This paper presents a novel device that propagates through small pipes, named the twisted bundled tube locomotive device. The device consists of three elastic silicone rubber tubes that are twisted and bonded. When any tube is pressurized, it inflates, and the device deforms into a helix. If these tubes are sequentially pressurized, the device exhibits helical rotation, that is, it rotates about its body axis while retaining its helical shape. Thus, the device moves along the pipe axis. Since helical rotation is generated by bending motion alone, the device is highly airtight, and thus strongly resistant to the environment. Helical rotating motion does not scratch the inner wall of the pipe or block the flow in the pipe. The device can be made sufficiently small to travel through thin pipes, because of its simple structure. The device is very flexible and can pass through an elbow-pipe without requiring complicated control. Therefore, the device could be adopted in endoscopes used for pipe inspection. The propulsion principle and the theoretical velocity of the device are discussed and confirmed in prototypes. The manufacturing method for the prototype is also presented. The small prototype (approximate diameter 6 mm) travels at 45 mm/s in a 20-mm diameter pipe, and it passes through the elbow. Moreover, a prototype equipped with a camera can send images of the camera view as it moves the pipe.

No abstract

Echo-guided intervention is a promising minimally invasive surgery in the ultrasound (US) image guide because of its non-invasiveness and the high visuality of blood vessels. However, detecting the position of an intervascular device is difficult under an echo-guided intervention. To overcome this problem, we proposed a novel position detection method for an echo-guided intervention with a small photoacoustic transmitter. The method detects the position of the intervascular device by receiving the US that the transmitter at the device tip emits. Because its accuracy decreases under weak signal conditions, this paper proposes a Kalman filter-based filtering method to improve the accuracy of the position detection. The proposed filter reduces the detection error based on a linear approximation of the system. Our experiment shows the filter reduces 52% of the root mean squared error during position detection in an elevation direction.

No abstract

Numerous studies have developed in-pipe locomotive devices to inspect pipes. However, it is difficult to achieve selective locomotion in a branched piping system. In this study, a novel steerable in-pipe locomotive device is proposed based on "a six-braided-tubes locomotive device, " which is an in-pipe locomotive device that is actuated by only six pneumatic inflatable tubes. It is one of the simplest in-pipe locomotive devices that is capable of forward and backward motion and can rotate in clockwise and counterclockwise directions along a pipe, can select the desired pathway in the branched pipe. In this paper, we discuss the background of pipe inspection, classify previously developed in-pipe locomotive devices, and clarify the aim of this study. Additionally, we also describe and extend the locomotive principles of six-braided-tubes locomotive devices. Moreover, we propose a novel attachment, termed steering hook, to enable steering in various types of branched systems. Finally, we experimentally confirm that the novel proposed principle allows the device to correct path selection in an in-pipe branched piping system.