Surgery assistance system for continuous resection of brain tumors-proposal of continuous tumor resection forceps, tumor cell separation, dehydration, and isolation mechanism.

The tumor resection ratio must be improved due the increased possibility of recurrence or malignancy. The purpose of this study was to develop a system that includes forceps with a continuous suction function and flow cytometry to diagnose the malignancy of the tumor for safe, accurate, and effective surgery. A newly developed continuous tumor resection forceps consists of a triple pipe structure, which enables continuous suction of the tumor by integrating the reflux water and suction system. The forceps includes tip opening/closure detection switch to control the adsorption and suction strength when tip is opened and closed. To perform accurate tumor diagnosis using flow cytometry, a filtering mechanism was developed for dehydrating reflux water from continuous suction forceps. In addition, a cell isolation mechanism comprising a roller pump and shear force loading mechanism was also newly developed. By using a triple pipe structure, a significantly larger tumor collection ratio was observed compared to the previous double-pipe structure. By performing suction pressure control with the opening/closure detection switch, inaccurate suction can be prevented. By widening the filter area of dehydration mechanism, it was possible to improve the reflux water dehydration ratio. The most appropriate filter area was 85 mm2. By using a newly developed cell isolation mechanism, the processing time can be reduced to less than 1/10 of the original time, keeping the same cell isolation ratio, when compared to the existing pipetting method. Neurosurgery assistance system with continuous tumor resection forceps and a cell separation, dehydration and isolation mechanism was developed. An effective and safe tumor resection, accurate and fast diagnosis of malignancy can be achieved by using the current system.

Development of a remote-control system for catheterization capable of high-speed force feedback.

PURPOSE: There is a growing interest in minimally invasive surgery as interventional radiology (IVR), which decreases the burden on a patient. However, occupational exposure is a problem because the treatment is performed using X-ray fluoroscopic images. This problem can be solved by the development of a teleoperation system, but rapid force presentation is important to perform safe surgery. The purpose of this study is to develop a new teleoperation system that can be controlled at a high speed and can provide feedback force sensation within 20 ms delay. METHODS: A master-slave-type remote-control system for catheterization was developed. A compact and high-speed force feedback system is realized using a novel electro-attractive material (EAM) device by which the resistance force is generated by the magnitude of the voltage applied. The linear and rotational movement of master is transferred to the slave device by UDP communication with the LAN cable, and the same movement is performed by two motors. The collision force of catheter or guidewire, detected by the sensor inside the slave device, is also transmitted to the master device. Two voltage-based methods for EAM: the ON/OFF and linear control methods, were implemented. RESULTS: After the collision force is detected by the slave sensor, the voltage is applied to the EAM in the master device for an average of 10.33 ms and 15.64 ms by the ON/OFF and linear control methods, respectively. These delays are less than required 20 ms. The movement of the master was stopped by the resistance force of EAM, and that of the slave was also stopped accordingly. CONCLUSION: A master-slave-type remote-control system for catheterization that is capable of high-speed force feedback was developed. With a low delay, the developed system achieved the requirements of 20 ms that was aimed for this study. Therefore, this system may facilitate the realization of IVR surgery that is safe for both doctors and patients.

A hybrid controller method with genetic algorithm optimization to measure position and angular for mobile robot motion control.

Due to the complexity of autonomous mobile robot's requirement and drastic technological changes, the safe and efficient path tracking development is becoming complex and requires intensive knowledge and information, thus the demand for advanced algorithm has rapidly increased. Analyzing unstructured gain data has been a growing interest among researchers, resulting in valuable information in many fields such as path planning and motion control. Among those, motion control is a vital part of a fast, secure operation. Yet, current approaches face problems in managing unstructured gain data and producing accurate local planning due to the lack of formulation in the knowledge on the gain optimization. Therefore, this research aims to design a new gain optimization approach to assist researcher in identifying the value of the gain's product with a qualitative comparative study of the up-to-date controllers. Gains optimization in this context is to classify the near perfect value of the gain's product and processes. For this, a domain controller will be developed based on the attributes of the Fuzzy-PID parameters. The development of the Fuzzy Logic Controller requires information on the PID controller parameters that will be fuzzified and defuzzied based on the resulting 49 fuzzy rules. Furthermore, this fuzzy inference will be optimized for its usability by a genetic algorithm (GA). It is expected that the domain controller will give a positive impact to the path planning position and angular PID controller algorithm that meet the autonomous demand.

Laser-Assisted High Speed Machining of 316 Stainless Steel: The Effect of Water-Soluble Sago Starch Based Cutting Fluid on Surface Roughness and Tool Wear.

Laser-assisted high speed milling is a subtractive machining method that employs a laser to thermally soften a difficult-to-cut material's surface in order to enhance machinability at a high material removal rate with improved surface finish and tool life. However, this machining with high speed leads to high friction between workpiece and tool, and can result in high temperatures, impairing the surface quality. Use of conventional cutting fluid may not effectively control the heat generation. Besides, vegetable-based cutting fluids are invariably a major source of food insecurity of edible oils which is traditionally used as a staple food in many countries. Thus, the primary objective of this study is to experimentally investigate the effects of water-soluble sago starch-based cutting fluid on surface roughness and tool's flank wear using response surface methodology (RSM) while machining of 316 stainless steel. In order to observe the comparison, the experiments with same machining parameters are conducted with conventional cutting fluid. The prepared water-soluble sago starch based cutting fluid showed excellent cooling and lubricating performance. Therefore, in comparison to the machining using conventional cutting fluid, a decrease of 48.23% in surface roughness and 38.41% in flank wear were noted using presented approach. Furthermore, using the extreme learning machine (ELM), the obtained data is modeled to predict surface roughness and flank wear and showed good agreement between observations and predictions.

Laser Discoloration in Acrylic Painting of Visual Art: Experiment and Modeling.

This study discloses a method for painting artwork using a CO2 laser. The continuous-wave laser beam, at a predetermined heat flux and a predetermined number of laser beam passes, mixes and displaces the plurality of colored polymer-based compositions, respectively, by way of melting and vaporizing them. Experiments showed a great accuracy of colors and designed patterns between the computer aided design (CAD) drawing and what was achieved after laser discoloration. It was found that lower values of power and speed provide sufficient energy and time to make a melt pool of colors and cause their vaporization from the surface. A detailed numerical simulation was performed to obtain a detailed understanding of the physics of laser interaction with paint using ABAQUS software. The comparative analysis indicated that the top layer of paint (including yellow and green colors) melted upon increasing cutting speed and employing one laser pass. For blue and red paints, two passes of lasers are required; in the case of red color, lower laser speed is also necessary to intensify the heat. This method can be applied for making art designs on each surface color because it is based on melting and vaporization using a laser.