The pressure exerted by the index finger tip was continuously recorded while the human subject was trying to maintain the pressure at the level of a given pressure (this pressure is named ‘target pressure’, 0.5-500g) with optical information for ten minutes, and the results obtained under various conditions were analysed.
1) The errors tended to be minimal in the range between 40 and 50g target pressure, and increased approximately in proportion to the target pressure above 50g.
2) When the subject relaxed his index finger, the errors decreased with decreasing target pressure in the range of less than 50g.
3) The errors were increased by excluding optical information. In target pressure less than 50g, the increment of the errors due to a decrease in the skin pressure intensity was further increased by exclusion of optical information.
4) In small target pressures, the errors tended to decrease transiently in evening, while in large target pressures the errors showed a gradual increase from morning toward evening.
5) The errors showed generally minimal values 2 or 3 minutes after the beginning of the measurement, and thereafter increased more remarkably in large target pressures than small ones.

The effects of the surface friction of a grasped object on the regulation of grip force during holding tasks using a precision grip were investigated. Using a force transducer-equipped grip apparatus, the grip force and load force acting on the object were measured continuously while surface materials (silk, wood, suede and sandpaper) and load weights (0.98N, 1.96N, 2.94N, 4.90N and 9.81N) were varied. From the recorded data, the average static grip force, slip force, safety margin force and static friction coefficient were evaluated.
It was found that both the slip force and safety margin force increased as the slipperiness of the object surface increased. Significant interactions between surface type and weight were observed in the slip force and static friction coefficient. The interaction effect resulted from the fact that the frictional relationships with the fingers changed according to both weight and surface conditions. This was considered due to the viscoelastic nature of finger skin. An increase in the safety margin force with surface slipperiness was considered due to psychological reaction, probably fear of dropping the object. Unexpected changes in surface conditions caused a greater safety margin force than trials without a surface change, which might also have been associated with psychological reaction to uncertainty of the new surface condition. A relatively large inter-subject variation was found in the slip force and safety margin force relative to slippery surfaces.

Objective : To examine the association between the combination therapy of calcium antagonists with angiotensin converting enzyme (ACE) inhibitors and underlying diseases for hypertensive patients.
Design : Cross-sectional survey of the drug utilization.
Methods : This survey included 603 hypertensive patients who had visited Toyama Medical and Pharmaceutical University Hospital, Toyama, Japan more than twice from January to June in 1996 and received the prescriptions of calcium antagonists and/or ACE inhibitors. Main outcome measure was the combined medication of calcium antagonists with ACE inhibitors. Underlying diseases under consideration were diabetes mellitus (DM), hyperlipidemia (LIPID), ischemic heart disease (IHD), chronic heart failure (CHF), and ischemic stroke (STROKE).
Results : Out of 603 hypertensive patients, 57.5% received only calcium antagonists, 23.7% received only ACE inhibitors, and 18.7% received both of them. Patients with either IHD or CHF tended to receive the combination therapy as compared to DM or LIPID. Although men tended to receive the combination therapy, a gender effect might be a confounder for the association. Logistic regression showed a 33% increase (P=0.265) in frequency of the combination therapy in patients with IHD after adjusting for age and gender.
Conclusion : Some underlying diseases were associated with more frequent prescriptions of the combination therapy for hypertensive patients, especially with ischemic heart diseases. This result should be regarded as an exploratory stage although the pattern of antihypertensive drug use could be reasonably explained from the pharmacological sense.