Toyomi Miyagawa

Development of a functional model for a master-slave combined manipulator for laparoscopic surgery

Minimally invasive surgery helps patients by accelerating postoperative recovery. However, its application is impeded because it is necessary for the surgeons performing such surgery to possess surgical skills of a high order. Therefore, a master-slave combined manipulator (MCM) has been proposed as a robotic tool that enhances the surgeons skill in laparoscopic surgery. The master grip and the slave hand are combined through the manipulator body, and a surgeon can operate the tool near the patient. The slave hand is controlled electrically by the master grip and its position is directly controlled by the surgeon. A prototype model of the MCM has been developed. The functions of the MCM have been verified by basic evaluation tests and the MCM has been used in a preliminary animal experiment. This paper describes the concept, the basic performance and the validation of the MCM.

A direct-drive pneumatic stepping motor for robots: designs for pipe-inspection microrobots and for human-care robots

A direct-drive stepping motor based on a new principle is reported. The features of the motor include: 1) high torque (4-20 times higher than that of the same-sized conventional electric motors); 2) high stepping resolution; 3) light weight; and 4) simple structure. The motors are suitable for robots in new applications such as microrobots and human-care robots. The mechanism and theoretical analysis for the motor are presented. Two models, which are designed for pipe-inspection microrobots and for human-care robots are shown respectively.

Attachment/detachment electrostatic micro actuators for pan-tilt drive of a micro CCD camera

Newly developed linear electrostatic micro actuators employing an attachment/detachment mechanism and fabricated by a bulk silicon micromachining process are described. The moving part (slider) of these actuators is sandwiched between two glass plates whose surfaces have many electrodes (fixed electrodes), is attached to these fixed electrodes by turns up and down, and is actuated in the course of the linear motion. A feature of these actuators is that anti-friction bearings are not required and the influence of friction is reduced significantly. Several difficulties have been identified regarding attachment/detachment operation actuators. The accumulation of charge caused by contact between each stator and slider is one of the most difficult problems, and it can lead to complete actuator failure. The newly developed actuators have micro pyramid stoppers which prevent the accumulation of charge on both surfaces of the moving part. When a diving voltage of about 80 [V] is applied, the slider moves successfully with a /spl plusmn/1 [mm] stroke at a speed of 1.0 mm/sec under the condition of no load. The authors further apply these actuators to a micro pan-tilt mechanism for altering the vision angle of a micro CCD camera and experimentally confirm their practical utility.

Development of a Master Slave Combined Manipulator for Laparoscopic Surgery

Minimally invasive surgery helps patients by accelerating postoperative recovery. However, its application is impeded because it is necessary for the surgeons performing such surgery to possess surgical skills of a high order. Thus, for laparoscopic surgery, a master slave combined manipulator (MCM) has been proposed that enhances the surgeons skill. The master grip and the slave hand with wrist joints are combined through the manipulator body, and a surgeon can perform the operation near to the patient. The slave hand is controlled by the master grip electrically and its position is directly controlled by the surgeon. The prototype model of the MCM has been developed and the function of the MCM has been verified by basic evaluation tests, and the MCM has been applied in an animal experiment. This paper describes the basic performance of the MCM.

Electrostatic linear micro actuators with vibrating motion for pan-tilt drive of a micro CCD camera

Newly developed linear electrostatic micro actuators employing a vibrating motion and fabricated by a bulk silicon micromachining process are described. The moving part (slider) of these actuators is sandwiched between two glass plates whose surfaces have many electrodes (fixed electrodes), is attached and detached to these fixed electrodes by turns, and actuates linearly on a macroscopic level. A feature of these actuators is that the influence of friction is reduced significantly and a large stroke is achieved. However, several difficulties have been identified regarding attachment/detachment operation actuators. The interactive forces, including the accumulation of charge caused by contact between each stator and slider create one of the most difficult problems. Our developed actuators incorporate micro pyramid stoppers, which prevent the accumulation of charge and other interactive forces, on both surfaces of the moving parts. The casing size of the prototype is 8/spl times/8/spl times/1.2 mm and achieves a 2 mm range of movement. The minimum driving voltage is 60 V and maximum velocity is 2.0 mm/s. The behavior of the slider is not simple and further analysis is very important in order to improve positioning accuracy, increase output force, and decrease driving voltage. The characteristics of the actuator (Stepping Model) obtained by experiments is reported. The authors further apply these actuators to a micro pan-tilt mechanism for altering the vision angle of a micro CCD camera and experimentally confirm their practical utility.

Electrostatic linear micro actuator with vibrating motion (application to the focusing mechanism of a miniature CCD camera)

A newly developed linear electrostatic micro actuator mechanism employing a vibrating motion is described. Features of this mechanism are that anti-friction bearings are not required, the influence of friction is reduced significantly, and a large stroke is achieved. The moving part (Slider) of this actuator is sandwiched between fixed electrodes (Stator), is alternately attached and detached to these fixed electrodes, and actuates linearly on a macroscopic level. Several difficulties have been identified regarding actuators operated by attachmen/ detachment. The interactive forces, including the accumulation of charge caused by contact between each slider and stator, create one of the most difficult problems. Our developed actuator incorporates micro stoppers, which prevent the accumulation of charge and other interactive forces on the surface of the slider or the stator. A voltage supply pattern such that the positive and negative charge appear alternately, is employed. The first prototype, casing size ...