Basic Study on Development of Device Using Strain Gauges to Prevent Dislodgement of a Blood-Access Needle During Hemodialysis Therapy and Its Systemization for Internet of Things

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.