6 Months Ended
Apr. 30, 2017
Apr. 30, 2016
Reconciliation of net loss to net cash used in operating activities:    
Net loss $ (1,428,771) $ (2,864,983)
Stock option compensation to employees and directors 451,655 329,749
Common stock issued to consultants 17,811 11,361
Depreciation of property and equipment 21,278 13,881
Amortization of patents 162,648 162,648
Accretion of interest on patent acquisition obligations to interest expense 228,026 250,881
Accrued interest on secured debenture 30,000
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:    
Prepaid expenses and other current assets 97,422 87,496
Accounts payable and accrued expenses 161,267 132,031
Royalties and contingent legal fees payable (18,883)
Net cash used in operating activities (1,806,272) (1,884,019)
Cash flows from investing activities:    
Disbursements to acquire short-term investments in certificates of deposit (2,250,000) (1,550,000)
Proceeds from maturities of short-term investments in certificates of deposit 750,000 1,800,000
Payments for purchases of property and equipment (14,121) (141,110)
Net cash (used in) provided by investing activities (1,514,121) 108,890
Cash flows from financing activities:    
Redemption of convertible preferred stock (500,000)
Proceeds from sale of common stock through a rights offering to shareholders 4,203,302
Proceeds from exercise of employee stock options 5,665 18,231
Net cash provided by financing activities 3,708,967 18,231
Net increase (decrease) in cash and cash equivalents 388,574 (1,756,898)
Cash and cash equivalents at beginning of period 2,488,323 4,369,219
Cash and cash equivalents at end of period 2,876,897 2,612,321
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) $ (4,399,902)