Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Jan. 31, 2022	Jan. 31, 2021
Reconciliation of net loss to net cash used in operating activities:
Net loss	$ (3,879)	$ (2,232)
Stock option compensation to employees and directors	2,135	875
Stock options and warrants issued to consultants	219	111
Gain on sale of equipment		(5)
Amortization of operating lease right-to-use asset	10	14
Change in operating assets and liabilities:
Prepaid expenses and other current assets	(188)	(270)
Accounts payable	368	279
Accrued expenses	147	72
Operating lease liability	(9)	(14)
Net cash used in operating activities	(1,197)	(1,170)
Cash flows from investing activities:
Disbursements to acquire short-term investments	(3,499)	(1,000)
Proceeds from maturities of short-term investments	5,349	1,640
Proceeds from sale of equipment		35
Net cash provided by investing activities	1,850	675
Cash flows from financing activities:
Net proceeds from sale of common stock in an at-the-market offering		5,957
Proceeds from exercise of stock options		104
Net cash provided by financing activities		6,061
Net increase in cash and cash equivalents	653	5,566
Cash and cash equivalents at beginning of period	29,128	6,417
Cash and cash equivalents at end of period	$ 29,781	$ 11,983