Simplifying Pacemaker Follow-up by the Implementation of the NASPE Standards on Computer Interface

One of the basic limitations for the development and use of more sophisticated pacemakers is the difficulty to provide adequate instrumentation and methodology for the follow-up in the clinical environment. To address this problem, the NASPE (North American Society of Pacing and Electrophysiology) Computer Committee has developed an interface standard to allow communication with the pacemaker programmer through many computer systems. The document recommends the use of the RS 232/c (CCITT V.24) interface with baud rates variable from 300 to 19,200, 7 bit word, no parity and Xon/Xoff protocol. The actual message format consists of an SOH code, a function code describing the action to he taken, a variable code defining the parameter on which the action is to be taken, and the actual numerical data. The CHECKSUM is calculated by summing all the ASCII codes beginning after the SOH code and ending with the last byte preceding the checksum itself. The last seven bits so calculated are attached to the message, and a consecutive ETX code ends the communication. At the receiving end, the checksum is recalculated and compared to the value received. If the two match, the message is accepted. Using this format, compatible computer software and pacemaker programmers can be developed independently and function as a unit. The protocol is capable of real-time ECG transmission.