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Haptic feedback is critical for many surgical tasks, and it replicates force reflections at the surgical site. To meet the force reflection requirements, we propose a force sensor with an optical fiber Bragg grating (FBG) for robotic surgery. The force sensor can calculate three directional forces of an instrument from the strain of three FBGs, even under electromagnetic interference. A flexible ring-shape structure connects an instrument tip and fiber strain gages to sense three directional force. And a stopper mechanism is added in the structure to avoid plastic deformation under unexpected large force on the instrument tip. The proposed sensor is experimentally verified to have a sensing range from -12 N to 12 N, and its sensitivity was less than 0.06 N.

This paper presents a frequency-dependent damping element, called an analog input shaper (AIS), to improve the stability of haptic interaction with virtual or real environments. High frequency inputs to a haptic interface, which usually occur in the collision with very stiff objects, can bring limit cycle oscillations and instabilities. In order to reduce these high frequency inputs and thus to improve the stability of haptic interaction, the AIS is added to the haptic system. Moreover, the AIS is applied to a passivity-based haptic stability control algorithm, called an energy-bounding algorithm (EBA), to increase the displayed impedance range by the EBA. Through scaled teleoperation experiments using an atomic force microscope (AFM), we show that the AIS can enhance stability during haptic interaction and consequently increase impedance range that a haptic interface can stably display. Also, we show that the AIS can alleviate conservativeness of the passivity-based haptic control algorithms.

An analogue input shaper (AIS) is proposed as a means for stably increasing the displayable impedance range of haptic interfaces. Usually, high-frequency inputs can occur during collisions with very stiff virtual objects and induce instabilities. The proposed AIS is basically a nonlinear low-pass filter and acts as a frequency-dependent dissipative element, which can eliminate unwanted high-frequency inputs to haptic interfaces. The proposed AIS is not placed in the power stage but in the signal stage, so that the AIS can be designed independent of motor parameters and does not affect transparency in free motion. In addition, two linear half-wave rectifiers are incorporated into the AIS to allow for a fast decrease of impedance and no negative input to the haptic interface when a haptic pointer leaves a virtual object. Through virtual wall experiments using two different haptic interfaces, the effectiveness of the proposed AIS is shown.

Haptics technology allows one to interact with virtual environments, augmented environments, and real environments providing tactual sensory information. Science and technology of haptics can in general be classified into three groups: machine haptics, computer haptics, and human haptics. This paper surveys the state-of-the-art of haptic control technology for virtual environments and teleoperation (real environments) and then proposes possible future research directions in the following areas: haptic stability control, bilateral teleoperation control, and stability enhancement control.

The hysteresis characteristic is one of the major setbacks in precise tracking position control of piezoelectric actuators. In this paper, a position control method for a piezoelectric actuator is presented. The controller is based on PID control method augmented with feedback linearization loop. The feedback linearization loop uses a plant model drawn from the Maxwell slip model. The control strategy is then further extended to include a repetitive control algorithm for tracking periodic inputs. Experiments were performed on a 2-axis linear positioner driven by piezoelectric actuators. The experimental results show that the tracking performance is noticeably improved by augmenting a PID controller with both feedback linearization loop and a repetitive controller.

This paper introduces a novel surgical robot for single-incision laparoscopic surgeries. The robot system includes the cone-type remote center-of-motion (RCM) mechanism and two articulated instruments having a flexible linkage-driven elbow. The RCM mechanism, which has two revolute joints and one prismatic joint, is designed to maintain a stationary point at the apex of the cone shape. By placing the stationary point on the incision area, the mechanism allows a surgical instrument to explore the abdominal area through a small incision point. The instruments have six articulated joints, including an elbow pitch joint, which make the triangulation position for the surgery possible inside of the abdominal area. The presented elbow pitch structure is similar to the slider-crank mechanism but the connecting rod is composed of a flexible leaf spring for high payload and small looseness error. We verified the payload of the robot is more than 10 N and described preliminary experiments on peg transfer and suture motion by using the proposed surgical robot.

In this paper, we introduce a remote center-of-motion (RCM) mechanism with a conical shape for laparoscopic surgeries that involve a single incision. The mechanism, which has two revolute joints and one prismatic joint, is designed to maintain a stationary point at the apex of the conical shape. By aligning the stationary point with the incision area, the mechanism allows a surgical instrument to explore the abdominal area through a small incision point. We have previously analyzed the reachable workspace of this mechanism. Here, we arrange two RCM mechanisms on a single conical structure but separated in space to avoid mutual interference, so as to enable the entire system to manipulate two surgical instruments through a single incision point without colliding. We describe the operational principle of this system, in addition to comparisons of various RCM mechanisms and the kinematics for parameter design and motion control. Finally, we describe preliminary experiments on peg transfer and suture motion by using the proposed RCM mechanism.

This paper proposes a new interactive interface TAXEL, which aims at developing a reconfigurable self-morphing visio-haptic interface. We first present the overall architecture and concept of a self-morphing visuo-haptic interface. Key hardware components are developed and tested, including three tactile actuators using a piezoelectric active linear actuator, a passive MR fluid actuator, and a thin film-type actuator, respectively, and a flexible visual display based on the light-waveguide technology. Using the developed components, a tactile platform that includes a 8×16 array of the linear actuators is implemented for a proof of concept. A rendering engine is also designed for the tactile platform with emphasis on the use of haptic feedback together with GUI. We also carried out a user study with virtual button simulation as a benchmark to evaluate the performance of the TAXEL tactile platform. Lastly, an integrated system with a visual display is demonstrated along with several application examples.

This paper discusses ‘the physical Karnopp model’ and ‘the modified Karnopp model’ that were proposed for dynamic simulation, friction compensation, and haptic rendering of surface friction, and shows that when these models are used for haptic display of virtual surface friction, the transparency can be deteriorated. Also, to remedy this problem, we propose a ‘more physically oriented Karnopp model’, which adds the Coulomb friction term in the slip state and removes the viscous friction term in the stick state. Moreover, the energy-bounding algorithm (EBA) is used for stable haptic display of the surface friction. Through experiments, the effectiveness of the proposed friction model and the EBA is shown.

This paper presents frequency-dependent digital damping referred to a digital input shaper (DIS). Compared to the previously proposed analog input shaper, the DIS makes the implementation of damping much more flexible and significantly reduces the electrical noise. Moreover, the DIS incorporates a position control method at the initial contact to improve the perceived contact hardness. Then, through a series of simulations and benchmark virtual wall experiments, we show that the DIS can significantly increase the impedance range that a haptic interface can stably display and that the initial contact hardness that a user perceives can be noticeably improved by using the proposed position control method. Finally, the DIS is applied to scaled teleoperation using an atomic force microscope and through contact experiments it is shown that it can indeed increase the scaled impedance of a real environment that can be stably displayed. ©

This paper addresses stable haptic interaction for AFM(atomic force microscope)-based nanomanipulation. The EBA(energy-bounding algorithm), a passivity-based haptic control algorithm, is modified to include the scaling factors in the scaled bilateral teleoperation, and a commercial AFM is revised to be used as a nanomanipulation system with a 1-DOF custom-built haptic interface. Preliminary experiments show that the modified EBA can maintain stability during the interaction between an AFM probe and the surface of a sample for any force scaling factors.

Paraneoplastic neutrophilia caused by a squamous cell carcinoma of the uterine cervix has been seen rarely. We report a case of relapsed squamous cell carcinoma of the uterine cervix with severe neutrophilia, rapid tumor growth and aggressive clinical course, possibly due to autocrine stimulation of cell growth by G-CSF and IL-6 without other possible causes of neutrophilia.

Objective: To evaluate the value of sonographic morphology indexing (MI) system and serum CA-125 levels in the assessment of the malignancy risk in patients with ovarian tumors. Methods: From September 2000 to July 2006, 202 patients who underwent surgery for ovarian tumors were reviewed retrospectively. In all patients, the MI score and serum CA-125 level were measured preoperatively. The association of the final pathologic diagnosis with the MI score and serum CA-125 level were examined. Results: There were 26 malignant tumors out of 141 ovarian tumors with a MI ≥5 (18%). With a cut-off value of 5, the sensitivity, specificity, PPV, and NPV of MI scores were 0.743, 0.293, 0.181, and 0.845, respectively. There were 22 malignant tumors out of 54 ovarian tumors with serum CA-125 ＞30 u/ml (41%). With a cut-off value of 30 u/ml, the sensitivity, specificity, PPV, and NPV of serum CA-125 level were 0.667, 0.808, 0.407, and NPV 0.925, respectively. On ROC curve, the optimal cut-off value of MI score was 6.5-7.5 and that of serum CA-125 level was 25.6-28.5 u/ml. With a cut-off value of 7, the sensitivity and 1-specificity of MI score were 0.875-0.917 and 0.023-0.203, respectively. After the exclusion of teratoma cases, the sensitivity and 1-specificity of MI score were 0.875-0.917 and 0.046-0.138, respectively. With a cut-off value of 25.6-28.5 u/ml, the sensitivity and 1-specificity of serum CA-125 level were 0.958 and 0.203-0.215, respectively. Conclusion: The sonographic MI system is an accurate and simple method to differentiate a malignant tumor from a benign ovarian tumor. The accuracy of the sonographic MI system improved when the serum CA-125 level was considered and ovarian teratomas were excluded.

This paper addresses an analog input shaper introduced in haptic control to improve the stability when interacting with virtual environments. High frequency inputs to a haptic device, which can occur in collision with a virtual wall with high stiffness, can bring limit cycle oscillations and instabilities. In order to reduce the high frequency input to an haptic device an analog input shaper is added to the control system. Since the input shaper acts as a low-pass filter, when a haptic pointer leaves the virtual wall with high stiffness, a user may feel slow decrease of impedance, moreover there may be negative impedance as if the wall is pulling. In order to prevent this, we add half-wave rectifiers which allow fast decrease of impedance and no negative input to a haptic device. The input shaper reduces the total energy supplied to a haptic device by preventing inputs with high frequency from flowing into a haptic device. Therefore it can be regarded as an artificial damping element. In order to apply the Energy-Bounding Algorithm (EBA),1 which can guarantee the stable haptic interaction, to a scaled teleoperation in a virtual nano-environment two scaling factors (velocity and force) are incorporated into EBA. By applying the analog input shaper to EBA in scaled teleoperation, the range of virtual wall stiffness which can be stably rendered by a haptic device is significantly extended.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Bilateral teleoperation using augmented reality is proposed for a multi-purpose robot called SpiderBot-II that is an indoor-installed wire-driven parallel manipulator. It is intended to be used for various applications, including in-house rehabilitation training and daily life assistance such as walking assistance and health monitoring, especially for the elderly or the handicapped that spends most of time at home. Through the teleoperation over the Internet, a therapist or an attendant in a remote site can give help to the physically disabled by directly manipulating the robot. For easy recognition of the obstacle, predefined markers are attached to each obstacle in the workspace. For better teleoperation, moreover, reaction force between obstacles and the end-effector, which is calculated using force field, is given to a remote operator and this enables the operator to perform the teleoperation more effectively. Force field, which is proportional to proximity between obstacles and the end-effector, is generated to facilitate the obstacle avoidance and visually augmented on the operator's screen for better recognition of obstacles.

The safety and comfort of user are the two important requirements that a service robot must fulfill to qualify as assistive device for elderly persons. Unlike scenarios of manipulation assistance, human user is physically attached with the robot in those of walking/mobility assistance. Any force/torque generated at the robot (end-effector) is transferred to human body that causes the discomfort and safety problem for the user. If the motion of robot system is made synchronized with human user's movement during walking, it can be more comfortable for elderly user. This paper proposes a new control strategy for synchronized movement of walking support system with the human user's walking. For this strategy, the average step size of a particular user is obtained through initial short test and the direction of motion is guided online by human user. Proposed scheme is implemented on SpiderBot-II, a wire-driven parallel mechanism, conceptualized for assisting elderly persons. User's comfort is assessed through measurement of link reaction forces during walking assistance. The rationale behind such scheme is the common assistance scenario during walking. The human assistant synchronizes his walking pattern and speed with that of elderly user to make it more comfortable for the latter. Preliminary experimental results show that this control scheme is capable of realizing a comfortable walking assistance for elderly persons.

In this paper, we considered variations of the antenna characteristic about PIFA for mobile RFID Band when we held the mobile phone. So we studied antenna characteristic by feeding point variation of antenna. After all, we determined that antenna gets different effects after compared antenna characteristic about hand effect of each feeding point and studied the results.

This paper proposes a novel planar walking algorithm for the Virtual Walking Machine that is a dual foot platform type locomotion interface. Unlike existing algorithms, the proposed algorithm utilizes a constraint relationship between two platforms as well as position control. Experiments on the VWM show that the proposed planar walking algorithm can generate straight and turning motions which are smoother, collision-free.

This paper proposes efficient hardware architecture to accelerate the deblocking filter for H. 264/JVT/AVC. Deblocking filter operations could be fulfilled for real-time with high clock frequency in the previous method, because loading, storing and filtering operations are processed on different cycles. This paper proposes a new architecture that executes loading/storing operations and filtering operations concurrently. The experimental result shows that the proposed architecture can save 38% of the total consuming cycle compared to the conventional method, and the new architecture makes the deblocking filter operation with the possibility of real time

Time delays in communication channels usually make teleoperation systems unstable. To cope with this, we apply the energy-bounding algorithm (EBA) that had been proposed for stable haptic interaction. The EBA restricts the energy generated by the sample and hold operator to consumable energy by the energy-consuming physical damping in the haptic system and some part of human arm to guarantee the passivity condition of whole system. This algorithm always guarantees stable haptic interactions, but compromises the displayable impedance range of the virtual environment. The EBA can be straightforwardly applied for bilateral teleoperation due to the analogy between the haptic simulation system and the teleoperation system. The video shows some feasibility test results of the EBA for bilateral teleoperation. Various test results for free, contact, and abrupt motions show that the EBA can ensure stable bilateral teleoperation for the fairy large amount of constant/variable time delays (2.5 sec (one-way) for free motion and 300 msec (one-way) for contact motion).

【Osteomyelitis is an exhaustive disease whose main feature is an inflammation of inner part of bone, bone marrow. In oral and maxillofacial area, we have maxillary and mandibular osteomyelitis and the latter is dominant because of its impaired blood supply. The main cause of osteomyelitis is a bacterial infection and the ways of infections are by periapical odontogenic infection, fracture, post-operative complication, and periodontal disease. The predominant etiologic factor is periapical odontogenic infection mostly caused by advanced dental caries. It is generally believed that periodontal disease could be a cause of osteomyelitis. But periodontal disease is usually confined to the alveolar bone area and not extends to the underlying bone marrow. Accordingly periodontal infection per se rarely cause produce oseomyelitis. Even though osteomyeltis could be occurred by periodontal disease, its virulence of infection is milder than periapical odontogenic infection. So it usually provokes sclerosing or hyperplastic osteomyelitis rather than suppurative type. We had a case of suppurative osteomyelitis caused by periodontal disease and treated it with periodontal and oral and maxillofacial surgical method.】