i've been playing with POE, how about this?

use strict;
use warnings;

use POE qw( Wheel::Run );

POE::Session->create(
    inline_states => {
        _start => \&_start,
        got_line => \&got_line,
        timeout => \&timeout,
    },
);

sub _start {
    my ( $kernel, $heap ) = @_[ KERNEL, HEAP ];
    $heap->{wheel_run} = POE::Wheel::Run->new(
        Program => <<_SH_, 
/bin/sh -c 'for i in 1 2 3 4; do echo kick; sleep 4; done; sleep 600'
_SH_
        StdoutEvent => 'got_line',
    );
    $heap->{seen_input} = 0;
    $heap->{timeout} = 10;
    $heap->{start} = time;
    $kernel->delay_set( timeout => $heap->{timeout} );
}

sub got_line {
    my ( $heap, $line ) = @_[ HEAP, ARG0 ];
    warn sprintf "%02d line: $line$/", time - $heap->{start};
    $heap->{seen_input} = 1;
}

sub timeout {
    my ( $heap, $kernel ) = @_[ HEAP, KERNEL ];
    warn sprintf "%02d timeout_check$/", time - $heap->{start};
    unless ( $heap->{seen_input} ) {
        warn "\tseems to have died$/";
        $heap->{wheel_run}->kill;
        delete $heap->{wheel_run};
        return;
    }
    warn "\tseems to still be kicking$/";
    $heap->{seen_input} = 0;
    $kernel->delay_set( timeout => $heap->{timeout} );
}

POE::Kernel->run;

__END__
00 line: kick
04 line: kick
08 line: kick
10 timeout_check
        seems to still be kicking
12 line: kick
20 timeout_check
        seems to still be kicking
30 timeout_check
        seems to have died
[download]

i'm sure there's a cleaner way that i haven't learned yet.