Abstract: A reading device for capacitive sensing element comprises a differential capacitive sensing element, a modulator, a charge-voltage conversion circuit, a phase adjustment circuit, a demodulator and a low-pass filter. The modulator outputs a modulation signal to the common node of the capacitive sensing element and modulates the output signal of the capacitive sensing element. The two input terminals of the charge-to-voltage conversion circuit are connected to two non-common nodes of the capacitive sensing element. The charge-to-voltage converter read the output charge of the capacitive sensing element and convert it into a voltage signal. The modulator generates a demodulation signal through the phase adjustment circuit. The demodulator receives the demodulation signal from the phase adjustment circuit and demodulates the output of the charge-to-voltage conversion circuit. The low-pass filter is connected to the output of the demodulator for filtering the demodulated voltage signal to output the read signal.

Abstract: An automatically retractable safety syringe includes a needle assembly consisting of a cannula, a needle hub and a rubber O-ring, a needle cap, a retracting spring, a breakable and retractable plunger, a plunger gasket and a medicine barrel; in accordance with the structure of the said automatically retractable safety syringe of the present invention, since the breakable plunger is assembled inside the medicine barrel, after being pushed all the way to the end, it is forced to break automatically into two parts for reducing it's length so as to provide enough space for the retracting spring to drive the needle assembly moving along the sliding passages for accomplishing an automatically retracting action.

Abstract: An automatically retractable safety syringe includes a needle assembly consisting of a connula, a needle hub and a rubber O-ring, a needle cap, a retracting spring, a breakable and retractable plunger, a plunger gasket and a medicine barrel; in accordance with the structure of the said automatically retractable safety syringe of the present invention, since the breakable plunger is assembled inside the medicine barrel, after being pushed all the way to the end, it is forced to break automatically into two parts for reducing it's length so as to provide enough space for the retracting spring to drive the needle assembly moving along the sliding passages for accomplishing an automatically retracting action.