If the debtor is a defendant in a civil trial when he files for bankruptcy, the trial must stop. Because you run a business, you'll probably be a creditor in a bankruptcy at some time. When you are, you may not do anything to collect on a patient's debt once you get notice that he or she has filed for bankruptcy. Some creditors, typically mortgage companies, will ask the court for relief from the stay. But, until the court grants such relief, the automatic stay is absolute.
Violations are a contempt of court.
The former, such as mortgage holders, are protected because the debtor must either pay or lose the security. Unsecured creditors, however, have no recourse. If you're an unsecured creditor, you'll probably never get what you're owed. That does not mean you should ignore a notice that a patient has filed for bankruptcy. Some Chapter 7 cases convert to Chapter 13 because the debtor wants to save his house.