public int GetCritical()
        {
            List <Patient> patientsToRemove = new List <Patient>();

            lock (allPatientsLock)
            {
                foreach (Patient p in AllPatients)
                {
                    if (DateTime.Now - p.ArrivedTime > Details.CriticalWaitingTimeA && p.Injury.Category == Category.A)
                    {
                        patientsToRemove.Add(p);
                        p.Critical = true;
                    }
                    else if (DateTime.Now - p.ArrivedTime > Details.CriticalWaitingTimeB && p.Injury.Category == Category.B)
                    {
                        patientsToRemove.Add(p);
                        p.Critical = true;
                    }
                    else if (DateTime.Now - p.ArrivedTime > Details.CriticalWaitingTimeB && p.Injury.Category == Category.C)
                    {
                        patientsToRemove.Add(p);
                        p.Critical = true;
                    }
                    else if (DateTime.Now - p.ArrivedTime > Details.CriticalWaitingTimeB && p.Injury.Category == Category.D)
                    {
                        patientsToRemove.Add(p);
                        p.Critical = true;
                    }
                }
            }

            foreach (Patient p in patientsToRemove)
            {
                lock (allPatientsLock)
                {
                    AllPatients.Remove(p);
                }

                PatientsA.Remove(p);
                PatientsB.Remove(p);
                PatientsC.Remove(p);
                PatientsD.Remove(p);
            }

            return(patientsToRemove.Count);
        }
        private void RemoveWaitingPatient(Patient patient)
        {
            Category category = patient.Injury.Category;

            switch (category)
            {
            case Category.A:
                PatientsA.Remove(patient);
                break;

            case Category.B:
                PatientsB.Remove(patient);
                break;

            case Category.C:
                PatientsC.Remove(patient);
                break;

            case Category.D:
                PatientsD.Remove(patient);
                break;
            }
        }