Dimensional Measurement System Research Articles

An ultrasonic system for measurement of absolute myocardial thickness using a single transducer

We have developed an ultrasonic instrument that can measure absolute regional myocardial wall motion throughout the cardiac cycle using a single epicardial piezoelectric transducer. The methods in place currently that utilize ultrasound to measure myocardial wall thickness are the transit-time sonomicrometer (TTS) and, more recently, the Doppler echo displacement method. Both methods have inherent disadvantages. To address the need for an instrument that can measure absolute dimensions of myocardial wall at any depth, an ultrasonic single-crystal sonomicrometer (SCS) system was developed. This system can identify and track the boundary of the endocardial muscle-blood interface. With this instrument, it is possible to obtain, from a single epicardial transducer, measurement of myocardial wall motion that is calibrated in absolute dimensional units. The operating principles of the proposed myocardial dimension measurement system are as follows. A short duration ultrasonic burst having a frequency of 10 MHz is transmitted from the piezoelectric transducer. Reflected echoes are sampled at two distinct time intervals to generate reference and interface sample volumes. During steady state, the two sample volumes are adjusted so that the reference volume remains entirely within the myocardium, whereas half of the interface sampled volume is located within the myocardium. After amplification and filtering, the true root mean square values of both signals are compared and an error signal is generated. A closed-loop circuit uses the integrated error signal to continuously adjust the position of the two sample volumes. We have compared our system in vitro against a known signal and in vivo against the two-crystal TTS system during control, suppression (ischemia), and enhancement (isoproterenol) of myocardial function. Results were obtained in vitro for accuracy (> 99%), signal linearity (r = 0.99), and frequency response to heart rates > 450 beats/min, and in vivo data were acquired for end-systolic dimension (r = 0.99), end-diastolic dimension (r = 0.99), and percent wall thickness (r = 0.99). Both in vitro and in vivo tests indicate that the SCS functions identically to the two-crystal TTS. Use of the SCS allows measurement of absolute wall thickness and hence myocardial function, for both acute and chronically instrumented animal studies, with minimal or no trauma to myocardium.

A fault identification and classification scheme for an automobile door assembly process

A process fault identification and classification scheme for an automobile door assembly process is presented based on multivariate in-line dimensional measurements and principal component factor analysis. First, the door assembly process and the dimensional measurement system are briefly introduced. Second, the technique of principal component factor analysis is presented for process fault identification. Process faults are summarized based on off-line identified case studies. Finally a machine classification scheme based on principal components and principal factors is presented and evaluated, using the pattern knowledge obtained off-line. This scheme is shown to be effective in classifying process faults using production data.

蓋膜ｉｍｐｒｉｎｔの深さの測定 ３次元状解析装置による観察

This study estimated the depth of imprint on the tectorial membrane using a new three dimensional measurement system. The tectorial membrane covers the surface of the organ of Corti. The tips of the sensory cell hairs are firmly embedded in the undersurface of the tectorial membrane. Scanning electron microscopic findings show the existence of small holes (hair imprint) made by tips of sensory hairs.Since the sensory cells of the organ of Corti are believed to be stimulated by bending the sensory hair, it is interesting to determine the depth of imprint. The three dimensional measuring system used in the present studies, was recently developed and can measure the surface structure of a material. The principles of the system are described.According to this system, the depth of imprint varies but average values are from 0.02 to 0.03 um. The bird's-eye view of the imprints obtained by this system are also shown. The findings are briefly discussed.

Submicron-dimentional measurement with two-laser-beam scanning using an acoustoopic deflector

A new submicron-order dimensional measurement system using a two-laser-beam scanning method and measurement results are described. Two fine spot beams, slightly separated, which are generated from an acoustoopic deflector, are scanned at 0.02 μm steps on an object by driving a signal which has two frequency components. The synthetic light intensity distribution of the two beams is adjusted to a particular distribution according to the dimension to be measured by varying that of the frequency. The shape of the reflected light intensity signal is adjusted to the particular U-shaped signal by controlling the synthetic light intensity distribution. From the value of the frequency which controls the U-shaped signal, the submicron dimentions can be measured with accuracies of ±0.02 μm.

Correction algorithms in a laser scanning dimension measurement system

The principal system error in a laser scanning dimension measurement system (LSDMS) is the variation of the scanning speed of the laser beam at different locations of the measuring region, which is caused mainly by the conventionally corrected lens. When a small spin gauge is positioned and measured within the measuring region of the LSDMS, the deviation of the scanning speed from a constant speed can be obtained. This deviation is the criterion on which two correction algorithms are based. The correction algorithms are proposed and discussed, and both show satisfactory improvement in the performance of the LSDMS.

A method to test the accuracy of critical dimension measurement systems (CDMS)

As already shown in previous articles different combinations of SEM's with PC-based measurement systems are available to determine the linewidth in the submicron area. One common problem for all these measurement tools is a missing test for measuring the accuracy of these systems. This investigation presents a method describing how the measuring accuracy of these systems can be checked. For this purpose different calibration specimens for light microscopy were tested for usability in low-voltage SEM imaging. Chrome on glass micrometer specimens proved to be especially useful. In comparison with specimens manufactured by photographic methods they combine good imaging qualities with thin high contrast lines with sharp edges. The test for consistant linewidths was done using quantitative Image Analysis, allowing the measurement of a high volume of data quickly and accurately. The resulting value was used as the absolute value for the determination of the accuracy of the CDMS. As such a comparison value was not available before, the accuracy of measurements could only be given within certain confidence limits. This latest method can now prove how accurate the resulting values really are. Initial tests using an AMRAY 1830 SEM and Critical Dimension Measurement System showed a distortion of the measuring results of 0.3% or 0.5% compared with the true value. This means a difference of 0.6 or 0.8 pixels. This result is better than the theoretical accuracy of a CDMS. Using these values, the error of linewidth measurements in the 1 micron range is only about 0.005 μm.

A New Calibration Method

When using robot manipulator to carry out autonomous tasks, the positioning accuracy of the robot manipulator relative to a reference coordinate frame is of great importance. The task program, which is generated off-line in CAD-system and used in actual robot positioning, may cause serious amount of the absolute positioning error of the robot manipulator. In this study a new kinematic model and a parameter identification algorithm an proposed in order to improve the absolute positioning accuracy of the robot end effector. Experiments were also carried out by utilizing the HYUNDAI Robot AE 7601 and KIMI-Tester, a three dimensional measurement system, which is developed in CAD/CAM laboratory 81 Korea Institute of Science and Technology.

上下顎レジン床総義歯粘膜面部の重合に伴う経日的形態変化について

The objective of this study was to clarify some of the dimensional change patterns of the denture base of the complete denture following polymerization. Dimensional changes of three polymerization method types were compared. The complete dentures were measured by using the three dimensional measurement system. The results obtained were summarized as follows. 1. Dimensional changes from the original model immediately after polymerization of complete upper and lower dentures were recorded and all three polymerization methods produced shrinkage on all three axes toward the center. Heat cured resin samples and microwave cured resin samples showed the same shrinkage with pour type resin samples only showing 1/2 that amount. 2. The gradual dimensional changes occurring after polymerization up until 4 weeks were also recorded. The heat cured resin samples showed no additional changes but remained in its shrunken state. The pour-type resin samples began to enlarge until almost all of them reached the original model size within 4 weeks. The microwave cured resin samples began to enlarge but only slightly and then soon stopped changing. 3. All polymerization method types showed more dimensional change in the lower plate than in the upper plate.

Improved denture measuring method using the three-dimensional measurement system

The following is a list of the test results using the three dimensional measurement system to measure a denture base as compared to the method used up until now.1. The new measuring method is a remarkable improvement upon the measuring method used up until now.2. The new measuring method takes about one fourth the time to measure as compared to the method used up until now.3. The precision obtained using the new measuring system will not change much with experience.4. Using the new method, measuring precision of the X axis direction was 5μm, the Y axis direction was 5μm, and the Z axis direction was 1μm.

Non-contacting, three dimensional measurement using an industrial robot.

This paper describes the development and the methodology of a non-contacting, three dimensional measurement system using an industrial robot, a CCD camera together with a laser analogue sensor, and some results obtained by applying it to the measurement of objects. A frame image of an object in the working area of the robot is firstly taken by the camera mounted on the upper stand over the robot. Then its pattern, position and dimensions are recognized by a personal computer. Using these recognized data, robot operating instructions are made automatically on the computer. Successively the robot approachs the object and begins to measure the distance between it and the laser sensor according to the principle of the triangulation. By this measurement system, workpieces and houseware having fairly complicated contours can be measured precisely and reconstituted as three dimensional data in the computer memory cells. The over-all measuring speed is several times that of the conventional system using a contacting probe.

Measurement of facial form using stereo-photogrammetry system

We have been developing a three dimensional measurement system by 35mm non-metric SLR camera and have been applying this system to the measurement of complete denture base surface area and edentulous cast model surface. The purpose of this study was to apply this system to the measurement of the facial form. The subject's head was fixed and 15 control points were arranged around his face. In order to make the process of stereo-matching easier, we projected mesh on the subject's face and took stereoscopic photographs. These photographs were measured by the digitizer and the 3-D coordinates of about 5000 measuring points were calculated by a personal computer. The geometric model of the face was displayed in three dimensional computer graphics. And the model of the face was carved out from the acrylic resin by the NC milling machine from these data.

Movements of the facial surface during oral functions

Movements of soft tissues surrounding the oral cavity, especially lips and cheeks, have a great influence on the masticatory and the phonetic functions. These movements could indicate the state of harmony between a denture and the soft tissues and the muscles surrounding it.The purpose of this study was to investigate the movements of the facial surface during oral functions by applying 35mm nonmetric SLR camera as a three dimensional measurement system.Total of 101 subjects with normal range occlusion were selected. Forty-one selected points were placed on the skin surface of the face of each subject. The movements of these points under the condition of thrusting lips, pulling mouth corners backward, intentional occlusion and smile were measured in three dimensions.The findings were as follows;1. This three dimensional measurement system was applicable to study the movements of facial surface.2. The mouth corner points showed the greatest and the most characteristic movement among 41 points.3. The significant correlation was indicated between the movement of the mouth corner point and the movements of most of other points. This suggested that the mouth corner point could indicate the movements of the facial surface most significantly.

３５ｍｍカメラによる三次元形態測定システム ＩＩ 全部床義歯の床内面積の測定

A three dimensional measurement system by 35mm non-metric SLR camera was developed (Part 1).The purpose of this study was to examine the propriety of the application of the above mentioned system with addition of one other instrument, for clinical prosthodontics, especially in the measurement of complete denture base surface area.In this experiment, three dimensional concave and convex curved metal test pieces were used to evaluate the accuracy of measuring curved surface.Additionally, this system was applied to the measurement of complete denture base surface area and edenturous cast model surface.And then the measurements were compared with one previous measurement system for accuracy.From the three dimensional data obtained from this system, three dimensional color photographic representations of measured objects were also attempted.Results were as follows:1. Measurement errors of the test piece surfaces were -1.6% on the average.2. This system was applicable to measure the denture base surface area.3. Measured objects could be represented by three dimensional color photographs (Photo. 6-11).

走査モアレ法のしま次数自動決定法

This paper describes an automatic decidable method of absolute sequence numbers of fringes that have been thought as the complicated problems in the automatic 3-dimensional measurement system with moiré topography. In the method, a system of the scanning moiré topography is constituted theoretically with two TV-cameras and a projector. By comparing with two pictures generated by two TV-cameras, the original fringe can be extracted logically in the picture. Then, absolute sequence number of original fringe becomes zero. Furthermore, with this result and the relative sequence numbers of fringes given by uphill or downhill judgement, the absolute sequence numbers of fringes can be determined automatically with regard to every fringe. The results show that the method is useful for the complex configuration. It may be concluded that the method accelerates the progress of the automatic 3-dimensional measurement system with moiré topography.

前歯の歯冠軸傾斜に関する研究 ３次元座標測定機による研究

前歯の歯冠軸傾斜に関する研究 ３次元座標測定機による研究

３５ｍｍカメラによる三次元形態測定システム 第１報 システムの開発と臨床応用のための基礎的研究

３５ｍｍカメラによる三次元形態測定システム 第１報 システムの開発と臨床応用のための基礎的研究

印象採得法の基礎的研討 ＩＩ トレーのスペーサーとベントについて

An impression in denture prosthodontics is the first step for the construction of full denture.An impression is in clinic so important that the prognosis for denture is depended upon. Therefore, a considerable amount of reaserch has been reported. Especially, the soft tissue as an impression objectives can be displaced under pressure so that the method in edentulous impression making has influence on contour variations of the master cast.According to the impression, it is supposed that the adaptability to denture goes down and the basal soft tissue is injured in function. Basic and clinical studies on the edentulous impression have been considered, however, it seems not to arrive at evidence conclusion.The basic study (Part. 1) was designed for the sake of how to make impression for the functional denture without injury to edentulous patient. As the result of this study, the simulation model supposed edentulous alveolar ridge and three dimensions repositioner were made. Then, three dimensional measurement system to compare simulation model with master cast was reported and published.In this study, the three dimensional measurement system and simulation model as the alveolar ridge are used for impression in denture construction. It is investigated with the three dimensional measurement system that impression tray (spacer, vent), impression material and these combination are influenced on the reproductivity of simulation model.The conclusions are follows1. The cast from the simulation model type G without displaceability, is not influenced by impression tray and impression material.2. The cast from the simulation model type A-3 with constant displaceability, is not influenced by impression material but by the impression tray. The best cast is produced by the impression used the tray (spacer, vent) with alginate impression material.3. The cast from the simulation model type C with difference displaceability in part, is only influenced by impression material. The best cast is produced by the impression tray without spacer and vent using alginate impression material.4. From these conclusions (1-3), when the impression for the denture construction is made of the soft tissue with the poor displaceability, the impression tray and material are not so important. However, for the soft tissue with the rich displaceability, it is necessary that the impression tray is more considerable than material.

上下がく中切歯におけるこう合小面および歯冠軸について ３次元座標測定機による研究

上下がく中切歯におけるこう合小面および歯冠軸について ３次元座標測定機による研究

Two High-Speed Dimensional Measuring Systems

Two high-speed, dimensional measurement systems have been developed. Both have several advantages over conventional measurement systems. Both have been designed around the use of line gratings. The first system measures and controls the flatness of opaque objects to a resolution of 100 microinches. The method is fast, non-contacting, self-calibrating, can be used in a limited access area, and can be applied to moving surfaces. The second system is used to measure and control the width of continuous opaque objects such as tapes. The method is noncontacting, minimizing frictional wear. One thousand measurements per second, at a resolution of 100 microinches, can be made.