Note 10 — Property and Equipment

Property and equipment, net consisted of the following:


	December 31, 2012			December 31, 2011
Medical equipment	$	3,033,792		$	1,283,726
Office equipment		87,163			73,927
Manufacturing equipment		303,143			262,290
Leasehold improvements		390,911			—
		3,815,009			1,619,943
Less accumulated depreciation and amortization		(1,374,928	)		(641,050	)
	$	2,440,081		$	978,893

Medical equipment, whose accumulated depreciation was approximately $902,000 and $521,000 at December 31, 2012 and 2011, respectively, primarily represents centrifuges that are leased or held for lease.

Depreciation expense was approximately $823,000 and $364,000, of which $446,000 and $321,000 were reported as cost of sales, for the years ended December 31, 2012 and 2011, respectively. The net book value of property and equipment disposed was $554,000 in 2012 and $48,000 in 2011. The disposal of property and equipment was primarily due to the sale of centrifuges.