The buckler, or small shield, was the favorite defensive tool in the Renaissance, because in an urban environemt, its size made it easy to carry and it still provided excelent defense.  Today, we can emply the principles of the Renaissance sword and buckler but with contemporary weapons; the knife and satchel.

Just another day at the office...	This satchel has hand straps on the back, making it ideal for defensive use.  A plexiglass insert makes the satchel effectively knife proof.  A hard trauma plate from a bullet proof vest would also work well in this capacity.  The knife in this case is a Kasper-Crawford production fixed-blade fighter.
Bad Guy attacks.	High thrust is defelected as Mike zones away and in...
Delivering a counter thrust to the body.	The Bad Guy deflects the body thrust and tries to redirect his knife down to the mid line, but Mike sticks to it with the satchel...
And delivers a powerful groin kick on the open low line, staggering the Bad Guy.	Mike follows with a smash with the satchel to knock the Bad Guy down.
	Follow up as appropriate.