Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Mar. 31, 2017	Sep. 30, 2016
ASSETS
Cash and cash equivalents	$ 14,563,812	$ 13,466,711
Short-term marketable securities	3,463,710	2,936,124
Accounts receivable	3,240,729	3,408,912
Inventories, net	5,120,115	4,763,909
Prepaid expenses and other	696,942	595,638
Total current assets	27,085,308	25,171,294
Long-term marketable securities	1,556,679	2,187,536
Deferred tax assets	8,844,243	8,527,000
Property and equipment, net	471,664	473,344
Intangible assets, net	63,510	62,905
Other assets	258,266	391,454
Total assets	38,279,670	36,813,533
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable	1,282,115	574,566
Accrued liabilities	2,188,586	1,503,044
Total current liabilities	3,470,701	2,077,610
Other liabilities, noncurrent	112,240	165,038
Total liabilities	3,582,941	2,242,648
Commitments and contingencies (Note 9)
Stockholders' equity:
Preferred stock, $0.00001 par value; 5,000,000 shares authorized; none issued and outstanding	0	0
Common stock, $0.00001 par value; 50,000,000 shares authorized; 31,800,103 shares issued and outstanding	318	318
Additional paid-in capital	87,109,366	86,467,215
Accumulated deficit	(52,409,428)	(51,895,099)
Accumulated other comprehensive loss	(3,527)	(1,549)
Total stockholders' equity	34,696,729	34,570,885
Total liabilities and stockholders' equity	$ 38,279,670	$ 36,813,533

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.