怎么从父类派生出一个子类

如何从父类派生出一个子类？
Imports Ryobi.Hsc.Wxs.Cmn.WxsCmnChstd
Public Class PatientProblemList
  Inherits List(Of PatientProblem)
  Friend Sub New()
  End Sub

  Public Function GetSyakudo() As List(Of PatientProblem)
  Dim clsPatientProblemList As New List(Of PatientProblem)
  For i As Integer = 0 To MyBase.Count - 1
  clsPatientProblemList.Add(Me.Item(i))
  Next
  Return clsPatientProblemList
  End Function
End Class


这样写对么？ 
基类是 PatientProblem
现在想派生出一个 PatientProblemList
流程图是
 PatientProblem-----〉PatientProblemList-------〉GetPatientProblemList
  Inherits List(Of PatientProblem)

[解决办法]
Inherits List(Of PatientProblem) 不对，基类是 PatientProblem 就应该是 Inherits PatientProblem.