GEOGRAPHIC AND SEGMENT INFORMATION

Operating segments are aggregated into reportable segments only if they exhibit similar economic characteristics. In addition to similar economic characteristics we also consider the following factors in determining the reportable segments: the nature of business activities, the management structure directly accountable to our chief operating decision maker for operating and administrative activities, availability of discrete financial information and information presented to the Board of Directors and investors.

Prior to the first quarter of 2017, we disclosed only one reporting segment. Beginning in 2017, our reportable segments are disclosed as principally organized and managed as three operating segments: Core, OEM and Advanced Energy. We adopted reportable segments to align with changes in how we manage our business, review operating performance and allocate resources as a result of the growth in Advanced Energy and the differing behavior of the Core and OEM product lines. The Corporate & Other category includes certain unallocated corporate, operational, research and development and marketing costs which were not specifically attributed to any reportable segment. Net assets are shared, therefore, not allocated to the reportable segments. The OEM segment is primarily development contract and product driven, all related expenses are recorded as cost of sales, therefore no segment specific operating expenses are incurred.

Summarized financial information with respect to reportable segments is as follows:



	Year ended December 31, 2017
(In thousands)	Core		OEM		Advanced Energy			Corporate (Other)			Total
Sales	$	28,649	$	2,598	$	7,636		$	—		$	38,883

Income (loss) from operations	8,620		1,353		(3,957		)	(11,281		)	(5,265		)

Severance and related expense	—		—		—			1,524			1,524
Interest expense, net	—		—		—			(136		)	(136		)
Change in fair value of derivative liabilities	—		—		—			183			183
Income tax benefit	—		—		—			(156		)	(156		)
Depreciation and amortization	—		—		—			696			696



	Year ended December 31, 2016
(In thousands)	Core		OEM		Advanced Energy			Corporate (Other)			Total
Sales	$	27,808	$	5,328	$	3,491		$	—		$	36,627

Income (loss) from operations	7,600		3,045		(4,812		)	(9,625		)	(3,792		)

Severance and related expense	—		—		—			—			—
Interest expense, net	—		—		—			(158		)	(158		)
Change in fair value of derivative liabilities	—		—		—			64			64
Income tax expense	—		—		—			64			64
Depreciation and amortization	—		—		—			734			734



	Year ended December 31, 2015
(In thousands)	Core		OEM		Advanced Energy			Corporate (Other)			Total
Sales	$	26,098	$	2,116	$	1,306		$	—		$	29,520

Income (loss) from operations	5,690		1,524		(4,688		)	(9,512		)	(6,986		)

Severance and related expense	—		—		—			—			—
Interest expense, net	—		—		—			(158		)	(158		)
Change in fair value of derivative liabilities	—		—		—			1,799			1,799
Income tax expense	—		—		—			25			25
Depreciation and amortization	—		—		—			812			812

We derive revenues from four major product lines: Electrosurgical, Cauteries, Lighting and Other products. We do not review or analyze our four major product lines below net sales. Sales for the product lines are summarized as follows:



	Year Ended December 31,
(In thousands)	2017		2016		2015
Sales by Product Line
Electrosurgical	$	25,727	$	20,901	$	17,558
Cauteries	7,141		7,101		6,886
Lighting	2,435		2,710		2,477
Other	3,580		5,915		2,599
Total	$	38,883	$	36,627	$	29,520

International sales in 2017, 2016 and 2015 were 14.8%, 12.5% and 16.9% of sales, respectively. Substantially all of these sales are denominated in U.S. dollars. Revenue by geographic region, based on the "ship to" location on the invoice are as follows:



	Year Ended December 31,
(In thousands)	2017		2016		2015
Sales by Domestic and International
Domestic	$	33,147	$	32,050	$	24,540
International	5,736		4,577		4,980
Total	$	38,883	$	36,627	$	29,520