The stethoscope used by doctors is a traditional hose type. Here is an acousto-optic display stethoscope that can both listen and see signals. The device uses a piezoelectric sensor and a signal amplifier to convert the beating of the heart into an acousto-optic signal.
24v wall charger,24v dc adapter,24v ac dc adapter,24v switching adapter,100-240V AC to DC 24V 3A 72W Power Adapter,12W Ac Switching Power Adapter,24V 0.5A Power Supply For Led Lights Shenzhen Waweis Technology Co., Ltd. , https://www.szwaweischarger.com