Early detection of extravasation in intravenous drip infusions is important because it causes inflammation and ulcers on the skin. However, in clinical situations, nurses determine extravasation using low-objectivity methods. The purpose of this study was thus to develop objective indicators for identifying extravasation. Subjects comprised six healthy men and women who underwent observation for extravasation using thermography. As a model of extravasation, saline was drip-infused at 1.7 ml/min through a catheter inserted into the subcutaneous tissue of the forearm. As a control group, saline was drip-infused through a catheter placed in a vein in the contralateral forearm at the same rate. To confirm that saline was leaking into the subcutaneous tissue, we observed the position of the catheter and the thickness of the subcutaneous tissue both before and after infusion using ultrasonography. Thermographic imaging around the tip of the catheter was performed every 10s from the start of infusion. In all subjects, thermography showed a low-temperature region appearing at the catheter tip within 2 min of starting infusion. These results suggest that thermography can be used to identify extravasation in a fast and non-invasive manner.

We developed a computer-aided image processing technique to assist in the detection of aspirated boluses by clinicians using B-mode video ultrasonography（BV-US）movies. This study used 42 ultrasonography movies from a previous study that investigated the performance of aspirated bolus detection. This image processing technique aimed to assist clinicians in detecting aspirated boluses and the anterior tracheal walls from BV-US movies in which aspirated bolus appearances were emphasized. We combined a method that focused on the region of interest and the correlation coefficient between current and previous images to emphasize the characteristics of aspirated boluses from brightness-adjusted BV-US images. The sensitivity and specificity of this image processing-assisted method were 0.91 and 0.94, respectively, when we used simultaneously collected videofluoroscopy or videoendoscopy results as references. For four silent aspiration movies for which detection did not occur without assistance of image processing, detection was achieved with image processing assistance. Aspirated boluses detected only with image processing assistance had significantly smaller areas, shorter minor axes, longer major axes, and higher average brightness levels than those detected without image processing. This method will contribute to help clinicians provide modification of food viscosity and posture at an early stage for patients with dysphagia.

We are developing a robotic needle insertion system for assisting central venous catheterization that relieves the difficulties of the manual procedure and reduces complications. If translational displacement and deformation of vein appear during needle insertion, the insertion success rate decreases. Therefore, we propose a method to control the translational displacement and deformation of vein and to improve the success rate of needle insertion by needle velocity, using the viscoelastic character of body tissues. In this study, we assessed the relationships of translational displacement and deformation of vein to needle velocity by an in vitro experiment using pig cervical vein and by finite element analysis. As a result, it was suggested that needle velocity can control the deformation of vein, but cannot control its translational displacement because of the large deviation of the translational displacement.

A previous study reported the effectiveness of supportive underwear for elevating the bladder neck and reducing symptoms of stress urinary incontinence in women. This study investigated the mechanism by which bladder neck elevation occurs by using supportive underwear. The positions of the bladder neck and anatomical structures of the pelvis with and without underwear of different forms, strengths, and supportive regions were compared in 10 parous women using magnetic resonance imaging. The underwear that supported from the femur to the buttock, with high strength, or that supported from the pubis to the coccyx was effective to elevate the position of the bladder neck. The levator plate was lifted forwards and upwards by the underwear in elevating the bladder neck. In addition, the perineal body was also lifted upwards. The support to the perineal body and the support from the pubis to the coccyx might be effective to elevate the bladder neck.

In current medical practice, it is necessary to have equipment to monitor vital signs such as electrocardiograms, sphygmomanometers, thermometers, and pulse oximeters. However, nurses consequently have to spend a lot of time checking patients’ vital signs appropriately by attaching and replacing electrodes, as well as reading and recording values. To alleviate this burden, we are developing“an earphone-type vital signs-monitoring device”in order to：1）check patients’ vital signs easily without having to attach electrodes, 2）transmit data wirelessly, and 3）allow the medical staff to monitor the data on portable terminals in real time. So far, we have made a prototype earphone-type single transducer to detect the heart rate. In its performance evaluation, our new device displayed marked positive correlations with the measurement by a conventional monitoring device. In the future, we will evaluate the performance to detect other vital signs with a greater number of subjects, and develop prototypes with shapes and materials to withstand prolonged use.