Quarterly Financial Information (Unaudited) (as restated), Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
Cash Flows From Operating Activities: [Abstract]
Net loss	$ (1,582)	$ (1,868)	$ (2,042)	$ (19,077)	$ 2,459	$ (3,974)	$ (3,910)	$ (1,515)	$ (5,492)	$ (20,592)	$ (4,033)	$ (21,514)
Adjustments to reconcile net loss to net cash provided by operating activities: [Abstract]
Depreciation and amortization			1,463			1,543	2,841	3,209	4,143	4,811	5,397	6,336
Provision for doubtful accounts			0			0	(49)	22	53	58	(30)	109
Gain on cancelation of distributor rights agreement			226			0	(11)	0	(11)	(40)	(11)	(40)
Impairment of intangible assets			0			0	0	0	0	23	0	23
Stock-based compensation			19			52	203	73	570	136	904	186
Deferred taxes			40			60	80	120	(22)	180	(303)	55
Loss on disposal of property and equipment											407	0
Loss on disposal of property and equipment and impairment of lasers placed in service			182				411		503
Loss on extinguishment of debentures				20,160	0	0		0		20,160	0	20,160
Amortization of debt discount			19			247	39	764	44	928	50	944
Amortization of deferred financing costs			20			54	42	115	79	171	107	188
Change in fair value of warrant liability	1,053	263	(40)	(421)	(657)	671	222	14	1,275	(407)	0	(595)
Change in fair value of embedded conversion feature			0	(1,993)	(2,903)	1,738	0	(1,165)	0	(3,158)	0	(3,158)
Changes in operating assets and liabilities: [Abstract]
Accounts receivable			650			102	710	(147)	361	130	(222)	184
Inventories			(20)			147	596	(670)	521	(716)	215	(193)
Prepaid expenses and other assets			(669)			(188)	(296)	243	(137)	406	(383)	475
Accounts payable			381			354	(895)	403	(614)	71	(513)	381
Other accrued liabilities			(16)			74	(3)	167	(754)	255	1,006	602
Other liabilities			227			36	255	84	(3)	108	(60)	159
Deferred revenues			(380)			(98)	(303)	(20)	(229)	(278)	171	(358)
Net cash provided by (used in) operating activities			60			818	(68)	1,697	1,795	2,246	2,896	4,140
Cash Flows From Investing Activities:
Lasers placed-in-service			(375)			(683)	(885)	(1,205)	(1,254)	(1,450)	(1,749)	(1,739)
Purchases of property and equipment			(6)			(200)	(6)	(206)	(6)	(321)	(13)	(320)
Payments on distributor rights liability			(24)			0	(23)	(75)	(23)	(115)	(23)	(135)
Net cash used in investing activities			(405)			(883)	(914)	(1,486)	(1,283)	(1,886)	(1,785)	(2,194)
Cash Flows From Financing Activities:
Proceeds from issuance of common stock			0				14,664		14,664		17,000	0
Offering costs			(202)				0		0		(2,336)	0
Repayments of long-term debt			0			0	(3,000)	1	(3,000)	(857)	(3,000)	(1,429)
Payments on notes payable			(105)			(100)	(306)	(201)	(357)	(304)	(357)	(374)
Net cash provided by (used in) financing activities			(307)			(100)	11,358	(201)	11,307	(1,161)	11,307	(1,803)
Effect of exchange rate changes on cash			0				0		0		0	(2)
Net (decrease) increase in cash and cash equivalents			(652)			(165)	10,376	10	11,819	(801)	12,418	141
Cash and cash equivalents, beginning of period	14,445	3,417	4,069	3,938	3,763	3,928	4,069	3,928	4,069	3,928	4,069	3,928
Cash and cash equivalents, end of period	$ 15,888	$ 14,445	3,417	$ 3,127	$ 3,938	3,763	14,445	3,938	15,888	3,127	16,487	4,069
Other accrued liabilities			(16)			74	(3)	167	(754)	255	$ 1,006	602
Effect of Adoption Higher / (Lower) [Member]
Cash Flows From Operating Activities: [Abstract]
Net loss			(181)			(1,739)	(332)	(1,925)	(1,624)	(3,481)		(2,683)
Adjustments to reconcile net loss to net cash provided by operating activities: [Abstract]
Depreciation and amortization			50				100		150
Impairment of intangible assets												(500)
Loss on extinguishment of debentures										(8,361)		(8,361)
Amortization of debt discount						(476)		(854)		(1,416)		(1,416)
Change in fair value of warrant liability			40			539	200	10	1,174	330		493
Change in fair value of embedded conversion feature						(1,738)		1,165		3,158		(3,158)
Changes in operating assets and liabilities: [Abstract]
Other accrued liabilities						135		282		417		304
Deferred revenues			(295)			(197)	(171)	(198)	(31)	(393)
Cash Flows From Financing Activities:
Other accrued liabilities						$ 135		$ 282		$ 417		$ 304
Accrued expenses			$ 104				$ 203		$ 331