Quarterly report pursuant to Section 13 or 15(d)

Balance Sheet Components - Additional Information (Details)

v3.22.1
Balance Sheet Components - Additional Information (Details)
3 Months Ended 12 Months Ended
Mar. 31, 2022
USD ($)
Customer
Mar. 31, 2021
USD ($)
Customer
Dec. 31, 2021
USD ($)
Customer
Schedule Of Balance Sheet Components [Line Items]      
Accounts receivable, net $ 33,983,000   $ 24,452,000
Percentage of Non-US revenue invoiced in Euros 73.20% 79.30%  
Transfer of inventory to rental equipment $ 533,000 $ 607,000  
Salvage value of expenditures for additions, improvements and replacements 0    
Repairs and maintenance expense 1,030,000 935,000  
Depreciation and amortization 3,613,000 2,834,000  
Impairments of long-lived assets 0 0  
Goodwill impairment loss 0    
Impairment of finite lived intangible assets 0   0
Construction in Process and Computer Software or Development Cost      
Schedule Of Balance Sheet Components [Line Items]      
Depreciation and amortization 0 $ 0  
Other Noncurrent Assets      
Schedule Of Balance Sheet Components [Line Items]      
Noncurrent inventories expected to be realized or consumed 797,000   1,943,000
Prepaid Expenses and Other Current Assets      
Schedule Of Balance Sheet Components [Line Items]      
Inventory raw materials 10,968,000   15,426,000
Customer Concentration Risk | Customer One      
Schedule Of Balance Sheet Components [Line Items]      
Accounts receivable, net 5,778,000   5,945,000
Customer Concentration Risk | Customer Two      
Schedule Of Balance Sheet Components [Line Items]      
Accounts receivable, net 4,268,000    
Customer Concentration Risk | Customer Three      
Schedule Of Balance Sheet Components [Line Items]      
Accounts receivable, net 3,673,000    
Customer Concentration Risk | Medicare's Service Reimbursement Programs      
Schedule Of Balance Sheet Components [Line Items]      
Accounts receivable, net $ 3,461,000   $ 2,685,000
Sales Revenue, Net | Customer Concentration Risk      
Schedule Of Balance Sheet Components [Line Items]      
Number of customers | Customer   1  
Sales Revenue, Net | Customer Concentration Risk | Medicare's Service Reimbursement Programs      
Schedule Of Balance Sheet Components [Line Items]      
Concentration Risk, Percentage 12.80% 9.50%  
Net Accounts Receivable | Customer Concentration Risk      
Schedule Of Balance Sheet Components [Line Items]      
Number of customers | Customer 3   1
Net Accounts Receivable | Customer Concentration Risk | Medicare's Service Reimbursement Programs      
Schedule Of Balance Sheet Components [Line Items]      
Concentration Risk, Percentage 10.20%   11.00%
Rental Revenue | Customer Concentration Risk | Medicare's Service Reimbursement Programs      
Schedule Of Balance Sheet Components [Line Items]      
Concentration Risk, Percentage 79.00% 83.90%  
Raw materials | Supplier Concentration Risk | Vendor one      
Schedule Of Balance Sheet Components [Line Items]      
Concentration Risk, Percentage 25.20% 19.90%  
Raw materials | Supplier Concentration Risk | Vendor two      
Schedule Of Balance Sheet Components [Line Items]      
Concentration Risk, Percentage 19.90% 10.80%  
Raw materials | Supplier Concentration Risk | Vendor three      
Schedule Of Balance Sheet Components [Line Items]      
Concentration Risk, Percentage 8.40% 9.60%