Method and apparatus for loading a beneficial agent into an expandable medical device

Abstract

The present invention relates to method and apparatus for dispensing a beneficial agent into an expandable medical device. The method includes the step of placing an expandable medical device on a mandrel, the medical device forming a cylindrical device having a plurality of openings and dispensing a beneficial agent into the plurality of openings.

What is claimed is:  
     
         1 . A method for dispensing a beneficial agent into an expandable medical device, the method comprising: 
 placing an expandable medical device on a mandrel, the medical device forming a cylindrical device having a plurality of openings; and    dispensing a beneficial agent into the plurality of openings.    
     
     
         2 . The method of  claim 1 , further comprising dispensing the beneficial agent with a piezoelectric microjetting dispenser.  
     
     
         3 . The method of  claim 2 , further comprising moving the dispenser from a first position to a second position to fill the plurality of openings of the medical device with the beneficial agent.  
     
     
         4 . The method of  claim 2 , further comprising moving the mandrel from a first position to a second position to fill the plurality of openings of the medical device with the beneficial agent.  
     
     
         5 . The method of  claim 1 , further comprising rotating the mandrel to fill the plurality of openings with the beneficial agent.  
     
     
         6 . The method of  claim 1 , wherein the plurality of openings have different volumes and the amount of beneficial agent dispensed is adjusted based on the size of the opening.  
     
     
         7 . The method of  claim 1 , further comprising adjusting an amount of the beneficial agent dispensed into an opening based on an amount of beneficial agent previously dispensed into the opening.  
     
     
         8 . The method of  claim 1 , wherein the medical device is an expandable intraluminal prosthesis.  
     
     
         9 . The method of  claim 1 , wherein the medical device is a stent.  
     
     
         10 . The method of  claim 1 , wherein the mandrel includes a resilient outer surface which seals a bottom side of the openings.  
     
     
         11 . The method of  claim 1 , further comprising dissolving the beneficial agent in a solvent before dispensing.  
     
     
         12 . The method of  claim 1 , wherein the beneficial agent comprises a drug.  
     
     
         13 . The method of  claim 1 , further comprising filling the plurality of openings with a barrier layer comprising a matrix material.  
     
     
         14 . The method of  claim 1 , further comprising filling the plurality of openings with a cap layer comprising a bioresorbable matrix.  
     
     
         15 . The method of  claim 1 , further comprising lubricating the medical device and the mandrel and sliding the cylindrical device onto the mandrel.  
     
     
         16 . The method of  claim 1 , further comprising mapping the medical device on the mandrel to obtain an actual specification of the medical device including locations of the openings.  
     
     
         17 . The method of  claim 16 , wherein the mapping is performed by a camera.  
     
     
         18 . The method of  claim 16 , wherein the mapping is performed by a machine vision system.  
     
     
         19 . The method of  claim 16 , further comprising storing a plurality of coordinates from the mapping of the medical device on a central processing unit.  
     
     
         20 . The method of  claim 19 , further comprising providing the central processing unit with a plurality of coordinates from a manufacturing specification for the medical device.  
     
     
         21 . The method of  claim 20 , further comprising comparing the plurality of coordinates of the actual specification to the plurality of coordinates from the manufacturing specification for the medical device.  
     
     
         22 . The method of  claim 21 , further comprising adjusting the dispensing of the beneficial agent based on a series of adjustments, the series of adjustments comprising comparing the plurality of coordinates of the actual specification to the plurality of coordinates from the manufacturing specification.  
     
     
         23 . The method of  claim 1 , further comprising an observation system for observing the dispensing of the beneficial agent into the plurality of openings.  
     
     
         24 . The method of  claim 1 , further comprising an observation system for mapping the medical device on the mandrel.  
     
     
         25 . The method of  claim 11 , further comprising drying the mandrel to evaporate the solvent and then dispensing an additional beneficial agent into the plurality of openings.  
     
     
         26 . The method of  claim 11 , further comprising baking the mandrel to evaporate the solvent and then dispensing an additional beneficial agent into the plurality of openings.  
     
     
         27 . The method of  claim 1 , further comprising verifying the dispensing of the beneficial agent into the plurality of opening of the medical device.  
     
     
         28 . The method of  claim 27 , wherein the verification step is performed using a refracted light beam.  
     
     
         29 . The method of  claim 27 , wherein the verification step is performed using a camera.  
     
     
         30 . The method of  claim 10 , further comprising removing the cylindrical device from the mandrel by inflating the resilient outer surface of the mandrel.  
     
     
         31 . The method of  claim 1 , further comprising a plurality of bearings, the plurality of bearings providing a means for supporting the mandrel.  
     
     
         32 . The method of  claim 1 , further comprising repeating the dispensing of the beneficial agent until the plurality of openings in the expandable medical device have been filled with the beneficial agent.  
     
     
         33 . A method for loading a beneficial agent in an expandable medical device, the method comprising: 
 dispensing a beneficial agent through a dispenser into a first opening in an expandable medical device;    providing relative movement between the dispenser and the expandable medical device such that the dispenser is moved from alignment with the first opening in the expandable medical device to alignment with a second opening in the expandable medical device; and    dispensing the beneficial agent into the second opening in the expandable medical device.    
     
     
         34 . The method of  claim 33 , further comprising repeating the relative movement between the dispenser and expandable medical device, and dispensing of the beneficial agent until the plurality of openings in the expandable medical device have been filled with the beneficial agent.  
     
     
         35 . The method of  claim 33 , further comprising adjusting an amount of the beneficial agent dispensed into each of the openings based on a shape of each of the openings.  
     
     
         36 . The method of  claim 33 , further comprising adjusting an amount of the beneficial agent dispensed into each of the openings based on a volume of each of the openings or a preprogrammed pattern of the openings.  
     
     
         37 . The method of  claim 33 , wherein the expandable medical device is an expandable intraluminal prosthesis.  
     
     
         38 . The method of  claim 33 , wherein the expandable medical device is a stent.  
     
     
         39 . The method of  claim 33 , further comprising dissolving the beneficial agent in a solvent prior to dispensing.  
     
     
         40 . The method of  claim 33 , further comprising mapping the expandable medical device on the mandrel to obtain an actual specification of the medical device including locations of the opening.  
     
     
         41 . The method of  claim 40 , further comprising comparing the plurality of coordinates of the actual specification to the plurality of coordinates from the manufacturing specification.  
     
     
         42 . The method of  claim 41 , further comprising adjusting the dispensing of the beneficial agent based on a series of adjustments, the series of adjustments comprising comparing the plurality of coordinates of the actual specification to the plurality of coordinates from the manufacturing specification.  
     
     
         43 . The method of  claim 33 , further comprising an observation system to observe the dispensing of the beneficial agent into the plurality of openings.  
     
     
         44 . The method of  claim 33 , further comprising a step of blocking a bottom side of the openings prior to dispensing.  
     
     
         45 . An apparatus for loading a beneficial agent in an expandable medical device, the apparatus comprising: 
 a mandrel;    an expandable medical device having a plurality of openings, the expandable medical device mounted on the mandrel; and    a dispenser configured to dispense a beneficial agent into the plurality of openings in the expandable medical device.    
     
     
         46 . The apparatus of  claim 45 , further comprising a plurality of bearings for receiving the mandrel.  
     
     
         47 . The apparatus of  claim 45 , further comprising a central processing unit for controlling the dispensing of the beneficial agent into the openings of the expandable medical device.  
     
     
         48 . The apparatus of  claim 45 , further comprising an observation system for dispensing the beneficial agent into the plurality of openings in the expandable medical device.  
     
     
         49 . The apparatus of  claim 48 , wherein the observation system is used to map the mandrel including a plurality of expandable medical devices fixed thereto.  
     
     
         50 . The apparatus of  claim 48 , further comprising a monitor for observing the dispensing of the beneficial agent into the plurality of openings of the expandable medical device.  
     
     
         51 . The apparatus of  claim 45 , wherein an exterior surface of the mandrel is encapsulated with a rubber-like material.  
     
     
         52 . The apparatus of  claim 45 , wherein the beneficial agent includes a solvent.  
     
     
         53 . The apparatus of  claim 45 , wherein the dispenser is a piezoelectric micro-jetting dispenser.  
     
     
         54 . The apparatus of  claim 45 , wherein the medical device is an expandable intraluminal prosthesis.  
     
     
         55 . The apparatus of  claim 45 , wherein the medical device is a stent.  
     
     
         56 . A method for loading a stent with a beneficial agent, the method comprising: 
 providing a stent with a plurality of holes; and    dispensing a beneficial agent through a piezo-electric microjet into the plurality of holes.    
     
     
         57 . The method of  claim 56 , further comprising encapsulating the mandrel with a resilient material.  
     
     
         58 . An apparatus for loading a beneficial agent in a medical device having a plurality of openings, the apparatus comprising: 
 a dispenser configured to dispense a beneficial agent into the plurality of openings in the medical device;    an observation system configured to locate and identify the plurality of openings; and    a central processing unit for controlling the dispensing of the beneficial agent into the openings of the medical device, wherein an amount and location of droplets of beneficial agent dispensed into each of the openings in the medical device is determined by the central processing unit based on information obtained from the observation system.    
     
     
         59 . The apparatus of  claim 58 , further comprising a mandrel for mounting a plurality of medical devices.  
     
     
         60 . The apparatus of  claim 59 , wherein the mandrel includes a resilient outer surface which seals a bottom side of the opening.  
     
     
         61 . The apparatus of  claim 58 , wherein the plurality of openings have different volumes and the amount of beneficial agent dispensed is adjusted based on the volume of the opening.  
     
     
         62 . The apparatus of  claim 58 , wherein the beneficial agent comprises a drug.  
     
     
         63 . A system for controlling a delivery of a beneficial agent into a plurality of openings of a medical device, the system comprising: 
 an observation system for mapping a medical device to obtain an actual position of a plurality of openings of the medical device;    a central processing unit for comparing the actual position of the plurality of openings of the medical device to an anticipated position from a manufacturing specification; and    a dispenser for dispensing a fluid beneficial agent into the plurality of openings.    
     
     
         64 . The system of  claim 63 , wherein the central processing unit compares the actual position of the medical device to the manufacturing specifications of the medical device on an opening by opening comparison.  
     
     
         65 . The system of  claim 63 , wherein the central processing unit compares the actual position of the medical device to the manufacturing specification of the medical device on a medical device by medical device comparison.  
     
     
         66 . The system of  claim 63 , wherein the medical device is on a mandrel.  
     
     
         67 . The system of  claim 63 , wherein the fluid beneficial agent is delivered in droplets.  
     
     
         68 . The system of  claim 63 , further comprising a motor providing relative movement between the dispenser and the medical device, such that the dispenser is moved from alignment with the first opening in the medical device to alignment with a second opening in the medical device.  
     
     
         69 . The system of  claim 63 , wherein the medical device is an expandable intraluminal prosthesis.  
     
     
         70 . The system of  claim 63 , wherein the medical device is a stent.  
     
     
         71 . A system for controlling a delivery of a beneficial agent into an opening, the system comprising: 
 a mandrel having a plurality of expandable medical devices;    a dispenser configured to dispense a first layer and a second layer of a beneficial agent into a plurality of openings in the expandable medical device; and    a central processing unit for controlling the dispensing of the beneficial agent into the openings of the expandable medical device.    
     
     
         72 . The system of  claim 71 , wherein the mandrel includes a resilient outer surface which seals a bottom side of the opening.  
     
     
         73 . The system of  claim 71 , wherein the plurality of opening have different volumes and the amount of beneficial agent dispensed is adjusted based on the volume of the opening.  
     
     
         74 . The system of  claim 71 , wherein the beneficial agent comprises a drug.  
     
     
         75 . A method of removing stents from a mandrel, the method comprising: 
 radially expanding the stents by injecting air into at least a portion of the mandrel to inflate the mandrel and expand the stents;    deflating the mandrel; and    sliding the expanded stents off the mandrel.    
     
     
         76 . The method  claim 75 , wherein the stents are radially constrained by a die during the inflation of the mandrel to prevent over expansion.