Note 5 - Stockholders' Equity (Deficit) (Details Textual) - USD ($)					12 Months Ended
	Apr. 19, 2022	Apr. 13, 2022	Jul. 27, 2021	Apr. 16, 2018	Sep. 30, 2022	Sep. 30, 2021	Feb. 02, 2022	Feb. 01, 2022	Apr. 13, 2018
Number of Shares Entitled Against Option (in shares)					1
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)					10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term (Year)					6 years
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total					$ 1,100,000	$ 551,000
Expected Forfeitures For Employee Service Share Based Compensation Nonvested Awards Compensation Cost Not Yet Recognized					$ 720,000	409,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)					2 years
Share-Based Payment Arrangement, Expense					$ 747,000	487,000
Proceeds from Stock Options Exercised					122,000	263,000
Share-Based Payment Arrangement, Expense, Tax Benefit					$ 0	$ 0
Number of Complete Employment Period On First Day of Each Offering Period (Day)					90 days
Employee Not Eligible To Participate					5.00%
Eligible Employees Contribution To Purchase Shares					10.00%
Share Based Compensation Arrangement By Share Based Payment Award, Maximum Fair Market Value of Shares To Be Purchased by Employee					$ 25,000
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee (in shares)					1,000
Share-based Compensation Arrangement by Share-based Payment Award, Offering Period (Month)					6 months
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent					85.00%
Employee Stock Ownership Plan (ESOP), Shares in ESOP, Total (in shares)					80,314
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)					19,353	9,773
Proceeds from Issuance of Common Stock					$ 3,967,000	$ 3,447,000
Stock Issued During Period, Shares, New Issues (in shares)			945,946
Shares Issued, Price Per Share (in dollars per share)			$ 3.70
Preferred Stock, Shares Authorized (in shares)					500,000	500,000
Preferred Stock, Shares Issued (in shares)					0	0
Stock Issued During Period, Value, New Issues			$ 3,500,000		$ 4,016,000	$ 3,517,000
Common Stock, Par or Stated Value Per Share (in dollars per share)					$ 0.01	$ 0.01	$ 0.01
Common Stock, Shares Authorized (in shares)					25,000,000	25,000,000	25,000,000	15,000,000
Public Offering [Member]
Proceeds from Issuance of Common Stock	$ 4,300,000
Stock Issued During Period, Shares, New Issues (in shares)	1,700,000	1,700,000
Shares Issued, Price Per Share (in dollars per share)		$ 2.55
Equity Offering, Underwritten Option Shares (in shares)		255,000
Payments of Stock Issuance Costs	$ 406,000
Conversion of Series A Preferred Stock to Common Stock [Member]
Convertible Preferred Stock, Conversion Price (in dollars per share)					$ 4.23
Series A Preferred Stock [Member]
Preferred Stock, Shares Authorized (in shares)					4,500	4,500
Preferred Stock, Shares Issued (in shares)					0	0
Preferred Stock [Member]
Stock Issued During Period, Value, New Issues					$ 0	$ 0
Preferred Stock [Member] | Series A Preferred Stock [Member]
Preferred Stock, Shares Authorized (in shares)					4,500	4,500
Preferred Stock, Dividend Rate, Percentage					9.00%	9.00%
Board of Directors Chairman [Member]
Stock Issued During Period, Shares, New Issues (in shares)			337,838
Stock Issued During Period, Value, New Issues			$ 1,250,000
Warrant to Purchase Common Stock [Member] | Board of Directors Chairman [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					232,558
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)					$ 2.50
Warrant Agreements Associated with July 2021 Stock Issuance [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			141,892
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 5.50
Warrant Agreements Associated with July 2021 Stock Issuance [Member] | Board of Directors Chairman [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			50,676
April 2022 Underwriters' Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	102,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 3.06
Warrants and Rights Outstanding, Term (Year)	5 years
Affiliated Entity [Member]
Stock Issued During Period, Shares, New Issues (in shares)				232,558
Shares Issued, Price Per Share (in dollars per share)				$ 2.15
Affiliated Entity [Member] | Warrant to Purchase Common Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)									232,558
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)									$ 2.50
Director Stock Option Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)					150,000
Number Of Shares To Be Granted On Each Meeting Under Directors Plan (in shares)					2,000
Employee Stock Purchase Plan [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)					300,000
Employee Stock Purchased Plan [Member]
Share-Based Payment Arrangement, Expense					$ 10,000	$ 9,000
Proceeds from Issuance of Common Stock					$ 37,000	$ 31,000