Consolidated Balance Sheets - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 4,662,897	$ 5,488,706
Accounts receivable, net	3,094,987	3,322,400
Inventories	1,783,787	1,595,668
Other current assets	324,658	879,365
Assets associated with discontinued operations	52,020	85,349
Total current assets	9,918,349	11,371,488
Property and equipment:
Leasehold improvements	151,377	151,377
Equipment at customers	3,872,730	3,762,632
Machinery and equipment	5,121,410	4,913,595
Accumulated depreciation and amortization	(6,641,029)	(6,266,097)
Property and equipment, net	2,504,488	2,561,507
Intangible and other assets, net	800,564	790,971
Total assets	13,223,401	14,723,966
Current liabilities:
Accounts payable	1,138,449	1,074,939
Accrued expenses	1,785,470	2,239,985
Notes payable	44,006	70,015
Current portion of long-term debt, less unamortized debt issuance costs	1,517,921	840,471
Liabilities associated with discontinued operations	17,578	92,942
Total current liabilities	4,503,424	4,318,352
Deferred gain on sale and leaseback of property	57,944	91,603
Long-term debt, less current portion and unamortized debt issuance costs	5,971,690	6,580,851
Other long-term liabilities	320,000	320,000
Total liabilities	10,853,058	11,310,806
Commitments and contingencies
Stockholders' equity:
Common stock, $.004 par value per share, 60,000,000 shares authorized, 28,315,081 and 27,428,752 shares issued at March 31, 2017 and December 31, 2016, respectively, including shares held in treasury	113,260	109,715
Common stock held in treasury, at cost - 86,000 shares	(101,480)	(101,480)
Additional paid-in capital	31,354,231	30,557,093
Accumulated deficit	(42,933,308)	(41,089,808)
Total stockholders' equity	2,370,343	3,413,160
Total liabilities and stockholders' equity	13,223,401	14,723,966
Series A Convertible Preferred Stock [Member]
Stockholders' equity:
Preferred stock, $.001 par value per share, 1,000,000 shares authorized	8,802,000	8,802,000
Series A Exchangeable Preferred Stock [Member]
Stockholders' equity:
Preferred stock, $.001 par value per share, 1,000,000 shares authorized	$ 5,135,640	$ 5,135,640