Schedule of Stock Option Activity (Details) - $ / shares	6 Months Ended
Oct. 31, 2021
Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Underlying Options Outstanding, Beginning	516,827
Weighted Average Exercise Price, Beginning Balance	$ 3.89
Weighted Average Remaining Contractual Term (In Years), Beginning	9 years
Shares Underlying Options Outstanding, Granted
Weighted Average Exercise Price, Granted
Shares Underlying Options Outstanding, Exercised	(6,666)
Weighted Average Exercise Price, Exercised	$ 1.05
Shares Underlying Options Outstanding, Expired	(1,806)
Weighted Average Exercise Price, Expired	$ 32.62
Shares Underlying Options Outstanding, Cancelled/forfeited	(110,382)
Weighted Average Exercise Price, Cancelled/forfeited	$ 2.58
Shares Underlying Options Outstanding, Ending	397,973
Weighted Average Exercise Price, Ending Balance	$ 4.16
Weighted Average Remaining Contractual Term (In Years), Ending	8 years 4 months 24 days
Shares Underlying Options Outstanding, Exercisable at Ending	239,780
Weighted Average Exercise Price, Exercisable at Ending	$ 4.98
Weighted Average Remaining Contractual Term (In Years), Exercisable at Ending	7 years 9 months 18 days
Performance Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Underlying Options Outstanding, Beginning	424,790
Weighted Average Exercise Price, Beginning Balance	$ 2.57
Weighted Average Remaining Contractual Term (In Years), Beginning	9 years 6 months
Shares Underlying Options Outstanding, Granted	66,667
Weighted Average Exercise Price, Granted	$ 0.62
Shares Underlying Options Outstanding, Exercised	(13,334)
Weighted Average Exercise Price, Exercised	$ 1.05
Shares Underlying Options Outstanding, Cancelled/forfeited	(193,433)
Weighted Average Exercise Price, Cancelled/forfeited	$ 2.80
Shares Underlying Options Outstanding, Ending	284,690
Weighted Average Exercise Price, Ending Balance	$ 2.03
Weighted Average Remaining Contractual Term (In Years), Ending	9 years 1 month 6 days
Shares Underlying Options Outstanding, Exercisable at Ending	27,334
Weighted Average Exercise Price, Exercisable at Ending	$ 1.05
Weighted Average Remaining Contractual Term (In Years), Exercisable at Ending	8 years 2 months 12 days

Weighted Average Remaining Contractual Term (In Years), Ending.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

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