Fig. 6: On-body validation for adults.
a Schematic of a hand dynamometer (hospital grip instrument) read with a computer and the smart ball sensor read with a cellphone. b Finger strength measurement using hospital grip instrument and our smart ball sensor. Comparison between a hospital grip instrument and the proposed smart ball sensor in grip strength of c palm and d four fingers of a stroke patient. e Relationship between the smart ball sensor and hospital grip instrument. The correlation coefficient of the results acquired by the two devices is 0.92. f A Bland–Altman plot of the smart ball sensor and hospital grip instrument. Here all the grip strength means the maximum value. g A digital photo of a pill shell filled with all the electronic accessories. h Photos of the maximum grip strength of a healthy man monitored by the smart ball sensor and read with a cellphone.
