12. Commitments and Contingencies (Detail) - (Table 2) Table of Product Warranty Liability Activity (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Product warranty liability at beginning of period	$ 140,000	$ 25,000
Additions to warranty accrual (including changes in estimates)	385,625	251,885
Warranty expenses during the period	(262,625)	(136,885)
Product warranty liability at end of period	$ 263,000	$ 140,000