Stock Based Compensation Expense (Detail) (USD $)	3 Months Ended
	Jun. 29, 2012	Jul. 01, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	$ 29,000	$ 36,000
Cost of Products Sold
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	3,000	4,000
Research and Development expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	7,000	13,000
General and Administrative expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	17,000	16,000
Sales and Marketing expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	$ 2,000	$ 3,000