Note 7 - Revenue - Remaining Performance Obligations (Details)	Mar. 31, 2022 USD ($)
Revenue, Remaining Performance Obligation, Amount	$ 4,945,000
Service [Member]
Revenue, Remaining Performance Obligation, Amount	2,008,000
Device Revenue [Member]
Revenue, Remaining Performance Obligation, Amount	1,486,000	[1]
Exclusivity Fee [Member]
Revenue, Remaining Performance Obligation, Amount	1,262,000
Product and Service, Other [Member]
Revenue, Remaining Performance Obligation, Amount	$ 189,000

[1] Represents the minimum purchase requirements under the distribution agreement the Company signed with its AXP distributor in China.