2. Summary of significant accounting policies (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounting Policies [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 100,000	$ 63,000
Depreciation	925,000us-gaap_Depreciation	1,216,000us-gaap_Depreciation	1,183,000us-gaap_Depreciation
Research and Development Expense	4,302,000us-gaap_ResearchAndDevelopmentExpense	4,065,000us-gaap_ResearchAndDevelopmentExpense	4,239,000us-gaap_ResearchAndDevelopmentExpense
Capitalized Computer Software, Net	169,000us-gaap_CapitalizedComputerSoftwareNet	370,000us-gaap_CapitalizedComputerSoftwareNet
Capitalized Computer Software, Amortization	201,000	199,000	189,000
Advertising Expense		$ 1,058,000us-gaap_AdvertisingExpense	$ 949,000us-gaap_AdvertisingExpense	$ 2,013us-gaap_AdvertisingExpense
Trade and Loan Receivables, Method of Accounting for Receivables that Can be Contractually Prepaid, Policy [Policy Text Block]	$1,191,000

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Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 720

-SubTopic 35

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A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 4

-Article 5

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-Section S99

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-Subparagraph (SX 210.5-02.4)

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For each income statement presented, the amount charged to expense for amortization of capitalized computer software costs.

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The carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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-Topic 230

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-Section 45

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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Disclosure of accounting policy for the classification and method of accounting for interest-only strips, loans, other receivables, or retained interests in securitizations that can be contractually prepaid or otherwise settled in a way that the holder would not recover substantially all of its recorded investment.

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