A system for the intravascular treatment of clot material from within a blood vessel of a human patient, the system comprising: a catheter configured to be intravascularly positioned at a treatment site proximate to the clot material within the blood vessel; a tubing assembly coupled to the catheter ; a fluid control device ; and a pressure source to generate negative pressure, wherein the pressure source includes: a pressure vessel having a tip configured to be coupled to the tubing assembly; a syringe having a plunger ; a first one-way valve coupling the pressure vessel to the syringe ; and a second one-way valve coupled to the syringe , wherein movement of the plunger in a first direction draws fluid from the pressure vessel into the syringe through the first one-way valve , and wherein movement of the plunger in a second direction forces fluid out of the syringe through the second one-way valve , wherein the tip defines a bore having a diameter greater than or equal to a diameter of the catheter , and wherein the fluid control device is movable between (a) a first position in which the pressure source is fluidly connected to the catheter via the tubing assembly and (b) a second position in which the pressure source is fluidly disconnected from the catheter . a catheter configured to be intravascularly positioned at a treatment site proximate to the clot material within the blood vessel; a tubing assembly coupled to the catheter ; a fluid control device ; and a pressure source to generate negative pressure, wherein the pressure source includes: a pressure vessel having a tip configured to be coupled to the tubing assembly; a syringe having a plunger ; a first one-way valve coupling the pressure vessel to the syringe ; and a second one-way valve coupled to the syringe , wherein movement of the plunger in a first direction draws fluid from the pressure vessel into the syringe through the first one-way valve , and wherein movement of the plunger in a second direction forces fluid out of the syringe through the second one-way valve , wherein the tip defines a bore having a diameter greater than or equal to a diameter of the catheter , and wherein the fluid control device is movable between (a) a first position in which the pressure source is fluidly connected to the catheter via the tubing assembly and (b) a second position in which the pressure source is fluidly disconnected from the catheter . a pressure vessel having a tip configured to be coupled to the tubing assembly; a syringe having a plunger ; a first one-way valve coupling the pressure vessel to the syringe ; and a second one-way valve coupled to the syringe , wherein movement of the plunger in a first direction draws fluid from the pressure vessel into the syringe through the first one-way valve , and wherein movement of the plunger in a second direction forces fluid out of the syringe through the second one-way valve , wherein the tip defines a bore having a diameter greater than or equal to a diameter of the catheter , and wherein the fluid control device is movable between (a) a first position in which the pressure source is fluidly connected to the catheter via the tubing assembly and (b) a second position in which the pressure source is fluidly disconnected from the catheter . <EOS>