Other intangible assets with definite lives (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016	Jan. 31, 2017
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Finite-Lived Intangible Assets, Amortization Method			Patents are capitalized and amortized on a straight-line basis over a period not to exceed the legal lives of the patents.
Finite Lived Intangible Assets, Intent or Ability to Renew or Extend Arrangement			The Company expenses costs incurred to renew or extend the term of intangible assets
Gross patents	$ 2,630,000		$ 2,630,000
Accumulated amortization	2,400,000		2,400,000		$ 2,380,000
Amortization expense, next twelve months	44,700		44,700
Amortization expense, year two	36,600		36,600
Amortization expense, year three	33,700		33,700
Amortization expense, year four	27,100		27,100
Amortization expense, year five	17,500		17,500
Amortization expense, thereafter	93,900		93,900
Patent amortization expense	$ 11,000	$ 11,000	$ 22,000	$ 22,000