Consolidated Statements of Cash Flows (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating Activities
Net income	$ 2,805,000	$ 4,424,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	1,644,000	2,251,000
Amortization	680,000	677,000
Gain on equipment disposals		(2,000)
Gain on revaluation of ACT liability		(758,000)
Deferred income taxes	(170,000)	410,000
Stock based compensation	844,000	2,197,000
Bad debt write-off (recovery)	(113,000)	32,000
Changes in operating assets and liabilities:
Accounts receivable	4,890,000	(6,502,000)
Inventories	(646,000)	(44,000)
Prepaid expenses, other current assets and other noncurrent assets	741,000	199,000
Accounts payable	(653,000)	846,000
Accrued liabilities and other noncurrent liabilities	(3,488,000)	(666,000)
Net cash provided by operating activities	6,534,000	3,064,000
Investing Activities
Proceeds from the sale of equipment		2,000
Purchases of property, equipment and patents	(2,071,000)	(1,700,000)
Net cash used in investing activities	(2,071,000)	(1,698,000)
Financing Activities
Proceeds from exercise of stock options		336,000
Payments to repurchase common stock	(7,889,000)	(3,367,000)
Excess income tax benefits from exercise of stock options		74,000
Net cash used in financing activities	(7,889,000)	(2,957,000)
Effect of exchange rate fluctuations on cash	(320,000)	65,000
Net decrease in cash and cash equivalents	(3,746,000)	(1,526,000)
Cash and cash equivalents at beginning of period	28,229,000	30,524,000
Cash and cash equivalents at end of period	$ 24,483,000	$ 28,998,000