9 Months Ended
Jul. 31, 2017
Jul. 31, 2016
Reconciliation of net loss to net cash used in operating activities:    
Net loss $ (3,223,171) $ (3,968,758)
Stock option compensation to employees and directors 932,773 570,190
Common stock issued to consultants 17,811 27,996
Depreciation of property and equipment 32,096 24,915
Amortization of patents 243,973 243,972
Accretion of interest on patent acquisition obligations to interest expense 228,026 383,238
Accrued interest on secured debenture 20,667
Gain on extinguishment of patent acquisition obligation (1,547,608)
Common stock issued to acquire patent license 11,800
Change in operating assets and liabilities:    
Accounts receivable (221,049)
Prepaid expenses and other current assets 21,795 70,100
Accounts payable and accrued expenses 437,265 150,859
Royalties and contingent legal fees payable (213,017)
Net cash used in operating activities (3,057,422) (2,698,705)
Cash flows from investing activities:    
Disbursements to acquire short-term investments in certificates of deposit (4,251,000) (1,900,000)
Proceeds from maturities of short-term investments in certificates of deposit 750,000 2,400,000
Purchase of property and equipment (16,885) (144,650)
Net cash (used in) provided by investing activities (3,517,885) 355,350
Cash flows from financing activities:    
Redemption of convertible preferred stock (500,000)
Payments made on secured debenture (1,000,000)
Proceeds from sale of common stock through a rights offering to shareholders 4,203,302
Proceeds from sale of common stock through a public offering 3,211,785
Proceeds from exercise of employee stock options 5,665 23,381
Net cash provided by financing activities 5,920,752 23,381
Net decrease in cash and cash equivalents (654,555) (2,319,974)
Cash and cash equivalents at beginning of period 2,488,323 4,369,219
Cash and cash equivalents at end of period 1,833,768 2,049,245
Supplemental disclosure of non-cash financing activities:    
Redemption of Series A convertible preferred stock into secured debenture (Note 7) (3,000,000)
Common stock issued to pay patent acquisition obligation (Note 6) $ (2,852,294)