Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Total
Balance at Jul. 31, 2017	$ 631,000	$ 110,141,000	$ (109,482,000)	$ 1,290,000
Balance, shares at Jul. 31, 2017	63,093,153
Issuance of common stock in private placements, net
Issuance of common stock in private placements, net, shares
Share-based compensation expense - stock options		1,280,000		1,280,000
Share-based compensation expense - restricted stock units		696,000		696,000
Stock issued for services	$ 1,000	50,000		51,000
Stock issued for services, shares	50,000
Warrant liability removed due to warrant exercise and cancellation		1,394,000		1,394,000
Issuance of common stock for vested restricted stock units
Issuance of common stock for vested restricted stock units, shares	18,750
Issuance of common stock upon the exercise of warrants	$ 49,000	2,584,000		2,633,000
Issuance of common stock upon the exercise of warrants, shares	4,914,505
Warrant inducement		876,000		876,000
Net loss			(6,058,000)	(6,058,000)
Balance at Apr. 30, 2018	$ 681,000	117,021,000	(115,540,000)	2,162,000
Balance, shares at Apr. 30, 2018	68,076,408
Balance at Jan. 31, 2018	$ 681,000	116,441,000	(113,848,000)	3,274,000
Balance, shares at Jan. 31, 2018	68,057,658
Share-based compensation expense - stock options		429,000		429,000
Share-based compensation expense - restricted stock units		151,000		151,000
Stock issued for services
Stock issued for services, shares	18,750
Issuance of common stock upon the exercise of warrants
Issuance of common stock upon the exercise of warrants, shares
Warrant inducement
Net loss			(1,692,000)	(1,692,000)
Balance at Apr. 30, 2018	$ 681,000	117,021,000	(115,540,000)	2,162,000
Balance, shares at Apr. 30, 2018	68,076,408
Balance at Jul. 31, 2018	$ 683,000	117,522,000	(116,924,000)	1,281,000
Balance, shares at Jul. 31, 2018	68,248,158
Issuance of common stock in private placements, net	$ 33,000	1,464,000		1,497,000
Issuance of common stock in private placements, net, shares	3,333,964
Share-based compensation expense - stock options		1,330,000		1,330,000
Share-based compensation expense - restricted stock units		1,007,000		1,007,000
Stock issued for services
Stock issued for services, shares
Warrant liability removed due to warrant exercise and cancellation
Issuance of common stock for vested restricted stock units	$ 1,000	(1,000)
Issuance of common stock for vested restricted stock units, shares	131,250
Issuance of common stock upon the exercise of warrants	$ 24,000	816,000		840,000
Issuance of common stock upon the exercise of warrants, shares	2,399,999
Warrant inducement		960,000		960,000
Net loss			(5,735,000)	(5,735,000)
Balance at Apr. 30, 2019	$ 741,000	123,098,000	(122,659,000)	1,180,000
Balance, shares at Apr. 30, 2019	74,113,371
Balance at Jan. 31, 2019	$ 717,000	121,186,000	(120,786,000)	1,117,000
Balance, shares at Jan. 31, 2019	71,713,372
Share-based compensation expense - stock options		83,000		83,000
Share-based compensation expense - restricted stock units		53,000		53,000
Stock issued for services
Stock issued for services, shares
Issuance of common stock upon the exercise of warrants	$ 24,000	816,000		840,000
Issuance of common stock upon the exercise of warrants, shares	2,399,999
Warrant inducement		960,000		960,000
Net loss			(1,873,000)	(1,873,000)
Balance at Apr. 30, 2019	$ 741,000	$ 123,098,000	$ (122,659,000)	$ 1,180,000
Balance, shares at Apr. 30, 2019	74,113,371