium. It also adds up to the weight, size of the scanner, and speed of overall scanning operation, limiting the field of applications. The main challenge is to develop a practical NCU transducer based UCT system.
[003] Reference may be made to the following:
[004] IN Publication No. 9038/DELNP/2010 relates to a system. includes transmitters to transmit an excitation energy into an object under observation; detectors to generate projection space data encoding energy received in response to -the transmitted excitation energy into the object; a controller to control the transmitters to transmit the excitation energy and the detectors to generate the projection space data; an image reconstructor to receive the projection space data and to process the projection space data by: computing a first quantity characterizing a difference between the projection space data and predicted projection data; computing a second quantity corresponding to at least one impulse response, each impulse response corresponding to a reference voxel of unit-intensity; computing an update value using the first quantity and an inverted function of the second quantity; and reconstructing an object space image representing the object under observation using the update value.
[005] Publication No. US2016317121 relates to an ultrasound CT (computed tomography) method on the basis of non uniform fast fourier transform (NUFFT). According to the ultrasound CT method, the imaging result of ultrasound CT obtained by a gridding method serves as an initial value of an iteration method, so that iterations approaching a truth value are reduced, and the amount of computation is decreased. Regularization factors are introduced and are optimized and analyzed by virtue of an improved conjugate gradient (CG) method, so that the convergence of the iteration method is ensured, and the iterations can approach the truth value of an image step by step. According to the method, air domain and frequency domain methods are combined with information of UTCT (ultrasound treatment computed tomography) and URCT (ultrasound reflection computed tomography), wherein the UTCT contains the information of the low frequency part of the image, the URCT contains the information of the relatively high band pass part of the image, the URCT can be used for restoring part of edge information lost by the UTCT, and the information is increased by virtue of the combination of the UTCT and UCRT, so that the effect of the restored image is better than that of the image formed by virtue of the independent UTCT or UCRT, and the better imaging effect is achieved.
[006] Publication No. US2005054924 relates to a three-dimensional (3-D) ultrasound computed tomography (UCT) system for providing a 3-D image of a target is presented. The 3-D UCT system includes an imaging chamber having a plurality of piezoelectric elements. The plurality of piezoelectric elements are arranged as a plurality of cylindrical rings. When activated, the plurality of piezoelectric elements generate and receive an ultrasound signal in a cone beam form. The 3-D UCT system also includes a processor coupled to the imaging chamber. The processor receives and processes the ultrasound signal and constructs the 3-D image of the target. A display device is also included with the 3-D UCT system. The display device exhibits the 3-D image of the target for analysis.
[007] Patent No. US7166982 relates to a motion control algorithm for the control of an AC electric machine, the apparatus comprising a motion control engine comprising a motion control sequencer, a motion control program memory, a port memory, a plurality of motion control modules, and a plurality of motion peripheral modules, the motion control sequencer executing a sequence of instructions stored in the motion control program memory directing the sequencer to execute motion control modules and motion peripheral modules in a specified sequence and with a specified connection of module inputs and module outputs and operational parameters stored in the port memory to generate the motion control algorithm. A microcontroller may be coupled to the motor control program memory and the port memory for monitoring the output of the motion control engine.
[008] Publication No. CN203432946 relates to an ultrasonic transducer rotating device for ultrasound computed tomography of a particle two-phase system. The ultrasonic transducer rotating device comprises a base, a track and a plurality of sliding blocks, wherein the round track is arranged on the base; ultrasonic transducers including an ultrasonic transmitting transducer and an ultrasonic receiving transducer are respectively arranged on the plurality of sliding blocks; the sliding block are moved to enable the ultrasonic transducers to move on the track, the area enclosed by movement of the sliding blocks on the track is a sample pool, and the ultrasonic transducers carry out different-angle measurement on the sample pool so as to realize multi-angle ultrasonic measurement.
[009] Patent No. US9354204 relates to a system including a segmented transducer probe. The segmented transducer probe includes a plurality of transducer segments adapted to transmit ultrasonic excitation signals into a test specimen and to receive echo signals resulting from the interaction of the ultrasonic excitation signals and the test specimen. The system also includes a processing system adapted to receive data from the segmented transducer probe that corresponds to the received echo signals and to utilize tomographic reconstruction methods to reconstruct an image corresponding to at least one volumetric slice of the test specimen.
[010] Publication No. EP3239706 relates to an apparatus for inspecting an object in the field of material testing. An emitter emits ultrasound waves towards a measuring area and a receiver receives ultrasound waves from the measuring area. The emitter emits ultrasound waves from different positions relative to the measuring area and/or the receiver receives ultrasound waves at different positions relative to the measuring area. The invention also refers to a corresponding method.
[011] Publication no. US10151731 provides the example systems and methods for non-destructive ultrasonic testing. One example system includes at least one air-coupled ultrasonic transducer configured to emit primary ultrasound waves that interfere with each other. The primary ultrasound waves include fundamental frequency components that are multiples of each other and emitted simultaneously in locked phase. Further, the interference of the primary ultrasound waves generates a plurality of frequency harmonics in the air. The system also includes at least one receiver configured to receive ultrasonic waves emitted from an object under test.
[012] In publication no. US7025725B2, a three-dimensional (3-D) ultrasound computed tomography (UCT) system for providing a 3-D image of a target is presented. The presented 3D UCT system includes an imaging chamber comprises of plurality of cylindrical rings of piezoelectric elements. These rings are arranged in vertical arrangement inside the imaging chamber. Microcontroller is used to activate one of the element to generate cone shaped beam and selectively triggers the receiving elements. A processing unit is coupled to the receivers to construct the 3D image of the target. A display device is connected to display the image of the target for analysis.
[013] Publication no. CN102305828A relates to a tomography detection system based on surrounding type array and its method. The system comprises an ultrasonic emitting receiving module, a signal collecting module, a control module, a signal processing module, a display module and a plurality of ultrasonic sensors. The system has a signal processing module that is connected with the signal collecting module, display module and control module. The signal collecting module is connected with the control module and the ultrasonic emitting and receiving module. An ultrasonic emitting and receiving module is connected with the ultrasonic wave sensor and a control module. The multi-path A/D circuit receives the ultrasonic wave signal and signal processing module process the data and tomographic reconstruction.
[014] Publication no. CN102539531A relates to a portable two-dimensional ultrasound CT for non-destructive testing of city tree. The instrument uses the modern electronic technology, computer imaging and feature recognition technology for detecting and judging the health condition of the tree so as to eliminate many potential safety hazard caused by tree suddenly toppled. The instrument has a Cyclone III series chip for performing sampling control, processing, buffer, control and communication transmission used as a control core, and a Joint Test Action Group (JTAG) - universal asynchronous receiver transmitter (UART) chip. An ultrasonic detection data processing module is used as a device of a multi-chip. An Avalon bus is connected with a metal oxide semiconductor (Mos) II processor to realize ultrasound two-dimensional image reconstruction function by System-on-a-Programmable-Chip (SOPC) technology in the Cyclone III series chip.
[015] The first practical UCT system publication was first reported in the late 1970s. In the listed prior arts, inventions are made in the field related to ultrasound computed tomography, instrument interfacing, development of automated control systems.
[016] The publication no. DE102016203812 relates to a system with a medical imaging device, which is designed to acquire first imaging data based on electromagnetic radiation. A control device designed to control the medical imaging device and control an ultrasound probe. The ultrasound probe consists of several elements arranged in an array. It requires a couplant to transmit the ultrasound wave into the tissue efficiently. The image produced with ultrasound sonography and CT machine (Electromagnetic radiation) is superimposed referred as USCT. The presented invention discloses the use of non-contact ultrasound transducer to produce the 2D image of the specimen. The invention highlights the scanning process and involved signal processing, reconstruction method and the controlling software. The presented UCT system has applications related to the industrial and research areas to study the material properties, inspection, visualization of specimen’s inner profile etc.
[017] Publication No. CN105997153 relates to an imaging method of ultrasonic CT. The imaging method comprises rotating a circular probe by 360 to obtain data groups and perform the iterative computation to obtain the velocity distribution V for imaging. The invention uses ultrasound probes having several elements to emit and receive the ultrasound data. The presented invention uses non-contact ultrasound transducers and involved imaging methods to produce the specimen’s profile. The amplitude analysis is performed to produce the reconstructed profile.
[018] The publication no. US9235889 relates to diagnostic imaging, particularly to systems, apparatus and methods for collecting, storing, and analyzing raw scan data as well as raw scan data processing and image reconstruction algorithms and software used for medical diagnostic imaging, non-destructive material analysis, security, and other imaging applications. The invention provides the method for managing the data generated in a diagnostic device. The presented invention uses a data acquisition module to acquire the data. The data is processed onboard and the raw data and analysis can be saved in the operating system memory.
[019] The publication nos. US4105018, CN102305828, CN102539531 presented ultrasound CT systems based on array transducer and corresponding signal emitting and receiving module. These systems utilize the contact transducer as their basic element for emitting and receiving the ultrasound waves. Hence, they require the use of a coupling media or a couplant to facilitate the efficient propagation of the ultrasound wave. The several systems described in the prior art relate to the conventional ultrasound sonography method to produce the image of specimen (called sonogram) based on acquired ultrasound wave reflection data. The presented system is based on the non-contact (air-coupled) ultrasound (NCU) transducer.
[020] Publication no. WO2013023987 and CN104865316 describes the systems comprising of air coupled ultrasonic transducer for non-destructive evaluation. One is related to the contactless method and an installation for non-destructive determination of defects in laminated structures, and the other describes a device for carrying out unilateral single side imaging. The NCU transducers are only used for crack detection and conventional reflection/transmission surface imaging. The presented invention uses the NCU transducer pair for computed tomography. The ultrasound waves travel through the object and the transmitted waves carries the information about the properties of the object. The transmitted wave data is used to produce the profile of the object through tomographic reconstruction.
[021] The other publications relate to control systems, rotating devices, data acquisition, signal processing and image reconstruction, and corresponding interfacing. They provide the knowledge to develop advanced, compact systems. In the present invention, work is carried out to develop a fully automatic Compact 2D ultrasound CT system for scanning of samples. The presented invention comprises the NCU transducers, pulse generator, data acquisition module, a signal processing module, specimen holder, controlling software, operating system and display. The system does not require the use of any couplant and medium for operation. The specimen holder has translational and rotational degrees of freedom to provide complete 2D scanning using a single transducer pair, reducing the system complexity and cost. For the wider applicability of the system, it is provided with tunable transducers working in a broad range of frequencies. The software is developed by embedding the interfacing and controlling codes of the different modules to automate the system. The resulted system is compact and portable. This may be the first publication that presents the practical applicability of the non-contact ultrasound transducer based ultrasound CT.
OBJECTS OF THE INVENTION:
[022] The principal object of the present invention is to provide electro-mechanical system and method for two dimensional (2D) ultrasound computed tomography (UCT) scanner.
[023] Another object of the present invention is to provide a compact, relatively lightweight, single non-contact ultrasound (NCU) transducer pair-based 2D UCT scanner.
[024] Yet another object of the present invention is to provide a method of using air-coupled transducers which enable the apparatus capable of working without the need of the medium and/or couplant.
[025] Still another objective of the present invention is to incorporate the interfacing, controlling and signal processing method to automate the UCT system.
SUMMARY OF THE INVENTION:
[026] The present invention relates to the field of non-destructive testing/evaluation (NDT). A fully automatic 2D ultrasound computed tomography (CT) system is developed using non-contact ultrasound(NCU) transducer pair. Other than the transducers, system comprises of an automated specimen holder to control the motion of the specimen, an automated pulse generator module to trigger the emitting transducer, an automatic data acquisition module to acquire the transmission data(coupled to the receiving transducer), an operating system consisting of controlling software and display. A preamplifier can be associated with the receiving transducer to amplify the signal and improve the signal-to-noise ratio. The system is automated to produce specimen’s inner profile in a single push of a button, non-invasively. The NCU transducer produces a cone-shaped ultrasound beam in a broad frequency range, acts as the emitter and receiver. The use of NCU transducers eliminates the requirement of medium and coupler to facilitate the efficient transmission of ultrasound waves. The parallel beam geometry is applied for the scanning process. The amplitude analysis approach is used for signal processing.
[027] The method performs the complete scanning automatically. Computationally efficient signal processing algorithms are developed and employed to process the acquired ultrasound signal. Along with signal processing, optimal transmission data selection, object detection algorithms are also employed. The feature to play between various reconstruction algorithms and filters is also provided. The software displays the scanning process and ongoing analysis in real-time. It also provides the functionality to select the ultrasound frequency and other parameters according to the application, access to raw data.
BREIF DESCRIPTION OF THE INVENTION
[028] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments.
[029] Figure 1 shows the block diagram of the present invention;
[030] Figure 2 shows two dimensional (2D) ultrasound computed tomography (UCT) scanner assembly;
[031] Figure 3 shows flowchart for scanning process according to the present invention;
DETAILED DESCRIPTION OF THE INVENTION:
[032] The present invention provides a system and method for two dimensional (2D) ultrasound computed tomography (UCT) scanner. The ultrasound CT has numerous applications in industrial and research areas to study the material properties, inspection, visualization of specimen’s inner profile etc. It can be also used for select medical applications such as studying the properties using phantom. The prior arts have a necessity of using a medium or coupler to scan a specimen. The specimen to be scanned need to be placed either in liquid medium, or a coupler need to be applied to facilitate the efficient transmission of ultrasound waves. This system is equipped with non-contact ultrasound (NCU) transducers, corresponding signal processing and scanning method. Thus the system is capable of working without the need of medium or coupler. Also, the system controlling software is embedded with interfacing and control algorithms to automate the process.
[033] Thus the present ultrasound CT system is of non-destructive testing/evaluation (NDT). It scans the specimen systematically in a number of views and projections to generate the profile of the specimen non-invasively. It employs a parallel beam geometry to scan the specimen. The resolution of the specimen’s scanned profile depends on the number of views selected. The number of rotation affect the quality of the profile. The greater the number of projections, better the accuracy of the internal structure in the profile will be. The ultrasound emitter produces the ultrasound waves that traverse through the specimen and detected by the receiver/detector. The detected signal is processed using amplitude analysis. The automatically controlled electro-mechanical assembly (fig. 2) of the scanner is integrated with its synchronized data acquisition, complex signal processing and inverse problem based image reconstruction method. The method displays the scanning process and ongoing analysis in real-time.
[034] Referring to Fig 1, the 2D UCT system comprises two air-coupled non-contact ultrasound transducer acting as the ultrasound wave emitter (4) and receiver (5); a specimen holder to control the motion of the specimen (3); pulse generator module (1) to trigger the emitting transducer (4); a preamplifier (6) coupled to receiving transducer; data acquisition module (7) to acquire the transmission data(coupled to the preamplifier); operating system (8) consisting of controlling software (8) and display (11). The specimen (2) to be scanned is placed on the specimen holder to linearly translate and rotate. The acquired data is processed on board by the signal processing module (10). The user interface (9) allows user to set parameters to operate the system.
[035] Pulse generator (1) produces the pulse of the desired frequency to trigger the emitting transducer which in turn produces the ultrasound waves. The pulse parameters such as rise time, fall time, number of pulses, amplitude, and pulse width can be set according to the application. The pulse applied to the transmitting transducer produces low-power ultrasound waves. Low power ultrasound waves are used for NDT applications as these waves are elastic in nature and cause no harm to the propagating medium. The specimen to be scanned will be placed on the specimen holder (14, 3) attached to a linearly translating and rotating platform. The parallel beam geometry is applied to scan the specimen. The scanning parameters can be defined according to the specimen information, desired resolution. The specimen is linearly translated several times (as per the given scanning resolution) for each rotation. The number of given projections decides the number of rotations.
[036] Referring to fig. 2, the ultrasound transducer housing (12) have two degree (y & z-axes) of motion for both the transducer holders, allowing the scanning of objects of varying size. The transducers height and distance can be adjusted, scales (15, 16) are provided to fix the position precisely. The transducer distance for a particular specimen can be AI optimized. Emitting (4) and receiving (5) transducers are placed in their respective holders, and coupled with the pulse generator and preamplifier respectively via BNC (13) connectors. The specimen holder is attached with a moving platform (17) in order to provide linear motion.
[037] The NCU transducer (4, 5) consist of piezoelectric material that produces a cone-shaped focused ultrasound beam in a broad frequency range. One transducer acts as the transmitter and another as the receiver. A preamplifier can be associated with the receiving transducer to amplify the signal and improve the signal-to-noise ratio. The use of a NCU transducer eliminates the requirement of a medium and/or coupler to facilitate the efficient transmission of ultrasound waves. The controlling software is embedded with the custom algorithms to communicate in between the various modules of the system to provide automatic 2D scanning. The user interface provides freedom to play between the various settings of the system such as number of projections, resolution for scanning according to the requirement, scanning frequency, amplitude, number of pulses, rise time, fall time, scanning speed, reconstruction method, filters. The display shows the real-time scanning process and the analysis. The users can also retrieve the raw data in simple steps for research/analysis.
[038] The scanning parameters can be defined from the user interface. Before starting the experiment user must define an experiment name so that a folder for the experiment will be created in the specified directory. The folder includes the raw data, selected parameters values, and the final results. The results folder consists of the sinogram of the scanned object, extracted data and reconstruction. Once the required parameters are set in the system, instructions are generated to perform different task systematically. The instructions are parsed to the microcontroller to control the mechanical system’s linear translation and rotational movement. For every rotation angle, the specimen is translated through a number of times according to the input parameters. At each translation, the emitting transducer is triggered by a pulse of the given frequency to produce the ultrasound wave. This ultrasound wave traverses through the specimen and is detected by the receiving transducer. The data acquisition module connected to the receiving transducer acquires the data and performs the analog to digital conversion. For each translation movement of the specimen, a data file is generated. The method calls the generated raw data for processing after every translation. The raw data can also be saved directly in the user system for further processing. The signal processing module is equipped with efficient signal processing algorithms to process the detected ultrasound signal. It employs amplitude analysis to extract the transmission data. Along with signal processing, a data selection algorithm is used to select the optimal transmission data.
[039] Figure 3 shows the flowchart according to the present invention. Following are the steps involve in scanning process,
The operator can enter the scanning parameters such as
Experiment name
Scanning Resolution
No. of projections
Wave parameter: Frequency, Amplitude, (Advanced: rise time, fall time, pulse width, number of pulses)
Specimen scanning distance
Experiment directory
Scanning speed
Automatic specimen detection and scanning distance (the distance upto which the object linearly translates) selection
Option to save or discard raw data
Reconstruction method selection
Reconstruction Filter selection for the specific method
Some of the basic parameter are necessarily need to be defined by the operator while advanced and optional parameter are predefined which can be modified.
Based on the entered data, pulse generator triggers the emitting transducer, which in turn produces the ultrasound wave.
The specimen is linearly translated several times (as per the given scanning resolution) for each rotation. The number of given projections decides the number of rotations. At each translation, the emitting transducer emits ultrasound waves that traverse through the specimen. The receiving transducer then detects the transmitted wave and transmission data is acquired by the data acquisition module. After completion of all translations for a rotation, data is processed and reconstructed. Then the specimen is rotated. The process is repeated until the scanning process is complete (Data is acquired for all the projections).
The raw data is processed to reconstruct the specimen’s profile/image.
[040] The emitting transducer is triggered at each linear translation to emit ultrasound waves that traverse through the specimen. The receiving transducer then detects the transmitted wave corresponding to each linear translation. The data acquisition module acquires the data. The data is processed by the signal processing module to extract the information. After completion of all translations for a rotation, the extracted information is processed to reconstruct the specimen’s profile. The rotational angle advances, and the specimen is again linearly translated step by step to continue scanning the specimen. The process is repeated until the scanning is complete.
[041] Thus the present system provides the user interface to control the system. The system has interface communication between various modules of the system, acquires the transmission data, processes the data, including signal processing, provide choices of tomographic reconstruction methods, control the microcontroller, which in turn control the motion of the specimen holder and shows the real-time scanning process and analysis on the display (of the operating system).
[042] Numerous modifications and adaptations of the system of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the true spirit and scope of this invention.

WE CLAIM:

1. A compact air-coupled single transducer pair two dimensional (2D) ultrasound computed tomography (UCT) scanner and its method of scanning comprises:
? pulse generator (1) characterized in that the pulse of the desired frequency to trigger the emitting transducer which produces the ultrasound waves;
? two non-contact (air coupled) ultrasound(NCU) transducer wherein the two transducer acting as the ultrasound emitter (4) and receiver (5);
? specimen holder (3) characterized in that translational and rotational degrees of freedom to control the motion of the specimen (2);
? data acquisition system (7) coupled to the receiving transducer to acquire the transmission data through the receiving ultrasound transducer.
? Operating system (8) consist of user interface (9), control/ processing unit (10) and display (11) to control the 2D UCT system and show the specimen’s real-time scanning process and analysis characterized in that the microcontroller, motor driver and circuitry to control the system.
2. The apparatus, as claimed in claim 1, wherein the said apparatus is capable of working without the need of the medium and/or couplant.
3. The apparatus, as claimed in claim 1, wherein the NCU transducers comprises piezoelectric material placed parallel facing each other, are operational on multiple frequencies over a range upto 45MHz, one of transducer (emitting transducer) is configured to produce the ultrasound waves and another is configured to detect the ultrasound waves, and the receiving ultrasound is associated with a preamplifier.
4. The apparatus, as claimed in claim 1, wherein the said apparatus display show the specimen’s real-time scanning process and analysis.
5. The method of scanning through the compact air-coupled single transducer pair two dimensional (2D) ultrasound computed tomography (UCT) scanner, includes the following steps:
a) Specimen is placed on the specimen holder; and the scanning parameters are entered into the user interface.
b) Based on the entered parameters, pulse generator triggers the emitting transducer, which in turn produces the ultrasound wave.
c) The specimen is linearly translated several times (as per the given scanning resolution) for each rotation and the number of given projections decides the number of rotations.
d) At each translation, the emitting transducer emits ultrasound waves that traverse through the specimen.
e) The receiving transducer then detects the transmitted wave and transmission data is acquired by the data acquisition module.
f) After completion of all translations for a rotation, data is processed and reconstructed.
g) Then the specimen is rotated and the process is repeated until the scanning process is complete.