Note 9 - Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2021				2020
Expected term (based upon historical experience) (in years)	5.5	-	5.8		5.0	-	5.8
Expected volatility	117	-	159	%	143	-	159	%
Expected dividends	None				None
Risk free interest rate	0.73	-	1.24	%			0.46	%

Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]

Options Outstanding						Options Exercisable
Exercise Prices		Number of shares		Weighted Average Remaining contractual Life (In Years)		Number of shares		Weighted Average Remaining contractual Life (In Years)
$	0.98		51,500		1.96		51,500		1.96
$	1.91		10,000		9.25		3,333		9.25
$	2.21		7,000		9.45		2,333		9.45
$	2.68		5,300		9.87		1,767		9.87
$	2.89		105,000		8.87		51,667		8.87
$	2.92		52,500		7.13		47,500		7.13
$	3.00		52,500		7.62		47,500		7.62
$	3.30		37,500		5.75		37,500		5.75
$	3.50		3,000		6.76		3,000		6.76
$	4.10		78,700		6.23		78,700		6.23
			403,000		6.81		324,800		6.33

The 2018 Non-qualified Stock Option Plan [Member]

Notes Tables

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Number of shares			Weighted average exercise price per share
Options outstanding at January 1, 2021		308,790		$	3.24
Granted		22,300			2.19
Cancelled/Expired		(17,090	)		3.13
Exercised		-			-
Options outstanding at December 31, 2021		314,000		$	3.17

	Number of shares		Weighted average exercise price per share
Options outstanding at January 1, 2021		36,000	$	0.98
Granted		-		-
Cancelled		-		-
Exercised		-		-
Options outstanding at December 31, 2021		36,000	$	0.98

	Number of shares		Weighted average exercise price per share
Options outstanding at January 1, 2021		43,000	$	3.00
Granted		-		-
Cancelled		-		-
Exercised		-		-
Options outstanding at December 31, 2021		43,000	$	3.00

	Number of shares			Weighted average exercise price per share
Options outstanding at January 1, 2021		16,000		$	23.33
Granted		-			-
Cancelled/Expired		(6,000	)		60.58
Exercised		-			-
Options outstanding at December 31, 2021		10,000		$	0.98

	Number of Shares			Weighted Average Price		Weighted Average Remaining Contractual Life (In Years)		Aggregate Intrinsic Value
Options outstanding at January 1, 2021		403,790		$	3.81
Granted		22,300			2.19
Cancelled/Expired		(23,090	)		18.06
Exercised		-			-
Options outstanding and expected to vest at December 31, 2021		403,000		$	2.90		6.81	$	94,003
Options exercisable at December 31, 2021		324,800		$	2.94		6.33	$	87,469