The accounting standards for reporting information about operating segments define operating segments as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker, who is the Company’s Chief Executive Officer, in deciding how to allocate resources and in assessing performance. For financial accounting and reporting purposes, the Company reports its results for the two reportable segments as follows: (1) the Medical Device unit, which designs, develops and manufactures interventional medical devices, primarily for the peripheral vascular market; surface modification coating technologies to improve access, deliverability, and predictable deployment of medical devices; as well as drug-delivery coating technologies to provide site-specific drug-delivery from the surface of a medical device, with end markets that include coronary, peripheral, neuro-vascular and urology, among others, and (2) the In Vitro Diagnostics unit, which consists of component products and technologies for diagnostic test kits and biomedical research applications, with products that include protein stabilization reagents, substrates, antigens and surface coatings.

The tables below present segment revenue, operating income from continuing operations and depreciation and amortization, for the years ended September 30, as follows (in thousands):

	2019			2018			2017
Revenue:
Medical Device	$	78,353		$	60,513		$	53,983
In Vitro Diagnostics		21,724			20,823			19,129
Total revenue	$	100,077		$	81,336		$	73,112

Operating income (loss):
Medical Device	$	4,794		$	(8,478	)	$	6,902
In Vitro Diagnostics		10,620			8,619			8,293
Total segment operating income		15,414			141			15,195
Corporate		(8,945	)		(8,940	)		(8,092	)
Total operating income (loss)	$	6,469		$	(8,799	)	$	7,103

Depreciation and amortization:
Medical Device	$	5,811		$	5,376		$	4,453
In Vitro Diagnostics		464			394			412
Corporate		1,037			661			690
Total depreciation and amortization	$	7,312		$	6,431		$	5,555

The Corporate category includes expenses that are not fully allocated to Medical Device and In Vitro Diagnostics segments. These Corporate costs are related to functions, such as executive management, corporate accounting, legal, human resources and Board of Directors. Corporate may also include expenses, such as litigation, which are not specific to a segment and thus not allocated to the operating segments.

Asset information by segment is not presented because the Company does not provide its chief operating decision maker assets by segment, as the data is not readily available.

Revenue from customers that equaled or exceeded 10% of total revenue was as follows for the years ended September 30:

The revenue from the customers listed is derived from two primary sources: licensing and product sales (primarily in the Medical Device segment).

Long-lived assets, including property and equipment and intangible assets net of accumulated depreciation and amortization, respectively, by country were as follows as of September 30: