Medical Clinic ERD

What's the best way of doing this?

Using the Crow’s Foot notation, create an ERD that can be implemented for a medical clinic, using the following business rules:
•      A patient can make many appointments with one or more doctors in the clinic, and a doctor can accept appointments with many patients.  However, each appointment is made with only one doctor and one patient.
•      Emergency cases do not require an appointment.  However, for appointment management purposes, an emergency is entered in the appointment book as “unscheduled.”
•      If kept, an appointment yields a visit with the doctor specified in the appointment.  The visit yields a diagnosis and, when appropriate, treatment.
•      With each visit, the patient’s records are updated to provide a medical history.
•      Each patient visit creates a bill.  Each patient visit is billed by one doctor, and each doctor can bill many patients.
•      Each bill must be paid.  However, a bill may be paid in many installments, and a payment may cover more than one bill.
•      A patient may pay the bill directly, or the bill may be the basis for a claim submitted to an insurance company.
•      If the bill is paid by an insurance company, the deductible is submitted to the patient for payment.