Patent ID: 6855132

Claim:
A method of delivering a medical substance to a patient comprising: providing a delivery device having a proximal end and a porous distal tip; introducing said delivery device into said patient and guiding said distal tip to an injection site in said patient; initiating an injection of medical substance through a pathway of said delivery device, said pathway having a substantially constant diameter along an entire length of said porous distal tip; inducing a gradient of hydraulic impedance on said medical substance by urging said medical substance through a gradient in the size of pores located on said porous distal tip; partially restricting flow of said medical substance out of a hole in said distal tip so as to prevent flow out of said hole from substantially exceeding a flow through said gradient in the size of pores located on said porous distal tip; and, causing said medical substance to weep multidirectionally under injection pressure from said distal tip to said injection site in said patient.