Note 1 - Nature of Business and Summary of Significant Accounting Policies - Disaggregated Revenues by Major Product Line (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Total revenues	$ 2,135,636	$ 2,547,600	$ 8,010,415	$ 8,024,590
Percent of revenues	100.00%	100.00%	100.00%	100.00%
System [Member]
Total revenues	$ 86,927	$ 615,160	$ 1,924,415	$ 2,954,963
Percent of revenues	4.10%	24.10%	24.00%	36.80%
Maintenance [Member]
Total revenues	$ 1,472,143	$ 1,384,407	$ 4,562,917	$ 3,990,141
Percent of revenues	68.80%	54.50%	57.00%	49.80%
Service and Other [Member]
Total revenues	$ 576,566	$ 548,033	$ 1,469,403	$ 1,079,486
Percent of revenues	27.00%	21.40%	18.30%	13.40%
Lease [Member]
Total revenues			$ 53,680	$ 0
Percent of revenues			0.70%	0.00%