C#

internal static object DeserializeFromNetworkStream(IFormatter formatter, NetworkStream ns)
{
  using (MemoryStream ms = new MemoryStream())
  {
    byte[] buffer = new byte[4096];
    while (true)
    {
      int read = ns.Read(buffer, 0, buffer.Length);
      if (read > 0)
      {
        ms.Write(buffer, 0, read);
        continue;
      }
      ms.Seek(0, SeekOrigin.Begin);
      break;
    }
    return formatter.Deserialize(ms);
  }
}

private static void SerialiseToNetworkStream<T>(NetworkStream ns, IFormatter formatter, T data)
{
    using (MemoryStream ms = new MemoryStream())
    {
        byte[] buffer;
        formatter.Serialize(ms, data);
        // Get the knowledge data.
        buffer = ms.GetBuffer();
        // Now, serialize this back over TCP
        int offset = 0;
        int size = 4096;
        int remaining = buffer.Length;
        while (remaining > 0)
        {
            if (size > remaining)
            {
                size = remaining;
            }
            ns.Write(buffer, offset, size);
            offset += size;
            remaining -= size;
        }
    }
}

protected override void OnPaint(PaintEventArgs e)
    {
    e.Graphics.FillRectangle(Brushes.Green, e.ClipRectangle);
    }

"I would then add a Paint method to my ECG class, and hand it either e.Graphics so it can draw itself."

using System.Drawing;
using System.Windows.Forms;
public partial class ECGMachine
   {
   ...
   public void Paint(Graphics g)
      {
      g.FillRectangle(Brushes.Red, g.ClipBounds);
      }
   ...
   }

...
myECGMachineINstance.Paint(e.Graphics);
...