Revenue Recognition

12 Months Ended

Dec. 31, 2023

Revenue from Contract with Customer [Abstract]

Revenue Recognition

Revenue Recognition

Revenue by Service Line

	Years Ended December 31,
(in thousands)	2023		2022
Biologics and drug delivery
Disposable products	$	2,154	$	3,690
Services and license fees	11,448		5,430
Subtotal – Biologics and drug delivery revenue	13,602		9,120
Functional neurosurgery navigation and therapy
Disposable products	7,589		7,587
Services	931		1,537
Subtotal – Functional neurosurgery navigation and therapy revenue	8,520		9,124
Capital equipment and software
Systems and software products	860		1,512
Services	973		795
Subtotal – Capital equipment and software revenue	1,833		2,307
Total revenue	$	23,955	$	20,551

Contract Balances

•Contract assets – The timing of revenue recognition may differ from the time of billing to the Company's customers. In most cases, customers are billed upon shipment of such products or delivery of such services and the related contract assets, which represent an unconditional right to consideration, and comprise the accounts receivable balance. When revenue is recognized in advance of its right to bill and receive consideration, the Company records this unbilled receivable as a contract asset, which is classified as other current assets in the accompanying consolidated balance sheets. Additionally, at December 31, 2022 the Company had deferred contract costs related to up-front costs for direct materials incurred to fulfill a customer contract. These costs were classified as other current assets and were recognized as expense in 2023.

	December 31, 2023		December 31, 2022
(in thousands)
Accounts receivable, net	$	3,211	$	2,665
Other contract assets
Unbilled receivables	$	733	$	43
Deferred contract costs	$	—	$	327

•Contract liabilities – Contract liabilities consist of amounts that have been invoiced and for which the Company has the right to bill, but that have not been recognized as revenue as the related goods or services have not been transferred. The Company's contract liabilities are generally comprised of the following (1) capital equipment and software-related service fees that are typically billed and collected at the inception of the service agreements, which have terms ranging from one to three years; (2) annual fees for agreements with customers that bundle the capital equipment and software-related service fees with software and hardware upgrades that are made commercially available over the term of the contract; and (3) up-front payments from customers made in connection with consulting services. The unearned portion of all such fees is classified as deferred revenue. At December 31, 2022, the Company also had a $0.5 million refund liability resulting from an up-front customer payment which was potentially refundable if the parties did not enter into the ensuing agreement. In 2023, the uncertainties underlying this amount were resolved and the amount was recognized as revenue.

	December 31, 2023		December 31, 2022
(in thousands)
Deferred revenues	$	3,154	$	1,457
Refund Liability	$	—	$	500

During the years ended December 31, 2023 and 2022, the Company recognized capital equipment and software-related service revenue of approximately $1.1 million and $0.5 million, respectively, which was previously included in deferred revenue in the accompanying consolidated balance sheets at December 31, 2022 and 2021, respectively.

Transaction price allocated to remaining performance obligations represents contracted revenue that has not yet been recognized, which includes deferred revenue that will be recognized as revenue in future periods. The majority of the remaining performance obligations relate to capital equipment and software-related service agreements and the upfront payments discussed under the heading “Contract Balances” above, which amounted to approximately $2.9 million at December 31, 2023. The Company expects to recognize approximately 80% of this revenue over the next twelve months and the remainder thereafter.