• comparison table for multi-sensor devices:

90.02 Research & medical grade ECG devices which some of those were used to study the accuracy of consumer grade HRMs in different papers

• g.tec medical devices are very expensive. It is worth to build those ourselves.

	Module	1 piece (USD)	32 pieces (USD)
1	TGAM Brain Wave Sensor	19.6	627.2
2	16 Bit I2C ADS1115	4 channels 3.29	26.23
3	ESP32	1.35	16.12
	total		669.47

• Ask an engineer and read a good paper about the quality of these components.

• Be careful, if you ask an engineer in the OpenBCI forum about it, who wants you to sell OpenBCI modules, ask an independent engineer as well.

• Be careful, if you ask an engineer in the EEVBLOG, who want to sell you Texas Instruments chips, ask an independent engineer as well.

– Component list:

– TGAM EEG module:

https://www.aliexpress.com/item/1005004344005084.html?spm=a2g0o.productlist.main.3.540a157boTfB9r&algo_pvid=4ffd9d92-89f0-4b5c-ad3d-dc4c99a6ba44&algo_exp_id=4ffd9d92-89f0-4b5c-ad3d-dc4c99a6ba44-1&pdp_ext_f=%7B%22sku_id%22%3A%2212000028982844996%22%7D&pdp_npi=2%40dis%21USD%2130.16%2119.6%21%21%21%21%21%402102196716737499325344784d06c2%2112000028982844996%21sea&curPageLogUid=yMMYvdALULT3

– 16 Bit I2C ADS1115 Module ADC 4 Channel With Pro Gain Amplifier RPi Development Board:

https://www.aliexpress.com/item/1005001636468832.html?spm=a2g0o.productlist.main.1.1ef36491P2NrtU&algo_pvid=feccf54c-cbb8-4be0-a287-e9cd76fe72f7&aem_p4p_detail=202301141851566155107864523500006781367&algo_exp_id=feccf54c-cbb8-4be0-a287-e9cd76fe72f7-0&pdp_ext_f=%7B%22sku_id%22%3A%2212000016918174924%22%7D&pdp_npi=2%40dis%21USD%212.34%211.92%21%21%21%21%21%40212279b716737511167762377d06b7%2112000016918174924%21sea&curPageLogUid=k0o12XbUQFjr&ad_pvid=202301141851566155107864523500006781367_1&ad_pvid=202301141851566155107864523500006781367_1

– battery packs as in this example:

https://www.aliexpress.com/item/32842954547.html?spm=a2g0o.productlist.main.61.42ab57e1l2KcAp&algo_pvid=94dc46ce-6672-490a-8891-4464365ce16f&algo_exp_id=94dc46ce-6672-490a-8891-4464365ce16f-30&pdp_ext_f=%7B%22sku_id%22%3A%2265133262288%22%7D&pdp_npi=2%40dis%21USD%2157.5%2144.85%21%21%21%21%21%40212248ba16737517378385745d06a2%2165133262288%21sea&curPageLogUid=6nR7PlFAXHPQ

• We made a similar comparison a view years ago in the OpenBCI forum. The costs for individual components tropped, but not those sold by William Croft from OpenBCI.
• New OpenBCI modules are available at Aliexpress, but can t we let manufactuer themselves, and is it not the better?