Hip protectors can reduce the incidence of hip fractures. However, low user acceptance and compliance in use remain a major obstacle in the effective use of hip protectors, due to its discomfort and extra effort needed to wear it, etc. A leak-allowed air cushion is an air-bubble cushion designed to have one or some orifices on the side. In this cushion, an impact load is shunted to open air with airflow through orifice(s), and the energy is dissipated by the friction of the airflow. With the lightness, the flexibility, and the inexpensiveness, this cushion has a potential to be accepted by the target users at high levels of compliance. The purpose of this study was to evaluate a potential of the cushion as a hip-protector material by comparing with other three commercially-variable impact attenuation materials: polyethylene elastmer; silicon gel; and porous polyurethane. To this end, we performed impact tests for pads made of the materials using a falling-mass impact loader. The pad made of leak-allowed air cushions reduced the peak impact force from 7700N (recorded with no pad) to 1213 N, which was 38—64 % lower than the attenuated peak forces recorded in the other material pads. We concluded that the leak-allowed air cushion could be a novel hip protector material with high capacity of impact-force attenuation.
Frequent fish consumption is related to a lower risk of coronary heart disease. However, the physiological mechanisms underlying this cardioprotective effect are as yet unknown. We therefore examined certain cardiovascular physiological variables of fish eaters during rest, whilst conducting mental arithmetic, and during recovery. The participants were 12 fish eaters (eating baked fish more than 3–4 times/week) and 13 controls (eating fish less than 1–2 times/week). Analysis of the collected data revealed that heart rate, blood pressure, and pulse wave velocity were significantly lower and pre-ejection period and baroreflex sensitivity were significantly higher in the fish eaters than in the controls during both rest and mental arithmetic, and that systolic and mean blood pressure recovery from mental arithmetic were faster in the fish eaters than in the controls. These findings suggest a possible physiological mechanism that may explain why frequent fish consumption reduces coronary heart disease risk.
Transthoracic admittance cardiography is a simple and non-invasive method for monitoring cardiac kinetic function. However, its application is relatively limited because few portable devices are available. We have therefore developed a new portable transthoracic admittance cardiograph and its experimental validation of performance has been made in this study. We measured cardiac kinetic function, including heart rate, pre-ejection period, left ventricular ejection period, stroke volume, and cardiac output, in 10 healthy adult male subjects at rest and during exercise using a conventional desktop device as a reference and a newly developed portable device. As a result, high correlations between the desktop and the portable devices were observed in all indices (all rs > .83, all ps < .001). In addition, despite a simple case study, 24-hour continuous ambulatory measurement in a normal daily life using this portable device was confirmed. These results clearly demonstrate the validity of performance and the practicability of this device.
Electrical impedance or admittance cardiography is a simple method for non-invasive, continuous measurement the stroke volume and cardiac output. For the Electrical impedance cardiography, the band-electrodes array proposed by Kubicek et al has been widely used, and various spot-electrodes array have been experimented in search of a less uncomfortable and equally reliable electrodes array that is easier to attach. From the uniformity of current distribution on the thorax, we have reinvestigated focusing on the measurement of contour maps of static and pulsatile components of a regional area along the medial line on the frontal part of the thorax. Consequently, the appropriate electrodes locations for current injection were determined as the back of an ear and on the lower abdomen, while those for voltage pick-up was on the medial portion at the level of clavicle and on the portion above the xiphisternum. Preliminary comparison experiments between the cardiac output values obtained by the electrical impedance cardiography and by a pulse dye-densitometry showed a fairy good agreement.
For the noninvasive and accurate measurement of instantaneous blood pressure (BP) in the radial artery, the performance of a device based on the principle of volume-compensation was assessed by comparison with simultaneous measurement of direct (invasive) radial artery pressure in nine healthy subjects. Bias and precision of systolic BP (SBP) and diastolic BP (DBP) derived from Bland-Altman plots of data from the present system and the direct method averaged -0.5 +/- 2.1 mmHg and 0.6 +/- 1.8 mmHg respectively, over a wide range of SBP and DBP. These results clearly indicate that, using this system, instantaneous radial artery pressure can be measured noninvasively with high accuracy.
Urine glucose level monitoring technique using near infrared spectroscopy in conjunction with the chemometric method was newly developed aiming for the use of home health care. The calibration models were obtained by the partial least square method and their validity were assessed using albumin added glucose solution and urine samples. From the results obtained, it was clearly demonstrated that the present method had a capability of predicting urine glucose level with reasonable accuracy (standard error of prediction; 22.3 mg/dl, correlation coefficient; 0.99) and appeared to be a useful means for long-term home health care
