• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.12
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• pp.105-112
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• 2020

The increase in the edentulous jaw which occurs in the aged population has led to personal dental health concerns. In the case of dental implant surgery, the duration of a patient's recovery depends on the surgical plan and their physicical ability. A device may be required to assist a physician in controlling vibration reduction of free-hand drilling and prescribing a good treatment plan that is suitable for the patient's condition. In this work, an artificial tooth-root implant assistant manipulator was studied. The structure and the vibration analysis of the dynamic restraint manipulator that is for drilling the alveolar bone in the mandible bone were performed, and the structural stability was analyzed. Further, a virtual prototype of an artificial tooth-root implant assisted manipulator was fabricated and tested. Hence, the state of the Remote Center of Motion (RCM) point and the driving state of the manipulator were confirmed. Furthermore, the drilling experiments were performed by using materials similar to a human jawbone in order to evaluate the performance of the drilling process that is operated using the assistant manipulator.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.6 s.171
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• pp.207-212
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• 2005

The purpose of this work is to develop the FES controller that can cope with the muscle fatigue which is one of the most important problems of current FES (Functional Electrical Stimulation). The feasibility of the proposed FES controller was evaluated by simulation. We used a fitness function to describe the effect of muscle fatigue and recovery process. The FES control system was developed based on the biological neuronal system. Specifically, we used PD (Proportional and Derivative) and GC (Gravity Compensation) control, which was described by the neuronal feedback structure. It was possible to control of multiple joints and muscles by using the phase-based PD and GC control method and the static optimization. As a result, the proposed FES control system could maintain the cycling motion in spite of the muscle fatigue. It is expected that the proposed FES controller will play an important role in the rehabilitation of SCI patient.

• Archives of Reconstructive Microsurgery
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• v.7 no.1
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• pp.35-40
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• 1998

The incidence of brachial plexus injury is increasing because of the development of motor vehicle but the the results of treatment was reported poor due to its complex anatomical structure and changes of function and sensory during the recovery after trauma. But the results of treatment has been improved by the recently introduced high sensitive diagnostic method that can evaluate accurately the site and extent of the injury and treatment method. Restoration of the elbow flexion is the most important goal of treatment after brachial plexus injury and nerve graft, neurotization and muscle transfer were used for methods of treatment. From December 1992 to May 1994, the author performed 6 cases of latissimus dorsi transfer at the same side for the improvement of elbow flexion in the patients of brachial plexus injury. There were 5 cases of male, one case of female and average age was 22 years old. The causes of injury were traffic accident in 3 cases, gun shot injury, falldown and birth injury in each one case and in all cases, the type of injury were upper arm type. The average follow up period were 1 year 5 months ranging from 12 months to 4 years 5 months. In all cases, active elbow flexion was impossible before operation and average muscle power was grade I. We analysed the active range of motion, muscle power and the functional results. At the last follow up, range of active elbow flexion was average $124^{\circ}$ and flexion contracture was average 11 degrees and the average of muscle power was grade IV. In the functional analysis, there were two cases of excellent, three cases of good and 1 case of fair. There was no complications including wound infection, vascular compromise and donor site problem. The results of latissimus dorsi transfer for improvement elbow flexion in the patients of brachial plexus injury is one of the useful mettled for the restoration of elbow flexion.

• Journal of Biomedical Engineering Research
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• v.28 no.5
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• pp.618-627
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• 2007

As our society progresses rapidly toward an aged society, there is a stiff increase in the population of the aged persons who have difficulties in adjusting themselves to environments due to declines of their physical functions. Therefore, there is a great need for the concept of 'Universal Design' that demands the design of overall social structure to care for the elderly. Due to this reason, the physical function of the aged persons should thoroughly be studied for the development of rehabilitation and training equipments to help the recovery of physical functions of the elderly. Among the variety of physical functions of the elderly, visual functions, motion characteristics, hearing functions, and somatosensory functions have significant influence toward everyday lives and are physical functions to study for the construction of urgently needed physical function databases of the elderly. This study concentrates on visual functions among the variety of physical functions of the elderly. To measure various visual functions of the elderly, a measurement room for the elderly has been developed, which can mimic everyday lives and perform measurements of visual functions with subjects in seated position. The measurement items for the construction of the database were capabilities in everyday vision according to changes in arrangement of colors and light intensity and capabilities in everyday vision, color distinction, dark adaptation, and light glare against changes in contrast.

• Economic and Environmental Geology
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• v.44 no.1
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• pp.83-94
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• 2011

Extra heavy oil reservoirs are distributed over the world but most of them is deposited in the northern part of the Orinoco River in Venezuela, in the area of 5,500 $km^2$, This region, which has been commonly called "the Orinoco Oil Belt", contains estimated 1.3 trillion barrels of original oil-in-place and 250 billion barrels of established reserves. The Venezuela extra heavy oil has an API gravity of less than 10 degree and in situ viscosity of 5,000 cP at reservoir condition. Although the presence of extra heavy oil in the Orinoco Oil Belt has been initially reported in the 1930's, the commercial development using in situ cold production started in the 1990's. The Orinoco heavy oil deposits are clustered into 4 development areas, Boyaco, Junin, Ayachoco, and Carabobo respectively, and they are subdivided into totally 31 production blocks. Nowadays, PDVSA (Petr$\'{o}$leos de Venzuela, S.A.) makes a development of each production block with the international oil companies from more than 20 countries forming a international joint-venture company. The Eastern Venezuela Basin, the Orinoco Oil Belt is included in, is one of the major oil-bearing sedimentary basins in Venezuela and is first formed as a passive margin basin by the Jurassic tectonic plate motion. The major source rock of heavy oil is the late Cretaceous calcareous shale in the central Eastern Venezuela Basin. Hydrocarbon materials migrated an average of 150 km up dip to the southern margin of the basin. During the migration, lighter fractions in the hydrocarbon were removed by biodegradation and the oil changed into heavy and/or extra heavy oil. Miocene Oficina Formation, the main extra heavy oil reservoir, is the unconsolidated sand and shale alternation formed in fluvial-estuarine environment and also has irregularly a large number of the Cenozoic faults induced by basin subsidence and tectonics. Because Oficina Formation has not only complex lithology distribution but also irregular geology structure, geological evolution and characteristics of the reservoirs have to be determined for economical production well design and effective oil recovery. This study introduces geological formation and evolution of the Venezuela extra heavy oil reservoirs and suggest their significant geological characteristics which are (1) thickness and geometry of reservoir pay sands, (2) continuity and thickness of mud beds, (3) geometry of faults, (4) depth and geothermal character of reservoir, (5) in-situ stress field of reservoir, and (6) chemical composition of extra heavy oil. Newly developed exploration techniques, such as 3-D seismic survey and LWD (logging while drilling), can be expected as powerful methods to recognize the geological reservoir characteristics in the Orinoco Oil Belt.