Dislodgement of a blood-access needle during hemodialysis can cause massive bleeding. To prevent the dislodgment, we developed a wired device using two types of strain gauges and examined whether it was capable of detecting a dangerous action leading to needle dislodgment. One of the two strain gauges was attached to the tape for fixing a needle normally on the skin and the other one on the tape to fix a connecting tube by a taping method termed ‘omega fixing’. Ten volunteers repeated the following task three times. The task was composed of the three consecutive actions: 1) keeping the arm still for 2 minutes, 2) keep themselves relaxed for 2 minutes and 3) performing a one-minute dangerous action causing needle dislodgment after one-minute still state. A statistically significant difference in strain was observed between the dangerous action and the other two. We found that an appropriate threshold in strain enabled detection of the dangerous action at a low significance level, for example 1.5% in this study, although a clear cut-off strain value that distinguished the dangerous action from the others was not found. Then, to systemize the device for IoT, we developed a wireless system and verified that it functioned equally to the wired system.

In Japan, the number of total knee arthroplasties (TKA) has been increasing as the society is progressively aging. TKA is an operation consisting in removing the damaged surface of a patient's knee joint and implanting an artificial one. The implantation angle of the artificial knee joint depends on the mechanical axis crossing the hip joint of the patient. However, it's difficult for medical doctors to accurately visualize a patient's mechanical axis in a clinical setting during the operation. Because the existing systems that can estimate the mechanical axis present several disadvantages such as cost, size, and complexity, they have not been widely used. The aim of this research is to develop a simple and low cost system to estimate a patient's mechanical axis in a clinical setting. A three-axis inertial measurement unit (IMU) is attached to the bone cutting guide. When the femur is swung, either horizontally or vertically, the angular difference in roll, pitch and yaw is proportional to the angular difference between the mechanical and sensor's axis. From this, the angular difference between mechanical and sensor's axis can be calculated. In our experiments, the angular differences were 0°, ±5.0°, ±10.0°, and ±15.0°, with calculated angle errors below 1.0°. These results indicate the effectiveness of our system for application in TKA.

The purpose of this study is to examine the variation when the same subject cooked the same dish multiple times. The ingredients and seasonings automatic measurement system consists of an electronic balance, food tables equipped with a builtin optical sensor, a sensor to measure the strength of the flame, an IH cooker, a data acquisition system, and a personal computer. Information such as food ingredients, the timing of when the ingredients are cooked, the quantities of the ingredients, and the strength of flame are recorded after cooking. Based on the information, nutritional values are calculated in real-time and saved as a comma-separated values (CSV) file. As a result of the measurement using the system, the amount of ingredients and seasonings used and the nutritional values varied in the three subjects. The necessity of measurement was shown quantitatively even if an experienced subject with long cooking experience. In particular, subjects who cooked less frequently showed larger variation when using liquid seasonings.