Ryosuke Tsumura

Histological evaluation of tissue damage caused by rotational needle insertion

Needles used in percutaneous insertion must be as thin as possible to minimize invasiveness. However, using extra-thin needles with a diameter less than 25G (0.53 mm diameter) can cause needle deflection. Needle deflection can be minimized by insertion with axial rotation along the needle shaft; this rotation is also useful for steering the insertion direction of the needle tip. However, although high rotation speeds may decrease needle deflection, this may increase tissue damage. Therefore, the purpose of this study was to histologically evaluate tissue damage caused by the rotational needle-insertion method, and to verify the needle-tip deflection caused by tissue damage. In this paper, we evaluated tissue damage and needle deflection caused by needle insertion with no rotation, unidirectional rotation, and bidirectional rotation. The results suggest that percutaneous needle insertion under unidirectional rotation is potentially risky in humans, as this causes wound-up tissue and expansion of the area of the hole created by the needle path. In contrast, needle insertion under bidirectional rotation appeared to minimize deflection, and prevented winding of tissue and expansion of the hole created by the needle path.

Novel Social Innovation Concept Based on the Viewpoint of the Infrastructure User

Recently, due to the deceleration of the markets in developed economies, the growing demand for infrastructure development in emerging countries has become more important in the global economy. Conventionally, developed countries have improved their infrastructure from governments and suppliers viewpoints. However, this approach has not always been the best when working in emerging countries. In this study, we propose an innovative approach inspired by the concept of social innovation, centered around the social viewpoint. It consists of a system for the successful implementation and sustainable development of new infrastructure projects in emerging countries. We focus on an ongoing railway project in Vietnam by looking at the applicability of this concept there. Finally, the concept is evaluated through rounds of discussion with experts from the government, academia and industry. It was concluded that the project is perceived to have great potential for the region, and it is regarded with high esteem by all stakeholders.

Trajectory Planning for Abdominal Fine Needle Insertion Based on Insertion Angles

Fine needles can easily be deflected, making accurate needle insertion into a tumor difficult. In particular, it is difficult to insert the needle into a tumor in the lower abdomen because the needle has to pass through various tissues. Therefore, for lower abdominal needle insertion, we intend to develop a planning method for the optimal insertion path to minimize the deflection based on computed tomography images. In this letter, we analyze the deflection while performing needle insertion with axial rotation under conditions of various insertion angles into individual tissues composing the lower abdomen (pork loin and porcine small bowel) and develop a basic planning procedure to determine the optimal insertion path based on the analysis. From the results, we confirmed that the insertion angle should be minimized as much as possible. We then develop a planning method based on insertion angles into individual tissues the needle needs to pass through. We assumed that it is possible to determine the optimal insertion path by providing a weighting factor to the effect of the insertion angle depending on the depth of insertion, considering that the effect of the insertion angle on deflection in deep places of the body is smaller than the effect around the body surface. To verify the concept of the proposed planning procedure, we perform experiments with a simple model composed of two tissues. From the results, we show that the optimal insertion path can be planned by setting the optimal ratio of individual weighting factors.

Development of registration marker for CT-guided needle insertion robot

For accurate insertion by CT-guided robot, we need registration between the coordinate of robot and CT by calculating the section images. In this paper, we intended to develop the geometric marker for registration. The requirements are geometric shapes that the error of 3 DOF (yaw and pitch angles and a craniocaudal distance) between CT image and the marker can be calculated and the material is suitable for CT imaging. Then, marker has four oblique prisms to calculate the error of 3DOF. Oblique prism has advantage on the point of reducing error of angle calculation because of the slope of inverse trigonometric function. From the result of evaluation, accuracy of registration system by geometric marker is satisfactory for insertion to the tumor in lower abdominal region.

Insertion method for minimizing fine needle deflection in bowel insertion based on experimental analysis

Accurate insertion of fine needles is difficult due to needle deflection. Needle deflection in the lower abdomen is particularly complex, as the needle has to pass through various tissues. As the area of the bowel is dominant in lower abdominal insertion, it is important to analyze the deflection during bowel insertion and to control the needle to minimize deflection. Few studies have focused on bowel insertion. We performed a fundamental deflection analysis of needle insertion in the bowel. Moreover, we have proposed an insertion method for minimizing the needle deflection based on our analysis. First, we performed needle insertion at various insertion positions and insertion angles into the hollow-shaped bowel, and determined the trend of the needle deflection during bowel insertion. The results revealed that the needle deflection was increased due to an increase in insertion angle, and therefore insertion angle should be minimized as much as possible. However, during actual bowel needle insertion, there are many situations in which the ideal path cannot be selected due to the arrangement of the bowel loops. We proposed an insertion method that can eliminate the total needle deflections during bowel insertion by controlling the needle tip direction at the breaching of each bowel wall. The results suggest that the needle deflection can be minimized by selecting the insertion path in which the sum of each insertion angle is zero. We verified the results of this insertion method in multiple bowels in in vivo experiments, and showed that it has the potential to be used in clinical practice.

Objective evaluation of oral presentation skills using Inertial Measurement Units

Oral presentation is considered as one of the most sought after skills by companies and professional organizations and program accreditation agencies. However, both learning process and evaluation of this skill are time demanding and complex tasks that need dedication and experience. Furthermore, the role of the instructor is fundamental during the presentation assessment. The instructor needs to consider several verbal and nonverbal communications cues sent in parallel and this kind of evaluation is often subjective. Even if there are oral presentation rubrics that try to standardize the evaluation, they are not an optimal solution because they do not provide the presenter a real-time feedback. In this paper, we describe a system for behavioral monitoring during presentations. We propose an ecological measurement system based on Inertial Measurement Units to evaluate objectively the presenters posture through objective parameters. The system can be used to provide a real-time feedback to the presenters unobtrusively.