Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Mar. 31, 2016	Sep. 30, 2015
Current assets:
Cash and cash equivalents	$ 14,976,589	$ 18,316,103
Short-term marketable securities	2,633,388	1,251,947
Accounts receivable	2,477,360	2,116,323
Inventories, net	5,202,430	4,926,172
Prepaid expenses and other	648,303	565,666
Total current assets	25,938,070	27,176,211
Long-term marketable securities	2,277,416	3,047,166
Deferred tax assets	9,196,706	8,339,000
Property and equipment, net	504,306	471,963
Intangible assets, net	60,748	58,385
Prepaid expenses and other, noncurrent	485,196	578,938
Total assets	38,462,442	39,671,663
Current liabilities:
Accounts payable	1,442,198	703,942
Accrued liabilities	2,019,057	870,555
Total current liabilities	3,461,255	1,574,497
Other liabilities, noncurrent	174,099	147,954
Total liabilities	3,635,354	1,722,451
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; 31,798,853 and 32,898,461 shares issued and outstanding	318	329
Additional paid-in capital	86,167,846	87,608,034
Accumulated deficit	(51,340,247)	(49,658,850)
Accumulated other comprehensive loss	(829)	(301)
Total stockholders' equity	34,827,088	37,949,212
Total liabilities and stockholders' equity	$ 38,462,442	$ 39,671,663

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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Namespace Prefix:	us-gaap_
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.