Note 5 - Stockholders' Equity (Deficit) - Summary of Options Outstanding Segregated By Range (Details)	12 Months Ended
	Sep. 30, 2022 $ / shares shares
Option Outstanding (in shares) | shares	2,095,538
Options Exercisable (in shares) | shares	1,163,820
Range One [Member]
Exercise Price, Lower range (in dollars per share)	$ 0.66
Exercise Price, Upper range (in dollars per share)	$ 2.49
Option Outstanding (in shares) | shares	377,032
Option Outstanding, Weighted Average Remaining Contractual Life (Year)	6 years 5 months 15 days
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$ 1.57
Options Exercisable (in shares) | shares	311,612
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 1.60
Range Two [Member]
Exercise Price, Lower range (in dollars per share)	2.61
Exercise Price, Upper range (in dollars per share)	$ 4.81
Option Outstanding (in shares) | shares	1,455,838
Option Outstanding, Weighted Average Remaining Contractual Life (Year)	8 years 6 months 7 days
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$ 3.44
Options Exercisable (in shares) | shares	589,874
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.55
Range Three [Member]
Exercise Price, Lower range (in dollars per share)	5.08
Exercise Price, Upper range (in dollars per share)	$ 8.92
Option Outstanding (in shares) | shares	155,558
Option Outstanding, Weighted Average Remaining Contractual Life (Year)	1 year 8 months 15 days
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$ 7.44
Options Exercisable (in shares) | shares	155,224
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 7.44
Range Four [Member]
Exercise Price, Lower range (in dollars per share)	9.08
Exercise Price, Upper range (in dollars per share)	$ 10.92
Option Outstanding (in shares) | shares	107,110
Option Outstanding, Weighted Average Remaining Contractual Life (Year)	1 year 7 months 24 days
Outstanding Options, Weighted Average Exercise Price (in dollars per share)	$ 10.09
Options Exercisable (in shares) | shares	107,110
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 10.09