Summary of Significant Accounting Policies and Select Balance Sheet Information - Schedule of Accrued Other Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Accrued Liabilities Current [Abstract]
Accrued professional fees	$ 489	$ 239
Accrued clinical study expense	1,667	2,206
Accrued purchases	1,195	647
Acquisition of in-process research and development and intangible assets	494	1,148
Due to customers	112	321
Construction-in-progress	23	272
Operating lease liability, current portion	518	436
Other	407	278
Total accrued other liabilities	$ 4,905	$ 5,547