Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Cash flows from operating activities:
Net loss	$ 98,838	$ (233,106)	$ (440,830)	$ 315,601
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization of property and equipment	246,890			198,975
Amortization of intangible assets	181,095			180,886
Amortization of other assets	11,218			12,189
Stock-based compensation expense	129,793	115,343	56,082	43,658
Change in allowance for doubtful accounts receivable	0			(12,483)
Change in allowance for inventory obsolescence	(1,740)			(31,046)
Amortization deferred gain on sale/leaseback	(37,611)			(37,612)
Change in fair value of earn-out liability	0			(375,000)
Change in operating assets and liabilities:
Trade accounts receivable	191,301			(713,704)
Inventories	399,279			255,680
Prepaid expenses	(10,900)			(87,373)
Other assets	(4,268)			(12,458)
Income tax receivable	(18,100)			(1,784)
Accounts payable and accrued expenses	806,846			385,821
Net cash provided by operating activities	1,992,641			121,350
Cash flows from investing activities:
Purchase of property and equipment	(65,969)			(26,065)
Net cash used in investing activities	(65,969)			(26,065)
Cash flows from financing activities:
Principal payments on long-term debt	(46,617)			(40,045)
Principal payments on finance lease liability	(72,198)			(58,334)
Payment of acquisition holdbacks	(125,000)			0
Net change in line of credit	(1,463,733)			(1,256,325)
Net cash used in financing activities	(1,707,548)			(1,354,704)
Net change in cash and cash equivalents	219,124			(1,259,419)
Cash and cash equivalents and restricted cash at beginning of the period	256,030		$ 436,697	1,696,116
Cash and cash equivalents and restricted cash at end of the period	475,154	$ 256,030		436,697
Supplemental disclosure of cash flow information:
Cash paid for interest	141,424			133,811
Supplemental disclosure of non-cash investing and financing activity:
Preferred stock dividends paid or to be paid in common stock	166,904			186,637
Finance lease obligations incurred to obtain ROU assets	3,086			0
Operating lease obligations incurred to obtain ROU assets	3,749,809			0
Inventory reclassified to demonstration equipment	$ 0			$ 239,106