FINANCING ARRANGEMENTS (Details)		12 Months Ended
	Jul. 01, 2015 USD ($) item	Dec. 31, 2018	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 15, 2017 USD ($)
Financing arrangements
Loss on Extinguishment of Debt			$ 174,834
Total long-term debt			5,656,872	$ 6,585,298
Discount on Devicix Notes Payable			(62,776)	(102,424)
Debt Issuance Costs			(238,468)	(25,896)
Long-term Debt			5,355,628	6,456,978
Current maturities of long-term debt			(1,002,586)	(1,565,347)
Long-term debt - net of current maturities			4,353,042	4,891,631
Future maturity requirements for long-term debt
2018			1,095,722
2019			805,880
2020			497,892
2021			497,892
2022			497,892
Future			2,261,594
Total long-term debt			$ 5,656,872	6,585,298
Devicix, LLC
Financing arrangements
Number of promissory notes | item	2
Line of credit
Financing arrangements
Weighted-average interest rate (as a percent)			3.74%
Outstanding balance			$ 8,502,853	7,315,262
Unused availability supported by entity's borrowing base			4,231,000	$ 5,710,602
Line of credit | Maximum
Financing arrangements
Interest rate margin on variable rate basis (as a percent)				3.75%
Line of credit | Minimum
Financing arrangements
Interest rate margin on variable rate basis (as a percent)				3.25%
Real estate term note 2 maturing on December 31, 2027
Financing arrangements
Maximum borrowing capacity			3,500,000
Capital Term loan
Financing arrangements
Debt instrument, face amount				$ 1,000,000
Outstanding balance				684,000
Capital Term loan | Maximum
Financing arrangements
Debt instrument, face amount			1,000,000
Equipment term loan tied to equipment purchased in Mankato acquisition
Financing arrangements
Debt instrument, face amount			2,700,000
Industrial revenue bond payable to the City of Blue Earth, Minnesota
Financing arrangements
Long-term Debt				200,000
Principal and interest payments			$ 80,000
Devicix Acq Note 1, subordinate debt, due July 1, 2019
Financing arrangements
Interest rate (as a percent)			4.00%
Long-term Debt			$ 393,834	643,585
Devicix Acq Note 2, subordinate debt, due July 1, 2019
Financing arrangements
Interest rate (as a percent)			4.00%
Long-term Debt			$ 511,984	836,661
Promissory note subject to offsets | Devicix, LLC
Financing arrangements
Promissory note liability	$ 1,000,000
Term of promissory note	4 years
Interest rate per annum	4.00%
Principal and interest payments	$ 22,579
Promissory note not subject to offsets | Devicix, LLC
Financing arrangements
Promissory note liability	$ 1,300,000
Term of promissory note	4 years
Interest rate per annum	4.00%
Principal and interest payments	$ 29,353
Bank of America | Line of credit
Financing arrangements
Maximum borrowing capacity					$ 16,000,000
Bank of America | Real estate term notes
Financing arrangements
Debt instrument, face amount					$ 5,000,000
Variable rate basis			one-month LIBOR
Interest rate margin on variable rate basis (as a percent)			2.25%
Interest rate (as a percent)			4.50%
Long-term Debt			$ 4,751,054
Principal and interest payments			41,000
Bank of America | Credit Agreement
Financing arrangements
Minimum fixed charge coverage ratio		1.00
Wells Fargo Bank, N.A.
Financing arrangements
Loss on Extinguishment of Debt			$ 174,834
Wells Fargo Bank, N.A. | Line of credit
Financing arrangements
Maximum borrowing capacity				15,000,000
Outstanding balance				7,315,262
Wells Fargo Bank, N.A. | Real estate term notes
Financing arrangements
Variable rate basis			three month LIBOR
Interest rate margin on variable rate basis (as a percent)			2.75%
Long-term Debt				2,415,428
Wells Fargo Bank, N.A. | Equipment notes maturing in May 2018
Financing arrangements
Variable rate basis			three-month LIBOR
Interest rate margin on variable rate basis (as a percent)			2.75%
Long-term Debt				$ 2,489,624