Note 6 - Stockholders' (Deficit) Equity and Equity-linked Instruments (Details Textual)

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Note 6 - Stockholders' (Deficit) Equity and Equity-linked Instruments (Details Textual)									1 Months Ended					3 Months Ended				4 Months Ended	9 Months Ended		12 Months Ended
		Jul. 11, 2025 $ / shares shares	Jul. 10, 2025 USD ($) $ / shares shares	Jun. 17, 2025	May 30, 2025 USD ($) $ / shares shares	May 29, 2025 USD ($) $ / shares shares	May 09, 2025 USD ($) $ / shares shares	Feb. 14, 2025 USD ($) shares	Jun. 30, 2025	Jan. 31, 2025 shares	Sep. 30, 2024 USD ($) $ / shares shares	Jun. 30, 2024 USD ($) shares	Dec. 31, 2023 shares	Sep. 30, 2025 USD ($) $ / shares shares	Jun. 30, 2025 USD ($) shares	Sep. 30, 2024 USD ($) $ / shares shares	Jun. 30, 2024 USD ($) shares	May 09, 2025 $ / shares shares	Sep. 30, 2025 USD ($) $ / shares shares	Sep. 30, 2023 USD ($)	Dec. 31, 2024 USD ($) $ / shares shares	Oct. 22, 2025 USD ($) $ / shares	Oct. 20, 2025 shares	Oct. 19, 2025 shares	Sep. 12, 2025 USD ($) $ / shares shares	May 31, 2024 shares	Nov. 30, 2023 shares	Aug. 23, 2023 $ / shares shares	May 29, 2023 shares
Common Stock, Shares Authorized (in shares)					400,000,000									400,000,000					400,000,000		400,000,000								100,000,000
Stock Issued During Period, Value, Reverse Stock Splits | $																			$ 34,000
Preferred Stock, Shares Authorized (in shares)														10,000,000					10,000,000		10,000,000								5,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares														$ 0.001					$ 0.001		$ 0.001				$ 0.001
Total Capital, Shares Authorized														110,000,000					110,000,000
Stock Issued During Period, Shares, New Issues										6,563											6,563
Preferred Stock, Stated Value | $														$ 1,000					$ 1,000
Preferred Stock, Shares Outstanding (in shares)														1,882,907					1,882,907		17,499
Difference From Fair Value of New Preferred Stock and Carrying Value of Original Preferred Stock | $																			$ (7,685,000)
Dividend Shares (in shares)																			96,828		63,821
Common Stock Dividends, Shares												23,076
Fair Value Shares Issued | $												$ 729,000							$ 372,000		$ 3,290,000
Placement Agent Fee, Percentage					8.00%
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares														$ 0.001					$ 0.001		$ 0.001
Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input											0.0421					0.0421
Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input											0.98					0.98					1.01
Conversion of Series A and AA to Series AAA [Member]
Conversion of Stock, Shares Converted														6,367
Converted to Common stock (in shares)														6,367
Minimum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input														0.036					0.036		0.0427
Minimum [Member] | Measurement Input, Expected Term [Member]
Warrants and Rights Outstanding, Measurement Input											3.89			1.96		3.89			1.96		2.71
Minimum [Member] | Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input														1.07					1.07
Maximum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input														0.0368					0.0368		0.0438
Maximum [Member] | Measurement Input, Expected Term [Member]
Warrants and Rights Outstanding, Measurement Input											4.47			3.98		4.47			3.98		4.74
Maximum [Member] | Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input														1.14					1.14
Warrants Issued With Placement Agent Agreement [Member]
Warrants and Rights Outstanding, Term														5 years					5 years
Class of Warrants and Rights, Number of Securities Called by Warrants or Rights, Percentage of Total Common Stock Issuable Upon Conversion of Preferred Shares														14.50%					14.50%
Placement Agent Warrants With Series A-2 Preferred Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights														2,210					2,210
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares														$ 68.4					$ 68.4
Placement Agent Warrants With Series A-2 Preferred Stock [Member] | Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares														304					304
Placement Agent Warrants With Series A-2 Preferred Stock [Member] | Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares														$ 536.4					$ 536.4
New Placement Agent Warrants, Exercise Price of 66.96 [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights														8,686					8,686
New Placement Agent Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares														$ 66.96					$ 66.96
New Placement Agent Warrants, Exercise Price of 68.40 [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights														4,994					4,994
Series AA Additional Investment Right [Member] | Measurement Input, Share Price [Member]
Warrants and Rights Outstanding, Measurement Input											34.4					34.4
Series AA Additional Investment Right [Member] | Minimum [Member] | Measurement Input, Conversion Price [Member]
Warrants and Rights Outstanding, Measurement Input											75.44					75.44
Series AA Additional Investment Right [Member] | Minimum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input											0.0513					0.0513
Series AA Additional Investment Right [Member] | Minimum [Member] | Measurement Input, Expected Term [Member]
Warrants and Rights Outstanding, Measurement Input											0.42					0.42
Series AA Additional Investment Right [Member] | Minimum [Member] | Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input											0.79					0.79
Series AA Additional Investment Right [Member] | Maximum [Member] | Measurement Input, Conversion Price [Member]
Warrants and Rights Outstanding, Measurement Input											530					530
Series AA Additional Investment Right [Member] | Maximum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input											0.0536					0.0536
Series AA Additional Investment Right [Member] | Maximum [Member] | Measurement Input, Expected Term [Member]
Warrants and Rights Outstanding, Measurement Input											0.92					0.92
Series AA Additional Investment Right [Member] | Maximum [Member] | Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input											0.91					0.91
Series AA Preferred Additional Investment Rights [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights											80,381					80,381										16,074
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease) | $												$ 294,000
Pre-Funded Warrant [Member]
Shares Issued, Price Per Share | $ / shares					$ 4.79
Class of Warrant or Right, Issued During Period			173,023		59,833
Class of Warrant or Right, Issued During Period, Exercise Price | $ / shares					$ 0.00001
Class of Warrant or Right, Grant Date Fair Value | $ / shares			$ 0.001
2025 Exchange Agreement [Member]
Shares Designated (in shares)																									16,426
Series AAA-3 & AAA-4 Junior Subscription Agreements [Member]
Stock Issued During Period, Shares, New Issues											1,096
Proceeds from Issuance or Sale of Equity | $											$ 1,096,000
Series AAA-3 and AAA-4 Junior Preferred Stock Warrants [Member] | Series AAA-3 & AAA-4 Junior Subscription Agreements [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares											$ 40					$ 40
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right											25					25
Class of Warrant or Right, Issued During Period, Purchase Price | $ / shares											$ 1,000
May III Purchase Agreement [Member]
Stock Issued During Period, Shares, New Issues					79,750
Proceeds from Issuance or Sale of Equity | $					$ 670,000
Shares Issued, Price Per Share | $ / shares					$ 4.8
May II Underwriting Agreement [Member]
Stock Issued During Period, Shares, New Issues						10,417
Shares Issued, Price Per Share | $ / shares						$ 4.8
Equity Offering, Maximum Shares to be Issued						104,167
Proceeds from Issuance of Common Stock | $						$ 380,000
May II Over Allotment Option [Member]
Option, Period						45 days
Stock Issuable During Period (in shares)						10,417
Underwriting Agreement [Member]
Shares Issued, Price Per Share | $ / shares							$ 6.8											$ 6.8
Equity Offering, Maximum Shares to be Issued							127,941											127,941
Proceeds from Issuance of Common Stock | $							$ 700,400
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares							$ 0.001											$ 0.001
Over-Allotment Option [Member]
Shares Issued, Price Per Share | $ / shares							$ 6.8											$ 6.8
Option, Period							45 days
Stock Issuable During Period (in shares)							15,441											19,191
Proceeds from Issuance of Common Stock | $							$ 104,999
Equity Purchase Agreement [Member]
Stock Issued During Period, Shares, New Issues								7,500						0					17,925
Shares Issued, Price Per Share | $ / shares														$ 13.6					$ 13.6
Proceeds from Issuance of Common Stock | $																			$ 231,000
Equity Offering, Maximum Amount | $			$ 20,000,000					$ 2,900,000
Equity Offering, Price Per Share, Percentage of Closing Price			92.00%					92.00%
Stock Issued During Period, Value, New Issues | $			$ 600,000					$ 159,000
Series AAAA Junior Convertible Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares		$ 1
Stock Issued During Period, Shares, New Issues		3,775,047
Preferred Stock Dividends, Percentage of Common Shares		60.00%
Preferred Stock, Percentage Consent Needed to Convert		1.00%
Preferred Stock, Shares Outstanding (in shares)	[1]													1,866,481					1,866,481
Series B Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares																									$ 0.001
Shares Designated (in shares)																									16,426
Preferred Stock, Stated Value | $																									$ 1
Preferred Stock, Convertible, Conversion Price (in dollars per share) | $ / shares																									$ 7
Preferred Stock, Shares Outstanding (in shares)	[2]													15,987					15,987
Series A Preferred Offerings [Member] | Subscription Agreements [Member]
Preferred Stock Dividends, Percentage of Common Shares														20.00%					20.00%
Preferred Stock, Percentage Consent Needed to Convert														51.00%					51.00%
Preferred Stock, Stated Value | $														$ 1,000					$ 1,000
Preferred Stock, Conversion Period With Discretion														1 year
Preferred Stock, Beneficial Ownership Limitations, Percentage of Outstanding Shares Required to be Converted When Common Stock Volume-weighted Average Price Over Previous 10 Days as Reported Equals More Than 250% of Conversion Price														50.00%					50.00%
Preferred Stock, Beneficial Ownership Limitations, Percentage of Outstanding Shares Required to be Converted When Common Stock Volume-weighted Average Price Over Previous 10 Days as Reported Equals More Than 300% of Conversion Price														100.00%					100.00%
Preferred Stock, Automatic Conversion Period														24 months
Preferred Stock Dividends, Period One														12 months
Preferred Stock Dividends, Period Two														24 months
Preferred Stock, Maximum Loans | $														$ 5,000,000					$ 5,000,000
Preferred Stock Voting Exceptions, Minimum Amount of Indebtedness Required | $														$ 5,000,000					$ 5,000,000
Series AAA Junior Preferred Stock [Member]
Preferred Stock, Shares Outstanding (in shares)														5					5
Dividend Shares (in shares)																4,840
Fair Value Shares Issued | $																$ 273,000
Shares Issued, Price Per Share | $ / shares											$ 1,000			$ 1,000		$ 1,000			$ 1,000
Series AAA Junior Preferred Stock [Member] | Subscription Agreements [Member]
Preferred Stock Dividends, Percentage of Common Shares														20.00%					20.00%
Preferred Stock Dividends, Period One														30 days
Preferred Stock Dividends, Period Two														60 days
Preferred Stock Dividends, Period Three														90 days
Subscription Agreements [Member] | Series AAA Convertible Preferred Stock [Member]
Preferred Stock, Period After Registration Agreement for Conversion														18 months
Preferred Stock, Down Round Feature, Period After Filing Date														24 months
Series AAA Convertible Preferred Stock [Member]
Preferred Stock, Shares Outstanding (in shares)														115					115
Dividend Shares (in shares)																10,801
Fair Value Shares Issued | $																$ 587,000
Series AAA Convertible Preferred Stock [Member] | Subscription Agreements [Member]
Preferred Stock, Stated Value | $														$ 1,000					$ 1,000
Series AAA Convertible Preferred Stock [Member] | Series A & AA Exchange Agreements [Member]
Stock Issued During Period, Shares, New Issues													4,011
Series A A Preferred Stock [Member]
Preferred Stock, Convertible, Conversion Price (in dollars per share) | $ / shares																												$ 104
Preferred Stock, Shares Outstanding (in shares)														153					153								7,322	10,706
Deemed Dividend on Preferred Stock | $																				$ 6,446,000
Dividend Shares (in shares)															6,359	3,972	11,907
Fair Value Shares Issued | $															$ 89,000	$ 216,000	$ 661,000
Series A A Preferred Stock [Member] | Subscription Agreements [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares														$ 0.001					$ 0.001
Preferred Stock, Period After Registration Agreement for Conversion														18 months
Equity, Minimum Preferred Stock Purchased | $														$ 3,500,000					$ 3,500,000
Preferred Stock, Convertible, Conversion Percentage														125.00%					125.00%
Series AAA-2 Convertible Preferred Stock [Member]
Preferred Stock, Shares Outstanding (in shares)														156					156
Dividend Shares (in shares)																12,258
Fair Value Shares Issued | $																$ 666,000
Series AAA-2 Convertible Preferred Stock [Member] | Series A & AA Exchange Agreements [Member]
Stock Issued During Period, Shares, New Issues														2,356
Series AAA and AAA-2 Convertible Preferred Stock [Member]
Dividend Shares (in shares)														88,883					88,883
Fair Value Shares Accrued | $														$ 271,000					$ 271,000
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio				40					40
Subsequent Event [Member]
Common Stock, Shares Authorized (in shares)																							750,000,000	400,000,000
Preferred Stock, Shares Authorized (in shares)																							10,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares																						$ 0.001
Preferred Stock, Stated Value | $																						$ 1,000
Placement Agent Fee, Percentage																						2.00%
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares																						$ 0.001
[1] Series AAAA Junior Preferred Stock was issued in exchange for certain debt outstanding, as described at Note 5. [2] Series B Preferred Stock was issued in exchange for certain preferred stock outstanding, as described below.