Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net loss	$ (2,647)	$ (2,630)
Depreciation and amortization	204	189
Stock-based compensation expense	443	476
(Recovery of) provision for bad debt expenses	(9)	17
Debt cost expense	144	41
Loss on disposal of fixed assets	6	1
Changes in assets and liabilities:
Accounts receivable	(54)	405
Inventories	(310)	(777)
Prepaid expenses and other current assets	(70)	(94)
Accounts payable	241	(73)
Accrued expenses	(110)	(158)
Accrued compensation	143	166
Deferred revenue	27
Net cash used in operating activities	(2,360)	(4,098)
Cash flows from investing activities:
Purchases of property and equipment	(36)	(76)
Proceeds from disposal of fixed assets	6
Net cash used in investing activities	(30)	(76)
Cash flows from financing activities:
Proceeds from exercise of stock options	6	207
Net proceeds from sale of common stock	878
Common stock repurchased		(4)
Payments of capital leases	(24)	(18)
Net cash provided by financing activities	860	185
Net decrease in cash and cash equivalents	(1,530)	(3,989)
Cash and cash equivalents at beginning of period	2,674	9,180
Cash and cash equivalents at end of period	1,144	5,191
Supplemental disclosure of cash flow information:
Interest	157	98
Income taxes	7	3
Non-cash financing activities:
Net transfers of inventory to fixed assets for use as demonstration equipment	57	110
Capital lease entered into for equipment purchase		135
Advances from Customers [Member]
Changes in assets and liabilities:
Deferred revenue	$ (368)	$ (1,661)