Clients without making a progress

Dear all, we are using BIG IP ltm, asm and apm modules. I have a requirement to block the connection from a client making a slow progress on below criteria.

Client has make a successful tcp connection but not sending a data more than 1 byte for next 50 seconds. block the client.

Please help how this can be achieved. dont want to play with idle timeout since it may affect legitimate connection. if this is possible with iRule i would like to log it first to alert. then can take blocking action.

Please assist!!!