Table 3.

Summary of the attachable, implantable and ingestible devices for health monitoring.

Attachable Devices
	Monitoring	Physiological Parameters	Ref.
Patch	Cardiovascular signal	Blood pressure and heart rate by measuring of ECG, BCG and pulse transit time with a thin, flexible patch	[59,60,61,65]
	Chemicals	Sweat volume and sweat components like hydration, glucose, lactate, pH and electrolytes	[69,71,72,73,74,77,90]
	Body temperature	Body temperature on skin	[79,82,83,84]
Contact lens	Chemicals	Glucose and lactate in tear fluid	[85,86,87,88,91]
Implantable and Ingestible Devices
	Monitoring	Physiological parameters	Ref.
Pace-maker	Cardiovascular signal	Heartbeat for treating arrhythmias	[92,93,94,95]
Tattoo	Salivary Sweat	Monitoring respiration and pathogenic bacteria detection with tooth enamel Lactate, glucose, alcohol and electrolytes (such as ammonium) with skin worn tattoo	[96,97,98,99,100]
Bioink	Interstitial fluid	Glucose, pH and electrolytes (such as sodium)	[101,102]
Smart pill	Medicine	Medicine when drug reaches stomach with patch	[103,104,105]