Develop an EE-R diagram for the physical therapy center described in Exercise 3.8, but expand it to assume that some visits require the use of the specialized equipment for electrotherapy, ultrasound, hydrotherapy, and so on, and the patient is charged for each use of such equipment. Patients may also be supplied with special devices to take home, such as exercise bands, neck pillows, and so on, and the patient is charged for these special supplies.

Exercise 3.8:

A database is needed to keep track of the operations of a physical therapy center. Every patient must be referred by a physician and have a prescription for physical therapy in order to receive treatments. A patient may have different physicians at different times. The database keeps all information about prescriptions and treatments, both past and current. When appointments are made, the information about scheduled date and time is recorded. No patient is ever scheduled for two visits on one day. The center has several physical therapists on different visits. When a patient makes a visit at an appointed time, the name of the therapist, the treatment, the date, the time, and the equipment used are all recorded for that visit. Each of these has only one value for the visit. This information will be used later for insurance billing, which is not part of this database. Draw a complete E-R diagram for this example.