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We describe the detection of cell nuclei in oral cytology using artificial intelligence (AI). We focused on the detection of cell nuclei because the ratio of cell nuclei to cytoplasm increases with increasing cell malignancy. As an initial step in the development of AI-assisted cytology, we investigated two methods for the automatic detection of cell nuclei in blue-stained cells in cytopreparation images. We evaluated the usefulness of the sliding window method (SWM) and the mask region-based convolutional neural network (Mask-RCNN) method in identifying cell nuclei in oral cytopreparation images. Thirty cases of liquid-based oral cytology were analyzed. First, we performed the SWM by dividing each image into 96 × 96 pixels. Overall, 591 images with or without blue-stained cell nuclei were prepared as the training data and 197 as the test data (from among 1576 images in total). Next, we performed the Mask-RCNN method by preparing 130 images of Class II and III lesions and creating mask images showing cell regions based on these images. By the SWM method, the highest detection rate for blue-stained cells in the evaluation group was found to be 0.9314. For Mask-RCNN, 37 cell nuclei were identified, and 1 cell nucleus was identified as a non-nucleus after 40 epochs (error rate: 0.027). Mask-RCNN was shown to be more accurate than SWM in identifying the cell nuclei. If the bluestained cell nuclei can be correctly identified automatically, the entire cell morphology can be grasped faster, and the diagnostic performance of cytology can be improved., Sensors and Materials, 35(2), pp.399-409; 2023

Endoscopic submucosa dissection (ESD) procedures, used to remove cancerous tissue from thin-walled organs such as the duodenum, often result in compromising the organ’s functionality, resulting in problematic leakage. While a device has been developed to enable the adherence of a cell sheet to provide additional protection (thickness) to the lining, the device is not suited to laparoscopic application. We have developed and tested a new device and procedure that can be used laparoscopically to adhere cell sheets to organs., Sensors and Materials, 33(3), pp. 973-979; 2021

We are currently developing a mobile scaffolding device that can dodge the piers of bridges without dismantling the scaffold when moving between spans to improve efficiency and safety in bridge inspections. The mobile scaffolding device treated in this paper is split in the center of the device when it crosses the piers. In this process, the mobile scaffold is cantilevered and poses a danger to the workers on board. Therefore, we implemented horizontal holding control by wire reeling to keep the mobile scaffold horizontal. However, in this control method, the direction of motion of the mobile scaffold is only partially constrained by the wire. Thus, the device is greatly excited when an external force is applied. It is difficult to damp these oscillations in wire-reeling control. We designed a semi-active dynamic absorber for vibration control by applying the skyhook theory, a basic theory of the active suspension. When a random input that simulates the wind force was given to the mobile scaffolding device with the dynamic absorber, the vibration of the device was reduced by half compared with that of the mobile scaffolding device without the dynamic absorber., Sensors and Materials, 33(3), pp. 959-972; 2021

Food consumption is increasing as the world population increases. While the eating of fish is spreading worldwide, the depletion of fishery resources has become a problem owing to overfishing, and the importance of aquaculture is increasing in order to continue to supply fish as food. In marine aquaculture, fish are grown in aquaculture cages in the sea. Thus, if a harmful algal bloom (HAB) reaches the cages, it will cause serious damage. Countermeasures against HAB are one of the important problems for aquaculture fishermen. In Nagasaki Prefecture in Japan, countermeasures against HAB include patrolling and sampling water by ships. These samples are then submitted to HAB experts for analysis. Following this analysis, notification is provided to aquaculture fishermen. When HAB is detected early, aquaculture fishermen can minimize the damage of HAB by stopping feeding and moving the aquaculture cages. In this study, we developed a system of early detection and notification of HAB to aquaculture fishermen. This is carried out by patrolling and sampling water using drones, detection of HAB by microscope and PC operation, and automatic notification by email and web application. As a result of this developed system, the identification accuracy of harmful plankton is more than 90%, and the time taken to find HABs can be shortened from the 6 h of the conventional approach to 15 min using this newly developed system., Sensors and Materials, 31(12), pp.4155-4171; 2019

We propose a method for detecting slug flow generated in horizontal pipes as a basic study for detecting slug flow generated in production facilities in oil and gas mining areas offshore. Generally, in process control, the damping function (low-pass filter) provided in a pressure sensor is used. However, in the proposed detection method, by not using such a damping function, the raw data measured by the existing sensor are sampled at a higher speed, and the obtained high-precision data are utilized. The effectiveness of the proposed detection method is confirmed by experiments and simulations., Sensors and Materials, 33(3), pp. 947-957; 2021

The increasing presence of coastal debris is problematic in many parts of the world. Coastal cleanups are very time-consuming and expensive. Part of this cost involves the monitoring of debris washed ashore. An effective way to enable careful analysis of the amounts of types of debris is the use of drone-based photography. However, many coastlines are not easily accessible. Therefore, to monitor extensive coastlines for coastal debris, an autonomous surface vessel (ASV) is being developed for use as a drone base station. The concept is for the user to remotely guide the ASV out of any given harbor, and once in the open sea, the vessel proceeds autonomously on preprogrammed GPS routes to specified locations. At the specified locations, when the conditions for drone operation are appropriate, the drone is released and takes photographs of coastal areas before returning to the ASV for recharging. This technology is expected to have wide potential for both open sea and coastal monitoring and potential application in assisting search and rescue operations., Sensors and Materials, 33(3), pp. 873-881; 2021

Transferring between a ship and an offshore platform is potentially dangerous owing to excessive motion caused by rough conditions. In this paper, we focus on a small vessel with consideration of three degrees of freedom of motion: heaving, rolling, and surging. To stabilize these motions using a relatively small device, we propose an underactuated mechanism including two linear actuators and a two-degree-of-freedom gangway connected to the transfer platform. First, we clarify the degrees of freedom and range of the mechanism. Next, we derive a model and design a controller to stabilize the system. Finally, the effectiveness of the mechanism and its controller are tested by numerical simulation as well as by an actual experiment on a small-scale model of the mechanism., Sensors and Materials, 33 (3), pp. 897-906; 2021

To meet a surgeon’s need to compare the physical properties of conventional surgical spring forceps (tweezers), a hydraulic-driven system (HDS) based on syringes and syringe pumps is used for driving a left–right symmetrical lever linkage system of a testing device. Furthermore, by using an Arduino microcontroller and four load cells, a simple real-time feedback control system was built to digitally control the operating tweezers in the bar parts and monitor the forces on the jaw side of a surgical tweezers. Then, the same models of surgical tweezers from two different manufacturers were tested with the following test items: (1) the transmission relationship between the input side (bar area) and the output side (jaw side), (2) the contact pressure between the input side and the output side (tested using a Fujifilm Prescale System), (3) the horizontal friction on the jaw side, (4) the horizontal friction in the pinch bar area, and (5) the vertical friction in the pinch bar area. Finally, by analyzing the test results, the performances of the two surgical tweezers were compared and evaluated., Sensors and Materials, 33 (3), pp. 919-932; 2021

In this study, we have developed a device with the aim of understanding the relationship between the force exerted by a surgeon on the handles/grips of laparoscopic forceps and the force transmitted to the forceps jaw side. To measure this relationship, force is applied to the handles/grips of a set of laparoscopic forceps using an electrically powered actuator and a pressure sensor load cell is used to measure the force applied. On the jaw side, a forcesensitive resistor (FSR) generates pressure information. A microprocessor uses the load cell data, and a proportional-integral-derivative (PID) controller stably maintains the actuation pressure to match that requested by the user's settings. A user interface has been developed for this device to allow both engineers and surgeons to use it. To date, two types of forceps have been analyzed, both Olympus HiQ+ series graspers, and the mechanical force transmission mechanisms involved have been described. The pressure distribution exerted on the jaw side has also been obtained using a Fujifilm PrescaleR system (FPS)., Sensors and Materials, 31(12), pp.4205-4214; 2019