Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating Activities:
Net income	$ 9,687,816	$ 3,327,088
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	$ 238,314	209,975
Provision for doubtful accounts		(3,772)
Warranty provision	$ 42,645	157,819
Inventory obsolescence	65,692	36,967
Share-based compensation	$ 619,201	585,753
Loss on sale or impairment of patents		$ 6,980
Deferred income taxes	$ (8,339,000)
Changes in operating assets and liabilities:
Accounts receivable	2,167,728	$ 678,253
Inventories	(1,096,128)	655,047
Prepaid expenses and other	(41,719)	479,928
Prepaid expenses and other, noncurrent	187,485	148,093
Accounts payable	(126,561)	(765,906)
Warranty settlements	(41,338)	(56,267)
Accrued and other liabilities	(3,228,324)	2,942,897
Net cash provided by operating activities	135,811	$ 8,402,855
Investing Activities:
Purchases of marketable securities	(4,299,414)
Capital expenditures	(344,266)	$ (326,957)
Patent costs paid	(10,477)	(14,890)
Net cash used in investing activities	(4,654,157)	(341,847)
Financing Activities:
Repurchase of common stock	(1,564,666)	(516,352)
Proceeds from exercise of stock options	504,371	544,893
Net cash (used in) provided by financing activities	(1,060,295)	28,541
Net (decrease) increase in cash	(5,578,641)	8,089,549
Cash and cash equivalents, beginning of period	23,894,744	15,805,195
Cash and cash equivalents, end of period	$ 18,316,103	23,894,744
Supplemental Disclosure of Cash Flow Information
Cash paid for taxes		$ 14,445