Movable Portion Research Articles

A non-resonant fiber scanner based on an electrothermally-actuated MEMS stage

Scanning fiber tips provides the most convenient way for forward-viewing fiber-optic microendoscopy. In this paper, a distal fiber scanning method based on a large-displacement MEMS actuator is presented. A single-mode fiber is glued on the micro-platform of an electrothermal MEMS stage to realize large range non-resonant scanning. The micro-platform has a large piston scan range of up to 800μm at only 6V. The tip deflection of the fiber can be further amplified by placing the MEMS stage at a proper location along the fiber. A quasi-static model of the fiber-MEMS assembly has been developed and validated experimentally. The frequency response has also been studied and measured. A fiber tip deflection of up to 1650μm for the 45mm-long movable fiber portion has been achieved when the MEMS electrothermal stage was placed 25mm away from the free end. The electrothermally-actuated MEMS stage shows a great potential for forward viewing fiber scanning and optical applications.

Early squamous cell carcinoma of the anterior tongue; Report of two cases

Squamous cell carcinoma (SCC) of anterior tongue is relatively common in India and forms a significant group of all head & neck malignancies. Mucoepidermoid carcinoma, melanoma and adenoid cystic carcinoma are other rare tumors found in the tongue. The purpose of this article is to report two cases of early SCC of anterior tongue which were managed with wide excision. The incidence, etiology, treatment and prognosis are discussed. th and 6 th decades but cases have been reported in young individuals too. Carcinoma of tongue is associated frequently with alcohol and tobacco chewing as a common etiology. The anterior tongue is a movable portion and extends from circumvallate papillae to the junction at the anterior floor of mouth. The anterior tongue is divided into four regions, tip, lateral borders and dorsal & ventral surfaces. Lymphatic drainage from anterior aspect is into submental nodes, and the lateral borders drain into the submandibular and upper deep jugular nodes and communications which occur in the midline can lead to contralateral neck drainage. The various treatment options for carcinoma of anterior tongue are wide excision, hemiglossectomy and primary excisions alongwith elective neck dissection. Here we show report of two cases of carcinoma of anterior tongue. II. Case reports Case 1 A 40 year old man reported to hospital with the complaint of a non healing ulcer over the tongue, since 3 months. It was initially small and it gradually progressed to present size. History revealed the habits of betel nut chewing and smoking. Clinical examination showed a ulcerative lesion in right lateral border of the anterior tongue, measuring 0.5X2.cm (fig.1). Neck nodes were not palpable and on palpation of the tongue induration was there but not crossing the midline.Incisional biopsy revealed moderately differentiated squamous cell carcinoma.(fig.2) Surgery was planned as wide excision of the lesion under general anesthesia. Wide excision is done with adequate safe margins.(fig.3)Hemostasis is achieved and primary closure is done.(fig.4) The post operative recovery was uneventful. The excised lesion was sent to histopathology for assessing margins and depth of tumor extension. Histopathology report suggested that all margins are free and the depth is less than 4mm. Follow up has been done for 2 years and there is no sign of recurrence. Case 2: A 30 year old male patient reported to hospital with ulcer over the tongue since one month. Clinical examination revealed a lesion of 1x1.5cm in anterior tongue.(fig.5) There were no palpable lymph nodes. Incisional biopsy is suggestive of well differentiated squamous cell carcinoma of tongue.Wide excision of the lesion is done under general anesthesia . Postoperative histopathology report was suggestive of well differentiated squamous cell carcinoma, with all clear margins and tumor thickness being less than 3 mm. Follow up has been done for 3 years. There is no report of recurrence.

A numerical simulation for reduction of rudder cavitation with gap flow blocking bars

In recent practices, a half circular prismatic bar protruding beyond the concave surface of the horn facing the gap has been formed along the centerplane of a rudder to lessen the gap flow between the horn and the movable portion of the rudder system. If a flow through the gap of a rudder is reduced considerably through this approach, previous numerical studies indicate that not only the gap flow but also the rudder cavitation can be noticeably diminished. In the present study, numerical simulations on two-dimensional rudder sections were performed to show that the blocking ability of the single centre bar can be improved by the proper choice of sectional shape. Moreover, a pair of blocking bars attached symmetric to the centerplane on the opposite convex surface of the movable portion is suggested in the study as well, to circumvent the difficulties arising from the practical application of the single centre bars. The bars are placed near the outer edges of the gap easily accessible at the maximum rudder angle to allow simple installation of the device during a maintenance period of a ship. It is found that the pair of blocking bars further improves the blocking effects and application to a practical three-dimensional rudder also backs up the fact.

A numerical simulation for reduction of rudder cavitation with gap flow blocking bars

In recent practices, a half circular prismatic bar protruding beyond the concave surface of the horn facing the gap has been formed along the centerplane of a rudder to lessen the gap flow between the horn and the movable portion of the rudder system. If a flow through the gap of a rudder is reduced considerably through this approach, previous numerical studies indicate that not only the gap flow but also the rudder cavitation can be noticeably diminished. In the present study, numerical simulations on two-dimensional rudder sections were performed to show that the blocking ability of the single centre bar can be improved by the proper choice of sectional shape. Moreover, a pair of blocking bars attached symmetric to the centerplane on the opposite convex surface of the movable portion is suggested in the study as well, to circumvent the difficulties arising from the practical application of the single centre bars. The bars are placed near the outer edges of the gap easily accessible at the maximum rudder angle to allow simple installation of the device during a maintenance period of a ship. It is found that the pair of blocking bars further improves the blocking effects and application to a practical three-dimensional rudder also backs up the fact.

Practically applicable devices for blocking the gap flow of a horn rudder to reduce rudder cavitation and their verification through numerical simulations

Rudder cavitation causes serious damage to the rudder and affects the safety and cost-effectiveness of a ship. In recent applications, a semicircular prismatic bar protruding beyond the concave surface of the horn facing the gap, located along the center-plane of the rudder, has been used to lessen the gap flow between the horn and the movable portion of the rudder system. Previous numerical studies with this single bar indicate that it can noticeably reduce rudder cavitation. In the present study, a pair of bars for blocking the vertical gaps, which are attached symmetrically to the center-plane on opposite convex surfaces of the movable portion, is suggested for circumventing the difficulties that arise in the practical application of single centre bars. Placed near the outer edges of the gap, the bars are are easily accessible at the maximum rudder angle to allow simple installation during routine ship maintenance. An additional blocking disk is inserted on top of the pintle block, blocking the horizontal gaps. Three-dimensional computations are conducted with these combined devices and the results show that the devices are remarkably efficacious in reducing rudder gap cavitation.

A Numerical study for the efficacy of flow injection on the diminution of rudder cavitation

The complete avoidance of cavitation, as a result of gap flow between the fixed and movable portion of a horn type rudder system, is difficult. To reduce gap flow, it is a common practice to attach a half round prismatic bar that protrudes beyond the concave surface of the horn facing the gap and laid along the centerplane of the rudder. However the employment of such a device does not always yield satisfactory results. Previously, the authors have shown that a pair of blocking bars, attached on the convex surface of the movable portion, better enhance the blocking ability of gap flow to that of a single centre bar installed on the concave surface. This also circumvents difficulties that might occur in practical applications. In the present study, a series of numerical computations show that flow injected into the gap of a rudder may also block the flow within, without employment of any physical devices, such as a half circular bar. This study also shows that the combination of flow injection and blocking bars may result in the synergic augmentation of blocking efficiency of gap flow, as demonstrated in computations for a three dimensional rudder system.

Osteoarthritis

PREVIEWOsteoarthritis is the most common joint disease in the world. A major cause of pain and disability, it usually develops in the smaller joints of the fingers, the weight-bearing joints of the leg, and the movable portions of the spine. Often, however, a patient's symptoms do not correspond with the clinical features. Here, Drs Morehead and Sack diagram the pathogenesis and diagnosis of osteoarthritis and delve into the treatments available today, acknowledging the controversial nature of some therapies.

Endoscopic sonography and endoscopic resection of a duodenal carcinoid

Scanning fiber tips provides the most convenient way for forward-viewing fiber-optic microendoscopy. In this paper, a distal fiber scanning method based on a large-displacement MEMS actuator is presented. A single-mode fiber is glued on the micro-platform of an electrothermal MEMS stage to realize large range non-resonant scanning. The micro-platform has a large piston scan range of up to 800 μm at only 6 V. The tip deflection of the fiber can be further amplified by placing the MEMS stage at a proper location along the fiber. A quasi-static model of the fiber-MEMS assembly has been developed and validated experimentally. The frequency response has also been studied and measured. A fiber tip deflection of up to 1650 μm for the 45 mm-long movable fiber portion has been achieved when the MEMS electrothermal stage was placed 25 mm away from the free end. The electrothermally-actuated MEMS stage shows a great potential for forward viewing fiber scanning and optical applications.

フィブロネクチン含有人工滑液における豚関節骨頭の摩擦振動特性に関する基礎研究

The purpose of this paper is to determine experimentally the fundamental data of the new artificial synovial fluid, which suppressed the use of sodium hyaluronate (HA). Consequently, a fundamental study is carried out using fibronectin (FN), which is the cell-adhesive proteins that exists in human blood and synovial fluid. The new artificial synovial fluid consisted of FN, dipalmitoyl phosphatidylcholine (DPPC), HA and isotonic sodium chloride solution (I.S.C.S.) as solvent. An evaluation of new artificial synovial fluid is employed by the friction tester with reciprocating slider. In order to verify from an engineering standpoint, the evaluated items are the total amount of wear between the cartilage on articular head of pig joints and the ultra high molecular weight polyethylene (UHMWPE) socket; and the amplitude of vibration which is analyzed with FFT at 80Hz, the resonant frequency of the movable portion in the friction tester. The results indicated that the artificial synovial fluid containing FN was effective in the reduction of the total amount of wear and the amplitude of vibration. Further, it turned out that the effect of vibrational reduction was better than the effect of wear reduction if FN is added to artificial synovial fluid. Therefore, the results at an engineering standpoint could confirm that the artificial synovial fluid containing FN had a good performance to the vibration-proof effect.

Micro Connector for High Packaging Density Fabricated by Using UV Thick Photoresist

A fork-type micro connector with high aspect ratio and high packaging density was fabricated using UV thick photoresist and Ni electroforming. A negative photoresist (THB-130N) was used as a mold of Ni electroforming. The tips of socket terminal of the micro connector were formed as movable portions using Cu sacrificial layer etching. In order to make firm contact of the micro connector, two-step guidance was adopted. The size of the terminal of fabricated micro connector was 50 mm- thickness and 15 mm-width (minimum). The maximum aspect ratio of the fabricated micro connector is 3.3 and the terminal pitch is 80 mm. Figure 1 shows SEM photograph of the socket terminal which was formed by the Ni electroforming. A contact resistance of a 50 mW,a contact force of 2.08mN,Young痴 modulus of 80 GPa and a permissible current of 400 mA (single pair of the plug and socket terminals) were obtained practicl use for the micro connector.

Semiconductor acceleration detecting apparatus

In a semiconductor acceleration detecting apparatus, an amplification circuit is provided on a movable portion of an acceleration detecting beam, not on a fixed portion thereof, and the size of the fixed portion and the circuit area thereon are thus reduced. A damage detecting circuit is mounted on the fixed portion to detect breakage of the acceleration detecting beam and damage to various circuits, and a damage detecting interconnection is disposed along a peripheral edge of the movable portion, across a diaphragm and across an outer peripheral edge of the movable portion. Consequently, the size of the acceleration detecting beam can be reduced without changing the size of the movable portion i.e., without changing the characteristics of the apparatus, thus reducing the entire size of the semiconductor acceleration detecting apparatus.

Capacitive sensor for detecting a physical value such as acceleration

A capacitive acceleration sensor is composed of a silicon plate, a glass plate and a substrate. The silicon plate has a fixed portion and a movable portion supported by the fixed portion through spring beams. The movable portion is moved in response to the change in the acceleration and is provided with a moving electrode thereon. The glass plate is provided with a fixed electrode and anodically bonded to the silicon plate so that the fixed electrode faces the moving electrode with a predetermined gap. On the glass plate, a first dummy electrode is formed at a location corresponding to the spring beams of the silicon plate. The dummy electrode has a terminal portion at one end so as to be electrically connected with the silicon plate during anodic bonding of the plates. On the substrate, a second dummy electrode is formed at a location corresponding to the movable portion of the silicon plate. The dummy electrode, similarly, has a terminal portion at one end so as to be electrically connected with the silicon plate during anodic bonding of the silicon plate and the substrate.

Laterally sensitive accelerometer and method for making

A micromachined capacitor structure having a first anchor (12) attached to the substrate (24), a tether (13) coupled to the anchor (12) and having a portion free to move in a lateral direction over the substrate (24) in response to acceleration. A tie-bar (14) is coupled to the movable portion of the tether (13), and at least one movable capacitor plate (16) is coupled to the tie bar (13). A first fixed capacitor plate (16) is attached to the substrate (24) laterally overlapping and vertically spaced from the at least one movable capacitor plate (16).

Theory and measurements of snores

Upper airway narrowing, collapsibility, and resistance are recognized predisposing factors for snoring and obstructive sleep apnea, but the mechanisms of their action and interaction are not known. We studied a simple theoretical model of the upper airways, consisting of a movable wall in a channel segment that connects to the airway opening via a conduit with a resistance. Inspiratory flow (V) through the channel segment causes local pressure changes due to viscous losses and the Bernoulli force that may overcome the elastic forces acting on the movable wall. The model predicts instability leading to upper airway closure over a wide range of parameter values. Increasing inspiratory V above a boundary, determined by values of upper airway resistance, segment compliance, length, width, and diameter, as well as gas density, leads to a dynamic airway closure. The mathematical model establishes the power relationships between parameters and provides physiologically realistic quantitative simulation of upper airway closure when values are adapted from literature and from radiographic measurements of upper airway motion induced by negative pressure. The rate of appearance of repetitive sound structures during snoring was favorably compared with the model's prediction of the time course of wall motion during collapse. V measurements during simulated snores revealed an asymmetric oscillatory pattern compatible with repetitive upper airway closure. We conclude that snoring may be modeled as a series of dynamic closure events of the upper airways. The model predicts that the width and length of the movable portion of the upper airways and the gas density are likely to affect the onset of snoring, in addition to other, previously recognized, parameters.

Diaphragm for use in condenser microphone type detector

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Ultrasonic apparatus for positioning a robot hand

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Dynamic vibration absorber

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Endless sound reproducing tape cartridge

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Bed having acoustical isolation

A bed comprising a frame, a mattress supported on the frame, and at the head of the bed a closure or chamber composed of two shell portions, to wit, a fixed lower portion fixed to the frame and a movable portion movable between an open position where it is retracted on the fixed portion and provides free access to the head of the bed and a closed position in which it leaves only a small opening towards the foot of the bed. Each shell portion of the chamber is constituted by a rigid frame covered with a sound insulating material and a sound absorbing material. The movable portion is itself constituted by two parts articulated to one another and to the fixed portion around a common horizontal transverse axis. One part of the movable portion is transparent and capable of being retracted into the other part which is opaque.

New telescope in Chile

On January 13, 1976, the largest optical telescope in the southern hemisphere was placed in full‐time operation at Cerro Tololo Inter‐ American Observatory, 480 km north of Santiago, Chile. The new instrument will give astronomers their best look yet at objects such as the Magellanic clouds.The telescope, located near the town of La Serena, is housed in a 41‐ m‐high building with a 450‐ton dome that rotates on 32 sets of wheels. The instrument is 14 m long. Its movable portion weighs 270 tons and is so delicately balanced that it can be moved by hand by one person. The mirrors are made of Cer‐Vit, an optical material insensitive to temperature changes. The 13.5‐ton main mirror measures 4 m in diameter and 61 cm in thickness. The secondary mirror is 1.3 m in diameter.