Medical Alert Systems Market By Type (Personal Emergency Response Systems (PERS), Nurse Calling System (NCS), and Smart Belt), Technology (Two-Way Voice System, Unmonitored Medical Alert Systems, Medical Alert Alarm (Button) System, and IP-based Systems), and Application (Home-Based Users, Senior Living Facilities/Senior Care Centers, Assisted Living Facilities, Hospitals and Clinics, and Others): Global Opportunity Analysis and Industry Forecast, 2021-2030