Note 8 - Segment Information (Details) - Key Financial Highlights by Reportable Segments (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Mar. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 4,110		$ 3,968		$ 7,862		$ 7,620
Gross profit	1,258		1,195		2,407		2,275
Operating loss	(1,441)		(1,283)		(3,319)		(3,672)
Interest expense, net	(106)		(44)		(189)		(85)
Depreciation and amortization	152		173		318		362
Stock-based compensation expense	195		(227)		349		328
Expenditures for fixed assets	(8)		46		17		46
As of September 30, 2014
Total assets	10,049		10,733		10,049		10,733		10,833
Medical [Member]
Segment Reporting Information [Line Items]
Net sales	3,267		3,399		6,327		6,428
Gross profit	1,023		981		1,921		1,774
Operating loss	(1,435)		(1,345)		(3,273)		(3,732)
Interest expense, net	(106)		(44)		(189)		(85)
Depreciation and amortization	151		170		314		355
Stock-based compensation expense	186		(221)		328		309
Expenditures for fixed assets	(8)		46		17		46
As of September 30, 2014
Total assets	10,542		11,240		10,542		11,240
Industrial [Member]
Segment Reporting Information [Line Items]
Net sales	843		569		1,535		1,192
Gross profit	235		214		486		501
Operating loss	(6)		62		(46)		60
Depreciation and amortization	1		3		4		7
Stock-based compensation expense	9		(6)		21		19
As of September 30, 2014
Total assets	1,865		1,333		1,865		1,333
Adjustments [Member]
Segment Reporting Information [Line Items]
Net sales		[1]		[1]		[1]		[1]
Gross profit		[1]		[1]		[1]		[1]
Operating loss		[1]		[1]		[1]		[1]
Interest expense, net		[1]		[1]		[1]		[1]
Depreciation and amortization		[1]		[1]		[1]		[1]
Stock-based compensation expense		[1]		[1]		[1]		[1]
Expenditures for fixed assets		[1]		[1]		[1]		[1]
As of September 30, 2014
Total assets	$ (2,358)	[1]	$ (1,840)	[1]	$ (2,358)	[1]	$ (1,840)	[1]

[1] Adjustments