Precise Measurement of Grasping Force for Noncollaborative Infants

Among the medical parameters used for infants, the grasping force is particularly important because it indicates their musculoskeletal and neurological development. Although several grasping force measuring devices have been developed for infants, their accuracy and reliability are limited owing to their direction-dependent sensing mechanisms. It is challenging to calculate the direction and area of the ambiguous forces applied by infants, and pediatricians cannot control the grasping method used by them. In this study, a direction-independent grasping force measuring device is proposed that features a high resolution (0.1 kPa), cyclic stability (20 000 cycles), and linear sensitivity (21.73 µV kPa⁻¹), and high accuracy and reliability. The grasping forces (average, minimum, and maximum) of the left (normal state) and right (injection needle inserted: uncomfortable state) hands of a 1-day old infant can be successfully analyzed using the proposed device. It can be used to obtain the standard grasping force data of infants, which can contribute toward understanding the correlation between the grasping force and neurological diseases. The proposed device can be used to quantitatively measure the grasping force of not only infants but also the elderly; therefore, additional studies may report that the grasping force can be a discriminable parameter for identifying neurological diseases.