Income taxes, Deferred Tax Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets [Abstract]
Net operating loss carryforwards	$ 33,238,000	$ 28,048,000
Net operating loss carryforwards - foreign	23,000	19,000
Excess of tax basis over book value of property and equipment	14,000	8,000
Excess of tax basis over book value of intangible assets	1,632,000	1,811,000
Stock-based compensation	1,613,000	1,613,000
Accrued employee compensation	698,000	427,000
Capitalized equity costs	49,000	49,000
Net change in reserve accounts	898,000	287,000
Gross deferred tax assets	38,165,000	32,262,000
Valuation allowance	(38,165,000)	(32,262,000)
Net deferred tax asset	0	0
Income Tax Penalties and Interest Expense [Abstract]
Income tax penalties	0	0
Interest on income taxes	$ 0	0
Earliest Tax Year [Member]
Operating Loss Carryforwards [Abstract]
Operating loss carryforwards, expiry date	Dec. 31, 2024
Latest Tax Year [Member]
Operating Loss Carryforwards [Abstract]
Operating loss carryforwards, expiry date	Dec. 31, 2025
Domestic [Member]
Operating Loss Carryforwards [Abstract]
Net operating loss carryforwards					$ 77,900,000
Operating loss carryforwards limited with no expiration	$ 56,500,000	56,500,000	$ 56,500,000	$ 56,500,000
Foreign [Member]
Operating Loss Carryforwards [Abstract]
Net operating loss carryforwards			100,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Abstract]
Net operating loss carryforwards					$ 77,900,000
Operating loss carryforwards limited with no expiration	$ 56,500,000	$ 56,500,000	$ 56,500,000	$ 56,500,000