| Schedule of accrued expenses and other current liabilities |
| | | | | | | December 31, | | 2021 | | 2020 | | | | | | | | Accrued salaries and commissions | | $ | 3,270,715 | | $ | 2,908,320 | Deferred revenue | | | 1,947,353 | | | 728,351 | Clinical studies | | | 1,767,826 | | | 781,041 | Accrued accounts payable | | | 1,044,088 | | | 631,642 | Accrued royalties | | | 769,262 | | | 916,695 | Professional fees | | | 314,068 | | | 317,575 | Customer rebates | | | 214,119 | | | 305,852 | Sales, payroll and income taxes payable | | | 785,818 | | | 1,159,215 | Travel and entertainment | | | 88,850 | | | 24,267 | Board of Director fees | | | 71,381 | | | 62,140 | Congresses | | | 40,861 | | | 35,589 | | | $ | 10,314,341 | | $ | 7,870,687 |
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