Visual Basic - Quiero graficar con un chart para que reciba una señal analógica, ¿cómo se asocia?

'''Para un ECG

'''https://www.youtube.com/watch?v=0PYCXe94u3k

''' Intento de programa en VB para leer un ECG.

''' https://www.youtube.com/watch?v=5r_MI384tes&t=257s

''' configuración de puertos en VB.

''' https://www.youtube.com/watch?v=Sy2vjWO0ydM

''' Valor de la señal y chart.

Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick

        ''Dim data As String

        ''Data = SerialPort1.ReadExisting().ToString()

        ''Chart1.ToString(data)

        '' PictureBox1.Image(data)

        Dim i As Single = SerialPort1.ReadExisting

        Label1.Text = "Valor de la señal:" & i.ToString

        Chart1.

    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Button1.Enabled = True

        If SerialPort1.IsOpen Then

        Else

            Try

                ''Catch ex As Exception

                SerialPort1.Open()

                SerialPort1.PortName = "COM3"

                ''iniciando el timer.

                Timer1.Start()

                With SerialPort1

                    .BaudRate = 9600

                    .DataBits = 8

                    .Parity = IO.Ports.Parity.None

                    .StopBits = IO.Ports.StopBits.One

                    .PortName = "Com3"

                    .Open()

                End With

            Catch ex As Exception

            End Try

            Button1.Enabled = False

            Button2.Enabled = True

        End If

    End Sub

End Class