Piezoresistive Breathing Sensing System with 3D Printed Wearable Casing

Table 1

Comparison of several features of the proposed sensor and other state-of-the-art sensors.

Study	Sensor	Processing unit	Data display	Sampling rate (Hz)	Data transfer	Energy storage
Proposal	Piezoresistive FlexiForce A201	Arduino Pro Mini (Atmega 328p)	PC, Android device	50	Bluetooth (HC-05 module)	3.7 V-150 mAh, Li-battery
Hesse et al. [12]	Piezoresistive FlexiForce A201	MSP430FG4618	PC	100	Flash memory/nRF24L01 module	CR2025 coin cell
Mahbub et al. [1]	PVDF transducer	ADC	—	—	IR-UWB	3 V-600 mAh Li-polymer battery
Rotariu et al. [35]	Piezoelectric belt	Arduino Leonardo	Tablet, PC	10	USB serial port	—
Ciobotariu et al. [34]	Piezoelectric belt	Personal digital assistant	PC	10	WiFi, GSM/GPRS, USB serial port	CR2023 3 V, 225 mAh Lithium coin battery
Hoffman et al. [2]	Capacitive	MSP430F1612	PC	6	Bluetooth (Stollmann BlueMod+B20)	590 mAh Li-polymer battery
Grlica et al. [36]	Capacitive	DAQ commercial unit	PC	9.1	USB serial port	2,000 mAh Li-ion battery
Yang et al. [37]	Capacitive	—	Smartphone	—	Bluetooth	Coin battery
Yang et al. [38]	Capacitive	PIC24FJ256	PC	10	Bluetooth	—
Min et al. [39]	Capacitive	DAQ commercial unit	PC	100	USB serial port	—
Witt et al. [6]	FBG	DAQ unit	DAQ unit	250	Optical fiber RF nanoLOC AVR module for telemonitoring	—
Jonckheere et al. [67]	FBG	DAQ unit	PC	—	USB serial comm.	—
Presti et al. [40]	FBG	DAQ commercial unit (interrogator)	PC	250	USB serial comm.	—
Massaroni et al. [41]	FBG	DAQ commercial unit (interrogator)	PC	250	USB serial comm.	—
Yang et al. [42]	Fiber optic microbend	Optical transceiver	PC	—	Bluetooth	—
Padasdao et al. [9]	DC brushed motor	—	—	—	—	—
Teichmann et al. [43]	Electromagnetic coupling sensing coil	Microcontroller	PC, Android device	100	Bluetooth	LiPo 2.95 Wh battery