Condensed Consolidated Balance Sheets (USD $)	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 27,151,258	$ 10,955,403
Available-for-sale securities		10,403,315
Accounts receivable, less allowance of $10,160 in 2011 and $10,160 in 2010	4,130,940	4,196,361
Inventory	7,628,018	10,539,116
Assets held for sale		1,000,000
Prepaid expenses and other current assets	1,357,134	1,584,466
Total current assets	40,267,350	38,678,661
Restricted cash	525,000	525,000
Property, plant and equipment, net	9,506,063	9,838,631
Investment in leased property, net		263,239
Intangible assets, net	8,848,390	9,871,394
Total assets	59,146,803	59,176,925
Current liabilities:
Accounts payable	1,208,218	3,560,048
Accrued expenses	3,644,267	4,336,229
Product warranty reserve	971,100	862,480
Current portion long term debt		9,956
Deferred revenue	3,748,253	4,349,749
Other current liabilities	70,698	1,901,372
Total current liabilities	9,642,536	15,019,834
Warrant liability	6,977,623
Other liabilities	1,273,575	1,243,728
Total liabilities	17,893,734	16,263,562
Stockholders' equity:
Common stock, $0.01 par value per share; 245,000,000 shares authorized; Issued (including shares in treasury): 22,574,555 at June 30, 2011 and 13,369,924 at December 31, 2010	225,745	1,336,992
Additional paid-in capital	782,834,787	769,659,871
Accumulated other comprehensive income	1,070,402	965,868
Accumulated deficit	(741,325,726)	(727,329,858)
Less common stock in treasury: 165,741 shares at June 30, 2011 and 180,449 shares at December 31, 2010	(1,552,139)	(1,719,510)
Total stockholders' equity	41,253,069	42,913,363
Total liabilities and stockholders' equity	$ 59,146,803	$ 59,176,925