In case a USB to Serial converter is needed custo med receommends to use the following brand:
VSCom USB-COM Mini (Chipset: FTDI FT232R)
Remarks: For the QRS trigger option from custo med, used to trigger the e.g a blood pressure device, a USB to serial converter is not recommended. A delay in the trigger from more than 100 ms will affect the quality of the measured blood pressure. custo med recommend to use a PCI- or PCIex-card with serial port.