Right of use assets and related obligations - Lease expense (Detail) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Lease, Cost	$ 369,263	$ 292,235
Anesthesia Services [Member]
Lease, Cost	118,943	74,265
Product Sales [Member]
Lease, Cost	125,160	108,985
Corporate Segment [Member]
Lease, Cost	$ 125,160	$ 108,985

Amount of lease cost recognized by lessee for lease contract.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 55
-Paragraph 53
-URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971

Name:	us-gaap_LeaseCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration