CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	3 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operating activities:
Net loss	$ (4,594)	$ (5,980)
Adjustments required to reconcile net loss to net cash used for operating activities:
Depreciation and amortization	1,046	959
Bad debt expense	15	53
Stock-based compensation	2,332	1,371
Write-down of inventory	156	623
Loss on disposal of fixed assets		5
Deferred tax provision	96	243
Gain on sale of WorldHeart common stock		(239)
Changes in assets and liabilities source (use):
Accounts receivable	847	767
Inventories	(1,601)	645
Prepaid expenses and other current assets	220	292
Accounts payable	(1,360)	705
Accrued expenses	(5,443)	(2,169)
Deferred revenue	(270)	78
Net cash used for operating activities	(8,556)	(2,647)
Investing activities:
Purchases of short-term marketable securities	(5,001)	(1,501)
Proceeds from the sale and maturity of short-term marketable securities	4,500	4,000
Proceeds from the sale of WorldHeart common stock		239
Expenditures for property and equipment	(472)	(289)
Net cash (used in) provided by investing activities	(973)	2,449
Financing activities:
Proceeds from the exercise of stock options	7,629	94
Net cash provided by financing activities	7,629	94
Effect of exchange rate changes on cash	220	(743)
Net decrease in cash and cash equivalents	(1,680)	(847)
Cash and cash equivalents at beginning of period	5,831	4,788
Cash and cash equivalents at end of period	4,151	3,941
Supplemental disclosure:
Fixed asset additions included in accounts payable	$ 44	$ 31