Long-Term Liabilities (Details) (USD $)	Apr. 26, 2013	Apr. 27, 2012
Long-Term Liabilities [Abstract]
Liability for uncertain tax benefits	$ 3,599,787	$ 2,260,226
Deferred license revenue	1,467,869	2,961,837
Accrued clinical studies and other	381,948	180,126
Total long-term liabilities	$ 5,449,604	$ 5,402,189

Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 13.A.4(a).Q1 Response)

-URI http://asc.fasb.org/extlink&oid=6600647&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 13

-Section A

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- Definition

Total obligations incurred as part of normal operations that is expected to be repaid beyond the following twelve months or one business cycle.

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- Definition

The noncurrent portion of the amount recognized for uncertain tax positions as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.24)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 48

-Paragraph 6, 7, 8

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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The noncurrent portion (due beyond one year or one operating cycle) of other accrued expenses (expenses incurred at the end of the reporting period but not yet paid) not otherwise defined in the taxonomy.

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