Note 12 - Segment Reporting - Summary of Operating Results by Reportable Segments (Details) - USD ($)	6 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Jun. 30, 2017
Net revenues	$ 6,013,000	$ 9,672,000	$ 14,525,000
Cost of revenues	3,858,000	7,479,000	8,686,000
Gross profit	2,155,000	2,193,000	5,839,000
Operating expenses	6,753,000	45,738,000	15,208,000
Operating loss	(4,598,000)	(43,545,000)	(9,369,000)
Depreciation and amortization	322,000	670,000	830,000
Stock-based compensation expense	291,000	652,000	1,461,000
Goodwill	13,976,000	781,000
Total assets	51,111,000	14,611,000
Operating loss	(4,598,000)	(43,545,000)	(9,369,000)
Clinical Development [Member]
Net revenues		203,000
Clinical Development [Member] | Operating Segments [Member]
Net revenues	186,000	202,000	492,000
Cost of revenues	205,000	274,000	466,000
Gross profit	(19,000)	(72,000)	26,000
Operating expenses	2,138,000	37,340,000	9,095,000
Operating loss	(2,157,000)	(37,412,000)	(9,069,000)
Depreciation and amortization	152,000	272,000	501,000
Stock-based compensation expense	164,000	473,000	970,000
Goodwill	13,195,000
Total assets	41,261,000	3,796,000
Operating loss	(2,157,000)	(37,412,000)	(9,069,000)
Device [Member]
Net revenues		9,469,000
Device [Member] | Operating Segments [Member]
Net revenues	5,827,000	9,470,000	14,033,000
Cost of revenues	3,653,000	7,205,000	8,220,000
Gross profit	2,174,000	2,265,000	5,813,000
Operating expenses	4,615,000	8,398,000	6,113,000
Operating loss	(2,441,000)	(6,133,000)	(300,000)
Depreciation and amortization	170,000	398,000	329,000
Stock-based compensation expense	127,000	179,000	491,000
Goodwill	781,000	781,000
Total assets	9,850,000	10,815,000
Operating loss	$ (2,441,000)	$ (6,133,000)	$ (300,000)