Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Mar. 31, 2018	Sep. 30, 2017
Current assets:
Cash and cash equivalents	$ 12,732,882	$ 12,764,421
Short-term marketable securities	4,063,109	4,359,542
Restricted cash	363,745	39,466
Accounts receivable, net	5,718,396	5,681,882
Inventories, net	5,443,342	5,257,234
Prepaid expenses and other	845,831	983,322
Total current assets	29,167,305	29,085,867
Long-term marketable securities	991,178	711,124
Deferred tax assets, net	5,463,661	8,331,000
Long-term restricted cash	104,146
Property and equipment, net	483,467	509,603
Goodwill	2,603,687
Intangible assets, net	1,833,847	55,689
Other assets	242,196	164,517
Total assets	40,889,487	38,857,800
Current liabilities:
Accounts payable	1,890,427	1,112,366
Accrued liabilities	3,414,362	2,561,395
Notes payable, current portion	896,317
Total current liabilities	6,201,106	3,673,761
Notes payable, less current portion	269,231
Total liabilities	6,470,337	3,673,761
Commitments and contingencies (Note 12)
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; 32,394,288 and 32,158,436 shares issued and outstanding, respectively	322	322
Additional paid-in capital	88,426,807	87,956,839
Accumulated deficit	(53,994,197)	(52,771,853)
Accumulated other comprehensive loss	(13,782)	(1,269)
Total stockholders' equity	34,419,150	35,184,039
Total liabilities and stockholders' equity	$ 40,889,487	$ 38,857,800

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).

Name:	us-gaap_AccountsPayableCurrent
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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682