Note 12 - Revenue - Remaining Performance Obligations 2 (Details)	Dec. 31, 2023 USD ($)
Revenue, Remaining Performance Obligation, Amount	$ 2,268,000
Service [Member]
Revenue, Remaining Performance Obligation, Amount	1,825,000
Device Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	41,000	[1]
Exclusivity Fee [Member]
Revenue, Remaining Performance Obligation, Amount	267,000
Clinical Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	$ 135,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Revenue, Remaining Performance Obligation, Amount	$ 1,507,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Service [Member]
Revenue, Remaining Performance Obligation, Amount	1,186,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Device Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	41,000	[1]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Exclusivity Fee [Member]
Revenue, Remaining Performance Obligation, Amount	267,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Clinical Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	$ 13,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Revenue, Remaining Performance Obligation, Amount	$ 527,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Service [Member]
Revenue, Remaining Performance Obligation, Amount	514,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Clinical Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	$ 13,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Revenue, Remaining Performance Obligation, Amount	$ 138,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Service [Member]
Revenue, Remaining Performance Obligation, Amount	125,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Clinical Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	$ 13,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Revenue, Remaining Performance Obligation, Amount	$ 13,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 | Clinical Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	$ 13,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Revenue, Remaining Performance Obligation, Amount	$ 83,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 | Clinical Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	$ 83,000

[1] Represents the minimum purchase requirements under the distribution agreement the Company signed with its AXP distributor in China and other revenue deferred at December 31, 2023.