Kotaro Yamasue

Effect of Salt Reduction Intervention Program Using an Electronic Salt Sensor and Cellular Phone on Blood Pressure Among Hypertensive Workers

Abstract We investigated the effectiveness of a workplace intervention program that utilized self-monitoring of daily salt excretion by an electronic salt sensor and sent personalized e-mail advice via cellular phone. Forty-one hypertensive male workers were assigned to intervention and control groups, then counseled together. Intervention group members were asked to measure daily salt excretion and received e-mail advice. After 4 weeks, a greater decrease of blood pressure (BP) was observed in the intervention group, with significant reductions to daily salt excretion and home BP. The new intervention program is considered useful for BP control among hypertensive workers.

The Blood Pressure Lowering Effect of Lactotoripeptides and Salt Intake in 24-H Ambulatory Blood Pressure Measurements

It is well known that the sour milk containing lactotripeptides has a blood pressure lowering effect The aim of this study was to evaluate the blood pressure (BP) lowering effect of lactotripeptides by monitoring home blood pressure, 24-h ambulatory measurements (ABPM), and daily urinary salt excretion. A total of 30 volunteers were given 200 ml of sour milk twice a day for 8 weeks after a 1-week run-in period. This preparation contained the lactotripeptides valine-proline-proline 2.66 mg and isoleucine-proline-proline 1.38 mg. The study participants had daily measurements of urinary salt excretion determined by an electric salt sensor and home blood pressure for each week during the run-in period, before the 4-and 8-week time points. 24-h ABPM was measured at the end of each week. Mean systolic blood pressure (SBP) during night sleep including base BP at 4 and 8 weeks were significantly lower than baseline values. Mean SBP and diastolic blood pressure (DBP) during night sleep of the 22 participants who belonged to the criteria of hypertension by 24-h ABPM was significantly decreased at 4 and 8 weeks. The change in 24-h mean SBP significantly correlated with mean urinary salt excretion over the three measurement periods. The 22 hypertensive subjects without taking lactotripeptides did not show significant change of blood pressure during 24 hours at 4 and 8 weeks. Our study confirmed the BP lowering effect of lactotripeptides during night-time sleep and showed that a lower intake of salt may increase the BP lowering effect of lactotripeptides through 24 hours in hypertensive subjects.

Masked Hypertension in Elderly Managerial Employees and Retirees

Masked hypertension is reported to have the same level of hazard risk of cardiovascular mortality and stroke morbidity as sustained hypertension. The number of managerial employees suffering from cardiovascular disease and stroke is known to be greater than other employee. The aim of this study was to compare the 24-h blood pressure (BP) recordings between elderly male managerial employees and retirees and to propose a strategy for identifying masked hypertension. A total of 38 males (16 managerial employees aged 50–69 years and 22 retirees aged 60–65 years) who were not taking any antihypertensive medications participated in this study. Their 24-h BP was measured by an ambulatory BP monitoring device. Daytime (9:00–17:00 h) BPs of the employees (mean, 139/92 mm Hg) were significantly higher than in the retirees (mean 124/80 mm Hg), while there was no difference in BP before and during sleep. In all, 5 of 16 employees (31%) who were diagnosed as normotensive (<140/90 mm Hg) at a periodic health check had hypertension (>135/85 mm Hg) in the morning measured by ambulatory BP monitoring, while 6 (38%) had a similar level of hypertension during the daytime (9:00–17:00h). These individuals were diagnosed as having masked hypertension. Multiple regression analyses showed that the job was the only factor that contributed to the difference in BP in the subjects during the daytime. This finding suggested that job stress seemed to be one of the main causes of masked hypertension. We argue that more frequent measurements of BP at the work place are necessary to identify subjects with masked hypertension.

Vital sign monitoring by using UWB Body Area Networks in hospital and home environments

We investigated advantages and drawbacks of wireless BAN (Body Area Network) systems using UWB (Ultra Wide Band) wireless technology that are expected robustness against interference, low power consumption, and little interference to a body for healthcare. Two types of low and high bands of radio frequency for UWB were examined using various sensors in hospital and home environments. The high band UWB BAN system with TDMA protocol in MAC worked well to prevent interference. The most serious drawbacks was shadowing problem due to a body. We verified most suitable routing to avoid the shadowing problem on the bed.

Measures against shadowing problem on a bed using high-band UWB-BAN

We investigated the advantages and drawbacks of wireless body area network (BAN) systems using high-band ultra-wide band (UWB) wireless technology for healthcare. These systems are expected to have robustness against interference, low power consumption, and little interference from a human body. The most serious drawback is the shadowing problem due to a body in a hospital or home care bed. We confirmed by experiments and theoretical analysis that setting a coordinator near the ceiling and another coordinator under the bed is one of the best measures to prevent the shadowing problem. In this study, a shadowing model was used. A helical antenna having high antenna gain in the axial direction was used in the coordinator. In comparison with a biconical antenna, the helical antenna showed better radiation performance and less dependence on the angle direction of the antenna of the sensor node.

Lifestyle monitoring with the use of an earphone-type thermometer, an ambulatory blood pressure monitoring and a new wristwatch-type pulsimeter with accelerometer

Abstract We investigated the relationship among 24-h blood pressure (BP), pulse rate (PR) and core temperature by using an ambulatory BP monitoring, a new wristwatch-type pulsimeter with accelerometer (WPA) and an ear thermometer simultaneously. Our results suggest that the ear temperature which reflects the core body temperature was lowest at base PR during sleep and 75% of normotensives and 54% of subjects without hypertensive medication had a significant correlation between BP and PR. Diabetic subjects showed a significantly higher PR during sleep than non-diabetic subjects. Three types of equipments, especially a new WPA, are expected to be useful for daily lifestyle monitoring to evaluate risk of complications of hypertension and diabetes.

Elliptical shape estimation by nonlinear least-squares method for breast cancer using UWB radar technology

Ultra wide band (UWB) microwave imaging has been proposed for detecting small malignant breast cancers and expected to detect breast cancers with safety, less-discomfort and accuracy for high resolution of UWB pulse. However, shape estimation for breast cancers has been remained as a challenge. In this paper, we propose an elliptical shape estimation method by nonlinear least-squares method in order to develop a breast cancer shape estimation using UWB radar technology. We define a regression formula of a nonlinear least-squares method for one cancer considering a two-dimensional (2D) space. We confirm that our method could estimate parameters of an elliptical shape under simple environment using 2D Finite Difference Time Domain(FDTD) calculation. We evaluate the performance of our proposed method under additive white Gaussian noise(AWGN) environment using theoretical signal sets. We could get good results of estimation of 5 elliptical parameters.

Are Overnight Urinary Indicators Associated with Morning Blood Pressure in the Elderly

Recent reports suggest that high blood pressure (BP) during the night is associated with hypertensive organ damage, and that increased BP in the morning is closely related to the incidence of stroke and ischemic heart disease. The aim of this study was to investigate the relationships between overnight urinary indicators and 24-hour (24-h) BP, especially in the morning and during sleep in the elderly. A total of 85 volunteers (males 43, females 42), aged between 51 and 76 years and not taking any antihypertensive medications, participated in this study. Their 24-h BP was measured by ambulatory BP monitoring every 30-minute using a TERUMO ES-H531 system. Overnight urine samples were collected using a proportional urine-sampling device, Urine mate P. Overnight sodium (UNan) and potassium (UKn) excretions were measured by an ion electrode method. Simple linear regression analyses showed that systolic blood pressure (SBP) in the morning and diastolic blood pressure (DBP) during sleep were negatively related with overnight urinary weight standardized for body weight (UWn/BW). Multiple regression analyses showed that SBP during the morning and during sleep was positively related to UNan and negatively related to UWn/BW. We also found a negative relationship between SBP during sleep and UKn. The study suggested that urine weight adjusted for BW was negatively related with 24-h BP, especially morning BP. Sodium excretion combined with a large volume of urine proportional to body weight may prevent increases in BP, especially in the morning.